Effective Colour Management for Textile Coloration- An instrumental way towards perfection


by:-   Zeeshan Khatri, G Yasin Sheikh, Khan Muhammad Brohi and Aslam A Uqaili

Textile coloration is a process of dyeing and printing textiles by use of colorants that include dyes and pigments. Meeting stringent requirement from Buyer that demands right colour on right time is not a simple task to achieve. The colour produced by the application of either dyes or pigments on textiles must be close matched with reference (standard) provided by buyer. The process of colour matching is a lengthy process and needs many trials to get close match. The colour quantification through instruments helps to cut most of the lead time, however, there is a serious need to manage colour during colour approval stage and coloration process. This paper presents a strategy towards effective colour management by using available instruments and techniques that involve in colour measurement and management systems, trips to control colour intelligently and give way to get closer match to the buyer’s reference in a shortest possible time.

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Technologies for the clothing industry


Synergies among makers of machinery, as well as systems and plants and the clothing industry aim both to the optimisation of the garment and to its suitability to be used according the customer’s demand.

As a consequence organisation of the production on one side, methods applied, machines, and component materials (from the fabric to the accessories) play a synergetic role which determines the product quality.

Organisation and information management, logistics, as well as specific hardware and software packages for CAD and CAM systems are representative of the high technological level offered by the Italian manufacturers

Receipt of goods

At their reception, all pieces must be immediately provided with a bar code with the following information: fabric variant, colour variant, real fabric width, total length, net length after detection of flaw lengths, entry date into the warehouse.

Today also the clothing manufacturing companies need to have a range of equipment for printing labels and bar codes. These printers through a serial or parallel port can be connected to any system.

Fabric inspection and detection of faults

Fabric quality control involves the control of a series of characteristics, such as dimensional stability, shade uniformity, colour stability at fusing and ironing temperatures, light and stain removal fastness, weft squareness, consistent tensile strength, wear resistance, resistance to seam sliding pressure. Finishing products must not hinder fusing, and must not cause fabric stripiness and creases; selvedge must be regular, not too loose, not too tight or too large.

To make these controls easier Italian inspection machine makers offer a series of options, suitable both for woven and knitted/elasticised fabrics. Programmable automatic winding machines are also offered for cutting optimisation.

An interesting development is a final control for measuring and controlling colour directly on any type of inspection table for any type of textile product. Thanks to an advanced system of colorimetric quality control an exact interpretation and evaluation of the readings is provided. Advantages include automatic calculation of tolerances, instrumental control of colour differences (center/selvedges, header/end), no need of tests for sample sets, and speeding up of the control process.

Piece transport from storehouse to spreading department

A keen problem is “what to do” with the flaw lengths appearing during spreading. A solution is the CAD marking system, which is able to study and calculate the various possibilities for fault cutting-out, and the number of superimposed fabric layers needed after flaw removing. This information, together those concerning length of marking, number of layers for each single step, size, fabric/colour variant, is to be stored in the central computer for subsequent use not only by the spreader but also the robotised truck (which has to draw pieces from the warehouse), and the carousel for feeding individual piece to the spreader.

Many options of spreading equipment provide flexibility in fabric handling, and are available from Italian manufacturers, either with cradle or programmed loading of the rolls without the help of the chuck.

Special solutions are offered for tubular fabrics, big rolls up to 400 kg, home linen. A high tech solution is a two-roll spreader, which may be used to obtain the multilayer stack for laser cutting the car safety air bags. This technology can be also applied for simultaneous spreading of the three layers composing the tie material or to couple already during preading filling and fabric of windcheaters.

New fabric spreading technologies are becoming popular: these technologies are the natural answer to a more and more pressing market request, that is tailor made clothing. Customers who are no more satisfied of already made-up suits are increasing more and more; they require tailor made clothing with fabrics and sizes chosen by them. To satisfy these requirements, new completely automated lines are being planned for the motion of fabric rolls, spreading and cutting of predetermined length fabrics which will feed the systems for shape cutting. These lines, inserted in CIM systems, allow the making up of “tailor made” suits at low costs and in short time.

Pattern grading and marking

For these two operations, in the sector of CAD for the clothing industry, a wide range of the most recent and known software packages has been developed enabling high operating speed thanks to personal computers of the latest generation. The system is composed of a workstation with digitizer table, where the identification of the pattern design is performed. The subsequent step is carried out on a workstation for the construction of the basic model and the marking. After completing these operations, the system is arranged for interfacing with automatic cutting.

