Flame resistant fabrics with increased strength

Abstract

Embodiments are directed to flame resistant fabrics formed of a plurality of spun body yarns and rip stops that extend between at least some of the spun body yarns in at least one of the warp or fill direction of the fabric. In some embodiments, the rip stops include at least two relatively tough yarns, and the relatively tough yarns include a core and a sheath.

We claim: 
     
         1 . A flame resistant fabric having a warp direction and a fill direction, the fabric comprising:
 (a) a plurality of spun body yarns each formed of a body yarn fiber blend and provided in both the warp direction and the fill direction of the fabric; and   (b) a plurality of rip stops extending between at least some of the spun body yarns in at least one of the warp direction or the fill direction of the fabric, wherein each rip stop comprises at least two relatively tough yarns and wherein each relatively tough yarn comprises a core and a sheath, wherein the core comprises an 100% aramid spun yarn and the sheath comprises a sheath fiber blend.   
     
     
         2 . The flame resistant fabric of  claim 1 , wherein the core comprises an 100% para-aramid spun yarn. 
     
     
         3 . The flame resistant fabric of  claim 1 , wherein the sheath fiber blend comprises FR rayon fibers, aramid fibers, and nylon fibers. 
     
     
         4 . The flame resistant fabric of  claim 3 , wherein the sheath fiber blend comprises 50-80% FR rayon fibers, 15-40% aramid fibers, and 5-20% nylon fibers. 
     
     
         5 . The flame resistant fabric of  claim 3 , wherein the aramid fibers are para-aramid fibers. 
     
     
         6 . The flame resistant fabric of  claim 1 , wherein the body yarn fiber blend and the sheath fiber blend are identical. 
     
     
         7 . The flame resistant fabric of  claim 1 , wherein the body yarn fiber blend and the sheath fiber blend each comprises 50-80% FR rayon fibers, 15-40% aramid fibers, and 5-20% nylon fibers. 
     
     
         8 . The flame resistant fabric of  claim 7 , wherein the body yarn fiber blend and the sheath fiber blend are identical. 
     
     
         9 . The flame resistant fabric of  claim 1 , wherein five to twenty-five spun body yarns are interposed between adjacent rip stops in the at least one of the warp direction or the fill direction. 
     
     
         10 . The flame resistant fabric of  claim 9 , wherein ten to twenty body yarns are interposed between adjacent rip stops in the at least one of the warp direction or the fill direction. 
     
     
         11 . The flame resistant fabric of  claim 1 , wherein the plurality of rip stops extend between at least some of the spun body yarns in both the warp direction and the fill direction of the fabric. 
     
     
         12 . The flame resistant fabric of  claim 1 , wherein the fabric comprises a weight between 5-7 ounces per square yard, inclusive. 
     
     
         13 . The flame resistant fabric of  claim 1 , wherein the flame resistant fabric is devoid of filament yarns. 
     
     
         14 . A flame resistant fabric having a warp direction and a fill direction, the fabric comprising:
 (a) a plurality of spun body yarns each formed of a body yarn fiber blend and provided in both the warp direction and the fill direction of the fabric, wherein the body yarn fiber blend comprises 50-80% FR rayon fibers, 15-40% aramid fibers, and 5-20% nylon fibers; and   (b) a plurality of rip stops extending between at least some of the spun body yarns in at least one of the warp direction or the fill direction of the fabric, wherein each rip stop comprises at least two relatively tough yarns and wherein each relatively tough yarn comprises a core and a sheath, wherein the core comprises an 100% aramid spun yarn and the sheath comprises a sheath fiber blend comprising 50-80% FR rayon fibers, 15-40% aramid fibers, and 5-20% nylon fibers,   wherein five to twenty-five body yarns are interposed between adjacent rip stops in the at least one of the warp direction or the fill direction.   
     
     
         15 . The flame resistant fabric of  claim 14 , wherein the core comprises an 100% para-aramid spun yarn. 
     
     
         16 . The flame resistant fabric of  claim 14 , wherein the 15-40% aramid fibers in the body yarn fiber blend and the sheath fiber blend comprise 15-40% para-aramid fibers. 
     
     
         17 . The flame resistant fabric of  claim 14 , wherein the body yarn fiber blend and the sheath fiber blend are identical. 
     
     
         18 . The flame resistant fabric of  claim 14 , wherein the plurality of rip stops extend between at least some of the spun body yarns in both the warp direction and the fill direction of the fabric. 
     
     
         19 . The flame resistant fabric of  claim 14 , wherein the fabric comprises a weight between 5-7 ounces per square yard, inclusive. 
     
     
         20 . A flame resistant fabric having a warp direction and a fill direction, the fabric comprising:
 (a) a plurality of spun body yarns each formed of a body yarn fiber blend and provided in both the warp direction and the fill direction of the fabric, wherein the body yarn fiber blend comprises 50-80% FR rayon fibers, 15-40% para-aramid fibers, and 5-20% nylon fibers; and   (b) a plurality of rip stops extending between at least some of the spun body yarns in both the warp direction and the fill direction of the fabric, wherein at least some of the plurality of rip stops consist of two relatively tough yarns and wherein each relatively tough yarn comprises a core and a sheath, wherein the core comprises an 100% para-aramid spun yarn and the sheath comprises a sheath fiber blend comprising 50-80% FR rayon fibers, 15-40% para-aramid fibers, and 5-20% nylon fibers,   wherein:
 the body yarn fiber blend and the sheath fiber blend are substantially identical; 
 ten to twenty body yarns are interposed between adjacent rip stops in the warp direction and the fill direction of the fabric; and 
 the fabric comprises a weight between 5-7 ounces per square yard, inclusive.