# US 8,540,912 B2 · Process of making poly(trimethylene arylate) fibers

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- Number: US 8,540,912 B2
- Document ID: US8540912B2
- Status: Granted
- Kind: B2
- Application number: 13/272,525
- Filed: 2011-10-13
- Published: 2012-10-25
- Granted: 2013-09-24
- Earliest claimed: 2010-04-27
- Assignees: E. I. Du Pont de Nemours and Company
- Applicants: W. Douglas Bates
- Inventors: W. Douglas Bates
- Web page: https://patentgrep.com/patent/US8540912B2

## CPC

- D01F 6/92: of polyesters
- D01D 5/16: using rollers, or like mechanical devices, e.g. snubbing pins
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS

## Abstract

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.

## Claims

### Claim 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.

### Claim 2 (depends on 1)

The process of claim 1 wherein the poly(trimethylene arylate) is poly(trimethylene terephthalate).

### Claim 3 (depends on 1)

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).

### Claim 4 (depends on 2)

The process of claim 2 wherein the polymer melt consists essentially 0.5 to 3% by weight of polystyrene dispersed in poly(trimethylene terephthalate).

### Claim 5 (depends on 2)

The process of claim 2 wherein the polymer melt comprises 0.5 to 2% by weight of polystyrene dispersed in poly(trimethylene terephthalate).

### Claim 6 (depends on 1)

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.

### Claim 7 (depends on 1)

The process of claim 1 further comprising accumulating the filament at a rate of at least 4,000 m/min.