FIRE INSULATING BARRIER MATERIAL FOR A FIREFIGHTER PROTECTIVE GARMENT
This invention relates to a fire insulating barrier material for use as a thermal barrier in a firefighter's protective garment.
The materials that currently exist for the preparation of fire insulating barriers generally comprise a multitude of layers, which make these materials complicated to assemble together. Conventional firefighter's protective garments are generally made using at least three distinct layers. The first layer is the outer shell which provides protection against fire, thermal flash hazards, mechanical constraints and other factors involved in fighting fires. The second layer is the moisture barrier that ensures comfort through the waterproof/breathability concept obtained by means of specific hydrophilic/hydrophobic membranes associated with a textile. The third layer is the thermal liner, which provides the most thermal insulation by entrapping air in a traditional thick needle punched batt slowing down heat transmission. To improve the durability of this layer, a woven facecloth fabric is quilted on it.
Keeping in mind that a compromise is required between adequate heat insulation and lightest possible weight, the combination of these three conventional layers defines the performance characteristics of the entire composite system. However, the known composite assemblies tend to be heavy and expensive to produce.
It would be therefore highly desirable to be provided with a fire insulating barrier material of a simpler confection and compact arrangement.
One aspect of the present invention is to provide a fire insulating barrier for a firefighter's protective garment comprising a first fire-resistant fabric layer and a second fire-resistant fabric layer attached to the first layer by pile yarns, thereby creating a space therebetween, the space containing an insulating substance. The fabric layers are intended to be either woven fabric or knitted fabric and the insulating substance can be selected from, but not limited to air, aerogel phase change materials, or a combination thereof.
In accordance with another aspect of the present invention, the fabric can be selected from the group consisting of aramid, polyacrylate, phenolic, polybenzimidazole, polyacrylonitrile oxide, polybenzoxazole, melamine and a combination thereof. The aramid can be selected from, but not limited to, polyaraphenylene terephtalamide, such as KEVLAR™, polymetaphenylene isophtalamide, such as NOMEX™, polyparaphenylene terephtalamide copolymer, such as TECHNORA™, polyamide imide such as KERMEL™, copolyimide such as P84™, or a combination thereof. The polyacrylate can be, without limitation, INIDEX™, the phenolic can be, without limitation, KYNOL™. The polybenzimidazole can be, without limitation, PBI™. The polyacrylonitrile oxide can be, without limitation, SIGRAFIL™. The melamine can be, without limitation, BASOFIL™. The polybenzoxazole can be, without limitation, ZYLON™.
In accordance with a further aspect of the invention, the material can have a thickness varying from 1 to 8 mm, more preferably from 2 to 3 mm.
In accordance with a further aspect of the invention, the material can be covered with a ^polymer, such as, but not limited to, polyurethane, polyether, polyester, polytetrafluoroethylene, polyolefin, polyethylene, polypropylene or a combination thereof. The polymer can be in a form of membrane typically laminated on the material, in the form of a coating or a combination thereof. More preferably, the - material has an E-PTFE membrane laminated thereto.
In accordance with a further aspect of the invention, the thermal barrier can comprise the fire insulating barrier material of the present invention and an outer shell. Preferably, the outer shell is fire resistant and/or waterproof. The invention is illustrated but is not restricted by the appended figures in which:
Fig. 1 is a cross-sectional view of a possible embodiment of the fire insulating barrier material;
Fig. 2 is a cross-sectional view of another possible embodiment of the fire insulating barrier material; and
Fig. 3 is a cross-sectional view showing an example of a thermal barrier made of the fire insulating material of Fig. 2 with an outer shell.
The present invention is concerned with a fire insulating barrier material (10) used in protective garment for firefighters. This material (10) is designed to be at least in compliance with the standard from the National Fire Protection Association (NFPA) known as NFPA 1971 , or any equivalent thereof.
The material (10) comprises a first fire-resistant layer of fabric (12) and a second fire-resistant layer of fabric (14), which can be either woven or knitted. This fabric forming the layers (12, -14) is preferably made of aramid, polyacrylate, phenolic, polybenzimidazole, polyacrylonitrile oxide, polybenzoxazole, melamine or a combination thereof. The aramid can be selected from, but not limited to, polyaraphenylene terephtalamide, such as KEVLAR™, polymetaphenylene isophtalamide, such as NOMEX™, polyparaphenylene terephtalamide copolymer, such as TECHNORA™, polyamide imide such as KERMEL™ and copolyimide such as P84™. The polyacrylate can be, without limitation, INIDEX™, the phenolic can be, without limitation, KYNOL™. The polybenzimidazole can be, without limitation, PBI ™. The polyacrylonitrile oxide can be, without limitation, SIGRAFIL™. The melamine can be, without limitation, BASOFIL™. The polybenzoxazole can be, without limitation, ZYLON™.
In Fig. 1 , the two layers (12, 14) of fabric are held together by a pile yarn (16) in such a way as to create a space (18) between the layers (12, 14). The layers (12, 14) can be made of the same material or of different materials. The space (18) contains an insulating substance such as, but not limited to, air, phase change materials (PCM) or aerogels. The expression "phase change material" is intended to mean a material used to store heat by melting. One of the advantages of the material (10) is that it can retain more insulating substance than the conventional needle punched batt of the same thickness.
In Fig. 2, the material (10) is provided with a waterproof, breathing membrane (20). The material (10) then forms a thermal barrier (22) with the membrane (22). The membrane (20) is non-flammable and can be an e-PTFE membrane directly laminated on the material (10) or can consists in a coating, such as a silicon coating having PCM encapsulated into.
The thermal barrier (22) can be provided with an outer shell (24) for further protection against direct exposure to flames, heat, abrasion, etc, as shown in Fig. 3. The outer shell (24) is preferably made of fire resistant and/or waterproof material. US patents Nos. 4,188,445; 4,255,817; 4,937,136; 5,007,112; 5,014,357; 5,050,241 and 5,136,723 disclose examples of outer shells that are suitable for fire-resistant garments.
When the material (10) of the present invention is used in a firefighter's protective garment, whether or not laminated with the membrane (20) or with the coating, and whether or not provided with the outer shell (24), it increases comfort while reducing the weight of the garment and still provide a good resistance to heat, flames and other hazards related to firefighting. It is particularly suitable for use in the confection of a bunker suit.
While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles .of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.
