Crimp analysis of worsted fabrics in the terms of fabric extension behaviour

Inside a woven fabric structure, warp and weft yarns acquire crimp as a result of yarns interlacing according to the weave pattern. Since warp and weft yarns are oriented in two perpendicular directions, applying tensile load in one direction causes extension in the load side and fabric contraction in the opposite direction. This process was investigated in this study by using an image processing procedure and it was found that fabric’s extension is in coincidence with yarn’s de-crimping process in the same direction. After the de-crimping stage, yarns in the load direction will be extended and at the same time crimp in the other direction will be increased, until jamming phenomenon happens in the fabric structure. The crimp interchange between warp and weft yarns follows a three-order polynomial function with a turning point in which the yarns in the load direction have no crimp.