Identifying Fibres Cotton
Cotton fibre is relatively strong due to the intrinsic structure of layers of criss crossed, minute, spiralled fibrules that compose the fibre cell. Strength is also determined by the character of the yarns which should be of long staple and tightly twisted.
Cotton fibre has very little natural elasticity. This characteristic can be altered to varying extents by hard twisting of the fibre into creped yarns and by using such fabric construction techniques as knitting.
Cotton fibre composed primarily of cellulose which is very absorbent. Its hollow centre of lumen aids in conveying moisture. Such factors as the amount of twist in the yarn would also affect absorbency. Fabric structure, such as the pile weave, will affect absorbency. Also the compactness of the weave influences the absorbency because the looser the structure the more absorbent the fabric will be.
Cleanliness And Washability
Although cotton attracts dirt particles of its roughness, this disadvantage is offset by the washability of the fabric. Cotton fabrics are not injured even in strong hot solutions of alkalis. they also withstand rough handling.
Reaction To Bleaches
Cotton may be safely bleached with ordinary household bleaches diluted to the manufacturers recommendations.
A great amount of shrinkage will occur if cotton fabric is loosely woven and stiffened with starch. Pre shrinking finishing processes minimise shrinkage in cotton fabrics.
Effect Of Light
Cotton fibres oxidise, turning yellow and losing strength from exposure to sunlight over a period of time. Cotton fabric should therefore be shaded from direct sunlight.
Reaction To Alkalis
Cotton is not harmed by alkalis. In fact a solution of sodium hydroxide is used to mercerize cotton, making it stronger, smoother and more lustrous.
Reaction To Acids
Cotton is not damaged by such volatile organic acids like acetic acid (vinegar). However, it is tendered if such non volatile organic acids as oxalic and citric (found in drinks) are allowed to remain on it and particularly if heat is also applied.
Affinity For Dyes
Cotton has a good affinity for dyes. Penetration of thoroughness of dye can be tested by ravelling a yarn and examining its unexposed surface.
Resistance To Perspiration
Acid perspiration has a slightly deteriorating effect on cotton.