Blended fiber yarns and fabrics including oxidized polymeric fibers

Abstract

An article comprising a fabric comprising: (a) a blended yarn comprising: (i) from about 10% to about 85% by weight of at least one biregional fiber comprising an oxidized polymer selected from the group consisting of acrylonitrile based homopolymers, acrylonitrile based copolymers, acrylonitrile based terpolymers, and combinations thereof; (ii) at least one companion fiber selected from the group consisting of FR polyester, FR nylon, FR rayon, FR treated cellulose, m-aramid, p-aramid, modacrylic, novoloid, melamine, wool, nylon, regenerated cellulose, polyvinyl chloride, antistatic fiber, poly(p-phenylene benzobisoxazole) (PBO), polybenzimidazole (PBI), polysulphonamide (PSA), and combinations thereof; and (b) optionally including a companion yarn different from said blended yarn; wherein said companion yarn includes p-aramid in an amount less than 20% of the fabric weight; and wherein the fabric has a weight from about 3 oz/yd.sup.2 to about 12 oz/yd.sup.2.

Claims

1. A fabric comprising: (a) a blended yarn comprising: (i) from about 10% to about 85% by weight of at least one fiber comprising an oxidized polymer selected from the group consisting of acrylonitrile based homopolymers, acrylonitrile based copolymers, acrylonitrile based terpolymers, and combinations thereof; (ii) at least two companion fibers selected from FR polyester, FR nylon, FR rayon, FR treated cellulose, m-aramid, p-aramid, modacrylic, wool, nylon, regenerated cellulose, antistatic fiber and combinations thereof; and (b) a companion yarn different from said blended yarn; wherein said companion yarn consists essentially of staple fibers comprising (i) p-aramid, wherein the p-aramid is present in an amount less than 20% of the fabric weight; and (ii) at least one fiber selected from FR polyester, FR nylon, FR rayon, m-aramid, modacrylic, FR treated cellulose, wool, nylon, regenerated cellulose, antistatic fiber, and combinations thereof; wherein a ratio of arc rating to weight is greater than 1.

2. The fabric of claim 1, wherein said fabric is woven.

3. The fabric of claim 1, wherein the fabric has a weight from about 3 oz/yd.sup.2 to about 12 oz/yd.sup.2.

4. The fabric of claim 1, wherein the blended yarn further comprises a fiber comprising an oxidized polymer which is substantially uniformly oxidized throughout the cross-section of the fiber.

5. The fabric of claim 4, wherein the fiber which is substantially uniformly oxidized has a density from about 1.30 g/cm.sup.3 to about 1.44 g/cm.sup.3.

6. The fabric of claim 1, wherein the fiber comprising the oxidized polymer is a biregional fiber, and wherein the oxidized biregional polymer has a density from about 1.20 g/cm.sup.3 to about 1.40 g/cm.sup.3.

7. The fabric of claim 6, wherein the biregional fiber has an unoxidized polymeric core and an oxidized polymeric sheath.

8. The fabric of claim 7, wherein the biregional fiber has a ratio of the radius of the core to the radius of the fiber (r:R) of from about 1:1.03 to about 1:7.

9. The fabric of claim 7, wherein the biregional fiber has a ratio of the radius of the core to the radius of the fiber (r:R) of from about 1:1.03 to about 1:1.4.

10. The fabric of claim 7, wherein the biregional fiber has a ratio of the radius of the core to the radius of the fiber of from about 1:1.105 to about 1:1.8.

11. The fabric of claim 1, wherein the oxidized polymer comprises polyacrylonitrile.

12. The fabric of claim 1, wherein the oxidized polymer has a density from about 1.20 g/cm.sup.3 to about 1.50 g/cm.sup.3.

13. The fabric of claim 3, wherein the fabric has a weight from about 4 oz/yd.sup.2 to about 9 oz/yd.sup.2.

14. The fabric of claim 1, wherein said arc rating is greater than 8.

15. The fabric of claim 1, wherein said arc rating is greater than 9, and said article has a weight from about 6.5 oz/yd.sup.2 to about 7.5 oz/yd.sup.2.

16. The fabric of claim 1, wherein said arc rating is greater than 8, and said article has a weight from about 5.0 oz/yd.sup.2 to about 6.5 oz/yd.sup.2.

17. The fabric of claim 1, wherein the fabric has been dyed.

18. The fabric of claim 1, wherein said fabric comprises a garment.

19. The fabric of claim 1, wherein the fiber comprising the oxidized polymer is present in the yarn in an amount from about 15% to about 50% by weight of the yarn.

