US-12616260-B2 - Flame resistant material for a protective garment

US12616260B2US 12616260 B2US12616260 B2US 12616260B2US-12616260-B2

Abstract

Oxidized polyacrylonitrile fiber (OPF) containing fabrics when used in the fire service, either in a NFPA 1971 or NFPA 1951 compliant protective garments, offer exceptional comfort and protection characteristics that ensure firefighters can safely perform their duties in structural fire, overhaul, urban search and rescue, and other various missions. OPF containing fabrics used in turnout gear outer shells and compliant with NFPA 1971, provide the best combination of protection as tested by the thermal protective performance test and comfort as tested by the total heat loss/resistance to evaporative heat transfer test.

Inventors

Matthew L. Colatruglio

Assignees

FIRE-DEX, LLC

Dates

Publication Date: 20260505
Application Date: 20220927

Claims (17)

1 . A material comprising: about 80 number % to about 90 number % of stretch-broken oxidized polyacrylonitrile fibers blended with flame resistant fibers; and about 10 number % to about 20 number % of stretch-broken aramid fibers.
2 . A protective garment, comprising: an outer shell; and a thermal liner disposed adjacent the outer shell, wherein at least a portion of the protective garment is formed from the material of claim 1 , wherein the protective garment has a Resistance to Evaporative Heat Transfer (Ret) of no more than 20 m 2 Pa/W, a Total Heat Loss (THL) in a range of about 205 to about 425 W/m 2 , and a Thermal Protective Performance (TPP) of greater than 35.
3 . The protective garment of claim 2 , wherein at least a portion of the outer shell is formed from the material comprising the at least one first fiber produced from an oxidized polyacrylonitrile.
4 . The protective garment of claim 2 , wherein at least a portion of the thermal liner is formed from the material comprising the at least one first fiber produced from an oxidized polyacrylonitrile.
5 . The protective garment of claim 2 , wherein the thermal liner includes at least one of a facecloth layer and an insulation layer, and wherein at least a portion of the at least one of the facecloth layer and the insulation layer is formed from the material comprising the at least one first fiber produced from an oxidized polyacrylonitrile.
6 . The protective garment of claim 2 , further comprising a moisture barrier disposed between the outer shell and the thermal liner.
7 . The protective garment of claim 6 , wherein at least a portion of the moisture barrier is formed from the material comprising the at least one first fiber produced from an oxidized polyacrylonitrile.
8 . The protective garment of claim 6 , wherein the moisture barrier comprises a substrate and a membrane disposed on the substrate.
9 . The protective garment of claim 8 , wherein at least a portion of the substrate of the moisture barrier is formed from the material comprising the at least one first fiber produced from an oxidized polyacrylonitrile.
10 . The protective garment of claim 8 , wherein the membrane is produced from at least one of a polytetrafluoroethylene (PTFE), an expanded polytetrafluoroethylene (ePTFE), a polyurethane (PU), and a urethane.
11 . A laminate, comprising: a first layer, wherein at least a portion of the first layer is formed from a material comprising about 80 number % to about 90 number % of stretch broken oxidized polyacrylonitrile fibers blended with flame resistant fibers and about 10 number % to about 20 number % of stretch broken aramid fibers; and a second layer disposed adjacent the first layer, wherein the laminate forms at least a portion of a particulate blocking material.
12 . The laminate of claim 11 , wherein the second layer is a particulate blocking film.
13 . The laminate of claim 11 , further comprising a third layer disposed adjacent the second layer.
14 . The laminate of claim 13 , wherein the third layer is at least one of a knit, a woven, and a stretch woven.
15 . The material of claim 1 , wherein the flame resistant fibers include meta-aramid fibers and para-aramid fibers.
16 . The material of claim 1 , wherein the stretch broken aramid fibers include stretch broken meta-aramid fibers and/or stretch broken para-aramid fibers.
