23—a Theoretical Analysis of the Tensile Properties of Plain-Knitted Fabrics. Part I: The Load-Extension Curve for Fabric Extension Parallel to the Courses

An investigation is described in which, by means of a two-dimensional model of the plain-knitted structure, load-extension curves for extension in the course direction were calculated theoretically. It was assumed initially that the only mechanism of fabric extension was elastic deformation of the loop shape. Account was taken of setting of the yarns into the relaxed-loop shape, but this was found not to have any significant effect on the theoretical load–extension curves. It was found that the intial portions of these curves were almost linear but that the slope could be greatly affected by the occurrence of lateral yarn compression. When yarn compression was taken into account, good agreement was obtained with experimental results for a nylon-monofilament fabric and a series of wool plain-knitted fabrics.