Flame resistant fabrics

Abstract

Embodiments of the present invention relate to flame resistant fabrics formed with inherently flame resistant fibers that provide the requisite thermal and arc protection, that have improved comfort, and that, in some embodiments, are less expensive than other fabrics formed with inherently flame resistant fibers. Improved comfort and lower cost can be achieved by predominantly locating the inherently flame resistant fibers on the front face of the fabric to impart the requisite thermal and arc protection and predominantly locating the more comfortable (and less expensive) fibers on the back face of the fabric positioned next to the wearer. In this way, overall protection of the fabric is maintained while improving comfort. Some embodiments of such fabrics may also achieve NFPA 70E PPE Category 2 protection.

We claim: 
     
         1 . A fabric formed by first yarns and a second yarns, wherein the fabric has a first side and a second side opposite the first side and wherein:
 i. the first yarns comprise a first fiber blend comprising aramid fibers, modacrylic fibers, and cellulosic fibers;   ii. the aramid fibers and the modacrylic fibers of the first fiber blend constitute at least 50% of the first fiber blend;   iii. the first fiber blend comprises more modacrylic fibers than aramid fibers;   iv. the second yarns comprises a second fiber blend that is different from the first fiber blend and that comprises aramid fibers, modacrylic fibers, and cellulosic fibers;   v. the second fiber blend comprises at least 60% cellulosic fibers;   vi. the second fiber blend comprises more modacrylic fibers than aramid fibers;   vii. the first yarns are predominantly exposed on the first side of the fabric;   viii. the second yarns are predominantly exposed on the second side of the fabric;   ix. the fabric has a char length of at least 6 inches and an afterflame of 2 seconds or less when tested pursuant to AS™ D6413 (2015);   x. the fabric has a fabric weight between 5 to 7 ounces per square yard, inclusive; and   xi. the fabric has an arc rating of at least 8 cal/cm 2  when tested pursuant to ASTM F1959 (2014).   
     
     
         2 . The fabric of  claim 1 , wherein the aramid fibers and the modacrylic fibers of the first fiber blend constitute at least 60% of the first fiber blend. 
     
     
         3 . The fabric of  claim 1 , wherein the first fiber blend comprises up to 2 times more modacrylic fibers than aramid fibers. 
     
     
         4 . The fabric of  claim 3 , wherein the first fiber blend comprises up to 3 times more modacrylic fibers than aramid fibers. 
     
     
         5 . The fabric of  claim 1 , wherein the first fiber blend comprises approximately 5-25% aramid fibers, 50-80% modacrylic fibers, and 15-40% cellulosic fibers. 
     
     
         6 . The fabric of  claim 1 , wherein the cellulosic fibers in the first fiber blend are non-FR lyocell fibers. 
     
     
         7 . The fabric of  claim 1 , wherein the modacrylic fibers in the first fiber blend are additive-containing fibers. 
     
     
         8 . The fabric of  claim 1 , wherein the aramid fibers in the first fiber blend comprise meta-aramid fibers and para-aramid fibers. 
     
     
         9 . The fabric of  claim 1 , wherein the second fiber blend comprises at least 70% cellulosic fibers. 
     
     
         10 . The fabric of  claim 1 , wherein the modacrylic fibers and aramid fibers of the second fiber blend constitute 40% or less of the second fiber blend. 
     
     
         11 . The fabric of  claim 1 , wherein the fabric is a woven fabric comprising a first fabric direction and a second fabric direction opposite the first fabric direction, wherein the first yarns are provided only in the first fabric direction and the second yarns are provided only in the second fabric direction. 
     
     
         12 . A garment formed with the fabric of  claim 1  and having a face side and a body side, wherein the first side of the fabric is exposed on the face side of the garment and the second side of the fabric is exposed on the body side of the garment. 
     
     
         13 . A fabric formed by first yarns and a second yarns, wherein the fabric has a first side and a second side opposite the first side and wherein:
 i. the first yarns comprise a first fiber blend comprising aramid fibers, modacrylic fibers, and cellulosic fibers;   ii. the aramid fibers and the modacrylic fibers of the first fiber blend constitute at least 70% of the first fiber blend;   iii. the first fiber blend comprises more modacrylic fibers than aramid fibers;   iv. the second yarns comprises a second fiber blend that is different from the first fiber blend and that comprises aramid fibers and non-FR cellulosic fibers;   v. the second fiber blend is devoid of modacrylic fibers;   vi. the second fiber blend comprises at least 50% non-FR cellulosic fibers;   vii. the first yarns are predominantly exposed on the first side of the fabric;   viii. the second yarns are predominantly exposed on the second side of the fabric;   ix. the fabric has a char length of at least 6 inches and an afterflame of 2 seconds or less when tested pursuant to AS™ D6413 (2015);   x. the fabric has a fabric weight between 5 to 7 ounces per square yard, inclusive; and   xi. the fabric has an arc rating of at least 8 cal/cm 2  when tested pursuant to ASTM F1959 (2014).   
     
     
         14 . The fabric of  claim 13 , wherein the aramid fibers and the modacrylic fibers of the first fiber blend constitute at least 80% of the first fiber blend. 
     
     
         15 . The fabric of  claim 13 , wherein the first fiber blend comprises up to 3 times more modacrylic fibers than aramid fibers. 
     
     
         16 . The fabric of  claim 13 , wherein the first fiber blend comprises approximately 5-30% aramid fibers, 50-80% modacrylic fibers, and 10-40% cellulosic fibers. 
     
     
         17 . The fabric of  claim 13 , wherein the second fiber blend comprises at least 60% non-FR cellulosic fibers. 
     
     
         18 . The fabric of  claim 13 , wherein the aramid fibers of the second fiber blend constitute 40% or less of the second fiber blend. 
     
     
         19 . The fabric of  claim 13 , wherein the fabric is a woven fabric comprising a first fabric direction and a second fabric direction opposite the first fabric direction, wherein the first yarns are provided only in the first fabric direction and the second yarns are provided only in the second fabric direction. 
     
     
         20 . A garment formed with the fabric of  claim 13  and having a face side and a body side, wherein the first side of the fabric is exposed on the face side of the garment and the second side of the fabric is exposed on the body side of the garment.