DIGITAL TECHNOLOGIES IN TEXTILE ART


by,

 Havva Halaceli

Cukurova University, Faculty of Fine Arts, Department of Textile Design,
Adana, Turkey

This is a digital age, dominated by information, communication and technology-based entertainment. This age is a result of rapid visual information-sharing. In this age, technology enables video sharing, saving every moment as visual data, and it is a result of rapid visual and information sharing. Today, artists use digital technologies as a means of expressing concepts. Woven textiles are also affected by the technological advances. Textiles have been essential for people from ancient times to now, for covering and protecting themselves from heat and cold. Weaving is a fine art form and a product of labor, including Coptic textiles and European tapestries; it can also utilize the speed, selection and color options of digital technologies that result from the mechanization and technological advances in the 20th century. Computerized Jacquard looms are one of the benefits of digital technologies that enable the weaving of complex imagery by allowing individual warp threads to be lifted.

Today, working with digital cameras, scanners and jacquard looms the textile artist becomes a designer and technology becomes a medium serving the artist’s creativity. In this study, the works of textile artists will be examined in view of time, technology and communication.
Keywords: Weaving, digital technology, jacquard loom

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ELECTRONIC TEXTILES: Wearable Computers, Reactive Fashion and Soft computation


Electronic textiles, also referred to as smart fabrics, are quite fashionable right now. Their close relationship with the field of computer wearable‘s gives us many diverging research directions and possible definitions. On one end of the spectrum, there are pragmatic applications such as military research into interactive camouflage or textiles that can heal wounded soldiers. On the other end of the spectrum, work is being done by artists and designers in the area of reactive clothes: “second skins” that can adapt to the environment and to the individual. Fashion, health, and telecommunication industries are also pursuing the vision of clothing that can express aspects of people’s personalities,social dynamics through the use and display of aggregate social information.

In my current production-based research, I develop enabling technology for electronic textiles based upon my theoretical evaluation of the historical and cultural modalities of textiles as they relate to future computational forms. My work involves the use of conductive yarns and fibers for power delivery, communication, and networking, as well as new materials for display that use electronic ink, nitinol, and thermochromic pigments. The textiles are created using traditional textile manufacturing techniques: spinning conductive yarns, weaving, knitting, embroidering, sewing, and printing with inks.

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Cloth Finishing


Cloth Finishing

( Originally Published Early 1900’s )

Importance of cloth finishing.-Cloth finishing is one of the chief arts in the textile industry. The appearance of the goods is often of first concern, and the appearance of any fabric is largely due to the methods of finishing.

BLEACHING

Bleaching is one of the most usual and important among the finishing processes. It has for its object the whitening or decolorizing of the textile fiber to which it is applied. Fibers, as they come from the plant, from the back of the sheep, or from the cocoon, are usually somewhat colored or stained. Some of them, like tussah silk or Egyptian cotton, are highly colored. This natural coloring of the fiber may be undesirable in many fabrics; hence, bleaching is employed to clear the fiber of this color. Again, most fibers accumulate stains of various kinds during the early processes of manufacture as, for example, in the spinning and weaving. This discoloration cannot be entirely removed by simple washing; hence, the bleaching process is applied to clear the fabric. In like manner, when the calicoes or other prints come from the printers, the white background between the colored figures may be soiled, spotted, or otherwise discolored; again, a light bleach is applied, but not enough appreciably to injure the color in the figures.

Bleaching agents.-There are two classes of bleaching substances, oxygen and sulphurous acid. Under certain conditions oxygen destroys the coloring matters entirely. Sulphurous acid probably does no more than change the color to white, leaving the coloring substances still in the textile. An object once bleached white by oxygen is not likely to turn yellow or to change back to its original color; whereas textiles bleached in sulphurous acid quite frequently do change back again after a time, especially when in contact with certain chemicals such as alkalies or soaps.

Grassing.-The oldest bleaching method is that of “grassing,” still used to a certain extent in Europe for bleaching linens. The linen fabrics are laid on the grass or ground for weeks. The oxygen of the air and that given off by green plants slowly attacks and destroys the little yellow color particles in the flax fiber. Slowly the linen becomes whiter and whiter until finally it is fully bleached. The particular value of the grass bleach over all others is its slowness. This guarantees permanence. Furthermore, the “grassing” process is not likely to be carried on a bit further than necessary. The oxygen which attacks the coloring matter may ultimately attack the cellulose in the fiber and does do so in chemical bleacheries unless the fabric is removed at the proper time. A few moments’ delay, therefore, in a chemical bleachery means great damage to the cloth; whereas a few days either one way or the other in grass bleaching makes practically no difference. Cotton also was at one time bleached in this manner, but the more rapid chemical oxygen bleachers have entirely superseded grass bleaching for this textile.

Chemical bleaching.-The principal chemicals used in oxygen bleaching are chloride of lime, hydrogen peroxide, sodium peroxide, and potassium permanganate. All these substances are heavily charged with oxygen. In the bleaching process, this oxygen is set free, and this free oxygen attacks the coloring matters in unbleached goods. The bleaching powder of commerce is chloride of lime, the principal bleaching substance used for cotton and for all other vegetable fibers excepting jute. It is, however, entirely unsuitable for wool and silk. Hydrogen peroxide is the best bleaching substance of all. It may be used on any sort of fiber, for it attacks nothing but the coloring matter. It is frequently used in removing stains and also in bleaching hair. But for general textile bleaching purposes it is too expensive, and is hard to keep in concentrated form for even a short time. It is used extensively, however, in bleaching wool mousselines that are to be printed. Hydrogen peroxide produces a much better result than sulphurous acid, the common bleaching substance for wool. When cheaper means of producing peroxide are discovered, this chemical is bound to take front rank among the bleaching agents. Potassium permanganate is another oxygen-loaded chemical that is sometimes used in bleaching woolens. Sodium peroxide is a compound somewhat cheaper to produce than hydrogen peroxide, and contains a large amount of live, active oxygen. It is a rather new bleaching agent, but is already used to a certain extent on wool and silk, especially tussah silk.

Sulphur bleach.-Sulphurous acid bleach is applied in the form of either a gas or a liquid. The gas is produced by burning sulphur in the air. The fumes that arise from burning sulphur are sulphurous acid gas. The liquid is produced by saturating water with this gas. Sulphur bleach is used mainly for animal fibers (wool and silk) and jute. The most common method employs the gas rather than the liquid. Rooms called sulphur chambers are built out of brick especially for this purpose. The fabric or yarn is brought into this chamber and hung up damp in loose folds while sulphur is burned in pots on the floor. The rising fumes saturate the damp textiles, the dampness materially assisting, and the fibers gradually whiten. In large wool bleacheries the cloth is run through the sulphur chamber on rollers, bleaching on the way. The process is inexpensive and results in a beautiful white. Its tendency to make wool harsh is corrected by washing in soap and water. When the wool is mixed with cotton there is danger of the cotton’s being destroyed by the acid. The sulphur bleach is ordinarily used for wool and silk.

Chloride of lime.-In cotton bleaching, chloride of lime is the most common chemical used. Cotton is generally bleached in the piece or fabric form. The usual exceptions are sewing cotton, absorbent cotton, and jeweler’s cotton. The last two are bleached in the state of loose fibers. When the cotton comes from the looms it is still in the natural color, although somewhat altered by the sizing in the warp and by the dirt; grease, and dust accumulated in the machinery. The cloth is now said to be “in the gray.” It is, however, more of a dirty yellow than gray, and presents a soft, flabby, fuzzy, unattractive appearance. It is now ready for the bleaching process.

The bleaching process.-The cloth is first run through a washing machine to remove as much of the discoloration and dirt as possible. Next, most fabrics are either sheared or singed; that is, they are run through machines which either cut off or burn off the fuzziness that is always found on cloth direct from the loom. The shearing process is performed by a machine that works on the same principle as a lawn mower, cutting all loose ends and fibers very close to the body of the cloth. The singeing is done by very quickly passing the cloth over a line of gas jets, or over a red-hot plate, where the heat burns off the fuzz but has no time to burn the fabric itself. Recently, singeing has been successfully performed by electricity. Cloth is sometimes singed on both sides, sometimes on only one. The shearing and singeing processes leave the cloth apparently smooth.

As a rule, cotton cloths are then bleached. There are four common methods, or “bleachers” as they are called: “madder bleach,” “Turkey red bleach,” “market bleach,” and “rapid bleach.” Of these the madder bleach is the most thorough. The others differ from the madder bleach mainly in degree of thoroughness. Goods to be dyed in deep colors need less whitening; hence, they are given, for example, the Turkey red bleach. Goods to be dyed black need almost no bleaching; for these the rapid bleach is sufficient. The market bleach is really the rapid bleach with the addition of blueing and other substances to cover up defects in the process.

The bleaching industry.-Cotton bleaching is often conducted as a separate industry. In England this is quite the rule. The cloth is sent from the weaving concerns to the bleacheries to be bleached on commission or at so much a yard. Sometimes the products of the loom are purchased by converters who hire others to do all the finishing processes, including bleaching. Occasionally bleachers buy the cloth in the gray, bleach it, and again market it. In this country bleaching and dyeing works are usually associated, and both are frequently under the same management as the cotton mills. This joining together or integration of related industries is typical of American business organization, not only in the textile industries, but also in many other great businesses, such as steel production and meat packing.

How the bleacheries handle cotton goods.-Piece goods arrive at the bleacheries in bolts or rolls of an average length of fifty yards. Each of these is stamped with the owner’s name, the length of the bolt, and other necessary particulars. The ends of several hundred rolls are first stitched together to form one long sheet sometimes as much as twenty-five miles long.

Moistening and bowking.-When all is ready, the cloth is moistened, run through a six-to eight-inch ring to rumple it and form it into the shape of a rope, and in this form if is laid away in coils for several hours in bins to soften the sizing in the warp. Next, the cloth is turned into a covered tank called a kier, in which is a weak solution of caustic soda or milk of lime. The liquid is kept moving through the tank by means of pumps. Here the cloth is stirred for about eight or ten hours, a process which removes all fats and wax found in the cloth, such, for example, as the natu ral wax found around the cotton fibers. All of this must be thoroughly removed before bleaching if the cloth is to be made snow white. The mixture in the “kier” is called the “lime boil,” and this particular part of the process is called “bowking.” The process concludes with a thorough washing in pure, fresh water.

Brown sour.-The next step, known variously as the “brown sour,” “gray sour,” or “lime sour,” follows the washing. The cloth is passed into tanks of water containing sulphuric or hydrochloric acid, sometimes both. This souring process counteracts the action of any caustic soda or lime that may remain in the cotton fiber from the previous treatment. Here a knowledge of the chemistry of bleaching is absolutely essential. The proportion of acid in the “brown sour” must be just sufficient to destroy the alkali in the fiber. If not strong enough, the alkali will not all be destroyed and will continue to cause trouble throughout the entire life of the cloth. If too much acid is used, then not only will the alkali be destroyed, but the cotton fiber will be endangered as well. Much of the poor cotton cloth in the market owes its lack of strength to poor bleaching methods. Linen is more sensitive to these chemical changes than cotton; hence the difficulty of getting good chemically bleached linens. The acid or souring bath is followed by a washing in pure water.

Lye boil.-In the full madder bleach the cloth after the acid bath is usually passed into a second alkali bath containing hot lye and resin soap. This is called the “lye boil.” After three hours of boiling under pressure, with the alkali liquor forced through every part of the cloth by means of pumps, all of the fats and acids in the fiber have been ex tracted and changed into soapsuds. The invariable washing in pure water follows.

Chemicking.-The cloth is now ready to be transferred into the real bleaching bath, the chloride of lime solution, or “chemick,” as bleachers name it. Through this bath the cloth is passed back and forth, the liquid being forced through every part of it. After one or two hours this part of the process is completed. The cloth is removed and passed between heavy wooden rollers, which press out the excess of the chloride of lime solution. The cloth is then coiled or piled in bins so as to be exposed to the air. It is here that the real bleaching takes place. The chloride of lime absorbed in the fiber has a strong affinity for air and for water. Both are attracted, and in the chemical processes that follow a certain amount of oxygen is crowded out of the air and water, and this free, active oxygen attacks the coloring matters and destroys them. Now again the proportions must be scrupulously adjusted so that not too much or too little oxygen is produced. Too much would result in an oxidation or destruction not only of the color particles, but also of the cotton fiber itself.

White souring.-The chemicking or bleaching is followed by washing in pure water and afterward by treatment in a weak acid bath known as the “white sour.” In this bath all action of the chloride of lime is stopped. Then follows another most careful washing in water to remove every particle of acid, whereupon the bleaching process is ended. The cloth is opened up flat, spread out, beaten, stretched or tentered, and dried over hot rollers. It is now ready for dyeing, for printing, for mercerizing, or, if to remain in the white, for the final finishing processes of sizing and calendering. Dyeing, printing, and mercerizing have already been described; hence, we need only give our attention to the final finishing processes.

CLOTH DRESSING

Whether the cloth shall be made soft or stiff, dull or glossy, and so on, depends upon the finish applied and the materials used. Certain sizings fill up the spaces between the threads in the fabric, stiffen the fabric, and give it greater weight and body. Other sizing materials give stiffness without adding weight. Some give weight without stiffness. Some help to make the fabric glossy, others to give the cloth some special appearance in imitation of a different fiber. It would take a volume to give in detail an account of how these various effects are obtained. Such a description is not necessary here. A fair idea of the possibilities of cloth finishing can be obtained by a study of fabrics themselves, especially with the help of a small magnifying glass and with such tests as boiling and rubbing.

Dressing materials,-The materials used in cotton finishing or dressing include starches, glue, fats, casein, gelatin, gluten, minerals, and antiseptic substances. The starches give stiffness and weight; glue gives tenacity to the starches and other materials. Minerals, such as clay, are used to give weight. Fats give the qualities of softness and help make the fabric more elastic. Wax, stearin, and paraffin are frequently used to develop a high luster in the calendering or pressing processes. Antiseptic substances such as zinc chloride, salicylic acid, and zinc sulphate are added to prevent the starches and fats used in the dressing from molding or putrefying.

Starches.-The starchy substances commonly used include wheat flour, wheat starch, potato starch, rice starch, and cornstarch. Sometimes the starch is baked until brown before using. In this form it is called dextrin or British gum. Dextrin gives a softer dressing than any other starchy material. Wheat and corn starches produce the stiffest effects. Potato starch comes between the two extremes. Starch is sometimes treated for a couple of hours with caustic soda at about the freezing point. At the end of this time the excess of alkali is neutralized with acid. The result is a gum, called apparatine, which stiffens the cloth and does not wash out so easily as most other stiffening substances. Starch treated with acid produces glucose, and this is used largely as a weighting or loading material.

Fats.-Among the fats used are tallow, stearin, several different kinds of oils and waxes, and paraffin. These are sometimes added to the starches to reduce the stiffness of the fabrics. Glycerin and magnesium chloride are frequently added for the same reason. Fats may be added to waterproof the cloth, although waterproofing is usually accomplished by rubberizing; that is, by soaking the cloth in a solution of crude rubber or caoutchouc.

Minerals.-The minerals are added for various reasons. China clay increases the weight as do also salts of lime and baryta. Alum, acetate of lead, and sulphate of lead are sometimes used. Adding large proportions of borax, ammonium phosphate, salts of magnesia, and sodium tungstate makes the fabric fireproof.

