Wet shrinkage

Qiana, introduced by Du Pont in 1968 but later withdrawn from the market, was made from bis(4-aminocyclohexyl)methane and dodecanedioic acid. This diamine exists in several cis—trans and trans—trans isomeric forms that influence fiber properties such as shrinkage. The product offered silk-like hand and luster, dimensional stabiUty, and wrinkle resistance similar to polyester. The yam melted at 280°C, had a high wet glass-transition temperature of - 85° C and a density of 1.03 g/cm, the last was lower than that of nylon-6 and nylon-6,6. Qiana requited a carrier for effective dyeing (see Dye carriers). 

Finishing of Wool. Wool (qv) competes for markets where warmth, wrinkle recovery, and abiUty to set in creases are important. Wool problems relate to shrinkage, particularly to its tendency to felt. This is caused by scaly stmcture, which tends toward fiber entanglement when wet and subjected to mechanical action. In order to compensate for this tendency, wool needs to be set and also made shrinkproof if it is to be laundered. 

Figure 10.42 Mercerising shrinkage rate using 5 g/l of a commercial wetting agent [280]...

Relative viscosity, 22 710, 715-716 Relaxation fabric shrinkage, 26 390 Relaxation, in wet fiber spinning,... 

Melamine resins also are used for the production of decorative laminates. The amino resins are able to modify textiles like cotton and rayon by imparting crease resistance, stiffness, shrinkage control, fire retardance and water repellency. They are also used to improve the wet strength, rub resistance and bursting strength of paper. 

There are also hundreds of additives used as process aids to improve such things as air release, cure rate, thickening, viscosity reduction, mold release, wetting and dispersion of fillers, thixotropy, shrinkage and static reduction. 

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