Cutting systems and cutting machines

For the cutting room various systems are offered so to meet the most diverse requirements not only of the medium and big clothing manufacturers, but also for small sized companies. The wide range of machines offered can handle the cutting of single-layer fabrics up to 15.5 cm stocked piles.

Sewing machines

The sector of sewing machines shows continuous updating and improvement. The trend is towards the use of more and more flexible and automatic sewing units able to perform some sequential sewing operations. On the other hand there is still the need to manufacture low cost sewing machines for the developing countries. Since present day fashion needs lead more and more to continuous model changes, clothing manufacturers very often have to increase the number of machines, with consequent high investment. This problem finds a solution in adopting a flexible modular system putting together three basic units: a cylinder bed sewing machine, a cuttingsewing machine and a flat a flat bed unit that can be completed by a series of universal kit for loop stitch goods (used for underwear, corsetry and knitwear). Advantages claimed for this system consist in: a complete production system that carries out sewing operations with very high performance, possibility of modifying the initial configuration, adapting it to new production needs, possibility of technological updating without having to replace the machine, justifiable investment also in case of fashion changes. A machine with shortened cylinder bed on the left of the needles and differential feed is offered for top stitching of pre-existent seams. A new subclass unit for top stitching the seams on medium-heavy knitwear has been prepared for smoothly sew crossed seams with high thickness. It equipped with thread cutting device. Also launched a brand new unit for flat topstitched assembly seams with bartacking on light and medium outerwear in a single operation.

The automatic units adopting a multistitch method allow to reduce operation times by about 50/60%, reduce the operation steps and hence the dwelling time of the semifinished garment in the cutting room. A series of units carries out the flat and topstitched assembly seams in one single phase without interruption. They are equipped with two heads, the first one with horizontal needle bar for the assembly seams, the second one with vertical needle bar for topstitching. The sewing system adopts a new method for the introduction of the fabric into the automatic unit. In fact the two fabric edges to be assembled are presenting themselves in open state, with the right side turned towards the operator, making easier the coupling of striped and chequered fabrics. For attaching pockets on shirts, working clothes and pyjamas etc., machinery with flexible systems controlled by microchips that can fold pockets, sewing them, and pile the garments in an automatic cycle. These machines offer high productivity, constant quality and the possibility to programme various sewing patterns that can be adapted to the different pocket models. The wide range of models offered include high frequency “sewing” systems for synthetic fabrics, which fuse by means of an 800 W ultrasound generator and a vibrating ultrasound group. The fusion speed can programmed up to 50 m/min and is driven by means of a treadle.

Quilting

Quilts are a popular home decoration element. Electronics broadens potential of quilting machines making them more versatile. An Italian company is engaged in the production of a series of models which mount a serious challenge to machine embroidery. The newest models of quilters, can operate at around 1,000 stitches/minute and are built with a quilting width up to 114 ins (290 cm). With three needle bars the patterning potential is immense. Giant rotating hooks with 700-mm bobbins are used in this machine which has
tack and jump mode. This is a means of still further creating more interesting surface effects.

Developments on these machines is aimed to a system of automatically cutting embroidery threads, and this will serve to conserve thread when a needles produces a discrete pattern and then needs to travel to a different position to perform its next task.

Embroidery

The Schiffli embroidery machines are now offered with computer control. The design preparation for multihead embroidery machines is today a normal practice. Besides punching of patterns on graphic screens and advanced systems for data processing of machine programs, one can use laser discs containing 20,000 patterns each, and affording to  immediately write the embroidery design on the machine disc, so that production can start at once.

Knitwear linking

The knitwear linking is carried out exclusively to sew full-fashioned knitted goods which are loaded onto pins so that the ribs of both webs perfectly match thus avoiding the risk of sliding.

Linking machines can be quipped with one or two needles and hook- or straight-shaped needles (different stitch formation obtained). Linking machines can have internal needle (the stitch is loaded from the plain side) or external needle (the stitch is loaded on the reverse side). The working speed can reach 1,500 stitches per minute; the quantity of needles per inch ranges from seven to sixteen; in special machines it can range from 2 to max 24 needles per inch. It’s also worth mentioning that some knitwear linking machines are equipped with microcomputer to synchronise all the speed values: adjusting sewing speed, prefeeding of rib borders, and positive drive pullers, which are controlled individually by conventional motors, in order to allow accurate alignment of the ribs.

