A study of selvedge waste length in rapier weaving by image analysis technique

One of the most important constraints of shutleless weaving machines is the necessity to form a false selvedge at both sides. the nature of selvedge formation in a rapier loom is analysed,and the variation in the length of weft yarn waste is measured by image analysis technique. the behaviour of weft yarn gripper at the entry into and exit from the shed are analysed by a high speed camera. the length of the trailing end of weft yarn is manually measured and digital image analysis technique is also used for the measurements. high speed film images are processed to measure the waste length of the weft and also the gap between the edge of the fabric and auxiliary warp yarns. an image processing software is used for 2d measuring by sub pixel edge detection on the subsequent still image frames of high speed film. the measurements by image processing are found to be very close to the actual values,and it proves to be advantageous especially in case of stretch weft yarns.