17 . The material of claim 1 , further comprising a reinforcement grid and/or matrix including filament produced from para-aramid, liquid crystal polymer, and/or ultra-high molecular weight polyethylene.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/248,805, filed Sep. 27, 2021, the entirety of which is herein incorporated by reference. FIELD The invention relates generally to a flame resistant material, and more particularly, to a flame resistant material containing oxidized polyacrylonitrile fiber (OPF) to improve comfort and protection of protective garments. BACKGROUND Conventional protective garments are designed to shield a wearer from a variety of environmental hazards, and firefighting turnout gear is representative of such garments. The firefighting turnout gear includes coats, pants, coveralls, helmets, gloves, footwear, and interface components. Typically, the turnout gear comprises an outer shell, a moisture barrier located beneath the outer shell, and a thermal liner located beneath the moisture barrier. The outer shell typically is constructed of an abrasion-, flame- and heat-resistant material such as a woven aramid material, typically Nomex® or Kevlar® (all are trademarks of E. I. DuPont de Nemours & Co., Inc.) or a polybenzamidazole, a polybenzoxazole, or an oxidized polyacrylonitrile (OPAN) material. The moisture barrier typically includes a semipermeable membrane layer which is moisture vapor permeable but impermeable to liquid moisture, such as CrossTech® (a trademark of W. L. Gore & Associates, Inc.) or Stedair® 4000 (a trademark of Stedfast Inc.). The membrane layer is bonded to a substrate of flame- and heat-resistant material, such as an aramid or PBI® material. Further, the thermal liner typically is constructed of a nonwoven fabric, usually spunlace, quilted to a facecloth. One of the most dangerous threats to wearers of protective garments is heat exhaustion, which could possibly result in death. The primary mechanism of a human body to prevent heat exhaustion and normalize core body temperature is to sweat (i.e. emit liquid moisture). Once the sweat on the skin evaporates into moisture vapor, it is able to carry heat away from the body. During active firefighting, for example, the wearer produces immense amounts of liquid moisture and heat that must be transferred from the body in order to cool the wearer and prevent an overheated state. If the wearer experiences an overheated state and remains therein, the wearer may succumb to heat exhaustion, which is the number one killer of firefighters today. It is paramount that the protective garments provide adequate protection. Requirements for protective garments that are employed as firefighting turnout gear must meet a Thermal Protective Performance (TPP) of 35 as defined in the National Fire Protection Association (NFPA) 1971, a Total Heat Loss (THL) of greater than 205 W/m2, and a relatively low Resistance to Evaporative Heat Transfer (Ret). Typically, improving TPP in protective garments results in increased fabric weight at a detriment of comfort and THL. Thus, there exists a need for an improved flame resistant material for protective garments, especially firefighting turnout gear, as measured by the Thermal Protective Performance test. The material also needs to achieve a desired comfort level and a lower core body temperature by efficiently moving heat via conduction and evaporative heat transfer. Both dry and wet (perspiration) heat transfer are measured by Total Heat Loss (THL) and Resistance to Evaporative Heat Transfer (Ret). Accordingly, it would be desirable to develop a flame resistant material that improves comfort and protection of protective garments. SUMMARY In concordance and agreement with the presently described subject matter, a flame resistant material that improves comfort and protection of protective garments, has surprisingly been developed. In one embodiment, a material, comprises: a plurality of first fibers produced from an oxidized polyacrylonitrile, wherein at least one of the first fibers is a stretch broken fiber; and a plurality of second fibers combined with the first fibers, wherein the second fibers are produced from at least one of an oxidized polyacrylonitrile, a flame resistant fiber and a non-flame resistant fiber. As aspects of some embodiments, at least one of the second fibers is an aramid fiber. As aspects of some embodiments, the material further comprises a plurality of third fibers blended with the first fibers and the second fibers. As aspects of some embodiments, at least one of the second fibers is a meta-aramid and at least one of the third fibers is a para-aramid. As aspects of some embodiments, the material comprises about 18% of the first fibers, about 22% of the second fibers, and about 60% of the third fibers. As aspects of some embodiments, at least one of the second fiber is a stretch broken fiber. As aspects of some embodiments, the material comprises about 5% to about 30% of the first fibers. In another embodiments, a protective garment, comprises: an outer shell; and a thermal liner disposed ad