The contribution of fluorescent brightening agents (called “FBA” hereinafter) has been examined to the recovery of whiteness of textiles which was colored somewhat yellow by wearing and aging. Using the four types of FBAs for detergent additives, i.e., triazinyl stilbene, distyryl biphenyl (direct), coumarin (basic) and phenyl amino carbostyryl (disperse) derivatives, the amount of sorption from washing bath and whitening effect of FBA on the textiles soiled with squalene and aged by heating were determined. The test specimens of cotton or nylon were soaked in the test tubes containing FBA solution for one hour at 40°C. The amount of FBA sorbed in cotton fabrics increased by soiling with squalene and aging. However these treatments had no effect on the amount of FBA sorbed in nylon fabrics. Moreover, FBA sorbed in yellowed fabrics had little effect on reducing the value b of yellowness and also on improvement of fluorescent intensity. Therefore, immediate washing are indispensable in order to prolong the serviceable life of clothes.
It is necessary to evaluate many characteristics of knitted fabrics, i.e., elongation, strength, shrinkage, etc., not separately but integratedly to determine the optimal knitting condition. This paper aims to classify many characteristics of knitted fabrics into a few overall characteristics (principal components) by the principal component analysis. Results obtained were as follows: 1) The fourteen characteristics were classified into two principal components. 2) The first principal component (Z1) represents “thickness” and “density”. The contribution ratio of Z1 was 46%. 3) The second principal component (Z2) represents “strength.” The contribution ratio of Z2 was 28%. 4) The contribution ratio of “material” to the Z1 was 87%. 5) The contribution ratio of “stitch formation” to the Z2 was 72%. 6) The conditions of knitting can be evaluated by the scores of these principal components.