US 12,215,442 B2
Flame resistant fabric comprising a PTW fiber blend
Paul Amaral, Watertown, CT (US); and David Ronner, Berkeley Heights, NJ (US)
Assigned to PTW HOLDINGS, LLC, El Paso, TX (US)
Filed by PTW HOLDINGS, LLC, El Paso, TX (US)
Filed on Mar. 30, 2022, as Appl. No. 17/708,592.
Prior Publication US 2023/0313422 A1, Oct. 5, 2023
Int. Cl. D02G 3/04 (2006.01); D02G 3/44 (2006.01)
CPC D02G 3/047 (2013.01) [D02G 3/441 (2013.01); D02G 3/443 (2013.01); D10B 2331/021 (2013.01)] 9 Claims
 
1. A yarn comprising a blend of:
50 wt. % of a flame resistant fiber having a limit of oxygen index of 43%, a thermal conductivity of 0.0063 watt/meter/K and a moisture regain of 12%;
30 wt. % of a para-aramid fiber; and
20 wt. % of wool,
wherein the yarn is free of thermoplastics and is sufficiently flame resistant such that a fabric consisting of the yarn is effective to limit a body burn percentage resulting from 4 seconds of flame exposure to less than 13% as measured by ASTM F1930.