A Study How to Quantitatively Determine Crimps On Crape Fabrics

Abstract

In order to quantitatively determine the crimps or waves of crape fabrics, we have analysed their appearance caused by shrinkages of single hard twist yarns and untwisting moment. The results are summerized: (1) The size of crape crimps is closely related to the number of spiral circles. Equation will be: m=0.2T/(1-f(s)) where m is the number of spiral circles: T, yarn twist and f(s), shrinkage of crape fabric. (2) The amplitude of crape crimps is related to the radius of spiral circles and given by the following formula: r=√<1-(1-f(s)²>)/ 0.4πT (3) The thickness of crape fabric is in proportion to the radius of spiral circles. It is greately influenced by the twist multiplier of hard twist yarns: (4) The degree of crimps, Ca-1, is a function of the fabric shrinkage as in the following formula; Ca-1 = A•f(s)^5/2 where A is an experimental constant determined by the weft yarn arrangements.