How the dressing is applied.-The dressing material is usually applied as a liquid paste to the back of the cloth and then run over hot rolls or cylinders in order to dry the paste quickly. Sometimes it is applied lightly to the surface, sometimes it is pressed in deeply by means of rollers. When both sides are dressed, the fabric is passed into and through the dressing material. When the cloth is dry, the sizing or dressing process is complete. If merely a dull, hard finish is desired, nothing further is necessary except to stretch and smooth out the cloth, measure, bolt, and press it. But if any kind of polish is demanded, then the cloth must be calendered, pressed, mangled, or ironed.

CALENDERING

Calendering is accomplished by passing the cloth between large rolls, from two to six, under heavy pressure. In the rolls the dressing is smoothed out, and the hard, dull finish becomes soft and glossy in appearance. Heated rolls give a better gloss. When the rolls are made to turn over each other at different rates, there is a heavy friction or ironing effect on the cloth. For the highest glosses not only starch but also fats and waxes are used, and all are ironed into the cloth under heavy pressure and at as great heat as the cloth will stand. When calendered the fabrics are usually dampened first, just as clothes are dampened by the housewife before she irons them. The dampening in a cloth-finishing plant is done by a special machine that sprays the cloth very evenly as it passes through.

The beetle finish.-There are several special finishes possible through variations in the calendering process. Beetling is one of these methods. The cloth is passed into a machine over wooden rollers and beaten by wooden hammers operated by the machine. The beetle finish gives to cotton or linen an appearance almost like satin and is very beautiful.

Watered effects.-Moire or watered effects are produced by pressing some parts of the threads in a fabric down flat while leaving the other parts of the threads in their natural or round condition. The effect is usually that of an indistinct pattern. It is obtained in different ways, sometimes by running the cloth through the calender double, or again by running the single fabric between rollers especially engraved with moire designs. Only soft fabrics are suited to this finish; hence, no dressing except fats is used for moire goods.

Embossing.-Soft fabrics are sometimes stamped with patterns in the manner of embossing by means of engraved calender rolls. This process is called stamping.

Schreiner finish.-Another special finish, known as “Schreiner finish,” is applied in the calendering operation by passing the cloth between rolls covered with great numbers of finely engraved lines. The number often runs as high as six hundred to the inch. Under a pressure of 4,500 pounds these lines are pressed into the fabric. The result is that the round threads are pressed flat, but the lines break up the flat surfaces into little planes that reflect the light much better than an ordinary flat surface would. This peculiar light reflection gives the cloth the quality of a very high luster. Heating the rolls makes this luster more lasting. The effect is very beautiful. Mercerized cotton finished in the Schreiner finish rivals silk in appearance.

Most of the finishes spoken of so far, the result of dressing and calendering, are easily destroyed. Wear destroys any of them in time. Washing destroys most of them. But as long as they last they are highly important elements in the appearance of the fabrics.

OTHER FINISHING PROCESSES

Dressings applied to the various textiles.-Dressings are usually applied in much greater quantity to cotton than to any other textile. Linen comes second, and the principal dressing substance used in linens is starch. Glue, gelatin, dextrin, albumen, and water glass are applied under certain conditions and for certain effects in woolen goods. The common weighting materials added to woolens are short hairs or short wool fibers, sometimes called flocks. Flocks are the ends of fibers sheared off from the surface of wool or worsted cloth. Woolen cloths are padded or impregnated with these in the fulling mills, sometimes adding from one-fourth to three-fourths to the weight of the wool. Such finishing processes as beetling, mangling, moireing, and stamping are never applied to woolens. Silk usually has very little dressing applied to it in the finishing process, and that little generally consists of gelatin, gum arabic, or tragacanth. The other finishing processes are very much the same for silk as they are for cotton.

Lisle finish.-Several other finishes, or modifications of the finishes just described, are used in cotton goods when it is desired to show special effects. The lisle finish is given yarns that are to be used in the manufacture of hosiery and underwear. The true lisle finish is obtained by using combed, long-stapled, sea-island or Egyptian cotton. The yarns made from these fibers are rapidly but repeatedly run through gas flames until they are entirely free from any projecting fiber ends or fuzz. The result is a very smooth, glossy thread. Another kind of lisle finish is obtainable in a finished fabric, as, for example, in hosiery, by treating with a weak solution of sulphuric or hydrochloric acid and then drying before washing out the acid. The goods are afterward tumbled around in a machine that exposes them to the air and heats them to about 100 degrees Fahrenheit. After a time the loose ends and fuzzy fibers become brittle and break off in the tumbling given the goods. When the goods present the proper lisle finish, they are cooled off and washed in an alkaline bath which stops the action of the dry acid and neutralizes it. After thorough washing in clean water, they are dried and are ready for dyeing or any other finishing process. Sometimes the acids are added to the dye bath to cause more speedily the same effect in the appearance of the goods. Some dyes are regularly made up with the acid mixture.

Wool finishing.-The finishing processes for woolens and worsteds are much more laborious and complex than those employed for cottons. A greater variety of machinery is required, and there are more steps in the process. The finishing of wool goods is divided into two main parts: the first is called the “wet finishing,” which includes washing, soaping, steaming, carbonizing, and the use of liquids; the second is called “dry finishing” and includes napping, shearing, polishing, measuring, and putting up in rolls or bolts.

Preparation of wool fabrics.-Woolen or worsted cloth, as it comes from the weave rooms to the finishers, is first inspected for flaws, broken threads, and weak places, and wherever these are found, chalk marks are made to assist the burlers and menders in finding the places. To aid in the inspection, the cloth is generally “perched” or thrown over a roller and drawn down in single thickness by the inspector as fast as he can look it over. A good light is desirable. Inspectors with practice attain great proficiency in finding weak places or imperfections in the cloth. After the bad spots in the fabric are repaired the goods are tacked together; that is, the pieces are fastened together in pairs with the faces of the cloth turned towards each other. The tacking is simply a stitching along the edge, done either by hand or machine. The purpose of tacking is to protect the faces of the cloth from becoming damaged in any way by the heavy operations to follow or from becoming impregnated with any foreign substance difficult to remove, such as short hairs or flocks.

Fulling.-The next step is the fulling. All kinds of clearfinished worsted dress goods for ladies and practically all wool cloths for men’s wear except worsteds are fulled. This is the most characteristic process in the wool industry; no other textile goes through any process like it. The wool fibers, it will be recalled, are jointed and have scales that cause the fibers to cling together readily. This, we have learned, is called the felting quality. By beating a mass of wool fibers, a very hard, compact mass can be obtained, because the fibers creep into closer and closer contact with each other, holding fast because of the scales. Fulling makes use of this principle. Wool cloth is shrunken and made heavier and closer in structure and consequently stronger. Fulled cloth may also take many more kinds of finish than unfulled fabrics. The fulling process is performed in machines that apply pressure, moisture, and heat to the goods. The cloths are soaked in hot, soapy water, pressed, rolled, and tumbled; as a result, the woolen fabrics contract and become closer in texture throughout.

Flocking.-Short wool fibers or flocks are frequently felted into wool fabrics in the fulling operation. A layer of these short fibers is spread over the back of the cloth and matted down by moistening. In the fulling operation these fibers sink into the fabric and therefore help to give the fabric weight and closeness. That this process is not always well done is evidenced by the fact that the flocks in the backs of suitings often wear loose, drop down, and collect at the bottom of garments, especially at points where the lining and the suiting are sewed together. Flocks must from most standpoints be considered as an adulteration of wool although their presence really helps some fabrics, such as kerseys. All crevices are filled up and the fabric is made solid. If the felting has been done well, the flocks perform a good service in the cloth, but otherwise the flocks come out easily and are a decided nuisance to the wearer of the goods. Flocks made from wool waste such as shoddy, mungo, and extract, when applied on shoddy wool cloth are bound to come out. But flocks cut from new wool, when applied to new wool cloth, produce an excellent effect if not too largely used. Adding 25 per cent in weight to the cloth by flocking is not unreasonable, but doubling the weight of the original fabric would be unjustifiable adulteration. Flocking adds little if any to the strength of the cloth.

Speck dyeing.-After fulling, the cloth is washed very carefully, and is usually given a light dye to cover up spots or imperfections due to foreign matter that could not be taken out before. If not so dyed, all the little specks in the cloth have to be removed by hand, a process called speck dyeing or burr dyeing.

Carbonizing.-Carbonizing is usually performed before the wool is spun into yarn, but in some cases not until the cloth is woven. In this case it takes the place of speck dyeing. The process is the same for cloth as for loose wool. The vegetable matter is destroyed by soaking the cloth in weak acids and then heating in an oven.

Napping.-After washing, stretching, and drying, most goods are ready to receive the finish. In most cases this first involves raising a nap or fuzz evenly all over the surface, and for this purpose machines have been invented. The oldest of such machines use teasel or thistle burrs, whereas the later napping machines use little wire hooks. Some claim that the teasel burr has certain qualities for raising the wool nap that cannot be produced in any steel wire or spring hook or barb. The principle, however, is the same in all inventions for this purpose. The gigs or napping machines all stretch the cloth and then cause it to pass over many fine little hooks of teasel burrs or of steel wire which draw out a multitude of little ends of wool fiber all over the surface of the cloth. In some cases, the napping or gigging is performed on wet cloth; in others, the cloth is dry. Dry napping is in fact now the more common, although the wet methods are still employed for certain cloths and finishes.

The finish of wool cloth depends upon the degree o f napping and upon the variety of fiber. Meltons require only a little napping; kerseys, beavers, and doeskins, a very thorough one. Cloths that must wear exceedingly well must be napped as little as possible, since the process reduces the strength of the fabric. Cassimeres are given several kinds of finish, Saxony finish, for example, or velour finish. Other fabrics are each given their characteristic finish by slightly varying the amount of nap, or the treatment of the nap after it has been raised. Among such fabrics are cheviots, kerseys, meltons, beavers, chinchillas, outing flannels, doeskins, reversibles, thibets, satinets, blankets, and others.

Lustering.-After napping, such fabrics as kerseys, beavers, broadcloths, thibets, venetians, tricots, plushes, uniform cloths, and all worsteds, require another special operation known as steam lustering. Steam is forced through the cloth for about five minutes, followed by cold water. The steam brings out the luster which the cold water sets or fixes.

Stretching and clipping.-The dry finishing processes begin with stretching (or tentering) and then drying the cloth. Special machines accomplish this as well as all the other processes. The cloth now passes through a shearing machine which brushes the nap in the direction desired, afterward clipping it evenly over all the surfaces. The clippers operate like the revolving blades of a lawn mower. Goods that have not been napped are generally singed in much the same manner as cotton fabrics. Next, the sheared fabrics are brushed, and perhaps polished by means of pumice cloth or sandpaper, to make the cloth smooth and lustrous.

Final steps.-Finally the goods are pressed and thereby given a finished appearance. This is usually performed by means of heavy presses, either with dry heat or with steam. The most common present-day method of pressing cloth is by running it between heavy rollers heated by steam. Care must be taken not to get the rolls too hot or the wool will be damaged. The cloth is next inspected again, run through a measuring machine, doubled, rolled, and wrapped in paper, and packed into cases ready for the clothing manufacturer or the dry goods jobber and the retail store.

Worsted finishing.-Worsteds are not generally fulled as are woolens. After burling, worsteds are usually singed and then crabbed. The crabbing process sets the weave so that in the later operations it will not be obliterated. It consists in running the cloth tightly stretched over rollers through a trough containing hot water. After an hour or two of this the cloth is scoured and rinsed and then closely sheared. There are several varieties of worsted, each of which requires its own special finish or after-treatment. Innovations are constantly introduced to alter the appearance a little in one way or another. Among these are the fancy or yarn-dyed worsteds, serges, worsted dress goods, and worsted cheviots.

CURRENT AND FUTURE TECHNOLOGIES FOR WEARABLES AND E-TEXTILES


The technologies embedded in wearables influence the comfort, wearability and aesthetics. According to Tao (2005) (Figure 1) a typical system configuration of a wearables includes several basic functions such as: interface, communication, data management, energy management and integrated circuits. This classification is based on general purpose wearable computers.

A similar classification is presented by Seymour (2009) with focus on fashionable wearables, a combination of aesthetic as well as functional pieces . Thus most common technological components used to develop fashionable wearables are: interfaces (connectors, wires, and antennas), microcontrollers, inputs (sensors), outputs (actuators), software, energy (batteries, solar panels), and materials (interactive or reactive materials, enhanced textiles).

Both classifications are overlapping each other, but for the purpose of this thesis they will be combined and all the concepts explained, with emphases on e-textiles. The project examples used in this section, supporting the theory are related to wearable textile technology already available on the market or projects currently being developed in research labs around the world showing promising results in becoming future technologies. The diversification of the project concepts goes from being very functional and practical towards more expressive and artistic.

Inputs

To obtain information for wearable devices components such as sensors are often used, for instance, environmental sensors, antennas, global positioning system receivers, sound sensors and cameras. Such sensors can be divided on active and passive(Langenhove & Hertleer, 2004)(Seymour, 2009). Active inputs are controlled by a user via a tactile or acoustic feedback system, which provides an intuitive interaction with the garment. Passive inputs collect biometric data from the human body as well as environmental data collected via wireless transmission system. The data is captured and further processed usually using a microprocessor. The table below provides suggestions for the type of inputs wearable systems can collect from a person or the environment.

Input Interfaces

The most common way for a user to interact with a device these days, involves the use of buttons, keyboards and screens, as they are proven to be easy to learn, implement and use with few mistakes. Fabric- based interfaces using keyboards and buttons are most common for wearables. They are usually designed from either multilayered woven circuits or polymer systems (Tao, 2005). At the dawn of ubiquitous computing environments, people will need to engage with many different devices with built-in microprocessors and sensors. As wearable devices become more complex, a need for more complex interfaces arises. People want more options on their devices, they want everything, but they also want them with the maximum of easy, freedom and comfort. This requires new ways of interaction, such as user engagement through voice, touch and gestures. The devices of the future will have no faces(Saffer, 2007). They will implement more intuitive ways of interaction.

Origin Inputs
Person Voice, visuals, pressure, bend, motion, biometric data, proximity, orientation, displacement, smell, acceleration
Environment Temperature, light, sound, visuals, humidity, smoke, micro particles

Figure 1 – Suggestions types of inputs that a wearable system can collect

Voice recognition – Voice-controlled interfaces are currently most common on phones. However there are few drawbacks in the technology. It is difficult to create voice-controlled interfaces in public spaces, from both technical and design perspective, when the system should always listen for a command. In this case, incorrect processing of information is possible due to large influence of background noise. How will the system know to differentiate between a command and a background noise is a design challenge that yet needs to be answered. Furthermore, the current voice recognition technology has a problem distinguishing between different people’s voice and additionally, it requires more processing power then previous technologies. Leading researchers believe these obstacles will be overcome as technology advances, predicting that in a very near future we will interact with voice – controlled devices and environments.

Gesture recognition – As devices gain better awareness of the movement of the human body through technologies such as Global Positioning System (GPS) sensors and sudden – motion sensors (SMSs), gesture recognition as a way of human interaction with devices is becoming even more achievable. Indeed, there are devices such as mobile phones equipped with tilt motion sensors, so that users can, for example, “pour” media data from their phone to another device (Dachselt & Buchholz, 2009). Donneaud (2007) created a large textile interface for playing electronic music. Figure 2 illustrates the textile interface that is constructed of two conductive fabrics which are fixed on a frame each one weaved with conductive threads in a different direction.

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Figure 2: Textile XY: interface for playing music

When the performer presses any point of this textile, the two fabrics connect and the current electrical value is sent to the computer. This textile interface is flexibility and transparency, involving the whole body through choreographic movements in the musical interpretation, thus allowing the performer to explore the textile interface by look, touch and gesture.

