# US 2013/0157054 A1 · High linear density, high modulus, high tenacity yarns and methods for making the yarns

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- Number: US 2013/0157054 A1
- Document ID: US20130157054A1
- Status: Published application
- Kind: A1
- Application number: 13/330,773
- Filed: 2011-12-20
- Published: 2013-06-20
- Earliest claimed: 2011-12-20
- Assignees: E.I. du Pont de Nemours and Company
- Inventors: Bhatnagar Chitrangad
- Web page: https://patentgrep.com/patent/US20130157054A1

## CPC

- D01D 5/06: Wet spinning methods {(D01D5/0046 takes precedence)}
- D01D 10/02: Heat treatment (heating for finishing D02J13/00)
- D01F 6/605: {from aromatic polyamides}
- Y10T 428/298: Physical dimension
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The present invention relates to a yarn, comprising (a) a plurality of fibers having an orientation angle of no more than 8.0 degrees and made of a para-aramid, (b) a linear density of at least 2666 dtex (2400 denier), (c) a modulus of at least 810 grams per dtex (900 grams per denier), and (d) a tenacity of at least 18 grams per dtex (20 grams per denier). The invention further relates to methods of making such yarn.

## Claims

### Claim 1

A yarn, comprising: (a) a plurality of fibers having an orientation angle of no more than 8.0 degrees and made of para-aramid, (b) a linear density of at least 2666 dtex (2400 denier), (c) a modulus of at least 810 grams per dtex (900 grams per denier), and (d) a tenacity of at least 18 grams per dtex (20 grams per denier).

### Claim 2 (depends on 1)

The yarn of claim 1, wherein there are 1100 to 2500 of the plurality of fibers and the fibers have a linear density of 1.10 to 2.50 dtex (1.00 to 2.25 denier).

### Claim 3 (depends on 1)

The yarn of claim 1, wherein the para-aramid is poly(p-phenylene terephthalamide).

### Claim 4 (depends on 1)

The yarn of claim 1, wherein the yarn has a linear density of 2666 to 3444 dtex (2400 to 3100 denier).

### Claim 5 (depends on 1)

The yarn of claim 1, wherein the modulus is from 810 to 990 grams per dtex (900 to 1100 grams per denier).

### Claim 6 (depends on 1)

The yarn of claim 1, wherein the tenacity is from 18 to 25 grams per dtex (20 to 28 grams per denier).

### Claim 7 (depends on 1)

The yarn of claim 1, wherein the orientation angle is 5.0 to 8.0 degrees.

### Claim 8 (depends on 1)

The yarn of claim 1, further comprising the fibers having an apparent crystallite size at the 110 intensity peak of 70 to 85 Angstroms.

### Claim 9 (depends on 1)

The yarn of claim 1, further comprising the fibers having a crystal perfection index of 55 to 70 percent.

### Claim 10

A continuous process for making a para-aramid yarn having a linear density of at least 2666 dtex (2400 denier), a modulus of at least 810 grams per dtex (900 grams per denier) and a tenacity of at least 18 grams per dtex (20 grams per denier), comprising:
extruding an anisotropic solution of para-aramid in a solvent-through a spinneret having a plurality of holes forming a plurality of fibers,
passing the fibers through a gas and then a coagulating liquid,
combining the fibers into a yarn,
washing the yarn with a washing solution,
removing some of the washing solution from the surface of the yarn,
treating the yarn by heating the yarn from 120° C. to 260° C. under a tension of 0.90 to 2.25 grams per dtex (1.00 to 2.50 grams per denier) for a first heating time of 1.6 to 6.0 seconds, and
after the first treating step, treating the heated yarn from 300° C. to 400° C. under a tension of 2.25 to 4.50 grams per dtex (2.50 to 5.00 grams per denier) for a second heating time of 0.2 to 5.0 seconds,
cooling the yarn to a temperature of 125 to 170° C.,
applying a finish on the yarn, and
winding the yarn on a spool for the first time in the process.

### Claim 11 (depends on 10)

The process of claim 10, wherein the yarn further has a linear density of 2666 to 3444 dtex (2400 to 3100 denier) and the fibers have an orientation angle of 5.0 to 7.5 degrees.

### Claim 12 (depends on 11)

The process of claim 11, wherein the yarn further comprises the fibers having an apparent crystallite size at the 110 intensity peak of 70 to 85 Angstroms and a crystal perfection index of 55 to 70 percent.

### Claim 13 (depends on 10)

The process of claim 10, wherein the para-aramid is poly(p-phenylene terephthalamide).

### Claim 14 (depends on 10)

The process of claim 10, wherein in the first treating step, the yarn is heated from 150° C. to 200° C. for the first heating time.

### Claim 15 (depends on 10)

The process of claim 10, wherein in the second treating step, the yarn is heated from 340° C. to 380° C. for the second heating time.

### Claim 16 (depends on 10)

The process of claim 10, wherein in the first treating step, the yarn is heated in a first oven section or by a first plurality of hot rolls and in the second treating step, the yarn is heated in a second oven section or by a second plurality of hot rolls.

### Claim 17 (depends on 10)

The process of claim 10, wherein in the first treating step, the yarn is heated by a first plurality of hot rolls and the time that the yarn contacts the hot rolls is the first heating time.

### Claim 18 (depends on 17)

The process of claim 17, wherein the first plurality of hot rolls includes at least two steam heated rolls and the yarn contacts the steam heated rolls to remove most of the wash solution from the yarn.

### Claim 19 (depends on 18)

The process of claim 18, wherein the first plurality of hot rolls includes a first plurality of electrically heated rolls and the yarn contacts the at least two steam heated rolls before the yarn contacts the electrically heated rolls.

### Claim 20 (depends on 17)

The process of claim 17, wherein in the second treating step, the yarn is heated by passing the wet fibers over a second plurality of hot rolls heated and the time the yarn contacts the rolls is the second heating time.

### Claim 21 (depends on 20)

The process of claim 20, wherein the second plurality of hot rolls are electrically heated.