20. The fabric of claim 1, wherein said yarn includes at least three companion fibers.

21. The fabric of claim 20, wherein the fiber comprising the oxidized polymer is present in the yarn in an amount from about 15% to about 50% by weight of the yarn.

22. The fabric of claim 20, wherein the three companion fibers are selected from: (a) the combination of FR rayon, nylon, regenerated cellulose, and p-aramid; and (b) the combination of wool, modacrylic and nylon and regenerated cellulose.

23. The fabric of claim 1, wherein said yarn includes four companion fibers.

24. The fabric of claim 1, wherein said yarn is a blended yarn made on a worsted spinning system.

25. An article comprising: (a) a blended yarn, wherein the blended yarn comprises at least one oxidized polymeric fiber and at least three companion fibers selected from the group consisting of FR polyester, FR nylon, FR rayon, FR treated cellulose, m-aramid, p-aramid, modacrylic, wool, nylon, regenerated cellulose, antistatic fiber, and combinations thereof; and (b) a companion yarn different from said blended yarn; wherein said companion yarn consists essentially of staple fibers comprising (i) p-aramid, wherein the p-aramid is present in an amount less than 20% of the fabric weight; and (ii) at least one fiber selected from the group consisting of FR polyester, FR nylon, FR rayon, FR treated cellulose, m-aramid, modacrylic, wool, nylon, regenerated cellulose, antistatic fiber, and a combination thereof; wherein the article is a woven fabric; wherein the article has an arc rating to weight ratio of greater than 1; and said fabric meets the standards for HRC level 2.

26. The article of claim 25, wherein the fabric has a weight from about 3 oz/yd.sup.2 to about 12 oz/yd.sup.2.

27. The article of claim 25, wherein the fabric has an arc rating of greater than 8.

28. A method comprising: (a) providing at least one fiber comprising an oxidized polymer selected from the group consisting of acrylonitrile based homopolymers, acrylonitrile based copolymers, acrylonitrile based terpolymers, and combinations thereof; (b) providing at least two companion fibers selected from FR polyester, FR nylon, FR rayon, FR treated cellulose, m-aramid, p-aramid, modacrylic, wool, nylon, regenerated cellulose, antistatic fiber, and combinations thereof; and (c) combining said fiber comprising oxidized polymeric fiber and said at least one companion fiber to form a blended yarn; wherein said fiber comprising the oxidized polymer is present in an amount from about 10% to about 85% by weight of the yarn; (d) providing a companion yarn different from said blended yarn; wherein said companion yarn consists essentially of staple fibers comprising: (i) p-aramid, wherein the p-aramid is present in an amount less than 20% of the fabric weight; and (ii) at least one fiber selected from FR polyester, FR nylon, FR rayon, FR treated cellulose, m-aramid, modacrylic, wool, nylon, regenerated cellulose, antistatic fiber, and a combination thereof; (e) combining the blended yarn with the companion yarn to form a fabric; and wherein a ratio of arc rating to weight is greater than 1.

29. The method of claim 28, wherein said yarn is prepared by using worsted carding.

30. The method of claim 28, wherein said yarn is prepared by using converted tow.

31. The method of claim 28, wherein said fiber comprising an oxidized polymer is selected from the group consisting of staple fiber, mid-fiber, worsted fiber, and continuous filament.

Description

EXAMPLES

(1) Test Methods: Test methods and minimum requirements for thermal protection include: a. ASTM D6413: Test method for Flame Resistance of Textiles (Vertical Test) b. NFPA 2112: (National Fire Protection Association) Standard on Flame-Resistant Garments for Protection of Industrial Personnel Against Flash Fire. Section 8.2 (Thermal Protective Performance Test) c. NFPA 1977: (National Fire Protection Association) Standard on Protective Clothing and Equipment for Wildland Fire Fighting. d. NAFPA 1951: (National Fire Protection Association) Standard on Protective Ensembles for Technical Rescue Incidents. e. ASTM F1930: Test Method for Evaluation of Flame Resistant Clothing for Protection Against Flash Fire Simulations Using an Instrumented Manikin f. ASTM F1959: Standard Test Method for Determining the Arc Rating of Materials for Clothing

(2) The following tables include fabric samples (TABLE 1) and the results (TABLES 2-4) according to each testing method. The fabrics were prepared as a twill using only the blended yarn including the fibers indicated in TABLE 1. The minimal requirements for each test method are included for comparison. Each of the inventive fabrics (1), (2), (3), and (4), respectively, met the minimum criteria required for its intended end use application.