Presence recognition – Person’s presence is another way of interaction with a system. Present- activated systems are one of the central research points for ambient intelligent environments. The main design and technical challenge here is what determines if the system should react to the presence of a person, how it should react and how fast this reaction should be after a change has been detected.

Outputs

There are a variety of output devices or materials which activate in wearables as a result of computation triggered by input data. Many outputs can stimulate any of the five the senses of the wearer or his audience. For example, shape memory alloy can change the silhouette of a fabric presenting a visual experience for an audience and a tactile experience for the wearer. The table below provides an overview of possible outputs to address specific senses.

Senses Outputs
Visual LEDs, EL wires, displays, photochromic ink, thermocromic ink, E-ink
Sound Speakers, buzzers
Touch Shape memory wires, conductive yarns, conductive fabric, motors/actuators
Smell and Taste Scent capsules

Figure 3 – Overview of possible outputs that address specific senses

Communication Technology

For electronic components to truly become part of bigger interactive systems they need to be connected in order to exchange information. Wires, cables, antennas and connectors are most common physical components used to connect electronics together. Wired connections are secure and practical in many cases, but they can cause inflexibility and add to the weight of the system. On the other hand, wireless connections increase flexibility and the lightness of the system, but increase its complexity.

The advances in wireless technologies have played a significant role in the development of wearables and e-textiles, reducing the number of devices attached to a system, simplifying its construction as well as minimizing the size. According to Seymour(2009) some of the most common wireless communication and location based systems are: UMTS (Universal Mobil Telecommunication System), GPRS (General Packet Radio Service), GSM (Global System for Mobile Communication), GPS (Global Positioning System), Cell Triangulation, WIFI, Bluetooth, IR (Infrared) and PAN (Personal Area Network). These communication systems can be further subdivided to long- range or short range communications(Tao, 2005), if the transfer of information is between two or more users via the internet or a network protocol or between two or more wearable devices worn by a user, respectfully.

Long-range communications

The long-range communication technologies advanced during the mobile revolution. All portable devices such as mobile phones, PDAs, MP3 players use radio frequencies to enable communication. From the list above the following communication systems: UMTS, GPRS, GSM, GPS, cell triangulation, WIFI are long-range. GSM is the communication system currently most suitable for voice transmission, as well as for data and files transmission at 9.6 kbps. For transfer of pictures and video a third-generation (3G) wireless system is also available, with the capacity of 384 kbps. GPS and cell triangulation is suitable for navigation purposes. The variety of communication systems opens many possibilities for wearable devices and the exchange of information.

Short-range communications

Short-range communication for wearables is a research area that still needs to be developed. Some of the approaches considered for implementation in wearables are wiring, infrared, Bluetooth technology, WIFI, Personal Area Network (PAN) and Fabric Area Network (FAN). Even though they have some disadvantages, they show promising results as future technologies embedded in devices and textiles.

Embedding wires in garments is cumbersome and constrictive, and therefore not adequate. For infrared to be effective it requires direct lines of sight, which is not practical and difficult to implement on different devices worn on the body. Bluetooth technology is widely used, with an open wireless communication protocol which ensures connection between several devices within a short communication range (10 m), overcoming problems of synchronization. This technology is embedded in a range of products (such as smart phones, headsets, mouse, keyboards, printers and game consoles) and has many applications in situations where low-bandwidth communication is required. Bluetooth devices can interact independently of the user, as well as advertise services they provide, thus making this network more secure than other types, as more of the security, network address and permission configuration can be automated. This also provides an easier access to services for the users. WIFI (also called “wireless Ethernet”) uses the same radio frequency as the Bluetooth, but with higher power, resulting with a stronger connection. The users have the advantage to move around within a broad coverage area and still be connected to the network, through a variety of WIFI enabled devices such as laptops, smart phones, PDAs.

From a collaboration research project in 1996 between MIT Media Lab and IBM Almaden Research Center a new wireless technology emerged called the Personal Area Network (PAN) also referred to it as Body Area Network. The technology is considered the backbone of wearable technology, allowing exchange of digital information, power and control signals within the user’s personal space. PAN takes advantage of the natural electrical conductivity of the human body combined with a transmitter embedded with a microchip, to create an external electric field that passes an incredibly tiny current (1 billionth of an amp- 1 nanoamp) through the body, used to transmit data (IBM, 1996). As a comparison, the electrical field created by running a comb through hair is more than 1000 times greater than the current required for PAN technology to be functional. The technology is still being refined but researchers see great potential in PAN, as an effective and cost-efficient communication network. Passing of simple data between electronic devices carried by two people would be easier than ever, such as exchanging business cards via a handshake. This scenario as fascinating as it sounds also imposes many security issues, because touching a person with a PAN is like tapping a phone line (Tao, 2005).

In 2001 Hum proposed a wireless communication infrastructure to enable networking and sensing on clothing called the Fabric Area Network (FAN). The technology promises to solve some of the problems Bluetooth and GSM are facing, regarding the public concern of health hazards from the increased amount of emissions in the body from these sources of radiation. The new and innovative method, in which the technology architecture is designed, uses radio frequency (RF) fields for data communication and powering, restricted only to the surface of the clothing thus eliminating radiation into the body. More specifically, the technology uses multiple radio frequency identification FRID links, which have been used in the industry for years for tagging and tracking products. Even though the technology is being promoted as emission-save, low-cost and easy to maintain, it still has much more development it needs to undergo before such networking and sensing clothing can be considered for mass production.

The technologies described above such as GSM, GPS, WIFI and Bluetooth are already widely used as part of wearable devices. Since, they have been proven to be stable communicational systems and well developed; attempts have been made in the research community for their implementation in computational and smart textiles. However, these technologies were not initially designed for integration in clothing and accessories and thus researchers are modifying and perfecting these wireless networks to meet the requirements that currently established communication systems, cannot fulfill. For that reason, wireless networks such as PAN and FAN were originally designed and are still investigated.

Data management technologies and integrated circuits

The storing and processing of data in wearables is carried out in integrated circuits (IC), microprocessors or microcontroller. Integrated circuits are miniaturized electronic circuits which are mostly manufactured from silicon because of its superior semi conductive properties. However silicon is not flexible and therefore ICs are not very suitable for incorporating them on clothing. Developing ICs from conductive or semi-conductive polymeric Having the properties of a polymermaterials can be of great importance for wearable electronics since these materials are flexible, lightweight, and strong and of low production cost (Rossi, Capri, Lorussi, Scilingo, Tognetti, & Paradiso, 2005). Their down side is that they are not as efficient as silicon, and thus scientists are looking into developing electronics in the near future that will be a combination of both silicon and conductive polymers which will be complimenting each other.

Among the most advanced integrated circuits there are the microprocessors which are the heart of any normal computer. Also known as the CPUs (Central Processing Units), they present complete computation engines fabricated on single chips. The microprocessor performs many functions some of which are executing a stored set of instructions carrying out user defined tasks as well as carrying the ability to access external memory chips to both read and write data from and to the memory. From the architecture of the microprocessors, more specialized processing devices were developed, such as microcontrollers.

A microcontroller is a single-chip computer, which is embedded in many everyday products and therefore it is also called “embedded controller”. If a product has buttons and a digital display, most likely it also has a programmable microcontroller that provides a real-time response to events in the embedded system they are controlling. Such automatically controlled devices, often consumer products, are remote controls, cell phones, office machines, appliances, toys and many more.

Even though microcontrollers are “small computers”, they still have many things in common to desktop computers or large mainframe computers. All computers have a CPU which executes many different programs. In the case of microcontrollers the CPU executes a single program and thus they are known as “single purpose computers”. Also microcontrollers have a hard disk, a RAM (random-access memory) and inputs and outputs, which are all combined on a single microchip. Other characteristics common for a majority of microcontrollers, besides being embedded inside other devices dedicated to run specific single task programs, are that they come as low-power devices, small and at low cost, which is of great importance for wearable e-textiles. While some embedded systems are very sophisticated, many of those implemented in wearable e-textiles have minimal requirements for memory and program length, with no operating system and low software complexity. The actual processor used in the microcontrollers can vary widely, where ones choice when designing interactive applications depends on the context in which the embedded system will be used. The programs running on the microcontrollers can be stand-alone or can communicate with the software running on other external devices, preferably through a wireless network.

Energy management technologies

One of the biggest problems in wearable and integrated electronic technology is power and the quest for alternative energy sources is essential. Today batteries in the form of AA batteries or lithium batteries are the most common source of energy utilized for running embedded systems and processing of captured data through a microcontroller. However their life span is limited and designers of wearables will have to find new and improved solutions to acquire the needed energy, either making it long lasting or easy to recharge on the move. At the same time the energy source must become light and discreet, which currently is the heaviest part of wearables.

The need for alternative sources of power is rising as the demand for greater design freedom in creating light, flexible and reliable wearable e-textile is increasing. Researchers see a potential in an alternative source of power based on the miniaturization of fuel cell technology. The way fuel cells generate electrical power is similar to batteries, as they convert the chemical energy of a given type of fuel (e.g. hydrogen and oxygen) into electrical energy. They have longer lives than batteries of similar size since oxygen does not need to be stored, only hydrogen in metal hydrides (Larminie & Dicks, 2003). Before 2010 Toshiba is planning to launch the first commercial direct methanol fuel cell-based (DMFC) batteries for cell phones and laptops.

In the beginning of 2009 researchers from the University of Illinois claimed they have developed the smallest working fuel cell, with dimensions 3 mm x 3 mm x 1 mm and it is made from four layers: a water reservoir, a thin membrane, a chamber of metal hydride, and an assembly of electrodes (Heine, 2009). Scientists claim that with the capacity of 0.7 volts and a 0.1 milliamp current for about 30 hours the mini battery can be used to run simple electronics. Researches see a great potential in fuel cell technology as it is considered to be a clean, efficient and silent technology, nevertheless the main hurdles preventing commercial introduction is high cost, lack of durability, high system complexity and lack of fuel infrastructure (Bruijn, 2005).

Another interesting alternative energy source for intelligent clothing is to harvest the kinetic energy from the human movement or the fluctuations in body temperature. Even though this energy is very minimal to drive wearable technology and can only be measured in microwatts, it is still a research field that attracts attention. Some research has been done in piezoelectric materials, which creates charge when mechanically stressed, thus inserting them on shoes, walking power can be harnessed (Tao, 2005).

Other forms of power supply are utilizing photovoltaic cells which are gathering the energy of the sun, allowing a sustainable approach to wearable technology. There are many examples of products that are incorporating solar panels onto the surface of wearable e-textiles, using thin film printed on flexible surfaces such as plastics; however the efficiency of this alternative energy source still needs to be improved.

Responsive Materials

Responsive materials represent a new generation of fibers, fabrics and articles, which are able to react in a predetermined way when exposed to stimuli, such as mechanical, electrical, chemical, thermal, magnetic and optical. They are reactive and dynamic and they have the ability to change color, shape and size in response to their environment. For many years researchers have devoted their work in developing responsive materials such as shape memory materials, chromic materials, micro and nanomaterial and piezoelectric materials.

By constantly improving and incorporating responsive materials in the development of light and flexible electronic components, conductive and semi-conductive materials, such as conductive polymers, conductive threads, yarns, coatings and inks, are receiving widespread attention. They are less dynamic then smart textiles but equally important in realizing fashionable, desirable, lightweight, soft and wireless computational textiles.

The following section gives an overview of conductive and responsive materials that are currently most used in wearable computational textiles.

Conductive fabrics and textiles are plated or woven with metallic elements such as silver, nickel, tin, copper, and aluminum. There are many different fabrics with various textures, looks and conductivity and few samples are illustrated in Figure 4 (left), those are: electronylon, electronylon nickel, clearmesh, softmesh, electrolycra and steelcloth. All these textiles show amazing electrical properties, with low surface resistance15, which can be used for making flexible and soft electrical circuits within garments or other products, pressure and position-sensing systems. They are lightweight, flexible, durable, soft and washable (some) and can be sewn like traditional textiles, which makes them a great replacement for wires in computational garments.

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Figure 4 : conductive fabrics (left) and Different types of conductive threads (Middle and right)

Conductive threads and yarns have a similar purpose to wires and that is to create conductive paths from one point to another. However, unlike wires they are flexible and can be sewn, woven or embroidered onto textile, allowing for soft circuits to be created. They contain metallic elements such as stainless steel or silver, with nylon or polyester as base fiber. Commercially available conductive threads usually vary in the resistance and the thickness of the thread. Figure 5 (middle and right) illustrates few commercially available threads. Since they are conductive when working with them, one has to take all the precautions as when using uncoated electric wire or a metallic surface without insulation. Conductive threads and yarns offer alternative ways of connecting electronics on soft and flexible textiles medium as well offering traditional textile manufacturing techniques for creating computational garments.

Conductive coatings are used to convert traditional textiles into electrically conductive materials. The coatings can be applied to different types of traditional fibers, yarns and fabrics, without changing their flexibility, density and handling.

Conductive ink is an ink that conducts electricity, providing new ways of printing or drawing circuits. This special ink can be applied to textile and other substrates. Since wearable e–textiles require great flexibility, conductive inks are become more interesting for designers and developers in this area. Conductive inks contain powdered metals such as carbon, copper or silver mixed with traditional inks.

Shape memory alloys (SMA or muscle wire) are composed of two or more metals usually nickel and titanium, combination also known as Nitinol. These wires, usually of very small diameter, have the capacity to actuate when heated and to return to their original shape when cooled. Their capacity to flex or contract is up to 5% and it is a result of dynamic changes in their internal structure generated by an electric current. Some SMA wires can be “programmed” (heated at a transition temperature) into a particular shape for ex. zigzag or coiled. They can remember the form, to which they return when cooled. SMAs are used for triggering movement, have been woven in textiles or can make fabrics shrink or curl in wearable e-textiles applications. Long before SMAs were introduced to wearable e-textile projects, they have been used in many different areas, like electronics, robotics, medicine, automotive industry and appliances. SMAs are more and more becoming an interesting material for designers working on interdisciplinary projects across the fields of computation, technology, science, design and art. They explore how new ways of combining SMAs with computation can aid the design of responsive garments, objects and spaces and provide more meaningful interfaces.

Piezoelectric materials have the ability to generate electrical charge when exposed to mechanical stress (sound, vibration, force or motion). Piezoelectric materials exhibit reversible effect because they can produce electrical charge when subjected to stress and also they can generate stress when an electrical field is applied. Therefore the materials can be used both as sensors and actuators. Piezoelectric materials can serve as excellent environmental sensors, but the number of interesting applications in wearable e-textiles is even greater if they are coupled with other sensors, for ex. solar cells where they can be used to convert light to sound, motion or vibration.

Chromic materials are those that radiate, erase or just change the color based on the induction caused by external stimuli. They are also known as non- emissive “active materials” (Berzowska & Bromley, Soft computation through conductive materials , 2007). The classification of chromic materials depends on the stimuli affecting them. Some of the most know are photochromic and thermochromic materials. Most of the color changing phenomena (photochromism, thermochromism, electrochromism, piezochromism etc.) are reversible.

Photochromic (inks and dyes) are materials that react to light as an external stimulus. They are typically available in powdered crystals of ultraviolet (UV) sensitive pigments that need to be dissolved in an ink for application. Once the material is exposed to sunlight, blacklight or other UV source it will change from clear to colored state. When the UV source is removed they revert to their original state. They can be applied on various media, including textile, paper, plastic, wood and glass and can be used to create dynamic patterns that change in accordance to light variations in their surroundings.

