Abstract
One of the most insidious and troublesome causes of two-tone dyeing in silk fabric has been traced to a difference in the average diameter ratios of silk filaments in two adjoining sections of the same fabric. By diameter ratio is meant the ratio of the smallest to the largest diameter of a given cross-section. When this average difference exceeds .04, two-tone dyeing becomes noticeable and extreme when it exceeds 0.12. This difference in diameter ratio is not noticeable to the eye by microscopic examination of cross-sections except in rare instances, but it can be determined only by statistical measurements of 100 filaments for each yarn to attain a desired accuracy of 1 % in the average value. The chief value of this discovery is to make obvious the futility of attempting to correct for this particular cause of two-tone by any chemical adjustments in soaking, boiling-off and dyeing. It also again emphasizes the danger of mixing lots of silk cocoons at the filatures. It is possible that an auxiliary method of grading raw silk can be developed on the basis of diameter ratio. Variations in the diameter ratios of different lots of Japanese cocoons from several districts are presented.
Get full access to this article
View all access options for this article.