Micro-stretching improvement of fabrics finished by shape memory polymer

Weft strength of cotton fabrics after and before shape memory finishing was improved by two means of micro-stretching,i.e.,stretch-stop and cyclic stretch(cyclic tension loads).Experimental results showed that the breaking strength of fabric can be enhanced when stretch-stop or cyclic stretch is applied to it under a certain stretching rate.The higher the stretching rate,the shorter the pause time needed for reaching the maximum breaking strength,and the less the cyclic times.Two-factor five-level orthogonal test method was used to test the strength of fabrics by stretch-stop,and the tensile parameters and strength improvement were analyzed.The results showed that for the unfinished fabrics,the maximum breaking strength(enhanced by 31.9%) was obtained by using stretch-stop with stretching rate of 4% and then pause for 3 minutes,while in the case of finished fabrics,with the same stretching rate the maximum breaking strength(enhanced by 42.1%) was obtained at a pause of 2 minutes.