Thermochromic inks are heat sensitive materials. They are made from various compounds that need to dissolve in the appropriate ink type for application. When exposed to a specific temperature they change from one color to another of from color to translucent. Thermochromic inks can be classified to three types, low – react to cold, body – react to body heat, touch and breath and high – react to hot liquids and air. They have the ability to infinitely shift color and with that create dynamic patterns on various substrates, including textiles.

Nanomaterials and microfibers have been the subject of enormous interest, over the past decades. They are materials fabricated on a molecular level. The technology is aimed at manipulating the structure of materials on atomic, molecular and nano16 level in a precise and controlled manner to create products or byproducts with specially engineered characteristics. Scientists use the prefix nano to denote a factor of 10-9 or one-billionth. One nanometer is one-billionth meter which is about 100,000 times smaller than the diameter of a single human hair (Qian & Hinestroza, 2004).

Many believe that the future development of many areas of our lives lie in nanotechnology, which fundamentals are based on the fact that properties of substances can change when their size is reduces to the nanometer range. The technology will be used in fabricating nanomachies, nanelectronics and other nanodevices to improve existing products and to create many new ones. Nanotechnology will also

have a great impact on textiles, being able to transform the molecular structure of the fibers and create fabrics that offer unsurpassed performance and comfort. The technology is likely to revolutionize wearable e-textiles, by not only developing very small and flexible electronic devices embedded in textile substrates, but it will go even further, ultimately having the electronic devices and system becoming the fabric itself. Researchers have already started to develop transistors in yarn form and to make conductive, carbon nanotube.

Refrance : E-textiles: The intersection of computation and traditional textiles (Interactive Sample Book by Marija Andonovska)

Technical Textiles – A Vision of Future


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Textiles are no more limited for use as apparels clothing is just are but not the only purpose of textiles with the rapid changes in the social economic structure of our society. Many efforts are made to some and protect human life. Textiles come to our help in every walk of life. Similarly, textiles enhancing the quality of human life trough protection against various hazards as well as protection of environment are today’s priorities were scientist all around the world are breaking their heads. Technical textiles are the fastest growing area of textile consumption in the world. As per the market survey it has projected an average growth rate of 4% for technical textiles during the period 1995-2005.

In most of the developed countries, technical textiles already account for 4% of the total textile production. Even in many developing countries, the proportion is well above 10%. At present, India’s contribution in this area is negligible at about 0.2%.However, due to competition from neighboring countries ad emerging economic power, India has tremendous potential for production, Consumption and export of technical textile. In the circumstances, textiles are playing major role through its diversified applications and undoubtedly the future of this technical textiles appears tom be bright in this, lot of uses are there. They are medical textiles, protective textiles, agricultural textiles, geo textiles, automotive textiles, smart textiles and industrial textiles.

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technical-textiles

Textile Waste Criteria


The EcoChic Design Award committee classifies ‘textile waste’ as: end-of-roll textiles; damaged textiles; textile scraps; textile swatches and sampling yardage; clothing samples; finished clothing waste or secondhand clothing waste.

Applicants are required to provide information and documentation of the type and source of their chosen textile waste in order for their application to be successful.

For a zero-waste design

Applicants are encouraged to use textile waste or other sustainable textiles but this is not a requirement.

For an up-cycling design

Applicants can use the following types of textile waste:

Damaged textiles: textiles that have been damaged, for example colour or print defects.

End-of-roll textiles: factory surplus textiles that have been leftover from garment manufacturing.

Textile scraps: cut-and-sew waste from garment manufacturing.

Textile swatches: leftover textile sample swatches.

Sampling Yardage: factory surplus sample textiles that have been leftover from sample manufacturing.

For a reconstruction design:

Applicants can use the following types of textile waste:

Clothing samples: samples from the design and production of clothing.

Finished clothing waste: unsold finished clothing waste that has not yet been worn.

Secondhand clothing: clothing that has been used and discarded by consumers.

Dyeable Polypropylene Fiber


The ability to dye polypropylene fibers using conventional disperse dyes makes the fibers more attractive for apparel end-uses.

TW Special Report

Polypropylene fibers possess a number of attractive properties when compared to other fibers (See Table 1). Despite desirable properties, polypropylene fibers traditionally have suffered from a major drawback that has limited their adoption in textile apparel applications: In contrast to other fibers, conventional polypropylene fibers cannot be dyed. Instead, the color has to be imparted at the fiber extrusion step through mass coloration or solution dyeing. The process involves adding a relatively thermally stable pigment color during the melt spinning of the fiber. The pigments used are not usually miscible with polypropylene. Thus, the pigments are present as discrete particles in the fiber, and the color imparted becomes permanent in the fiber. While this has the benefit of very good colorfastness, there are two significant disadvantages. The first is that introducing new colors involves a relatively complex color-matching step. The second is the absence of greige goods to be dyed. This means that relatively large lots of fiber are made for every new color, and the time required to go from a new color concept to the final fabric or garment can be long.

There has been a long-standing interest in commercializing a dyeable polypropylene fiber. Ideally, it should have a dyeing profile similar to or compatible with large-volume fibers such as polyester, nylon or cotton, so that it is compatible with the dyeing and related processes that are already well-established. Furthermore, it should not change the essential benefits of polypropylene fibers presented in Table 1, especially its low density and its low surface energy. There have been several attempts to make dyeable polypropylene fibers, but they have not been successful because the resulting product did not meet these criteria.
FiberVisions has developed a revolutionary new polypropylene fiber, CoolVisions™ dyeable polypropylene fiber, that meets the needs of facile dyeing and polypropylene fiber characteristics by incorporating an additive within the polypropylene fiber. The fiber can be dyed using conventional disperse dyes in a manner similar to that used for polyester fibers. The fibers feature a wide array of inherent benefits and properties including:

  • light weight and comfort;
  • cottony softness;
  • easy care, easy wear;
  • moisture management;durability;
  • breathability;
  • thermal insulation; and
  • stain resistance.

FWfeaturechart

Lightweight And Comfortable

Polypropylene fibers are among the lightest in weight of all commercial fibers. The increased number of polypropylene fibers per kilogram of fabric offers added value compared to many other fibers, resulting in improved coverage for the same weight range or equal coverage in lighter-weight fabrics for comfortable garments. In addition, CoolVisions fibers are inherently softer than traditional polypropylene fibers, resulting in greater comfort, according to FiberVisions. This combination of attributes makes garments made from these new fibers inherently easy care, easy wear.

Moisture Management

According to FiberVisions, CoolVisions polypropylene fibers outperform all other dyeable fibers in low-moisture-absorption tests. In addition, garments made from polypropylene tend to have a high moisture-vapor-transmission rate. This is important in comfort, especially when one wants the skin to stay cool and dry. The mechanical properties of polypropylene fibers are not affected when the fabric is wet an inherent advantage compared to fibers like rayon, which can lose strength substantially.
As with traditional polypropylene, CoolVisions offers excellent chemical resistance and aqueous stain resistance. Bleach and other household cleaning chemicals do not affect the fibers, which also are not attacked by microbial organisms such as mold, mildew and bacteria.

windsurfers
Dyeable polypropylene fibers are suitable for apparel end-uses including sports applications.

Dyeing Characteristics

CoolVisions dyeable polypropylene fibers can be dyed using commonly available polyester high-energy disperse dyes and in standard high-pressure dyeing processes used for polyester fibers, but with lower dyeing temperatures possible. The color range and color-matching process are similar to those for polyester fibers.
The ability to dye fabrics results in many benefits over the use of fabrics made with traditional solution-dyed fibers, including value chain and styling benefits. Some of the value-chain benefits include the ability to store greige goods, match colors quickly, produce smaller lot volumes and serve niche or fashion-related color lines, respond rapidly to market demand, and offer a wider range of colors without greatly increasing inventory costs. There are added financial benefits from reduced working capital needs and shortened production times. Styling benefits include reduction in barré found in solution-dyed garments and the ability to print with dye inks rather than pigment inks. Dye-printed fabrics exhibit a softer hand and better colorfastness than pigment-printed fabrics. CoolVisions fibers also have been engineered to have an inherently soft hand and cotton touch not found in traditional polypropylene fibers.
As noted previously, CoolVisions fibers contain an additive that acts as a dye receptor. The additive is present in the fibers as small domains into which the disperse dyes dissolve during the dyeing process. At dyeing temperatures greater than the boiling point of water, the disperse dyes diffuse readily through the polypropylene fiber into the encapsulated domains of the additive. Under actual garment use conditions — which include much lower temperatures — the diffusion of the disperse dyes back out of the fiber is greatly diminished, resulting in good colorfastness. As with polyester fibers, high-energy disperse dyes should be used to obtain optimum colorfastness.
The approach of encapsulating the additive within the polypropylene fiber has many benefits. The surface of the fiber is essentially unchanged, resulting in excellent aqueous stain resistance and low water absorption. The polypropylene fiber also serves to protect the dyes from chemicals such as chlorine, resulting in excellent bleach fastness.
Since the ability to dye the polypropylene fiber is imparted by the incorporation of an additive, the level of the additive affects the depth of shade. This has a couple of benefits, according to FiberVisions: The additive level can be controlled quite well, resulting in reduced shade sensitivity to processing conditions. In addition, the level can be intentionally changed to produce fibers that dye to different depths, thereby offering an additional styling tool.
FiberVisions officially launched CoolVisions dyeable polypropylene fibers at the recent Outdoor Retailer Show in Salt Lake City. A number of partner companies are currently working with these fibers to develop new fabrics and apparel styles. Activities are underway to develop air-jet spun and filament-type products to broaden the range of styling tools.

September/October 2006

REEF:- TEXTILE WORLD

Multiaxis Three Dimensional (3D)


  • Introduction

Textile structural composites are widely used in various industrial sections, such as civil and defense (Dow and Dexter, 1997; Kamiya et al., 2000) as they have some better specific properties compared to the basic materials such as metal and ceramics (Ko & Chou 1989;Chou, 1992). Research conducted on textile structural composites indicated that they can be considered as alternative materials since they are delamination-free and damage tolerant (Cox et al, 1993; Ko & Chou 1989). From a textile processing viewpoint they are readily  available, cheap, and not labour intensive (Dow and Dexter, 1997). The textile preform fabrication is done by weaving, braiding, knitting, stitching, and by using nonwoven techniques, and they can be chosen generally based on the end-use requirements. Originally three dimensional (3D) preforms can be classified according to fiber interlacement types. Simple 3D preform consists of two dimensional (2D) fabrics and is stitched depending on stack sequence. More sophisticated 3D preforms are fabricated by specially designed automated loom and manufactured to near-net shape to reduce scrap (Brandt et. al., 2001; Mohamed, 1990). However, it is mentioned that their low in-plane properties are partly due to through-the-thickness fiber reinforcement (Bilisik and Mohamed, 1994; Dow and Dexter, 1997; Kamiya et al., 2000). Multiaxis knitted preform, which has four fiber sets as ±bias, warp(0°) and weft(90°) and stitching fibers enhances in-plane properties (Dexter and Hasko, 1996). It was explained that multiaxis knitted preform suffers from limitation in fiber architecture, through-thickness reinforcement due to the thermoplastic stitching thread and three dimensional shaping during molding (Ko & Chou 1989).

Multiaxis 3D woven preform is developed in the specially developed multiaxis 3D weaving and it’s in-plane properties are improved by orienting the fiber in the preform (Mohamed and Bilisik, 1995; Uchida et al, 2000). The aim of this chapter is to review the 3D fabrics, production methods and techniques. Properties of 3D woven composites are also provided with possible specific end-uses.

  • Classifications of 3D fabrics

3D preforms were classified based on various parameters. These parameters depend on the fiber type and formation, fiber orientation and interlacements and micro and macro unit cells structures. One of the general classification schemes has been proposed by Ko and Chou (1989). Another classification scheme has been proposed depending upon yarn interlacement and type of processing (Khokar, 2002a). In this scheme, 3D woven preform is divided into orthogonal and multiaxis fabrics and their process have been categorized as traditional or new weaving, and specially designed looms. Chen (2007) categorized 3D woven preform based on macro geometry where 3D woven fabrics are considered solid, hollow, shell and nodal forms. Bilisik (1991) proposes more specific classification scheme of 3D woven preform based on type of interlacements, yarn orientation and number of yarn sets as shown in Table 1. In this scheme, 3D woven fabrics are divided in two parts as fully interlaced 3D woven and non-interlaced orthogonal woven. They are further sub divided based on reinforcement directions which are from 2 to 15 at rectangular or hexagonal arrays and macro geometry as cartesian and polar forms. These classification schemes can be useful for development of fabric and weaving process for further researches.

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2D woven fabric is the most widely used material in the composite industry at about 70%. 2D woven fabric has two yarn sets as warp(0°) and filling(90°) and interlaced to each other to form the surface. It has basically plain, twill and satin weaves which are produced by traditional weaving as shown in Figure 1. But, 2D woven fabric in rigid form suffers from its poor impact resistance because of crimp, low delamination strength because of the lack of binder fibers (Z-fibers) to the thickness direction and low in-plane shear properties because no off-axis fiber orientation other than material principal direction (Chou, 1992). Although
through-the-thickness reinforcement eliminates the delamination weakness, this reduces the in-plane properties (Dow and Dexter, 1997, Kamiya et al., 2000). On the other hand, uniweave structure was developed. The structure has one yarn set as warp (0°) and multiple warp yarns were locked by the stitching yarns (Cox and Flanagan, 1997).

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Fig. 1. 2D various woven fabrics (a) and schematic view of processing (b) (Chou, 1992).

Bi-axial non-crimped fabric was developed to replace the unidirectional cross-ply lamina structure (Bhatnagar and Parrish, 2006). Fabric has basically two sets of fibers as filling and warp and locking fibers. Warp positioned to 0° direction and filling by down on the warp layer to the cross-direction (90°) and two sets of fibers are locked by two sets of stitching yarns’ one is directed to 0° and the other is directed to 90°. Traditional weaving loom was modified to produce such fabrics. Additional warp beam and filling insertions are mounted on the loom. Also, it is demonstrated that 3D shell shapes with high modulus fibers can be knitted by weft knitting machine with a fabric control sinker device as shown in Figure 2.

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Fig. 2. Non-interlace woven fabric (a) and warp inserted knitted fabric (b) (Bhatnagar & Parrish, 2006).

  • Triaxial fabrics

Triaxial weave has basically three sets of yarns as ±bias (±warp) and filling (Dow, 1969). They interlaced to each other at about 60° angle to form fabric as shown in Figure 3. The interlacement is the similar with the traditional fabric which means one set of yarns is above and below to another and repeats through the fabric width and length. Generally, the fabric has large open areas between the interlacements. Dense fabrics can also be produced. However, it may not be woven in a very dense structure compared to the traditional fabrics. This process has mainly open reed. Triaxial fabrics have been developed basically in two variants. One is loose-weave and the other is tight weave. The structure was evaluated and concluded that the open-weave triaxial fabric has certain stability and shear stiffness to ±45° direction compared to the biaxial fabrics and has more isotropy (Dow and Tranfield, 1970).

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Fig. 3. Triaxial woven fabrics; loose fabric (a), tight fabric (b) and one variant of triaxial woven fabric (c) (Dow, 1969).

The machine consists of multiple ±warp beams, filling insertion, open beat-up, rotating heddle and take up. The ±warp yarn systems are taken from rotating warp beams located above the weaving machine. After leaving the warp beams, the warp ends are separated into two layers and brought vertically into the interlacing zone. The two yarn layers move in opposite directions i.e., the front layer to the right and the rear layer to the left. When the outmost warp end has reached the edge of the fabric, the motion of the warp layers is reversed so that the front layer moves to the left and the rear layer to the right as shown in Figure 4. As a result, the warp makes the bias intersecting in the fabric. Shedding is controlled by special hook heddles which are shifted after each pick so that in principle they are describing a circular motion. The pick is beaten up by two comb-like reeds which are arranged in opposite each other in front of and behind the warp layers, penetrate into the yarn layer after each weft insertion and thus beat the pick against the fell of the cloth.

