Shiffon finish is known as weight reduction finish, which is given to PET fabrics to make them silk-like. Garments of nature silk are greatly valued for their softness, draping suppleness, warm and sensuous feeling and comfort properties. If polyester fabric is constructed from very fine denier yarn, the feel of the fabric is close to nature silk. However, it is uneconomical to weave or knit fabrics from very fine denier yarn. Shiffon finish is based on controlling hydrolysis of polyester with sodium hydroxide. It gives some loss of weight of the fabric which reduces the denier of the fibre and thus, gives a thin fabric. There is no notable difference in dye affinity between normal and shiffon finished polyester.
static electricity is formed when two dissimilar materials are rubber together. Antistatic treatments are based on the principle of making the fibre conductive so that high charge densities are dissipated before aparks can form. This is done by the application of both anionic and cationic agents to the fibres. These agents attract water and form a conductive surface on the synthetic fibres.
enzyme finishing is based on the use of cellulose that can hydrolyze the cellulosic fibres and make them thin and soft under certain conditions. Don’t not like application of fabric softener which overcome the negative qualities of a harsh and unpleasant hand, enzyme finishing can impart a permanent soft hand to the fabric and eliminate the fibre ends protruding from the surface of the fabric.
this finish is achieved by applying the chemicals, which will kill the microorganisms or inhibits the growth of bacteria. The normal amount of the chemical applied depends on the efficiency of the particular product.
the principle of the water proofing is to form a layer of continuous film on the surface of the fabric. The interstices between the warp and weft yarns are blocked by the continuous film and both water and air will not pass through the treated fabric. GORE-TEX is one of the best known of these products, and it is used extensively in outdoor clothing for active sports.
Water repellent finish:
a water-repellent fabric allows air but prevents water to pass through itself, it only resists penetration by water but is not completely waterproof.
Water repellent finish is also achieved by applying hydrophobic materials to the fabric, but these materials are only applied to the fibres and yarns and yarns of the fabric. The interstices between the warp and weft yarns of the fabric are not blocked so air and water vapor can pass through the fabric. The surface tension of the fabric has been decreased greatly by the hydrophobic materials and as a result it’s difficult for the fabric to be wetted by water and it is also difficult for the water having low static hydraulic pressure to pass through the fabric.