Ironing and pressing

This sector includes a great number of units that are used for different purposes, and sees the leadership of Italian makers.

There are automatic, pneumatic and rotary ironing presses for all pieces of clothing; ironing systems for intermediate and final ironing include pneumatic toppers for trousers ironing, steaming dummies, finishing cabinets, heated vacuum boards, and the blowironing units.

All ironing machines and systems are now equipped with electronic systems so that crucial parameters such as speed, temperature and pressure may be set. The safety systems installed have been further improved for a better safeguard of the staff operating on the machines.

Finishing

The importance of finishing is becoming more and more crucial in the textile/clothing sector thanks also to the new “informal comfort” standard suggested by the fashion dictations in the last few years which started in the past with a new kind of treatment for jeans. Now the finished garment needs to be a “high-profile” piece of clothing not only from a purely technical point of view but also in terms of esthetical content, which must be in line with the visual, hand, and colour trends.

A wide and continuously evolving range of washers and tumblers especially studied for garment washing, dyeing and drying have been developed to allow many kinds of treatments such as bleaching and stone washing, and to obtain delavé and used look. Also worth remembering is the continuous evolution of drum type washing machines and the driers, available in a vast range of models specifically designed for washing, dyeing and drying operations on garments.

Folding and packaging

At the end of the production line, garments are arranged with reference tags, put into a bag and packed according to the forwarding specifications. These operations are carried out by means of folding and packing machines (for shirts, home linen, and underwear the complete process of folding and packing is carried out automatically in only one operation). A series of other systems are used to pile-up, pack, wrap-up and tie-up the garments.

Quality Control Aspects of Garment Exports


Introduction

For every industry or business, to get increased sales and better name amongst consumers and fellow companies it is important to maintain a level of quality. Especially for the businesses engaged in export business has to sustain a high level of quality to ensure better business globally. Generally quality control standards for export are set strictly, as this business is also holds the prestige of the country, whose company is doing the export. Export houses earn foreign exchange for the country, so it becomes mandatory to have good quality control of their products. In the garment industry quality control is practiced right from the initial stage of sourcing raw materials to the stage of final finished garment. For textile and apparel industry product quality is calculated in terms of quality and standard of fibres, yarns, fabric construction, colour fastness, surface designs and the final finished garment products. However quality  expectations for export are related to the type of customer segments and the retail outlets. There are a number of factors on which quality fitness of garment industry is based such as – performance, reliability, durability, visual and perceived quality of the garment. Quality needs to be defined in terms of a particular framework of cost. The national regulatory quality certification and international quality programmes like ISO 9000 series lay down the broad quality parameters based on which companies maintain the export quality in the garment and apparel industry. Here some of main fabric properties that are taken into consideration for garment manufacturing for export basis:
• Overall look of the garment.
• Right formation of the garment.
• Feel and fall of the garment.
Physical properties.
Colour fastness of the garment.
• Finishing properties
• Presentation of the final produced garment.

Sourcing of Fabrics

There are certain problems that could be faced by garment manufacturers when sourcing for certain fabrics, so precautions should be taken for it beforehand to minimize the problems. The garment exporters source cotton fabrics mainly from handloom sectors, powerlooms and mills. Each of these sectors presents their own unique set of problems to the garment exporters. Sourcing cotton from handloom sectors might present some set of problems like colour variation, missing ends and picks, irregular weaves and unreliable supplies. However, the handloom sector is significant source of heavier cotton. Common problems faced in powerloom cotton sourcing are broken ends and reed marks, thick and thin places, difference in width and massive variation in costing. The major problem in mill-made fabric sourcing is to meet huge demands from the mills. Fabrics have to be ordered well in advance in mills and the long time taken for producing the fabric is a matter of concern for garment exporters. Mills generally hesitate to take small orders which pose a problem for small scale exporters.

It is not that sourcing problems which only confined to cotton fabrics, but also to other fabrics as well. In silk garment industry there are some sorts of problems faced by silk garment exporters. Some of the problems that could be faced by silk garment exporters are as follows:

• Shortage of imported silk yarns in the quantities required, as a result delivery is delayed.
Silk material is very vulnerable to stains during manufacturing process as well as stocking, staining results in rejection so a lot of care has to taken during these procedures.
• Roll length of the silk yarn is often insufficient.
• Colour fastness of dyed silk material is sometimes not satisfactory.
• There are also chances of warp breakage.

