Process of making poly(trimethylene arylate) fibers
View Patent ↗A fine denier poly(trimethylene arylate) spun drawn fiber is characterized by high denier uniformity. A process for preparing uniform fine denier yarns at spinning speeds of 4000 to 6000 m/min is further disclosed. The poly(trimethylene arylate) fiber hereof comprises 0.1 to 3% by weight of polystyrene dispersed therewithin. Fabrics prepared therefrom are also disclosed.
1. A process comprising extruding a polymer melt comprising 0.1 to 3% by weight, based on the total weight of polymer, of polystyrene dispersed in poly(trimethylene arylate), through an orifice forming a continuous filamentary extrudate, quenching the extrudate to solidify it into a continuous filament, wrapping the continuous filament around a first driven roll heated to a temperature in the range of 70 to 100° C. and rotating at a first rotational speed, followed by wrapping the filament around a second driven roll heated to a temperature in the range of 100 to 130° C. and rotating at a second rotational speed wherein the ratio of the second rotational speed to the first rotational speed lies in the range of 1.75 to 3; and, thereby forming a spun drawn filament having a denier of ≦3, a denier coefficient of variation of ≦3%, and a birefringence of ≧0.055.
2. The process of claim 1 wherein the poly(trimethylene arylate) is poly(trimethylene terephthalate).
3. The process of claim 1 wherein the polymer melt consists essentially of 0.5 to 3% by weight of polystyrene dispersed in poly(trimethylene arylate).
4. The process of claim 2 wherein the polymer melt consists essentially 0.5 to 3% by weight of polystyrene dispersed in poly(trimethylene terephthalate).
5. The process of claim 2 wherein the polymer melt comprises 0.5 to 2% by weight of polystyrene dispersed in poly(trimethylene terephthalate).
6. The process of claim 1 further comprising wrapping the filament around a third driven roll rotating at a third rotational speed, and wherein the ratio of the third rotational speed to the second rotational speed is <1.
7. The process of claim 1 further comprising accumulating the filament at a rate of at least 4,000 m/min.