VISCOELASTIC STUDIES OF TEXTILE FABRICS

We devised an appratus, by which we observed the behaviour of structural shearing deformation of fabrics dynamically. This behaviour relates to the three factors-elasticity, viscosity and friction-, and shows non-linearity which depends upon the amplitudes i. e. deformation, and it can be divided into three zones according to the degrees of deformation.When very small, deformation depends upon only yarn bending without relative sliding between warp and weft yarns at their crossing points. Therefore the apparent elastic modulus of shearing deformation is very high.When the deformation increases and surpasses such a critical value as the Bingham point, both yarns begin to slide relatively, and its behaviour apparently shows linearity. As this deformation further increases the behaviour deviates from the linear relation again, and cubic buckling appears.The behaviours of a glass cloth and a saran screen can be modelized as truss and rahmen respectively. Apparent elastic modulus of elasticity and frictional force of cotton plain fabrics increases in proportion with cover factors and tensions applied to the sample fabrics.