Patent ID: 6702864
Filing Date: 2004-03-09
Classification: D04B,Y10S,Y10T

Abstract:
A process of making a high stretch elastic knitted fabric from polytrimethylene terephthalate which comprises:(a) making a drawn textured yarn with an elongation to break of 30 to 60 percent by combining the steps of: (i) spinning a polytrimethylene terephthalate polymer into a partially oriented yarn, and (ii) draw texturing the yarn in a false-twisting texturing machine at a draw ratio of 1.05 to 2.0 and a yarn temperature of 50Â° C. to 200Â° C., and (b) knitting the yarn into a fabric composed of intermeshing loops of the yarn wherein the stitch length is from 22 cm/100 stitches to 26 cm/100 stitches, and (c) scouring the knitted fabric according to the following procedure: (i) load the fabric into a dyer with water at 30 to 40Â° C. for 12 to 15 minutes, and (ii) add 0.5 to 1.5% on weight of fabric of spin finish remover, and (iii) raise the temperature to 100Â° C. at a rate of 1.0 to 2.5Â° C., and (iv) hold for 5 to 10 minutes, and (d) drying the fabric: (i) on a belt at a speed 13 to 23 meter/minute through a forced air oven at a temperature of 88 to 98Â° C. with a residence time of 52 to 62 seconds, or (ii) on a belt at a speed 13 to 23 meter/minute through a tenter frame forced air oven at a temperature of 135 to 145Â° C. with a residence time of 52 to 62 seconds, and (e) dyeing the knitted fabric at atmospheric pressure by dispersing a dye and the fabric in water and increasing the temperature according to the following procedure: (i) preheating the fabric to a temperature of from 25Â° C. to an upper limit of 44 to 54Â° C. by increasing the temperature at a rate of 1.0Â° C. to 2.5Â° C. per minute, and (ii) adding the dye chemicals to the fabric in water, and (iii) preheating the fabric to a temperature of from 44 to 54Â° C. to 55 to 65Â° C. by increasing the temperature at a rate of 1.0Â° C. to 2.5Â° C. per minute, and (iv) preheating the fabric to a temperature of from 55 to 65Â° C. to 105 to 115Â° C. by increasing the temperature at a rate of 1 to 2Â° C. per minute, and (v) maintaining the dyeing solution at this temperature for from 30 to 50 minutes, and (f) finishing the dyed knitted fabric according to the following procedure: (i) cooling the dyed knitted fabric to 82 to 98Â° C. at a cooling rate of 1Â° C. to 2Â° C. per minute, and (ii) adding reduction agent(s) for scouring which is carried out for from 3 to 7 minutes, and (iii) cooling the dyed knitted fabric to 55 to 65Â° C. at a cooling rate of 1.0Â° C. to 2.5Â° C. per minute, and (iv) washing the dyed knitted fabric with room temperature water for from 10 to 20 minutes, and (v) adding a solution of 0.25 to 0.75 weight percent weak organic acid, and (vi) heating the dyed knitted fabric to 44 to 54Â° C. at a rate of 1.0 to 2.5Â° C. per minute and holding it at that temperature for from 5 to 15 minutes, and (vii) washing the dyed knitted fabric at 34 to 44Â° C. for 5 to 10 minutes, and (viii) removing the fabric, and (g) drying the fabric: (i) on a belt at a speed of 13 to 23 meter/minute through a forced air oven at a temperature of 88 to 98Â° C. with a residence time of 52 to 62 seconds, or (ii) on a belt at a speed of 13 to 23 meter/minute through a tenter frame forced air oven at a temperature of 135 to 145Â° C. with a residence time of 52 to 62 seconds.