STUDIES ON THE COMPRESSIVE SHRINKING PROCESS FOR SPUN RAYON FABRICS

Abstract

The compressive shrinkage procss for cellulosic fabrics is investigated by using the experimental apparatus. Materials used are spun rayon challis, cotton shirting, and several Broads. Broad fabrics are woven by regular rayon, super rayon (Avisco XL), cotton-like rayon staple yarns and cotton yarns respectively, and have same ends and picks per cm. These yarns have same yarn count 60′s/2 and twist too. The references between residual shrinkages and physical properties of fabrics after treatment are as foliws; (1) Although the cotton fabrics have almost no residual shrinkages after compressive shrinking treatment, the spun rayon fabrics have some residual shrinkages. Regular rayon and super rayon fabrics have much residual shrinkages, but cotton-like rayon has not so much. Even though the compressive shrinkages incresae more than latent shrinkages of the fabrics, residual shrinkages of spun rayon fabrics are not only be reduced, but the fabrbrics also become crumpled.(2) Fabrics, which have large residual shrinkages, generally, have not so good dimensional stability. Especially they have large difference in length between conditioned and wet states but not necessarily so much relaxation shrinkages or progressive shrinkages.(3) On Broads fabrics, which have much residual shrinkages are made of fibers with much water imbibition and low modulus when wet.(4) In the standard state, moreover, spun rayon fabrics elongate more than cotton fabrics do under the same loads. There might be some unknown factors due to which residual shrinkages of spun rayon fabrics are not removed even after the industrially compressive process, e. g. sanforizing process, is applied.