Influence of Fiber Geometry on the Mechanical Properties of Assemblies During Processing

Abstract

Sixteen samples of polyester-rayon blends, as well as a 100% rayon, and eight 100% polyester samples have been processed on the worsted system from raw stock through the 3rd pin-drafting stage. The blends in which 3-in. (nominal) staple was used were 65% polyester and 35% viscose rayon. The polyester samples provided all combinations of the following fiber variables, each represented by two contrasting levels: (a) surface roughness, (b) cross-sectional shape, (c) linear density, and (d) crimp. A single rayon sample of 3-den, bright, crimped staple was used in the blends. The total of 25 sliver samples from the card and first and third pin-drafting stages were evaluated for static-cohesion properties, as represented by maximum cohesive tenacity, textile modulus, and extension to maximum force. It was found that, generally, in blended slivers from all three stages of processing, fiber crimp in the polyester component had a statistically very significant effect on the three parameters measured. The rayon in the blends seemed to have little or no effect on the values of the parameters, as judged by comparison of these with corresponding values for the 100% polyester slivers. Measurements on the slivers showed slightly better evenness in the blended slivers containing the crimped polyester fibers than in those containing the samples without crimp. Blending of the rayon with the polyester samples was found to produce no significant differences in evenness.