SynopsisIt has been shown that the breaking load histograms of raw, slack-mercerized, and mercerizedstretched cottons can be represented by @-distributions. The breaking load distribution is positively skewed for raw cotton. The influence of slack mercerization is to make the distributions symmetric and to reduce the variability of the breaking load by the elimination of weak links. The mode of the distribution shifts toward higher breaking load upon mercerization, and this shift increases with the extent of applied stretch. For various raw and mercerized cottons, the effect of increasing the gauge length is to reduce the mean, mode, and variability of the breaking load and to make the distributions less and less asymmetric. The application of stretch to swollen fibers influences the load distribution on the side of higher load and renders the distribution asymmetric.

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The analysis of sets of fabrics of different woven constructions made from the same count of yarn indicates that the differences in mechanical properties arise mainly from weave differences. Increase in flex abrasion is compensated by a de crease in'tear strength and vice versa. Analysis reveals that the initial properties of the twill weave are more balanced for higher levels of crease recoveries than those of the other fabrics. Twill-weave fabrics show high tensile strength. While basket-weave fabrics give higher tear strength, the plain-weave fabrics are best suited for high flex abrasion resistance. Further, higher initial properties of the weave result in fabrics with improved mechanical properties after resin treatment.

Optimum conditions for the partial degumming of silk yarn with soap and sulphuric acid (20%) are presented. The purpose of the study was to achieve an economical partial degumming process capable of yielding silk suitable for weaving of fabric with the required amount of stiffness. The colour strength of partially degummed silk was observed to improve, without affecting the wash fastness characteristics.

SynopsisBreaking load frequency distributions have been obtained at different test gauge lengths for several raw cottons differing in fiber cell wall maturity. The curve-fitting procedure for the analysis of the shape of observed breaking load histograms is described. The procedure yields several important parameters characterizing the raw cotton, such as the mean, mode, skewness, standard deviation, and the C.V. of breaking load. It is found that for all raw cottons, the observed breaking load distributions have it positive skew and are of B type. The effect of fiber maturity and the test gauge length on the shape of observed distributions has been analyzed. The effect of weak links on the variability of breaking load in raw cotton is discussed.