| 摘要 |
PURPOSE:To obtain high-strength and high-elastic modulus yarns, by melt spinning a polyester having a specific intrinsic viscosity to provide a yarn having a birefringence ratio within a specific range, swelling the resultant yarn and drawing the swollen yarn at a specific temperature under a specific stress. CONSTITUTION:An ethylene terephthalate based polyester having >=0.5-<1.2 intrinsic viscosity (IV) is melt spun to provide a yarn having 0.002-0.060 birefringence ratio, which is then impregnated with a swelling agent consisting essentially of, e.g. acetone, swelled and drawn at <=90 deg.C temperature at >=7 times draw ratio and then drawn at a temperature within the range of 150-250 deg.C while applying >=5g/d stress to afford the aimed yarn having 13.4g/d tensile strength and 197g/d tensile elastic modulus. |
