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JP-2026514473-A - Improved flame-retardant nonwoven fabrics and composites and clothing made using them

JP2026514473AJP 2026514473 AJP2026514473 AJP 2026514473AJP-2026514473-A

Abstract

Embodiments of the present invention replace at least a portion of the flame-retardant fibers (e.g., aramid) conventionally used in the filling of thermal liners with heat-stable polyamide fibers (e.g., nylon fibers). The TPP performance of garments incorporating the embodiments of thermal liners intended herein is comparable to, if not improved to, garments formed using conventional thermal liners.

Inventors

  • セルフ、 ロバート
  • スミス、 ウィリー クリアランス

Assignees

  • サザンミルズ インコーポレイテッド

Dates

Publication Date
20260511
Application Date
20240418
Priority Date
20230418

Claims (20)

  1. A flame-retardant thermal liner comprising a flame-retardant face cloth and at least one nonwoven layer attached to the face cloth, wherein the at least one nonwoven layer comprises heat-stable nylon fibers.
  2. The flame-retardant thermal liner according to claim 1, wherein the at least one nonwoven layer comprises two nonwoven layers, each containing heat-stable nylon fibers.
  3. The flame-retardant thermal liner according to claim 1, wherein the at least one nonwoven layer comprises a first nonwoven layer and a second nonwoven layer, the first nonwoven layer comprises the heat-stable nylon fibers, and the second nonwoven layer does not contain the heat-stable nylon fibers.
  4. The flame-retardant thermal liner according to claim 1, wherein the at least one nonwoven layer comprises at least 20% by weight of thermally stable nylon fibers.
  5. The flame-retardant thermal liner according to claim 4, wherein the at least one nonwoven layer further comprises flame-retardant fibers.
  6. The flame-retardant thermal liner according to claim 5, wherein at least one nonwoven layer contains 30 to 80% by weight of flame-retardant fibers.
  7. The flame-retardant thermal liner according to claim 6, wherein the flame-retardant fiber comprises at least one of aramid fiber, modacrylic fiber, or flame-retardant cellulose fiber.
  8. The flame-retardant thermal liner according to claim 5, wherein the flame-retardant fibers include para-aramid fibers, and the at least one nonwoven layer includes at least 20% by weight of para-aramid fibers.
  9. The flame-retardant thermal liner according to claim 5, wherein at least one nonwoven layer does not contain meta-aramid fibers.
  10. The flame-retardant thermal liner according to claim 1, wherein the at least one nonwoven layer comprises spunlace fabric.
  11. The flame-retardant thermal liner according to claim 1, wherein the at least one nonwoven layer comprises 40 to 70% by weight of thermally stable nylon fibers and 30 to 60% by weight of flame-retardant fibers.
  12. The flame-retardant thermal liner according to claim 11, wherein the flame-retardant fiber includes para-aramid fiber.
  13. The flame-retardant thermal liner according to claim 11, wherein the at least one nonwoven layer comprises 50 to 70% by weight of thermally stable nylon fibers and 30 to 50% by weight of flame-retardant fibers.
  14. It is a clothing composite, a. Outer shell layer containing flame-retardant fabric; b. A moisture barrier layer; and c. A thermal liner layer comprising a flame-retardant face cloth and at least one nonwoven layer attached to the face cloth, wherein the at least one nonwoven layer comprises heat-stable nylon fibers. The flame-retardant face cloth is exposed on the first surface of the garment composite, and the outer shell layer is exposed on the second surface of the garment composite opposite to the first surface. Clothing composite.
  15. The garment composite according to claim 14, having a thermal protection performance rating of at least 35 calories/ cm² when tested in accordance with ISO 17492.
  16. The garment composite according to claim 15, wherein the thermal protection performance rating, when tested in accordance with ISO 17492, is at least 40 calories/ cm² .
  17. The garment composite according to claim 14, wherein the garment composite has a thermal protection performance rating when tested according to ISO 17492, and the ratio of the thermal protection performance rating to the weight of the garment is between 2.0 and 3.0 (including the values at both ends).
  18. The garment composite according to claim 14, wherein the at least one nonwoven layer further comprises flame-retardant fibers, and the garment composite has a thermal protection performance rating when tested according to ISO 17492, wherein the ratio of the thermal protection performance rating of the garment composite to the weight of the garment composite is greater than the ratio of the thermal protection performance rating to the weight of a comparative garment composite having at least one nonwoven layer formed of 100% flame-retardant fibers, but otherwise compositionally identical to the garment composite.
  19. The garment composite according to claim 18, wherein the ratio of the thermal protection performance evaluation to the weight of the garment composite is at least 5% greater than the ratio of the thermal protection performance evaluation to the weight of the comparative garment composite.
  20. A nonwoven fabric formed from a fiber blend containing flame-retardant fibers and heat-stable nylon fibers.