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Fig. 4. The schematic views of weaving method of triaxial woven fabrics; bias orientation (a), shedding (b), beat-up (c) and take-up (d) (Dow, 1969).

A century ago, the multiaxis fabric, which has ±bias, warp(axial) and filling, was developed for garment and upholstery applications (Goldstein, 1939). The yarn used in weaving is slit cane. The machine principal operation is the same with triaxial weaving loom. A loom consists of bias creel which is rotated; ±bias indexing and rotating unit; axial warp feeding; rigid rapier type filling insertion and take up units.

Tetra-axial woven fabric was introduced for structural tension member applications. Fabric has four yarn sets as ±bias, filling and warp (Kazumara, 1988). They are interlaced all together similar with the traditional woven fabric. So, the fabric properties enhance the longitudinal direction. The process has rotatable bias bobbins unit, a pair of pitched bias cylinders, bias shift mechanism, shedding unit, filling insertion and warp (0°) insertion units. After the bias bobbins rotate to incline the yarns, helical slotted bias cylinders rotate to shift the bias one step as similar with the indexing mechanism. Then, bias transfer mechanism changes the position of the end of bias yarns. Shedding bars push the bias yarns to make opening for the filling insertion. Filling is inserted by rapier and take-up advances the fabric to continue the next weaving cycle.

Another tetra-axial fabric has four fiber sets as ±bias, warp and filling. In fabric, warp and filling have no interlacement points with each other. Filling lays down under the warp and ±bias yarns and locks all yarns together to provide fabric integrity (Mamiliano, 1994). In this way, fabric has isotropic properties to principal and bias directions. The process has rotatable bias feeding system, ±bias orientation unit, shedding bars unit, warp feeding, filling insertion and take-up. After bias feeding unit rotates one bobbin distance, ±bias system rotates just one yarn distance. Shedding bars push the ±bias fiber sets to each other to make open space for filling insertion. Filling is inserted by rapier and take-up delivers the fabric. The fabric called quart-axial has four sets of fibers as ±bias, warp and filling yarns as shown in Figure 5. All fiber sets are interlaced to each other to form the fabric structure (Lida et al, 1995). However, warp yarns are introduced to the fabric at selected places depending upon the end-use.

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Fig. 5. Quart-axial woven fabric (a) and weaving loom (b) (Lida et al., 1995).

The process includes rotatable ±bias yarn beams or bobbins, close eye hook needle assembly, warp yarn feeding unit, filling insertion unit, open reed for beat-up and take-up. After the ±bias yarns rotation just one bobbin distance, heddles are shifted to one heddle distance. Then warp is fed to the weaving zone and heddles move to each other selectively to form the shed. Filling insertion takes place and open reed beats the filling to the fabric formation line. Take-up removes the fabric from the weaving zone.

  • 3D orthogonal fabric

3D orthogonal woven preforms have three yarn sets: warp, filling, and z-yarns (Bilisik, 2009a). These sets of yarns are all interlaced to form the structure wherein warp yarns were longitudinal and the others were orthogonal. Filling yarns are inserted between the warp layers and double picks were formed. The z-yarns are used for binding the other yarn sets to provide the structural integrity. The unit cell of the structure is given in Figure 6.

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Fig. 6. 3D orthogonal woven unit cell; schematic (a) and 3D woven carbon fabric perform (b) (Bilisik, 2009a).

A state-of-the-art weaving loom was modified to produce 3D orthogonal woven fabric (Deemey, 2002). For instance, one of the looms which has three rigid rapier insertions with dobby type shed control systems was converted to produce 3D woven preform as seen in Figure 7. The new weaving loom was also designed to produce various sectional 3D woven preform fabrics (Mohamed and Zhang, 1992).

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Fig. 7. Traditional weaving loom (a) and new weaving loom (b) producing 3D orthogonal woven fabrics (Deemey, 2002; Mohamed and Zhang, 1992).

On the other hand, specially designed weaving looms for 3D woven orthogonal woven preform were developed to make part manufacturing for structural applications as billet and conical frustum. They are shown in Figure 8. First loom was developed based on needle insertion principle (King, 1977), whereas second loom was developed on the rapier-tube insertion principle (Fukuta et al, 1974).

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Fig. 8. 3D weaving looms for thick part manufacturing based on needle (a) and rapier (b) principles (King, 1977; Fukuta et al, 1974).

3D angle interlock fabrics were fabricated by 3D weaving loom (Crawford, 1985). They are considered as layer-to-layer and through-the-thickness fabrics as shown in Figure 9. Layerto-layer fabric has four sets of yarns as filling, ±bias and stuffer yarns (warp). ±Bias yarns oriented at thickness direction and interlaced with several filling yarns. Bias yarns made zigzag movement at the thickness direction of the structure and changed course in the structure to the machine direction. Through-the-thickness fabric has again four sets of fibers as ±bias, stuffer yarn (warp) and fillings. ±Bias yarns are oriented at the thickness direction of the
structure. Each bias is oriented until coming to the top or bottom face of the structure. Then, the bias yarn is moved towards top or bottom faces until it comes to the edge. Bias yarns are locked by several filling yarns according to the number of layers.

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Fig. 9. 3D angle interlock fabrics (a) and schematic view of 3D weaving loom (b) (Khokar, 2001).

Another type of 3D orthogonal woven fabric, which pultruded rod is layered, was introduced. ±Bias yarns were inserted between the diagonal rows and columns for opening warp layers at a cross-section of the woven preform structure (Evans, 1999).

The process includes ±bias insertion needle assembly, warp layer assembly and hook holder assembly as shown in Figure 10. Warp yarns are arranged in matrix array according to  preform cross-section. A pair of multiple latch needle insertion systems inserts ±bias yarns at cross-section of the structure at an angle about 60°. Loop holder fingers secure the bias loop for the next bias insertion and passes to the previous loop.

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Fig. 10. 3D orthogonal fabric at an angle in cross-section (a) and production loom (b) (Evans, 1999).

3D circular weaving (or 3D polar weaving) was also developed (Yasui et al., 1992). A preform has mainly three sets of yarn: axial, radial and circumferential for cylindrical shapes and additional of the central yarns for rod formation as shown in Figure 11. The device has a rotating table for holding the axial yarns, a pair of carriers which extend vertically up and down to insert the radial yarn and each carrier includes several radial yarn bobbins and finally a guide frame for regulating the weaving position. A circumferential yarn bobbin is placed on the radial position of the axial yarns. After the circumferential yarn will be wound over the radial yarn which is vertically positioned, the radial yarn is placed radially to the outer ring of the preform. The exchanging of the bobbins results in a large shedding motion which may cause fiber damage.

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Fig. 12. 2D shaped woven connectors as H-shape (a), TT-shape (b) and Y-shape (c) (Abildskow, 1996).

A 2D woven plain fabric base laminated connector was developed. It was joined adhesively to the spar and sandwiched panel at the aircraft wing (Jonas, 1987). Integrated 2D shaped woven connector fabric was developed to join the sandwiched structures together for aircraft applications (Abildskow, 1996). The 2D integrated woven connector has warp and filling yarns. Basically, two yarn sets are interlaced at each other. Z-fibers can be used based on connector thickness. The connector can be woven as Π, Y, H shapes according to joining types as shown in Figure 12. Rib or spars as the form of sandwiched structures are joined by
connector with gluing.

  • Multiaxis 3D fabric

Multiaxis 3D woven fabric, method and machine based on lappet weaving principles were introduced by Ruzand and Guenot (1994). Fabric has four yarn sets: ±bias, warp and filling as shown in Figure 13. The bias yarns run across the full width of the fabric in two opposing layers on the top and bottom surfaces of the fabric, or if required on only one surface. They are held in position using selected weft yarns interlaced with warp binding yarns on the two surfaces of the structure. The intermediate layers between the two surfaces are composed of other warp and weft yarns which may be interlaced.

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Fig. 13. Multiaxis 3D woven fabric (a), structural parts (b) and loom based on lappet weaving (c) (Ruzand and Guenot, 1994).

The basis of the technique is an extension of lappet weaving in which pairs of lappet bars are used on one or both sides of the fabric. The lappet bars are re-segmented and longer greater than the fabric width by one segment length. Each pair of lappet bars move in opposite directions with no reversal in the motion of a segment until they fully exceeds the opposite fabric selvedge. When the lappet passes across the fabric width, the segment in the lappet bar is detached, its yarns are gripped between the selvedge and the guides and it is cut near the selvedge. The detached segment is then transferred to the opposite side of the fabric where it is reattached to the lappet bar and its yarn subsequently connected to the fabric selvedge. Since a rapier is used for weft insertion, the bias yarns can be consolidated into the selvedge by an appropriate selvedge-forming device employed for weaving. The bias warp supply for each lappet bar segment is independent and does not interfere with the yarns from other segments.

A four layers multiaxis 3D woven fabric was developed (Mood, 1996). That fabric has four yarn sets: ±bias, warp and filling. The ±bias sets are placed between the warp (0°) and filling (90°) yarn sets so that they are locked by the warp and filling, where warp and filling yarns are orthogonally positioned as shown in Figure 14. The bias yarns are positioned by the use of special split-reeds together and a jacquard shedding mechanism with special heddles. A creel supplies bias warp yarns in a sheet to the special heddles connected to the jacquard head. The bias yarns then pass through the split-reed system which includes an open upper reed and an open lower reed together with guides positioned in the reed dents. The lower reed is fixed while the upper reed can be moved in the weft direction.

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Fig. 14. Four layers multiaxis woven fabric (a) and Jacquard weaving loom (b) (Mood, 1996).

The jacquard head is used for the positioning of selected bias yarns in the dents of the upper reed so that they can be shifted transverse to the normal warp direction. The correct positioning of the bias yarns requires a series of such lifts and transverse displacements and no entanglement of the warp. A shed is formed by the warp binding yarn via a needle bar system and the weft is inserted at the weft insertion station with beat-up performed by another open reed.

Another multiaxis four layer fabric was developed based on multilayer narrow weaving principle (Bryn et al., 2004). The fabric, which has ±bias, warp and filling yarn sets, is shown in Figure 15. The fabric was produced in various cross-sections like ┴, ╥, □. Two sets of bias yarns were used during weaving and when +bias yarns were reached the selvedge of the fabric then transverse to the opposite side of the fabric and become –bias. All yarns were interlaced based on traditional plain weave.

A narrow weaving loom was modified to produce the four layers multiaxis fabric. The basic modified part is bias insertion assembly. Bias yarn set was inserted by individual hook. The basic limitation is the continuous manufacturing of the fabric. It is restricted by the bias yarn length. Such structure may be utilized as connector to the structural elements of aircraft components.

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Fig. 15. Four layers multiaxis woven fabric (a) and narrow weaving loom (b) (Bryn et al., 2004).

A multiaxis weaving loom was developed to produce four layers fabric which has ±bias, warp and filling yarns as shown in Figure 16. The process has warp creel, shuttle for filling insertion, braider carrier for +bias or –bias yarns, open reed and take-up. Bias carriers were moved on predetermined path based on cross-sectional shape of the fabric. Filling is inserted by shuttle to interlace with warp as it is same in the traditional weaving. Open reed beats the inserted filling to the fabric fell line to provide structural integrity (Nayfeh et al., 2006).

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Fig. 16. Schematic view of multiaxis weaving loom (Nayfeh et al., 2006).

A multiaxis structure and process have been developed to produce the fabrics. The pultruded rods are arranged in hexagonal array as warp yarns as shown in Figure 17. Three sets of rods are inserted to the cross-section of such array at an angle about 60°. The properties of the structure may distribute isotropically depending upon end-use (Kimbara et al., 1991).

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Fig. 17. Multiaxis pultruded rod fabric (a) and devise to produce the fabric (b) (Kimbara et al., 1991).

A fabric has been developed where ±bias yarns are inserted to the traditional 3D lattice fabric’s cross-section at an angle of ±45° (Khokar, 2002b). The fabric has warp, filling, Z-yarn which are orthogonal arrangements and plain type interlaced fiber sets were used as (Zyarn)- interlace and filling-interlace as shown in Figure 18. The ±bias yarns are inserted to such structure cross-section at ±45°. The fabric has complex internal geometry and production of such structure may not be feasible.

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Fig. 18. The fabric (a) and specially designed loom to fabricate the multiaxis 3D fabric (b) (Khokar, 2002b).

Anahara and Yasui (1992) developed a multiaxis 3D woven fabric. In this fabric, the normal warp, bias and weft yarns are held in place by vertical binder yarns. The weft is inserted as double picks using a rapier needle which also performs beat-up. The weft insertion requires the normal warp and bias layers to form a shed via shafts which do not use heddles but rather have horizontal guide rods to maintain the vertical separation of these layers. The binders are introduced simultaneously across the fabric width by a vertical guide bar assembly comprising a number of pipes with each pipe controlling one binder as shown in
Figure 19.

The bias yarns are continuous throughout the fabric length and traverse the fabric width from one selvedge to the other in a cross-laid structure. Lateral positioning and cross-laying of the bias yarns are achieved through use of an indexing screw-shaft system. As the bias yarns are folded downwards at the end of their traverse, there is no need to rotate the bias yarn supply. So, the bias yarns can supply on warp beams or from a warp creel, but they must be appropriately tensioned due to path length differences at any instant of weaving. The bias yarn placement mechanism has been modified instead of using an indexing screw shaft system, actuated guide blocks are used to place the bias yarns as shown in Figure 20.

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Fig. 19. The multiaxis 3D woven fabric (a), indexing mechanism for ±bias (b) and loom (c)  (Anahara and Yasui, 1992).

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Fig. 20. Guide block mechanism for ±bias yarns (Anahara and Yasui, 1992).

A folded structure of the bias yarns results in each layer having triangular sections which alternate in the direction of the bias angle about the warp direction due to the bias yarn interchanges between adjacent layers. The bias yarns are threaded through individual guide blocks which are controlled by a special shaft to circulate in one direction around a rectangular path. Obviously, this requires rotation of the bias yarn supply.

Uchida et al. (1999) developed the fabric called five-axis 3D woven which has five yarn sets: ±bias, filling and warp and Z-fiber. The fabric has four layers and sequences: +bias, –bias, warp and filling from top to bottom. All layers are locked by the Z-fibers as shown in Figure21

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Fig. 21. Five-axis fabric (a) and newly developed weaving loom (b) (Uchida et al., 1999).

The process has bias rotating unit, filling insertion, Z-yarn insertion, warp, ±bias and Z-fiber feeding units, and take-up. A horizontally positioned bias chain rotates one bias yarn distance to orient the yarns, and filling is inserted to the fixed shed. Then Z-yarn rapier inserts the Z-yarn to bind all yarns together and all Z-yarn units are moved to the fabric fell line to carry out the beat-up function. The take-up removes the fabric from the weaving zone.

Mohamed and Bilisik (1995) developed multiaxis 3D woven fabric, method and machine in which the fabric has five yarn sets: ±bias, warp, filling and Z-fiber. Many warp layers  re positioned at the middle of the structure. The ±bias yarns are positioned on the back and front faces of the preform and locked the other set of yarns by the Z-yarns as shown in Figure 22. This structure can enhance the in-plane properties of the resulting composites.

