The following properties a cotton fibre should have to contain of:-
1. Fibre Fineness: Fineness is one of the most important parameter determining the yarn quality. This is the best cotton properties that almost all of the cotton importers wants. Cotton Fibre fineness influences the number of fibre in cross section. The finer fibre results the higher no. of fibre in yarn cross-sections. Fibre fineness influences primarily-
a) Spinning limit.
B) Lustre. C) Yarn Strength. D) Handle E) Yarn Evenness F) Productivity.
2. Maturity: The maturity of cotton fibre defines in terms of the development of the cell wall. A fully mature fibre has a developed cell wall. On the other hand, an immature fibre has a very thin cell wall. A fibre is to be considered as mature fibre when the cell wall of moisture swollen fibre represents 50% to 80% of the round cross section, as immature fibre represents 30% to 45% and as dead when it represents less than 25%.
Immature fibres lead to –a) napping b) loss of yarn strength c) high proportion of short fibre d) varying dyeability. So good cotton properties is to said as matured cotton fibre.
3. Fibre Length: The average length of spinnable fibre is called staple length. Staple length is one of the most important fibre characteristics. The quality, count, strength, etc depend on the staple length of the fibre. Higher the staple length, higher the yarn quality. Staple length influences –a) yarn evenness b) lustre of the product c) spinning limit d) yarn strength e) yarn hairiness f) handle of the product
The following length grouping are currently used in stating the trade staple or basic cotton properties-
Short Staple: 1″ or less.
Medium Staple: 1 and 1/32 inch to 1 and 1/8 inch
Long Staple: 1 and 5/32 inch to 1 and 3/8 inch.
Extra Long Staple: 1 and 13/32 inch and above.
4. Cotton Fibre Strength: Toughness of fiber has a direct effect on yarn and fabric strength. Cotton Properties means such type of physical behavior of a fibre. The higher the fibre strength, the higher the yarn and fabric strength. Very weak cotton tends to rupture during processing both in blow room and carding, creating short fibres and consequently deteriorate yarn strength and uniformity. Some significant breaking strength of fibres are-
Polyester >>35 to 60 CN/Tex
Cotton>>>>15 to 40 CN/Tex
Wool>>>>12 to 18 CN/Tex
5. Cotton Fibre Cleanness: In addition to usable fibre, cotton stocks contain various kinds of foreign matters. Some vegetable matters are- a) husk portion, b) seed portion c) stem portion d) leaf portion e) wood portion.
Some mineral matters are- a) earth b) sand c) dust.
Some other foreign materials are- a) metal fragments b) cloth fragments c) packing materials.
6. Cotton Fibre Elongation: Elongation is specified as a percentage of the starting length. Textile products without classify would hardly be usable. They must be deformed and also return to the original shape. The fibre elongation should be at least 1 to 2%. The greater crease resistance of wool compared with cotton arises due to difference in theirelongation.