Flame Resistant Fabrics Formed with Stretchable Yarns

Abstract

Flame resistant fabrics formed with a combination of body yarns and stretch yarns that exhibit excellent physical and thermal properties. The body yarns are formed at least in part with flame resistant materials. The stretch yarns are corespun yarns having an elastic core surrounded by a fiber sheath formed at least in part with flame resistant materials. The fiber sheath protects the elastic core from direct exposure to heat and flame that would otherwise cause the core to degrade or melt.

We claim: 
     
         1 . A flame resistant fabric having a warp direction and a fill direction, the fabric comprising:
 (a) a plurality of 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 modacrylic fibers, cellulosic fibers, and aramid fibers; and   (b) a plurality of stretch yarns extending between at least some of the body yarns in at least one of the warp direction or the fill direction of the fabric, wherein each stretch yarn comprises an elastic core surround by a sheath, wherein the sheath comprises a sheath fiber blend comprising modacrylic fibers, cellulosic fibers, and aramid fibers, wherein:
 i. the fabric has a char length of 6 inches or less and an afterflame of 2 seconds or less when tested pursuant to ASTM D6413 (2015); 
 ii. the fabric has an arc rating of at least 8 cal/cm 2  when tested pursuant to ASTM F1959 (2014); 
 iii. the fabric exhibits thermal shrinkage of no more than 10% in both the warp and fill directions when tested pursuant to ASTM F 2894 (2021); and 
 iv. the fabric comprises a percent stretch and a percent recovery in the at least one of the warp direction or the fill direction in which the plurality of stretch yarns extend, wherein the percent stretch is at least 10% and the percent recovery is at least 90% after 100 industrial launderings, whereby in each industrial laundering the fabric is subjected to a standard 140° Fahrenheit industrial wash for 30 minutes and the fabric is dried for 30 minutes in an industrial dryer with a stack temperature not exceeding 155° Fahrenheit.