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Fig. 22. The unit cell of multiaxis fabric (a), top surface of multiaxis small tow size carbon  fabric (b) and cross-section of the multiaxis carbon fabric (c) (Mohamed and Bilisik, 1995; Bilisik, 2010a).

The warp yarns are arranged in a matrix of rows and columns within the required crosssectional shape. After the front and back pairs of the bias layers are oriented relative to each other by the pair of tube rapiers, the filling yarns are inserted by needles between the rows of warp (axial) yarns and the loops of the filling yarns are secured by the selvage yarn at the opposite side of the preform by selvage needles and cooperating latch needles. Then, they return to their initial position as shown in Figure 23. The Z-yarn needles are inserted to both front and back surface of the preform and pass across each other between the columns of the warp yarns to lay the Z-yarns in place across the previously inserted filling yarns. The filling  is again inserted by filling insertion needles and secured by the selvage needle at the opposite side of the preform. Then, the filling insertion needles return to their starting position. After this, the Z-yarns are returned to their starting position by the Z-yarn insertion needles by passing between the columns of the warp yarns once again and locking the bias yarn and filling yarns into place in the woven preform. The inserted filling, ±bias and Z-yarns are beaten into place against the woven line as shown in Figure 24, and a takeup system moves the woven preform.

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Fig. 23. Schematic view of multiaxis weaving machine (a) and top side view of multiaxis weaving machine (b) (Mohamed and Bilisik, 1995; Bilisik, 2010b).

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Fig. 24. Top surface of multiaxis large tow size carbon fabric (a) and weaving zone of the multiaxis weaving machine (b) (Bilisik, 2009a).

Bilisik (2000) developed multiaxis 3D circular woven fabric, method and machine. The preform is basically composed of the multiple axial and radial yarns, multiple circumferential and the ±bias layers as shown in Figure 25. The axial yarns (warp) are arranged in a radial rows and circumferential layers within the required cross-sectional shape. The ±bias yarns are placed at the outside and inside ring of the cylinder surface.
The filling (circumferential) yarns lay the between each warp yarn helical corridors. The radial yarns (Z-fiber) locks the all yarn sets to form the cylindrical 3D preform. A cylindrical preform can be made thin and thick wall section depending upon end-use requirements.

A process has been designed based on the 3D braiding principle. It has machine bed, ±bias and filling ring carrier, radial braider, warp creel and take-up. After the bias yarns are oriented at ±45° to each other by the circular shedding means on the surface of the preform, the carriers rotate around the adjacent axial layers to wind the circumferential yarns. The radial yarns are inserted to each other by the special carrier units and locked the circumferential yarn layers with the ±bias and axial layers all together. A take-up system removes the structure from the weaving zone. This describes one cycle of the operation to weave the multiaxial 3D circular woven preform. It is expected that the torsional properties of the preform could be improved because of the bias yarn layers.

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Fig. 25. The unit cell of multiaxis 3D circular woven fabric (a), Multiaxis 3D aramid circular woven fabric (b) and the weaving loom (c) (Bilisik, 2000; Bilisik, 2010c).

  • Multiaxis 3D knitted fabric

Wilkens (1985) introduced a multiaxis warp knit fabric for Karl Mayer Textilmaschinenfabric GmbH. The multiaxis warp knit machine which produces multiaxis warp knit fabric has been developed by Naumann and Wilkens (1987). The fabric has warp (0° yarn), filling (90° yarn), ±bias yarns and stitching yarns as shown in Figure 26. The machine includes ±bias beam, ±bias shifting unit, warp beam feeding unit, filling laying-in
unit and stitching unit. After the bias yarn rotates one bias yarn distance to orient the fibers, the filling lays-in the predetermined movable magazine to feed the filling in the knitting zone. Then the warp ends are fed to the knitting zone and the stitching needle locks the all yarn sets to form the fabric. To eliminate the bias yarn inclination in the feeding system, machine bed rotates around the fabric. The stitching pattern, means tricot or chain, can be arranged for the end-use requirements.

Hutson (1985) developed a fabric which is similar to the multiaxis knitted fabric. The fabric has three sets of yarns: ±bias and filling (90° yarn) and the stitching yarns lock all the yarn sets to provide structural integrity. The process basically includes machine track, lay down fiber carrier, stitching unit, fiber feeding and take-up. The +bias, filling and –bias are laid according to yarn layer sequence in the fabric. The pinned track delivers the layers to the stitching zone. A compound needle locks the all yarn layers to form the fabric.

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Fig. 26. Top and side views of multiaxis warp knit fabric (a) (Wilkens, 1985), bias indexing mechanism (b), warp knitting machine (c) (Naumann and Wilkens, 1987).

Wunner (1989) developed the machine produces the fabric called multiaxis warp knit for Liba GmbH. It has four yarn sets: ±bias, warp and filling (90° yarn) and stitching yarn. All layers are locked by the stitching yarn in which tricot pattern is used as shown in Figure 27. The process includes pinned conveyor bed, fiber carrier for each yarn sets, stitching unit, yarn creels and take-up.

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Fig. 27. Warp knit structure (a), stitching unit (b) and warp knit machine (c) (Wunner, 1989).

A multiaxis warp knit/braided/stitching type structure for aircraft wing-box has been developed by NASA/BOEING. The multiaxis warp knit fabric is sequence and cuts from 2 to 20 layers to produce a complex aircraft wing skin structure. Then, a triaxial braided tube is collapsed to produce a stiffener spar. All of them are stitched by the multi-head stitching machine which was developed by Advanced Composite Technology Programs. The stitching density is 3 columns/cm. The complex contour shape can be stitched according to requirements as shown in Figure 28. When the carbon dry preform is ready, resin film
infusion technique is used to produce the rigid composites. In this way, 25 % weight reduction and 20 % cost savings can be achieved for aircraft structural parts. In addition, the structures have high damage tolerance properties (Dow and Dexter, 1997).

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Fig. 28. Warp knit structure (a), multilayer stitched warp knit structure (b), layeringstitching- shaping (c) and application in airplane wing structure (d) (Dow and Dexter, 1997).

Moisture Management


  • By:- DR. PETRY, TEXTILE AUXILARIES

  • Definition

In general, „moisture management“ is understood to be the ability of a textile to absorb gaseous or liquid humidity from the skin, to transport it from the inside of a textile to the outer surface and to release it into the surrounding air.

To evalua;te the „moisture management“ of a textile one has to know about both the basic temperature regulation of the human body, and about the properties of the textile required by this regulation.

click to download :- MoistureManagement


The Care Of Textiles


( Originally Published Early 1900’s )

Importance of proper care.-Not a small share of the dissatisfaction that arises among consumers of textiles regarding specific fabrics is due to lack of proper care of the cloth. Each textile has its own constitution and therefore needs its special attention. Linen must be treated differently from cotton, and both in turn must receive a care quite different from that needed by wool. Silk calls for still different care. A textile fabric cannot be expected to give its fullest service unless cared for according to its specific qualities.

GENERAL DIRECTIONS FOR CARE OF TEXTILES

Certain general observations concerning the care of textiles are applicable to all alike; these we shall first note. Such little attentions as keeping garments and fabrics free from dust by frequent brushings are matters of everyday knowledge by all, but are by no means always observed. Nor is the danger from dust clearly understood. If dust were simply dead, inert matter as it seems to the eye, there would be little danger of loss from letting garments and cloths go undusted for some time. But dust, unfortunately, usually contains great numbers of little germs, living organisms, that fly about with currents of air, seeking food and resting places. It so happens that the textile fibers are excellent foods for some of these germs. Leaving the dust on a garment may mean leaving some of these hungry and industrious little germs which attach themselves upon a fabric and multiply at a very rapid rate, soon covering entire spots if not whole garments. When this has occurred, no amount of brushing can dislodge them all. They eat their way into the very heart of the fiber, leaving it weakened, discolored, and dust stained.

Protection from mildew.-One of the commonest forms of cloth destruction is that called mildew. Mildew is caused by the penetration of large numbers of microscopic plants into the cloth fiber. When the work of these tiny forms of life has gone far enough, the color of the fabric changes and in time the cloth actually falls to pieces; nothing remains but the mildew plants themselves and their waste matter. Knowing these facts concerning the dangers of dust, we can see the value of the injunction to brush clothing after every using and to store it or hang it away only after it is perfectly dry. Moisture helps these little organisms materially.

Unused garments should be hung away carefully so that wrinkles may not form. Sleeves of valuable garments should be pressed out flat or filled with tissue paper. All spots should be removed as soon as possible for fresh spots or stains are always more easily eradicated than old ones. Light injures some colors, especially on fabrics that were never intended for daytime use. Such fabrics should be kept in dark, cool closets, or should be so wrapped as to keep out sharp light.

Storing textiles.-Storing goods is a science in itself. Providing the right temperature and the right amount of moisture, regulating the light-such things are matters which need to be carefully studied by anyone who has anything to do with textiles. Cloths and garments to be stored should, as a rule, be wrapped in blue, brown, or other dark-colored paper, first, for the sake of protection from light which penetrates lighter papers more easily, and, second, because light papers-whites and yellowstend to spot light-colored fabrics with yellow, as the bleaching process used in whitening paper is cheap and somewhat imperfect.

Goods to be packed should be perfectly dry, clean., brushed, and in order, that is, properly folded. All steel pins should be carefully removed or rust spots will form. Cloth should be rolled into bolts, ribbons into rolls, embroidery and laces should be wound on cards. This is, to be sure, the way in which these goods come to the retail store; but the point needs to be emphasized that in this same fashion these goods should be kept, even at home, and in small quantities. Consumers should carefully heed this caution.

Protection from insects.-All textiles are subject to attacks by insect or other living organisms, commonly called pests, the particular variety depending upon the given textile. As we have already seen, mildew attacks cotton and linen. Mildew is similar in nature to molds, several of which attack not only vegetable fibers but also wool and silk. Housewives of the past kept insects out of their linen chests by using aromatic oils or essences, such as cloves, tobacco leaves, camphor, cedar sprigs, wintergreen, and so on. This practice had some value but these aromatic substances simply acted as deterrents. They by no means prevented all depredations. There is only one certain preventive and that is to keep the textile goods where insects cannot get at them. Above all, textile goods should be frequently looked over, aired, and dusted, so as to prevent anything that does attack them from getting a very long start.

Prevention of destruction of textiles by moths.-Recently the Bureau of Entomology of the United States Department of Agriculture concluded some practical investigations on the best methods of preventing the destruction of textile goods by moths and published a circular on the subject entitled, “The True Clothes Moths.” The following description and recommendations as to remedies are taken therefrom:

“The destructive work of the larvae of the small moths commonly known as clothes moths, and also as carpet moths, fur moths, etc., in woolen fabrics, fur and similar material during the warm months of summer in the North, and in the South at any season, is an altogether too common experience. The preference they so often show for woolen or fur garments gives these insects a much more general interest than is perhaps true of any other household pest.

“The little yellowish or buff-colored moths sometimes seen flitting about rooms, attracted to lamps at night, or dislodged from infested garments or portieres, are themselves harmless enough, and in fact their mouth-parts are rudimentary, and no food whatever is taken in the winged state. The destruction occasioned by these pests is, therefore, limited entirely to the feeding or larval stage. The killing of the moths by the aggrieved housekeeper, while usually based on the wrong inference that they are actually engaged in eating her woolens, is nevertheless a most valuable proceeding, because it checks in so much the multiplication of the species which is the sole duty of the adult insect.

“The clothes moths all belong to the group of minute Lepidoptera known as Tineina, the old Latin name for cloth worms of all sorts, and are characterized by very narrow wings fringed with long hairs. The common species of clothes moths have been associated with man from the earliest times and are thoroughly cosmopolitan. They are all probably of Old World origin, none of them being indigenous to the United States. That they were well known to the ancients is shown by job’s reference to a “garment that is moth eaten,” and Pliny has given such an accurate description of one of them as to lead to the easy identification of the species. That they were early introduced into the United States is shown by Pehr Kalm, a Swedish scientist, who took a keen interest in house pests. He reported these tineids to be abundant in 1748 in Philadelphia, then a straggling village, and says that clothes, worsted gloves, and other woolen stuffs hung up all summer were often eaten through and through by the worms, and furs were so ruined that the hair would come off in handfuls.

“What first led to the association of these and other household pests with man is an interesting problem. In the case of the clothes moths, the larvae of all of which can, in case of necessity, still subsist on almost any dry animal matter, their early association with man was probably in the role of scavengers, and in prehistoric times they probably fed on waste animal material about human habitations and on fur garments. The fondness they exhibit nowadays for tailor-made suits and other expensive products of the loom is simply an illustration of their ability to keep pace with man in his development in the matter of clothing from the skin garments of savagery to the artistic products of the modern tailor and dressmaker.

“Three common destructive species of clothes moths occur in this country. Much confusion, however, exists in all the early writings on these insects, all three species being inextricably mixed in the description and accounts of habits.

“The common injurious clothes moths are the case-making species (Tinea pellionella L.), the webbing species or Southern clothes moth (Tineola biselliella Hummel), and the gallery species or tapestry moth (Trichophaga tapetzella L. ) . “A few other species, which normally infest animal products, may occasionally also injure woolens, but are not of sufficient importance to be here noted.

“The case-making clothes moth.-The case-making clothes moth (Tinea pellionella L.) is the only species which constructs for its protection a true transportable case. It was characterized by Linnaeus, and carefully studied by Reaumur, early in the last century. Its more interesting habits have caused it to be often a subject of investigation, and its life history will serve to illustrate the habits of all the clothes moths.

“The moth expands about half an inch. Its head and forewings are grayish yellow, with indistinct fuscous spots on the middle of the wings. The hind wings are white or grayish and silky. It is the common species in the North, being widely distributed and very destructive. Its larvoe feed on woolens, carpets, etc., and are especially destructive to furs and feathers. In the North it has but one annual generation, the moths appearing from June to August, and, on the authority of Professor Fernald, even in rooms kept uniformly heated night and day, it never occurs in the larval state in winter. In the South, however, it appears from January to October, and has two or even more broods annually.

“The larva is a dull white caterpillar, with the head and the upper part of the next segment light brown, and is never seen free from its movable case or jacket, the construction of which is its first task. If it be necessary for it to change its position, the head and first segment are thrust out of the case, leaving the thoracic legs free, with which it crawls, dragging its case after it, to any suitable situation. With the growth of the larva it becomes necessary from time to time to enlarge the case both in length and circumference, and this is accomplished in a very interesting way. Without leaving its case the larva makes a slit halfway down one side and inserts a triangular gore of new material. A similar insertion is made on the opposite side, and the larva reverses itself without leaving the case and makes corresponding slits and additions in the other half. The case is lengthened by successive additions to either end. Exteriorly the case appears to be a matted mass of small particles of wool; interiorly it is lined with soft, whitish silk. By transferring the larva from time to time to fabrics of different colors the case may be made to assume as varied a pattern as the experimenter desires, and will illustrate, in its coloring, the peculiar method of making the enlargements and additions described.

“On reaching full growth the larva attaches its case by silken threads to the garment or other material upon which it has been feeding, or sometimes carries it long distances. In one instance numbers of them were noticed to have scaled a fifteen-foot wall to attach their cases in an angle of the cornice of the ceiling. It undergoes its tranformations to the chrysalis within the larval case, and under normal conditions the moth emerges three weeks later, the chrysalis having previously worked partly out of the larval case to facilitate the escape of the moth. The latter has an irregu lar flight and can also run rapidly. It has a distinct aversion to light, and usually conceals itself promptly in garments or crevices whenever it is frightened from its resting place. The moths are comparatively short-lived, not long surviving the deposition of their eggs for a new generation of destructive larvae. The eggs are minute, not easily visible to the naked eye, and are commonly placed directly on the material which is to furnish the larva: with food. In some cases they may be deposited in the crevices of trunks or boxes, the newly hatched larvae entering through these crevices.