Basic Thumb Rules for Garment Exporters

For a garment exporter there are many strategies and rules that are required to be followed to achieve good business. The fabric quality, product quality, delivery, price, packaging and presentation are some of the many aspects that need to be taken care of in garment export business. Some rules that are advisable for garment exporters are listed below:

• Quality has to be taken care by the exporter, excuses are not entertained in international market for negligence for low quality garments, new or existing exporters for both it is mandatory to use design, technology and quality as major upgradation tools.
• Apart from superior quality of the garment, its pricing, packaging, delivery, etc has to be also taken care of.
• The garment shown in the catalogue should match with the final garment delivered.
• It is important to perform according to the promises given to the buyer, or else it creates very bad impression and results in loss of business and reputation.
• In international market, quality reassurance is required at every point.
• Proper documentation and high standard labels on the garment are also important aspects as these things also create good impression.
• Timely delivery of garments is as important as its quality.
• If your competitor has the better quality of garment in same pricing, it is better to also enhance your garment quality.
• Before entering into international market, garment exporters have to carefully frame out the quality standards, or else if anything goes wrong it could harm the organization. And after that strictly follow it.
• The garment quality should match the samples shown during taking the orders.
• The garment exporters should know to negotiate a premium price after quality assurance is done.

Quality is a multi-dimensional aspect. There are many aspects of quality based on which the garment exporters are supposed to work.

• Quality of the production.
• Quality of the design of the garment.
• Purchasing functions’ quality should also be maintained.
• Quality of final inspection should be superior.
• Quality of the sales has to be also maintained.
• Quality of marketing of the final product is also important as the quality of the garment itself.

See to it that………..

There are certain quality related problems in garment manufacturing that should not be overlooked: Sewing defects – Like open seams, wrong stitching techniques used, same colour garment, but usage of different colour threads on the garment, miss out of stitches in between, creasing of the garment, erroneous thread tension and raw edges are some sewing defects that could occur so should be taken care of. Colour effects – Colour defects that could occur are – difference of the colour of final produced garment to the sample shown, accessories used are of wrong colour combination and mismatching of dye amongst the pieces.

Sizing defects – Wrong gradation of sizes, difference in measurement of a garment part from other, for example- sleeves of ‘XL’ size but body of ‘L’ size. Such defects do not occur has to be seen too. Garment defects – During manufacturing process defects could occur like – faulty zippers, irregular hemming, loose buttons, raw edges, improper button holes, uneven parts, inappropriate trimming, and difference in fabric colours.

Conclusion

Quality is ultimately a question of customer satisfaction. Good Quality increases the value of a product or service, establishes brand name, and builds up good reputation for the garment exporter, which in turn results into consumer satisfaction, high sales and foreign exchange for the country. The perceived quality of a garment is the result of a number of aspects, which together help achieve the desired level of satisfaction for the customer. Therefore quality control in terms of garme

Quality Control Aspects of Garment Exports


  • Introduction

For every industry or business, to get increased sales and better name amongst consumers and fellow companies it is important to maintain a level of quality. Especially for the businesses engaged in export business has to sustain a high level of quality to ensure better business globally. Generally quality control standards for export are set strictly, as this business is also holds the prestige of the country, whose company is doing the export. Export houses earn foreign exchange for the country, so it becomes mandatory to have good quality control of their products. In the garment industry quality control is practiced right from the initial stage of sourcing raw materials to the stage of final finished garment. For textile and apparel industry product quality is calculated in terms of quality and standard of fibres, yarns, fabric construction, colour fastness, surface designs and the final finished garment products. However quality
expectations for export are related to the type of customer segments and the retail outlets

There are a number of factors on which quality fitness of garment industry is based such as – performance, reliability, durability, visual and perceived quality of the garment. Quality needs to be defined in terms of a particular framework of cost. The national regulatory quality certification and international quality programmes like ISO 9000 series lay down the broad quality parameters based on which companies maintain the export quality in the garment and apparel industry. Here some of main fabric properties that are taken into consideration for garment manufacturing for export basis:
• Overall look of the garment.
• Right formation of the garment.
• Feel and fall of the garment.
Physical properties.
• Colour fastness of the garment.
Finishing properties
• Presentation of the final produced garment.

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