A sharp technique for identification of defective points in false twist textured yarns

Abstract

Fast Fourier Transformation technique has been used to classify the defective points in the yarn surface into three classes, namely less important defective points of textured yarn containing surface fibres and broken filaments; medium defective points; and large and unusual defective points. The results obtained from textured yarn with 300 Nm show that this method can be considered for commonly used yarns in acceptable accuracy. This method can detect the defects in a fraction of seconds and can be installed on machines.