“The webbing, or southern clothes moth.-The webbing, or southern clothes moth (Tineola biselliella, Hummel) is the more abundant and injurious species in the latitude o£ Washington and southward. It occurs also farther north, though in somewhat less numbers than the preceding species. It presents two annual broods even in the northern states, the first appearing in June from eggs deposited in May, and the second in August and September. It is about the size of pellionella. The forewings are, however, uni formly pale ocherous, without markings or spots. Its larva feeds on a large variety of animal substances-woolens, hair, feathers, furs, and in England it has even been observed to feed on cobwebs in the corners of rooms, and in, confinement has been successfully reared on this rather dainty food substance. The report that it feeds on dried plants in herbaria is rather open to question, as its other recorded food materials are all of animal origin.

“The larva of this moth constructs no case, but spins a silky, or more properly cobwebby, path wherever it goes. When full grown, it builds a cocoon of silk, intermixed with bits of wool, resembling somewhat the case of pellionella, but more irregular in outline. Within this it undergoes its transformation to the chrysalis, and the moth in emerging leaves its pupal shell projecting out of the cocoon as with the preceding species.

“The tapestry moth.-The tapestry moth (Trichophage tapetzella, L.) is rare in the United States. It is much larger than either of the other two species, measuring three-fourths inch in expansion of wings, and is more striking in coloration. The head is white, the basal third of the forewings black, with the exterior two-thirds of a creamy white, more or less obscured on the middle with gray; the hind wings are pale gray.

“This moth normally affects rather coarser and heavier cloths than the small species and is more apt to occur in carpets, horse blankets, and tapestries than in the finer and thinner woolen fabrics. It also affects felting, furs, and skins, and is a common source of damage to the woolen upholstering of carriages, being rather more likely to occur in carriage houses and barns than in dwelling houses. Its larva enters directly into the material which it infests, constructing burrows or galleries, which it lines more or less completely with silk. Within these galleries it is protected and concealed during its larval life, and later undergoes its transformation without other protection than that afforded by the gallery. The damage is due as much or more to its burrowing than to the actual amount of the material consumed for food.

“REMEDIES.-There is no easy method of preventing the damage done by clothes moths, and to maintain the integrity of woolens or other materials which they are likely to attack demands constant vigilance, with frequent inspection and treatment. In general, they are likely to affect injuriously only articles which are put away and left undisturbed for some little time. Articles in daily or weekly use, and apartments frequently aired and swept, or used as living rooms, are not apt to be seriously affected. Carpets under these conditions are rarely attacked, except sometimes around the borders, where the insects are not so much disturbed by walking and sweeping. Agitation, such as beating, shaking, or brushing, and exposure to air and sunlight, are old remedies and still among the best at command. Various repellents, such as tobacco, camphor, naphthaline cones or balls, and cedar chips or sprigs, have a certain value if the garments are not already stocked with eggs or larvae. The odors of these repellents are so disagreeable to the parent moths that they are not likely to come to deposit their eggs as long as the odor is strong. As the odor weakens the protection decreases, and if the eggs or larvae are already present, these odors have no effect on their development; while if the moths are inclosed with the stored material to be protected by these repellents, so that they cannot escape, they will of necessity deposit their eggs, and the destructive work of the larvae will be little, if at all, restricted. After woolens have been given a vigorous and thorough treatment and aired and exposed to sunlight, however, it is of some advantage in packing them away to inclose with them any of the repellents mentioned. Cedar chests and wardrobes are of value in proportion to the freedom of the material from infestation when stored away, but, as the odor of the wood is largely lost with age, in the course of a few years the protection greatly decreases. Fur and such garments may also be stored in boxes or trunks which have been lined with heavy tar paper used in buildings. New papering should be given to such receptacles every year or two. Similarly, the tarred paper moth bags obtainable at dry-goods houses are of some value; always, however, the materials should first be subjected to the treatment outlined above.

“To protect carpets, clothes, and cloth-covered furniture, furs, etc., these should be thoroughly beaten, shaken, brushed, and exposed as long as practicable to the sunlight in early spring, either in April, May, or June, depending on the latitude. The brushing of garments is a very important. consideration, to remove the eggs or young larvae which might escape notice. Such materials can then be hung away in clothes closets which have been thoroughly cleaned, and, if necessary, sprayed with benzine about the cracks of the floor and the baseboards. If no other protection be given, the garments should be examined at least once a month; during summer, brushed, and, if necessary, exposed to sunlight.

“It would be more convenient, however, so to inclose or wrap up such material as to prevent the access of the moths to it, after it has once been thoroughly treated and aired. This can be easily effected in the case of clothing and furs by wrapping tightly in stout paper or inclosing in well-made bags of cotton or linen cloth or strong paper. Doctor Howard has adopted a plan which is inexpensive, and which he has found eminently satisfactory. For a small sum he secures a number of the large pasteboard boxes, such as tailors use, and in these packs away all winter clothing, gumming a strip of wrapping paper around the edge, so as to seal up the box completely and leave no cracks. These boxes with care will last many years. With thorough preliminary treatment it will not be necessary to use the tar-impregnated paper sacks sold as moth protectors, which may be objectionable on account of the odor.

“In the case of cloth-covered furniture and cloth-lined carriages, which are stored or left unused for considerable periods in summer, it will probably be necessary to spray them twice or three times, viz., in April, June, and August, with benzine or naphtha, to protect them from moths. These substances can be applied very readily with any small spraying device, and will not harm the material, but caution must be exercised on account of their inflammability. Another means of protecting such articles is to sponge them very carefully with a dilute solution of corrosive sublimate in alcohol, made just strong enough not to leave a white stain.

“The method of protection adopted by one of the leading furriers of Washington, who also has a large business and experience in storing costly furs, etc., is practically the course already outlined. Furs when received are first most thoroughly and vigorously beaten with small sticks, to dislodge all loosened hair and the larvae or moths. They are then gone over carefully with a steel comb and packed away in large boxes lined with heavy tar roofing paper, or in closets similarly lined with this paper. An examination is made every two to four weeks, and, if necessary, at any time, any garment requiring it is rebeaten and combed. During many years of experience in this climate, which is especially favorable to moth damage, this merchant has prevented any serious injury from moths.

“Cold storage.-The best method of protection, and the one now commonly adopted by dealers in carpets, furs, etc., is cold storage. The most economical degree of cold to be used as a protection from clothes moths and allied insects destructive to woolens and furs has been definitely determined by the careful experiments carried out at the instance of Dr. Howard by Dr. Albert M. Read, manager of a large storage warehouse company in Washington, D. C. These experiments demonstrated that a temperature maintained at 4o degrees Fahrenheit renders the larval or other stages of these insects dormant and is thoroughly effective: The larvae, however, are able to stand a steady temperature as low as 18 degrees Fahrenheit without apparently experiencing any ill results. Dr. Read’s experiments have extended over two years, and his later results as reported by Dr. Howard are very interesting. They have demonstrated that while a temperature kept uniformly at 18 degrees Fahrenheit will not destroy the larvae of Tineola bisellinella or of the black carpet beetle (Attagenus piceus), an alternation of a low temperature with a comparatively high one invariably results in the death of the larvae of these two insects. For example, if larvae of either which have been kept at a temperature of 18 degrees Fahrenheit are removed to a temperature of 4o degrees to 5o degrees Fahrenheit, they will become slightly active and, when returned to the lower temperature and kept there for a little time, will not revive upon a retransfer to the warmer temperature.

“It is recommended, therefore, that storage companies submit goods to two or three changes of temperature as noted before placing them permanently in an apartment kept at a temperature of from 4o degrees to 42 degrees Fahrenheit. The maintenance of a temperature lower than the last indicated is needless and a wasteful expense. Where the cost of cold storage is not an item to be seriously considered, the adoption of this method for protection of goods during the hot months is strongly recommended.”

Care in laundering.-Care of textiles in laundering is highly important. Many a valuable fabric has been ruined by improper washing. Beautiful colors are sometimes spoiled, while soft, smooth, finely finished goods come out of the laundry rough, hard, and ugly in appearance. How goods shall be cleaned is a matter of great importance and one upon which the salesman needs to inform his customers so that they may get the greatest service out of their purchases.

There are four things to be considered before laundering or cleaning any textile fabric:

1. The kind of weave and the probable effect of washing and rubbing upon it.

2. The kinds of textile fibers used in the fabric.

3. The weight and strength of the fabric.

4. The degree of fastness of the colors.

Kind of weave.-The kind of weave is important to this extent, that if the weave is loose and sleazy, the fabric will not stand rubbing. Certain brocades and satins or sateens, for example, are not to be rubbed because the Jacquard figures would be damaged by so doing. The plain weaves show dirt the most easily, but likewise wash the most easily. Closely woven goods in twills do not soil easily, but hold dirt very tenaciously; such fabrics need most careful washing. Any weave that helps the cloth to absorb is in its nature more difficult to clean than an open weave fabric.

Kind of fiber.-The kind of textile fibers used in the fabric should be determined in advance, for each textile fiber demands methods of laundering different from the others. For example, cotton can stand more rubbing and more soaping than any of the other fabrics in proportion to its weight and strength. But cotton is quite susceptible to damage when brought in contact with acids. The chief difficulties in laundering cotton goods are in retaining brightness of dye or printing and in ironing with irons of proper temperature. Cotton can stand a great deal of what would be abuse to other textiles.

Linen is similar to cotton in most respects. Bleached linens show tendencies to yellow with time; they then require special treatment such as exposing to sunlight and laying out on the snow or grass.

Wool, on the other hand, presents a number of entirely different problems. Wool is in danger of shrinking, hardening, and scorching, as well as of losing its colors. Washing in too hot or too cold water, the use of alkalies or strong soaps, or rubbing and running through tight wringer rolls shrinks and hardens wool fabrics. Alkali may even destroy wool fiber. For these reasons wool needs special care in laundering.

Silk, like wool, an animal fiber, requires no less careful handling in laundering.

Weight and strength of fabric.-The weight and strength of the fabrics to be cleaned should be considered in order to determine what laundering processes the fabric will stand.

Colors of fabrics.-Finally, the fastness of the colors should be considered. Dyes that are fast under one method of washing may fade under another. Hence in preparing to launder an article, a colored woolen fabric, for example, precautions should be taken to prevent injury either to the wool or to the coloring matters.

Mixed goods.-Mixed or union goods present a special problem that is sometimes difficult to solve. The usual method is to launder the material as if it were entirely composed of the weakest kind of fiber in its composition. Wool and cotton should be laundered as if it were all wool. Cotton and silk should be laundered like silk.

Cleaning wool.-Wool fabrics or garments should be washed in soft water. Before placing the fabrics in the water, the water should be heated to a temperature of 85 degrees to 100 Fahrenheit, little more than lukewarm. Into the water should be placed enough soap of good quality, as free as possible from any uncombined alkali, to make suds. The addition of a little ammonia will help take the dirt out of the fabrics. Next, the garments, blankets, or fabrics, should be brushed and shaken to remove any loose lint, dust, or other particles. They are then to be placed in the water and allowed to soak for an hour, after which they should be kneaded and drawn backwards and forwards, up and down in the suds. They should never be rubbed or wrung. Soap should not be rubbed directly upon the fabric. Soap and rubbing cause the wool to felt; the better the grade of wool, the greater and more rapid the felting. The wool fabrics may now be removed to another tub of water of the same temperature but with less soap and ammonia; here they are stirred about in the same careful manner, rinsed, and removed for a final rinsing to a third tub with pure wafer of the same lukewarm tempera ture. After the last rinsing, the water is pressed out gently and the fabrics are dried. Sunshine and the open air are the best driers, though out of the question in a laundry. The drying temperature should never be more than 100 degrees Fahrenheit. Napped goods should be freshened after drying by rubbing with a piece of flannel. Soft woolens, delaines, cashmeres, and serges should be soaked for only a short time. If the fabrics need stretching, this should be done just before drying. Most woolens do not need ironing. Those fabrics that must be ironed should be covered with damp muslin and pressed with a heavy iron just warm, not hot. A hot iron will shrink flannel. and turn it yellow. Cashmere should be dampened before ironing.

Laundering silks.-Silks need about the same treatment as that given to wool, although silks do not mat or felt as do wools under conditions of heat, alkali, and rubbing. The water to be used in washing silks should be soft, of an even warm, not hot temperature, and only a neutral soap free from alkali should be used. Silks should not be rubbed but simply drawn backwards and forwards and poked up and down in the water. Nor should silks be crushed, squeezed, or wrung out with a wringer unless placed between folds of linen cloth. Silk goods should be ironed slightly damp, except pongee, which should be ironed dry. The face of a silk fabric should not be touched with a hot iron. The proper method is to protect the silk fabric by covering it with linen when ironing.

Cleaning colored goods.-Colored goods of any kind need special precautions that depend upon the nature of the dyes in the cloth. A complete set of directions for laundering colored goods would take up more space than can be given here. It will be sufficient for present purposes to enumerate the conditions that are especially likely to cause fading.

1. Long soaking in water.

2. Boiling or overheating.

3. Cold water or freezing.

4. Alkalies-washing sodas, washing fluids, washing powders, and poor soaps.

5. Washing two different colors in the same tub at the same time. There may be an affinity between these that may cause either or both to run.

6. Exposing to direct sunlight.

7. Ironing with too hot irons.

Setting the colors.-Colors may sometimes be set so that they will not come out in washing under ordinary circumstances. This desirable object is accomplished by using salt, alum, borax, vinegar, or ox gall in the wash water. The occasions for such agents vary greatly, and no general direction can or should be given. What will set some colors is likely to cause others to fade.

Methods of cleansing fabrics.-The purpose of laundering is both to remove dirt and impurities and to whiten or brighten the cloth. In the ordinary washing this is done both by mechanical and chemical means. The rubbing, boiling, rinsing, and so on, are mechanical means; ammonia, borax, washing powder, and several other substances commonly applied to loosen dirt or dissolve it, are chemical means. Coarse, heavy fabrics that can stand it may have both mechanical and chemical methods applied, but the finer the goods, the more careful the decision must be as to which method is advisable. In general, it may be said that, whenever possible, chemical help should be used, provided it is of such nature as not to injure the fabric; for chemical cleansing saves labor, while mechanical means all require labor or power.

Bluing.-Bluing, commonly a preparation made of Prussian blue, is used in laundering to whiten clothes. Most textiles are somewhat yellowish in tone, and if the bleaching and washing have been imperfectly done, the yellow is very decided. Bluing mixes with the yellow, and the result is a whiter appearing fabric. The use of too much bluing is damaging to both cotton and linen fabrics; it causes stains which are removed with difficulty.

Starching.-Laundered goods are frequently starched. The purpose of starch is the same here as in the manufacture and finishing of textiles. It increases the weight, stiffness, and body of the fabric. But starch serves another important purpose. Starched fabrics are not soiled so easily as soft fabrics, and they wash out very easily. Starch in fabrics makes it easier to remove stains, the starch being an absorbent and therefore drawing much of the stain to itself. Simply washing the starch out removes much of the stain. Starch neutralizes some staining substances such as tannin from tea and coffee. Where the starch is heavy, however, it makes the fabric brittle and breaks it to pieces prematurely.

