Physical Ageing and Annealing in Fibers and Textile Materials

Abstract

The viscoelastic behavior of annealed fabric specimens produced from wool and manmade fibers has been assessed by measuring the fabric bending stress relaxation characteristics. The study reveals that the presence of water provides an effective me dium for de-ageing of fabrics produced from both wool and manmade fibers. Optimum annealing conditions occur when these fabrics are heated below the glass transition temperature of each fiber type at the equilibrium moisture regain corresponding to 20°C, 65% RH (the time taken depending on the annealing temperature). Under these conditions, the fabric bending stress relaxation rate is reduced to its minimum value, thus resulting in maximum fabric recovery from bending or wrinkling. The application of horizontal and vertical shift factors produces a master stress relaxation curve of aged and annealed fabric specimens produced from both wool and manmade fibers.