Bielastic fabric and its manufacturing process

Abstract

There are described a bielastic fabric comprising biopolyamide yarn and elastane yarn, having excellent elastic properties and high dimensional stability, and a cost-effective, efficient process for obtaining it.

1 . A process of manufacturing a bielastic fabric comprising a biopolyamide yarn and an elastane yarn, the process comprising the steps of:
 a) stitching the biopolyamide yarn and the elastane yarn to obtain a fabric,   b) heat-setting the fabric at a temperature that is not higher than 160° C. for a time period of 100 seconds or less; and, optionally,   c) dyeing the fabric thus heat-set,   
       wherein the biopolyamide yarn is a yarn of a polyamide made of polymerized monomers partly or totally derived from castor oil. 
     
     
         2 . The process of  claim 1 , wherein the heat-setting step b) is carried out over the time period of 30-70 seconds. 
     
     
         3 . The process of  claim 1 , wherein the heat-setting step b) is carried out at the temperature of 100-160° C. 
     
     
         4 . The process of  claim 1 , wherein the heat-setting step b) is carried out in warm air, in a tentering machine. 
     
     
         5 . The process of  claim 1 , wherein the dyeing step c) comprises the following substeps:
 i) scouring at 80-100° C. for 10-20 minutes,   ii) neutralizing of the scouring at 50-70° C. for 5-20 minutes,   iii) dyeing, with a dye dosage for 15-30 minutes at 90-110° C. with permanence for 20-40 minutes,   iv) stripping at 30-50° C. for 5-20 minutes,   v) treating with a fixer at 50-90° C. for 10-30 minutes, and   vi) conducting a final cold washing.   
     
     
         6 . The process of  claim 1 , wherein the biopolyamide yarn of step a) has a count of 10-200 dTex. 
     
     
         7 . The process of  claim 1 , wherein the elastane yarn of step a) has a count of 10-200 dTex. 
     
     
         8 . The process of  claim 6 , wherein the biopolyamide yarn of step a) has the count of 20-150 dTex. 
     
     
         9 . The process of  claim 7 , wherein the elastane yarn of step a) has the count of 15-100 dTex. 
     
     
         10 . The process of  claim 1 , wherein the fabric obtained in step a) comprises at least 60% of the biopolyamide yarn and at least 5% of the elastane yarn. 
     
     
         11 . The process of  claim 1 , wherein the stitching of step a) is a jersey stitching or an interlock stitching. 
     
     
         12 . The process of  claim 1 , wherein the fabric includes a weft direction and a warp direction, such that the fabric obtained in step a) comprises 75-90% of the biopolyamide yarn and 10-25% of the elastane yarn, and has a jersey stitch, and a basis weight of 180-210 g/sqm, and, after step b), has 45-90% of elasticity in the weft direction and 35-80% of elasticity in the warp direction, or
 wherein the fabric obtained in step a) comprises 75-90% of the biopolyamide yarn and 10-25% of the elastane yarn, and has a jersey stitch, and a basis weight of 100-140 g/sqm, and, after step b), has 120-200% of elasticity in the weft direction and 120-200% of elasticity in the warp direction, or   wherein the fabric obtained in step a) comprises 75-90% of the biopolyamide yarn and 10-25% of the elastane yarn, and has an interlock stitch, and a basis weight of 160-200 g/sqm, and, after step b), has 110-190% of elasticity in the weft direction and 50-100% of elasticity in the warp direction.   
     
     
         13 . The process of  claim 1 , wherein the fabric includes a weft direction and a warp direction, such that the fabric obtained in step a) comprises 80-90% of the biopolyamide yarn and 10-20% of the elastane yarn, and has a jersey stitch, and a basis weight of 190-200 g/sqm, and, after step b), has 50-80% of elasticity in the weft direction and 45-70% of elasticity in the warp direction, or
 wherein the fabric obtained in step a) comprises 70-80% of the biopolyamide yarn and 20-30% of the elastane yarn, and has a jersey stitch, and a basis weight of 110-130 g/sqm, and, after step b), has 140-180% of elasticity in the weft direction and 140-180% of elasticity in the warp direction, or   wherein the fabric obtained in step a) comprises 70-80% of the biopolyamide yarn and 20-30% of the elastane yarn, and has an interlock stitch, and a basis weight of 170-190 g/sqm, and, after step b), has 130-180% of elasticity in the weft direction and 60-90% of elasticity in the warp direction.   
     
     
         14 . The process of  claim 1 , wherein the polyamide in the biopolyamide yarn of step a) is biopolyamide 6, biopolyamide 6.6, biopolyamide 6.10, biopolyamide 6.12, biopolyamide 11, biopolyamide 12, or a mixture thereof.