Yellow discoloration.-Yellow discoloration in fabrics fresh from the laundry is practically inexcusable. It is caused by definitely known practices that can readily be obviated by study, care, and by purchasing necessary equipment. The causes which most commonly produce this yellow discoloration are:

1. The use of hard water. All laundering should be done in soft water. Where soft water is not available, hard water can usualy be made soft by chemical means that will not injure fabrics.

2. The use of too much carbonate of soda or washing soda. Washing soda has little or no cleansing effect in itself. It is an active chemical that seeks to combine with some other substance. In laundering, its chief use is to soften hard water. It can easily be used in too large quantities, making the clothes yellow rather than white.

3. Insufficient rinsing.

4. The use of too little water in the wash tubs. Better results are always obtained by using more water than is necessary rather than less.

5. Washing too hurriedly, and using strong soaps and ammonia to hasten the process.

6. Too quick drying in overheated air.

Theory of removing stains.-The removal of stains is a subject that may properly be considered here. Here, as in laundering, the character of the textile must be most carefully considered. But not only that; the character of the stain should also be known if it is to be removed without damaging the goods. The aim in stain removal is, of course, to find some substance that will attack, draw out, or loosen the staining material, yet leave the goods unharmed. Various substances may thus be used. Some stains can best be removed by covering them with an absorbent material that will draw out the staining substances. Others can be eradicated best by covering them or moistening them with some liquid that will dissolve them but will not attack the dyes or injure the cloth fiber. Sometimes the stain should be treated with a chemical that will combine with the staining material and form a new substance that can be washed out with water. Finally, where all other methods fail, the stain may be removed by bleaching. The removal of stain may, therefore, be accomplished usually by some one of the following methods:

1. Absorbents.

2. Solvents.

3. Acids or alkalies, or other chemicals.

4. Bleaching agents.

ABSORBENTS.-The common absorbents that may be used for stain removal purposes include blotting paper, common brown paper, powdered chalk, whiting, pipe clay, fuller’s earth, magnesia, gypsum, starch, melted tallow, corn meal, bran, and so on. Absorbents can be used to best advantage on fresh stains still moist. Hot grease, fresh ink stains, coffee or tea stains can be treated in this way, not to remove them entirely but rather to remove a large part of the staining substance and prevent it from spreading further. Absorbents are especially valuable for use preliminary to treatment by some other method.

SOLVENTS.-Solvents actually attack and dissolve the staining substance so that it may be flooded out by the dissolving liquid. Some of the common solvents are water, hot or cold, alcohol, gasoline, benzine, kerosene, turpentine, and chloroform. The removal of ordinary soil by means of washing in water is the most frequent example of this method. Cold water will remove milk and cream stains, stains from sugar, candies, and cocoa. Hot water may be used to remove fresh coffee stains. The mineral oils, benzine, gasoline, and kerosene, are useful solvents of grease, oil, wax, and paint. Gasoline is probably the best for use with woolen and silk fabrics but not with cotton. Gasoline, however, is very volatile, and passes off rapidly in the form of inflammable gas. It should, therefore, be used out of doors in the daylight; and never in a room where there is a fire or a gas flame or kerosene light, otherwise disaster is likely to occur. Vaseline, itself a mineral grease from the same source as kerosene or gasoline, may be softened and loosened by soaking the stained fabric in one of these mineral oils. When sufficiently liquid, the whole may in turn be dissolved in ammonia and water or washing soda and water, whereupon the mineral oil combines with the alkali in the form of an emulsion which can be washed out. Alcohol is a solvent for grass stains, for varnish and paint, and for several other substances. Its great value is enhanced by the fact that it will not harm delicate fabrics. Frequently, too, it is an excellent solvent for medicine stains. Turpentine is the universal solvent for paint, varnish, resins, oils, rubber, and the like. It is also a chemical solvent for iodine, sulphur, and phosphorus. Chloroform is the best of the solvents, and likewise the most expensive. It acts powerfully on grease, wax, camphor, rubber, iodine, and many other sorts of stains. No other solvent is so satisfactory for use on delicately colored textiles. When colors seem faded, chloroform is the best known substance for reviving them. Grease, itself the most frequent staining agent, must be used in some instances as a solvent for other substances. Tar and pitch may be removed by the use of lard, as may grass stains too if they are fresh. After obliterating the original stain, the grease is removed by some regular grease solvent, such as benzine, hot water and soap, or gasoline.

CHEMICAL ACTION.-Stains made by acids, such as fruit juices, wine, or lemon juice, or even by stronger acids, are best eradicated by means of some solvent; unhappily it is not always possible to find at hand a solvent other than water, and this is not effective after the acids have dried. In the failure of solvents, the best plan is to apply an alkali which combines chemically with the acid, forming thus a new substance which ordinarily will be easily dissolved by water. Ammonia is one of the best alkalies for this purpose, not being likely to injure even delicate fabrics.

“For the removal of stains and spots from colored goods and carpets, ammonia takes first place. It is one of the first chemicals to be used. It can be applied to cottons, wools, and silks, and leaves no trace of its use. Grease flies before its application, and when diluted with water, spots caused by orange or lemon juice or vinegar are removed by it from the most delicate materials. From carpets, curtains, and suits of clothing, it will remove almost every stain.”-The Modern Laundry, Vol. IL, page 82.

Washing soda (carbonate of soda) and cooking soda (bicarbonate of soda) are also valuable alkalies for use on uncolored cottons and linens. Furthermore, acid stains may be dissolved and removed by the use of certain weak acids, such as oxalic, citric, and tartaric acids, sour milk, and very weak muriatic acid. The theory seems to be the same as for the using of kerosene on vaseline. The acid liquids combine with the staining material and dissolve it, making it easy to wash out with water.

Acivs.-Acids must be used carefully because of their destructive effects on cotton and linen and on many dye substances. The acids named above, except sour milk and muriatic acid, are all vegetable acids and quite weak: Oxalic acid is made from the sorrel plant. Citric acid is made from lemons or other citrus fruits; tartaric acid, from grape juice. Each of these is valuable in removing fruit stains, iron rust, and old-fashioned, iron-gall, ink stains. When salt is added to any of them, a bleaching process sets in. Tartaric acid is a highly useful and safe acid for stain removal; no textile is injured by it. Since it is, however, a weak acid, its action is neither rapid nor strong enough to remove certain very deep stains.

BLEACHING.-If no other means succeeds a stain must be removed by bleaching. There are several bleaching methods and substances, differing greatly in effectiveness. Practically none of them can be used on colored goods without endangering the colors in the fabric. Some are destructive to the fabrics themselves and must be used with care and judgment. A few of the most common may be named here.

Oxygen.-Sunlight and air together form a gentle but effective bleaching agent provided that haste is not imperative. All discolored white goods may be improved by exposure to sunlight. Sulphur fumes are used most frequently for wool and silk goods. The method of application is very simple. The spot to be bleached is dampened in water and then held over burning sulphur so that the fumes penetrate the spot directly. After the stain has whitened, the fabric needs washing in soapsuds, and rinsing in clean water.

Bleaching powder.-Bleaching powder or chloride of lime is the most frequently used bleach for cotton and linen goods. It is valuable in removing refractory stains such as ink spots, mildew, old blood stains, and iron rust. The spot is covered with chloride of lime and moistened with some acid such as vinegar, oxalic acid, tartaric acid, or sour milk. The bleaching is rapid and should be stopped by rinsing thoroughly in water just as soon as the stain disappears. A bleach weaker than chloride of lime but working on the same principle is known as Javelle water. Javelle water is made as follows for household use:

1 pound sal soda or pearl ash,

1/4 pound chloride of lime,

2 quarts cold water.

After this mixture is allowed to stand for several hours, the clear liquor is poured off for use. It must be kept in a dark, cool place if it is to retain its strength. Javelle water may be used for the same purposes as bleaching powder, and, being less active, it does not require such cautious handling. Many housekeepers use Javelle water for practically all sorts of colored stains. This doubtless saves time, but is hardly economical, for Javelle water does destroy textile fiber.

Peroxide of hydrogen.-Peroxide of hydrogen is an excellent bleach, and should be used much more frequently than at present, for it seems to have no destructive effect on textile fiber. Its only disadvantage as compared with Javelle water is its higher cost.

Borax may at times be used as a mild bleaching agent in laundering clothes that show yellowish tints or streaks. Lemon juice and salt make a bleach that works much like chloride of lime, though it is not quite so strong. Any acid added to salt starts chemical bleaching.

PRINCIPLES OF REMOVING STAINS.-In concluding our study of the principle of removing stains, we may enumerate certain points of practice:

1. The sooner the stain is attended to, the better. Fresh stains are always easier to remove than old ones.

2. Use stain removers in the following order until something is found that is strong enough to remove the stain: absorbents, solvents, chemical combinations, bleaching agents. Never use a stronger means of removing a stain than is necessary.

3. Determine first, if possible, what caused the stain and work directly upon that information.

4. Do not rub a chemical into a stain. Dab it in, using a cloth, sponge, or the fingers.

5. Use pure chemicals in removing stains. Impure ones are likely to leave other stains fully as difficult to remove as the original stain.

6. Strong chemicals, such as acids, should be applied drop by drop to the stained fabric moistened with water or steam. The use of a medicine dropper for this purpose is most convenient. Using this, one can readily watch the progress of the remedy and control it.

7. To keep stains from spreading under the influence of solvents, it is best first to apply the solvent in a ring around the stain and then gradually to work in towards the center of the stain.

STAINS AND HOW THEY MAY BE ERADICATED.-The following list of stains arranged in alphabetical order gives the more ordinary ones together with the best means for treating each. Some stains are quite indelible, such as certain ink stains and brown stains from scorching. In such cases, the only remedy is to cover the spot by dyeing; even then the stain may show through the dye.

Acid.-To stop the corrosive action of acids spilled on fabric, the fabric should be dipped at once, if possible, into ammonia. If the stain becomes dry, ammonia will not be strong enough. Tie up a little washing soda or cooking soda in the stained part, make a lather of soap and cold soft water, immerse the fabric, and boil until the spot disappears. This treatment frequently causes colored goods to fade, but moistening with chloroform will often restore the original color. If chloroform fails a solution of nitrate of silver will often be of service. If this does not succeed there is no hope of recovering the fabric without redyeing. When yellow stains on brown or black woolen or worsted goods are caused by very strong acids, such as nitric acid, they should be padded repeatedly with a woolen pad soaked in a concentrated solution of permanganate of potash.

Aniline and aniline inks.-Wet the stained spot in acetic acid, and then apply diluted chloride of lime, and wash out carefully.

Apple and pear.-Soak in paraffin for a few hours and then wash. The paraffin, when melted, is a strong absorbent for such fruit colors.

Blood.-If fresh, soak for twelve hours in cold water; then wash in tepid water. If the mark still remains, cover it with a paste of cold water and starch, and expose to the sun for a day or two. Old stains require bleaching with Javelle water, or an application of iodide of potassium diluted with four times its weight of cold water.

Brass.-Brass stains on fabrics may be removed by dabbing with rancid lard or rancid butter.

Burns.-These are caused perhaps by overheated irons. If bad, they are hopeless, and must be hidden by dyeing. Slight burns yield to treatment with soap and water.

Changed colors.-Stains are often caused by local fading of dye. They can, in most cases, be removed by reviving the dye. The manner of doing this depends upon the kind of dye. If the nature of the dye is unknown, dilute ammonia should be tried, or dilute acid, or chloroform. It does not matter which is tried first, but the effect must be carefully watched, and the first chemical washed out at once when it is clear that it wil’ not be successful. The solutions of acid or ammonia should be very dilute, at least at first.

Coffee.-Pour boiling soft water through the stain, and while it is still wet hold in the fumes of burning sulphur. Washing with soap and water is, however, usually sufficient without using the sulphur. Glycerin also removes coffee stains; it should be diluted by the addition of four times as much water and a little ammonia.

Chocolate and cocoa.-Cocoa stains can be removed by using cold water. Otherwise the treatment should be the same as for coffee stains.

Fruit.-Fruit stains can be treated like coffee stains if fresh; if old, rub on both sides with yellow soap, cover thickly with cold water, starch, and bleach by exposing to the sun and air for three or four days. Fruit stains are acid stains and may also be removed by treating with alkalies. One method is to apply ammonia and alcohol mixed in equal proportions.

Grass.-Dab with spirits of wine or alcohol. Application of tartaric acid or cream of tartar is sometimes effective if used in boiling water, the stained fabric being dipped in several times. A grass stain may sometimes be removed by rubbing lard over the spot and then washing. Grass stains differ greatly in ease of removal. Sometimes ammonia will take out such stains, especially if it is found that an acid treatment has no effect. Intractable spots need bleaching.

Grease.-Grease stains if still fresh should be treated at first with absorbents such as fuller’s earth, chalk, talcum powder, or flour. Ironing small grease spots over brown paper is sometimes helpful. The use of absorbents should be supplemented by some solvent such as benzine, gasoline, turpentine, or chloroform. To keep the grease from spreading, the solvent should first be applied in a ring around the outside of the spot, after which the spot may be covered. In using the grease solvents any proximity to fire must be carefully avoided.

Ink.-The great difficulty in removing ink stains is due to the fact that ink is made from so many different chemical substances. The best way to treat an ink stain is to apply some solvent that will not harm the fabric no matter what sort of chemical caused the stain. Fresh ink stains may frequently be washed or rubbed out in milk. If the stains do not begin to fade at once, the fabric should be allowed to stand in the milk for at least twelve hours. In the meantime, the milk beginning to sour, the weak acid will make itself felt on the stain. If this does not remove the stain, it should next be treated as for aniline ink. Most of the directions given in household guides for treating ink stains are valueless because they apply to inks that are now no longer made and used. If the methods suggested above do not succeed, then the stain should be covered with melted tallow for a few hours. This should be removed by washing in hot soapsuds. If this fails, then the spot should be bleached out with Javelle water.

Iodine.-Soak the stain in ammonia. Rub with dry bicarbonate of soda (cooking soda) until stain comes out. Iron rust.-Apply citric acid, oxalic acid, or tartaric acid. If this acid treatment does not remove the spot, bleach it by covering it with lemon juice and salt and exposing it to sunlight.

Medicine.-Medicine stains may usually be dissolved and removed by means of alcohol.

Mildew.-Treat as for iron stains. Boiling in strong borax water is recommended. Mildew is usually very refractory. The bad color can be removed by bleaching if the remedies proposed above do not seem sufficient, but it is more than likely that the fabric will be very tender after the bleaching process.

Milk and Cream.-Milk stains can be removed with cold water or with cold water and soap. Hot water sets the milk stain and makes it difficult to remove.

Mud.-Dip in gasoline or benzine. Small spots may be concealed by using chalk or white watercolor when it is not convenient to have the cloth cleaned with a solvent at once.

Paint.-Dab with turpentine. A mixture of turpentine and chloroform is often very effective in removing old paint stains from even delicate fabrics. Naphtha soap should be used in washing out paint oil stains.

Perspiration.-Use strong soap solutions and expose to sunshine. Perspiration under the arm is of a different chemical composition from that of other parts of the body, and is neutralized by dilute hydrochloric acid. The acid should be very dilute, about one part acid to seventy-five or a hundred parts water.

Tar.-Cover with lard, let stand a while, and then wash in hot soapsuds.

Tea.-Treat as for coffee stains. Tea contains tannic acid, and may therefore be treated by using ammonia or some other alkali.

Varnish.-Treat like paint stains.

Vaseline.-Vaseline is not soluble in acids or alkalies, but can be dissolved in kerosene or benzine, and then washed out with hot soapsuds.

Wine.-Treat like fruit stains. Fresh wine can be very largely neutralized by spreading salt over the spot while wet.