Viscoelastic Behavior of Fibers During Woven Fabric Bagging

Abstract

The aim of this paper is to study the viscoelastic behavior of fibers during the woven fabric bagging process through a series of experiments and a mathematical model to simulate bagging under the testing conditions. Through a large number of computational experiments, the elastic modulus E1 , viscoelastic modulus E2, fiber relaxation time T, and three weighting coefficients ( k3, k4, k5) are determined for six woven fabrics made from different fibers. A comparison of the experimental measurements with the predicted bagging behavior of the fabrics reveals that the mathematical model is able to predict bagging behavior with reasonable accuracy. The results show that the viscoelastic behav ior of fibers in the six fabrics is significantly different during bagging. Nylon and polyester have a high elasticity ratio ( E, ), a low viscoelasticity ratio ( E2), and a large relaxation time T. Silk, viscose, and cotton fibers have a low elasticity ratio ( E, ), a high viscoelas ticity ratio ( E2), and a small relaxation time T. For cotton and wool, with the same level of viscoelasticity ( E2), the stress relaxation process is determined by relaxation time T. These results suggest that fiber viscoelastic behavior plays a key role in determining fabric rheological behavior during bagging.