(3) TABLE-US-00001 TABLE 1 FABRICS 1 2 3 4 Fabric weight, 5.5 6.2 6.8 8.5 oz/yd Fabric 35% FR rayon 35% FR rayon 54% oxidized 44% oxidized composition by 22% oxidized 24% oxidized biregional PAN biregional weight biregional PAN biregional PAN 20% FR rayon PAN 22% modacrylic 20% modacrylic 16% m-aramid 18% p-aramid 6% polyamide 6% polyamide 9% polyamide 16% FR rayon 15% p-aramid 15% p-aramid 1% antistat 12% PVC 10% polyamide

(4) TABLE-US-00002 TABLE 2 TEST RESULTS NFPA 70E (Electrical Workers) Minimum Requirements Fabric 1 Fabric 2 Fabric 3 ATPV >8 8.9 10.7 10.8 HRC Class Arc Rating HRC-2 HRC-2 HRC-2

(5) TABLE-US-00003 TABLE 3 TEST RESULTS NFPA 2112 (Chemical Workers) Minimum Requirements Fabric 1 Fabric 2 Fabric 3 Vertical Flammability <2 sec AF 0 0 0 0 0 0 Afterflame, W F.sup.1 Vertical Flammability Char <4 char length 0.8 1.2 2.7 3.3 2.8 1.8 Length, W F.sup.1 TST Shrinkage (500 F./5 min.) <10% 5.8 6.7 4.4 7.7 9.9 5.2 as received), W F.sup.1 TST Shrinkage (500 F./5 min.) <10% 7.2 7.6 5.6 6.7 8.2 6.1 after 3 launderings, W F.sup.1 TPP (Thermal Protective 3 cal/cm.sup.2/6 cal/cm.sup.2 8.7/12.1 9.5/12.2 9.2 12.8 Performance) as received Contact.sup.2/Spaced.sup.3 TPP (Thermal Protective 3 cal/cm.sup.2/6 cal/cm.sup.2 8.7/11.8 10.3/13.2 10.3/ Performance) after 3 13.9 launderings Contact.sup.2/Spaced.sup.3 % Manikin Body Burn <50% 27.0 21.6 24.0 .sup.1Warp Fill .sup.2Fabric in contact with thermal sensor .sup.3Fabric spaced inch from thermal spacer

(6) TABLE-US-00004 TABLE 4 TEST RESULTS NFPA 1977 (Wildland Fire Fighters) Minimum Requirements Fabric 4 Vertical Flammability <2 sec AF (after 100X washes @105 F.) 0 Afterflame, W F.sup.1 Vertical Flammability Char <4 char length (after 100X washes 0.45 Length, W F.sup.1 105 F.) TST Shrinkage (500 F./5 min.) <10% (0X washes) 3.9 4.8 Radiant Protective Performance >7 (after 5X washes @ 105 F.) 9.7 Heat Loss >450 W/m.sup.2 697 Trap Tear Strength >22N 182 Laundry Shrinkage, W F.sup.1 <5% (after 5X washes @ 105 F.) 3.0 1.4 .sup.1Warp Fill

(7) TABLE-US-00005 TABLE 5 TEST RESULTS NFPA 1951 (Technical Rescue) Minimum Requirements Fabric 4 Vertical Flammability <2 sec AF (before and 10X washes@140 F.) 0 Afterflame, W F.sup.1 Vertical Flammability Char <4 char length (before and after 0.45 Length, W F.sup.1 10Xwashes @140 F.) TST Shrinkage (500 F./5 min.), <10% (before and after 10X washes @ 3.9 4.8 W F.sup.1 140 F.) TPP (Thermal Protective >10 (after 10X washes @ 140 F.) 18.7 Performance) Spaced.sup.2 Heat Loss >650 W/m.sup.2 697 Grab Tensile >400N (after 10X washes @140 F.) 622 Trap Tear Strength >30N (after 10X washes @140 F.) 182 Strength After Stoll Abrasion >250N (after 500 abrasion cycles) 378 Laundry Shrinkage, W F.sup.1 <5% (after 5X washes @140 F.) 3.0 1.4 .sup.1Warp Fill .sup.2Fabric in contact with thermal sensor

(8) While there have been described what are presently believed to be the preferred embodiments of the invention, those skilled in the art will realize that changes and modifications may be made thereto without departing from the spirit of the invention, and it is intended to include all such changes and modifications as fall within the true scope of the invention.