Abstract: A type of semi-dull polyester drawn yarns and preparing method thereof are disclosed. The preparing method is to melt spinning a modified polyester with FDY technique, wherein the modified polyester is the product of the esterification and the successive polycondensation reactions of evenly mixed terephthalic acid, ethylene glycol, main chain silicated diol, fluorinated dicarboxylic acid, matting agent and doped Bi2O3, in which the main chain silicated diol could be dimethylsiloxane diol, dimethyldiphenyldisiloxane glycol or tetramethyldisiloxane diol, and in which the fluorinated dicarboxylic acids could be 2,2-difluoro-1,3-malonic acid, 2,2-difluoro-1,4-succinic acid, 2,2-difluoro-1,5-glutaric acid or 2,2,3,3-tetrafluoro-1,4-succinic acid. The obtained fiber has a dye uptake of 87.5-91.8% when dyed at 120° C., and has an intrinsic viscosity drop of 18-26% when stored at 25° C. and R.H. 65% for 60 months.

Abstract: A type of semi-dull polyester drawn yarns and preparing method thereof are disclosed. The preparing method is to melt spinning a modified polyester with FDY technique, wherein the modified polyester is the product of the esterification and the successive polycondensation reactions of evenly mixed terephthalic acid, ethylene glycol, main chain silicated diol, fluorinated dicarboxylic acid, matting agent and doped Bi2O3, in which the main chain silicated diol could be dimethylsiloxane diol, dimethyldiphenyldisiloxane glycol or tetramethyldisiloxane diol, and in which the fluorinated dicarboxylic acids could be 2,2-difluoro-1,3-malonic acid, 2,2-difluoro-1,4-succinic acid, 2,2-difluoro-1,5-glutaric acid or 2,2,3,3-tetrafluoro-1,4-succinic acid. The obtained fiber has a dye uptake of 87.5-91.8% when dyed at 120° C., and has an intrinsic viscosity drop of 18-26% when stored at 25° C. and R.H. 65% for 60 months.

Abstract: A porous ultra-soft ultra-fine denier polyester fiber and preparation method. The modified polyester is spun with a porous spinneret to produce the porous ultra-soft ultra-fine denier polyester fiber, and the spinneret holes on the porous spinneret are arranged in an elliptical arrangement. The porous ultra-soft ultra-fine denier polyester fiber is obtained by metering, extruding, cooling, oiling and high-speed winding the modified polyester chips. The preparation method of modified polyester is as follows: terephthalic acid reacts with ethylene glycol to produce ethylene terephthalate. The modified polyester is obtained by the reaction of terephthalic acid with branched diol. The fiber of the invention has good properties and the deviation rate of fiber density. The deviation rate of fiber density is ?0.5%, the CV value of breaking strength is ?4.0%, the CV value of elongation at break is ?8.0%, the CV value of yarn unevenness is ?2.0%.

Abstract: A polyester obtained by the esterification of terephthalic acid and ethylene glycol and the polycondensation catalysed by a mixture of magnesium ethylene glycol and antimony ethylene glycol followed by granulation. In the polyester sections, the carboxyl end group is less than 15 mol/t, the mass percentage of oligomer is lower than 0.5%, and weight percentage of diethylene glycol is lower than 0.5%.

Abstract: A porous ultra-soft ultra-fine denier polyester fiber and preparation method. The modified polyester is spun with a porous spinneret to produce the porous ultra-soft ultra-fine denier polyester fiber, and the spinneret holes on the porous spinneret are arranged in an elliptical arrangement. The porous ultra-soft ultra-fine denier polyester fiber is obtained by metering, extruding, cooling, oiling and high-speed winding the modified polyester chips. The preparation method of modified polyester is as follows: terephthalic acid reacts with ethylene glycol to produce ethylene terephthalate. The modified polyester is obtained by the reaction of terephthalic acid with branched diol. The fiber of the invention has good properties and the deviation rate of fiber density. The deviation rate of fiber density is ?0.5%, the CV value of breaking strength is ?4.0%, the CV value of elongation at break is ?8.0%, the CV value of yarn unevenness is ?2.0%.

Abstract: A polyester obtained by the esterification of terephthalic acid and ethylene glycol and the polycondensation catalysed by a mixture of magnesium ethylene glycol and antimony ethylene glycol followed by granulation. In the polyester sections, the carboxyl end group is less than 15 mol/t, the mass percentage of oligomer is lower than 0.5%, and weight percentage of diethylene glycol is lower than 0.5%.