Description

Cross-reference to related applications This application claims the benefit of U.S. Provisional Application No. 63/460,177, filed on 18 April 2023, entitled “Improved Flame Resistant Thermal Liners and Garments Made with Same,” which in its entirety is incorporated herein by reference. Field: Embodiments of the present invention relate to improved nonwoven fabrics, and protective composites and garments incorporating such nonwoven fabrics. Background Protective clothing is designed to protect the wearer from hazardous environmental conditions they may encounter. Such clothing includes that designed for firefighters and other rescue workers, industrial workers, electrical workers, and military personnel. Firefighters, emergency responders, search and rescue workers, and military service personnel may be exposed to extreme heat and/or flames during their work. Protective clothing is designed and manufactured as a way to combat injury. These protective garments, commonly called turnout gear (including coveralls, trousers, and jackets), can be manufactured from special flame-retardant materials designed to protect workers from both heat and flames. To ensure that clothing adequately protects the wearer in dangerous situations, standards have been published specifying the performance of such clothing (or its constituent layers or parts). The National Fire Protection Association (NFPA) 1971 (Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting, 2018 edition, incorporated herein by reference) specifies the required performance of firefighters' clothing. Structural firefighter clothing, such as firefighter turnout gear, typically consists of a matching coat and pants and is primarily designed to prevent the wearer from suffering severe burns. Turnout gear or clothing 10 conforming to NFPA 1971 typically includes three layers (as shown in Figures 1 and 2): an outer shell 12, an intermediate moisture barrier 14, and a thermal liner 20. The outer shell 12 is usually a woven fabric made from flame-resistant fibers and is considered the first line of protection for the firefighter. It needs to be not only flame-resistant but also strong and durable so as not to tear, abrade, or snag during normal firefighting operations. The moisture barrier 14 is also flame-retardant and exists to prevent water, harmful chemicals, bacteria, and bodily fluids from penetrating the turnout gear and affecting the wearer. The moisture barrier 14 may consist of a flame-retardant nonwoven or woven fabric 16 laminated to a water-impermeable layer 18 of a material such as expanded polytetrafluoroethylene ("ePTFE"), polyurethane, or a combination thereof. The thermal liner 20 is flame-retardant and provides most of the thermal protection that a single garment can offer. Conventional thermal liners consist of a batting 22 of flame-retardant insulating material quilted onto a lightweight facecloth 24, the facecloth 24 also made of flame-retardant fibers. The facecloth 24 is typically quilted onto the batting 22 in a crossover or chicken wire pattern. The thermal liner 20 is the innermost layer of a firefighter's garment, with the facecloth 24 typically facing the wearer. The thermal liner filling 22 may be a single layer of nonwoven fabric, but more typically, it is formed of multiple nonwoven layers. For example, the nonwoven fabric used in many thermal liners is 1.5 ounces/square yard ("osy") and/or 2.3 osy spunlace fabric. These spunlace fabrics are typically formed using expensive, inherently flame-resistant fibers such as para-aramid and/or meta-aramid fibers, with a high percentage (often 100%). NFPA 1971 requires garments and/or individual layers or sections thereof to pass a variety of performance tests, including having a char length of 4 inches or less and an after-flame of 2 seconds (or less) when measured according to the test method described in ASTM D6413 (Standard Test Method for Flame Resistance of Textiles, 2015 edition, incorporated herein by reference). To test the char length and after-flame time, a cloth sample is suspended vertically over a flame for 12 seconds. The cloth must self-extinguish within 2 seconds (i.e., the after-flame time must be 2 seconds or less). After the cloth has self-extinguished, a specific amount of weight is attached to the cloth, and the cloth is lifted so that the weight is suspended from the cloth. The fabric typically tears along the carbonized portion. The length of the tear (i.e., the carbonization length) should be no more than 4 inches when tested in both the machine/warp and cross-machine/weft directions. Fabric samples are typically tested for suitability both before washing (i.e., when the fabric contains chemicals, often flammable, that remain in the fabric from the finishing process) and after a certain number of washes (five washes in NFPA 1971). NFPA 1971 also includes requirements regarding the degree to which a fabric shrinks when exposed to heat,