Thermally Stable Flame Resistant Fabrics Produced from Thermally Stable Yarn in Only One Fabric Direction and Garments Made from Same

Abstract

Flame resistant fabrics that comply with applicable thermal requirements (e.g., char length, after flame, thermal shrinkage, etc.) but only include thermally stable fibers in yarns extending in a single fabric direction (warp or weft). The yarns extending in the other direction (warp or weft) are devoid of thermally stable fibers.

We claim: 
     
         1 . A flame resistant fabric having a first side and a second side opposite the first side, wherein the fabric is formed of a plurality of yarns oriented in a first fabric direction and in a second fabric direction opposite the first fabric direction, wherein the plurality of yarns comprises first yarns and second yarns and wherein:
 i. the first yarns comprise a first fiber blend comprising thermally stable fibers, cellulosic fibers, and modacrylic fibers, wherein the thermally stable fibers constitute less than 25 wt. % of the first fiber blend;   ii. the modacrylic fibers and the cellulosic fibers of the first fiber blend collectively constitute at least 60 wt. % of the first fiber blend;   iii. the first fiber blend comprises more modacrylic fibers than thermally stable fibers;   iv. the first fiber blend comprises more cellulosic fibers than thermally stable fibers;   v. the second yarns comprise a second fiber blend that is different from the first fiber blend and that comprises modacrylic fibers and cellulosic fibers, wherein the second fiber blend is devoid of thermally stable fibers;   vi. the first yarns are provided only in the first fabric direction and not in the second fabric direction;   vii. the second yarns are provided in the second fabric direction;   viii. the fabric has a fabric weight between 8 to 12 ounces per square yard, inclusive;   ix. the fabric has a char length of 6 inches or less and an after flame of 2 seconds or less when tested pursuant to ASTM D6413 (2022); and   x. the fabric exhibits thermal shrinkage of no more than 10% in each of the first fabric direction and the second fabric direction in accordance with NFPA 2112 (2023).   
     
     
         2 . The fabric of  claim 1 , wherein the modacrylic fibers and the cellulosic fibers of the first fiber blend collectively constitute at least 70 wt. % of the first fiber blend. 
     
     
         3 . The fabric of  claim 2 , wherein the modacrylic fibers and the cellulosic fibers of the first fiber blend collectively constitute at least 80 wt. % of the first fiber blend. 
     
     
         4 . The fabric of  claim 1 , wherein the thermally stable fibers comprise aramid fibers. 
     
     
         5 . The fabric of  claim 1 , wherein the thermally stable fibers constitute less than 20 wt. % of the first fiber blend. 
     
     
         6 . The fabric of  claim 1 , wherein the modacrylic fibers and the cellulosic fibers of the second fiber blend collectively constitute at least 60 wt. % of the second fiber blend. 
     
     
         7 . The fabric of  claim 6 , wherein the modacrylic fibers and the cellulosic fibers of the second fiber blend constitute at least 70 wt. % of the second fiber blend. 
     
     
         8 . The fabric of  claim 7 , wherein the modacrylic fibers and the cellulosic fibers of the second fiber blend constitute at least 80 wt. % of the second fiber blend. 
     
     
         9 . The fabric of  claim 8 , wherein the modacrylic fibers and the cellulosic fibers of the second fiber blend constitute at least 90 wt. % of the second fiber blend. 
     
     
         10 . The fabric of  claim 1 , wherein the second fiber blend consists of the modacrylic fibers and the cellulosic fibers. 
     
     
         11 . The fabric of  claim 1 , wherein the first fiber blend comprises about 8-20 wt. % thermally stable fibers, about 40-55 wt. % modacrylic fibers, and about 30-45 wt. % cellulosic fibers. 
     
     
         12 . The fabric of  claim 11 , wherein the thermally stable fibers comprise aramid fibers. 
     
     
         13 . The fabric of  claim 1 , wherein the second fiber blend comprises about 40-60 wt. % modacrylic fibers and about 40-60 wt. % cellulosic fibers. 
     
     
         14 . The fabric of  claim 1 , wherein the fabric has an overall fabric fiber blend and wherien the thermally stable fibers comprise less than about 10% of the overall fabric fiber blend. 
     
     
         15 . The fabric of  claim 1 , wherein the first yarns are predominantly exposed on the first side of the fabric and the second yarns are predominantly exposed on the second side of the fabric. 
     
     
         16 . The fabric of  claim 1 , wherein at least some of the cellulosic fibers in the first fiber blend are non-flame resistant. 
     
     
         17 . The fabric of  claim 1 , wherein at least some of the cellulosic fibers in the second fiber blend are non-flame resistant. 
     
     
         18 . A garment formed with the fabric of  claim 1  and having a face side and a body side. 
     
     
         19 . The garment of  claim 18 , wherein the first yarns of the fabric are predominantly exposed on the first side of the fabric, the second yarns of the fabric are predominantly exposed on the second side of the fabric, the first side of the fabric is exposed on the body side of the garment, and the second side of the fabric is exposed on the face side of the garment. 
     
     
         20 . A flame resistant fabric having a first side and a second side opposite the first side, wherein the fabric is formed of a plurality of yarns oriented in a first fabric direction and in a second fabric direction opposite the first fabric direction, wherein the plurality of yarns comprises first yarns and second yarns and wherein:
 i. the first yarns comprise a first fiber blend comprising about 8-20 wt. % thermally stable fibers, about 40-55 wt. % modacrylic fibers, and about 30-45 wt. % cellulosic fibers, wherein the thermally stable fibers comprise aramid fibers;   ii. the modacrylic fibers and the cellulosic fibers of the first fiber blend collectively constitute at least 70 wt. % of the first fiber blend;   iii. the first fiber blend comprises more modacrylic fibers than cellulosic fibers;   iv. the second yarns comprise a second fiber blend that is different from the first fiber blend and that comprises about 40-60 wt. % modacrylic fibers and about 40-60 wt. % cellulosic fibers, wherein the second fiber blend is devoid of thermally stable fibers;   v. the first yarns are provided only in the first fabric direction and not in the second fabric direction;   vi. the second yarns are provided in the second fabric direction;   vii. the fabric has a fabric weight between 8 to 12 ounces per square yard, inclusive;   viii. the fabric has a char length of 6 inches or less and an after flame of 2 seconds or less when tested pursuant to ASTM D6413 (2022); and   ix. the fabric exhibits thermal shrinkage of no more than 10% in each of the first fabric direction and the second fabric direction in accordance with NFPA 2112 (2023).