Title of Invention

"FIRE PROTECTIVE COMPOSITE FABRIC FOR FIRE APPROACH SUIT AND A PROCESS FOR PREPARATION THEREOF"

Abstract

This invention relates to a fire protective composite fabric for fire approach suite to provide whole body protection to a fire-fighter against radiation from fire of highly flammable gas /liquid fire comprising an outermost layer of Polyethylene terephthalate (PET) film aluminised on both sides and laminated with thermal resistant adhesive to E-glass fabric, characterized in that middle layer being moisture barrier layer comprising E-glass fabric coated with neoprene based coating and innermost layer made is of Fire Retardant (FR) cotton fabric. Further this invention relates to a process for the preparation of a fire protective composite fabric comprising the steps of preparing an outermost layer by laminating metallised PET film in vacuum, with E-glass fabric, preparing a middle layer by applying neoprene based coating on E-glass fabric, preparing innermost layer from Fire Retardant (FR) cotton.

Full Text

FIELD OFFIELD OF INVENTION This invention relates to a fire protective composite fabric for fire approach suit and a process for preparation thereof. PRIOR ART Fire approach suit provides protection against radiant heat to the whole body of a person, from head to foot, who is engaged in exterior fire fighting operations involving fires producing very high levels of conductive, convective and radiant heat such as in case of bulk flammable gas and/or bulk liquid fires. The use of 'Fire Approach Suit' enables a fire-fighter to go sufficiently close the fire to be able to throw extinguishant effectively. A fire approach suit may be in overall style or in two piece style consisting of jacket with sleeves, trouser, boots and hoods incorporating helmet and visor assembly. The fabric used in a fire approach suit is a fire protective fabric. One of the fire protective fabric known in the art for preparation of 'fire approach suit' is based on aluminised glass fabric. The main advantage of the above-mentioned type of fabric is that it is single layer and provides less protection up to 05 minutes only. Another disadvantage of the above-mentioned type of fabric is that it allows permeation of hot fumes and vapours to the body of the wearer. Yet another disadvantage of the above-mentioned type of fabric is that it causes irritation to the wearer. Another type of fire protective fabric known in the art which is suitable for fire approach suit is Aluminised Asbestos Suit. The main disadvantage of the above-mentioned type of fabric is that it is carcenogenic. - Another disadvantage of the above-mentioned type of fabric is that it causes irritation to the wearer as its fibers enter into the skin. Yet another disadvantage of the above-mentioned type of fabric is that it has low tearing strength due to which it provides less protection against sharp objects. Still another protective fabric known in the art is Fire Retardant (FR) Fabric. A disadvantage of the above fabric is that it is a chemically treated fabric, which is injurious to health. Another disadvantage of the above fabric is that is provides less protection against heat. OBJECTS OF INVENTION The main object of the present invention is to provide a fire protective fabric suitable for a fire approach suit which provides protection to fireman against radiant heat particularly from bulk flammable gas/liquid fires. Another object of the present invention is. to provide a three-layered fire protective fabric with outer most layer of reflective glass fabric, second layer of neoprene coated glass fabric as moisture barrier and third layer of Fire Retardant (FR) cotton fabric. Still another object of the present invention is to provide a fire protective fabric for fire approach suit where-in the outermost layer is capable of reflecting back radiant heat to the extent of 90-95%. DESCRIPTION OF INVENTION According to this invention there is provided a fire protective composite fabric for fire approach suite to provide whole body protection to a fire¬fighter against radiation from fire of highly flammable gas/liquid fire comprising an outermost layer of Polyethylene terephthalate (PET) film aluminised on both sides and laminated with thermal resistant adhesive to E-glass fabric, characterized in that middle layer being moisture barrier layer comprising E-glass fabric coated with neoprene based coating and innermost layer made is of Fire Retardant (FR) cotton fabric. Further according to this invention there is provided a process for the preparation of a fire protective composite fabric comprising the steps of: - (a) preparing an outermost layer by laminating metallised PET film in vacuum, with E-glass fabric. (b) preparing a middle layer by applying neoprene based coating on E-glass fabric (c) preparing innermost layer from Fire Retardant (FR) cotton. PROCESS FOR PREPARATION OF FABRIC According to this invention, the fire protective fabric suitable for 'fire approach suit' comprises of three layer: (a) Outer most layer : Heat reflective glass fabric (b) Middle layer : Moisture barrier or vapour barrier (c) Innermost layer : Fire Retardant Cotton (a) Preparation of Outer most Layer: The outermost layer of the fabric i.e. heat reflective glass fabric is a multi-layer composite fabric consisting of five layers namely, aluminium layer of .01 to .03 microns preferably 0.02 microns, Polyethylene tereohthalate (PET) film of 10 to 15 microns preferably 12 micron, aluminium layer of .01 to .03 microns preferably 0.02 micron, Fluoro-elastomeric based resin of 40 to 45 microns preferably 43 micron and support layer of E-glass fabric which is a strong fire retardant glass fabric with thinkness of 420 to 440 microns preferably 430 microns. Polyethylene terephthalate (PET) film having optical density of 2 on a scale of 0-10 was metallised under high vacuum condition of the order of W4 to 10'5 torr. The aluminium wire melts as it touches the electrically heated boats (two such boats are provided for metallisation on both sides of the polymeric film). The high level of vacuum inside the metallisation plant provides un-ofastructive movement of aluminium vapours which get deposited on both sides of PET film.. The high vacuum is also conducive to forming stronger bond between the film and the aluminium vapours. This aluminised PET film is laminated with E-glass fabric by using a thermal resistant adhesive system. This laminate is cured at temperature around 195°C for 10 minutes. The E-glass fabric was prepared by using glass yarn of the type EC68 Tex240 TPM x 25 160 TPM on automatic shuffle loom. The resulting fabric of 500 GSM was then desized at 400°C by passing through a heating chamber for one to three minutes. The adhesive system based on fluoro-elastomeric resin, is prepared by mixing of elastomeric resin (viton A 35) and methyl ethyl ketone in stiochiometric ratio (91 parts by weight) while adding magnesium oxide (7.5 parts by weight) and hexamethylene diamine carbamate (1.5 parts by weight). (b) Preparation of Middle Layer The middle layer is prepared by giving 200 GSM neoprene coating to 150 GSM E-glass fabric. The neoprene coating comprising of neoprene 63 to 67% preferably 65%, carbon black powder 14 to 16% preferably 15%, antimony trioxide 14 to 16% preferably 15% and methyl alcohol 04 to 06% preferably 05%. Neoprene coating is prepared by refluxing neoprene carbon black, antimony trioxide in methyl alcohol on a steam bath for 02 hours. This moisture barrier layer is prepared by applying 175 to 225 gm preferably 200 gm of Neoprene rubber paste to the glass fabric. The resulting product was then cured at 140-150°C in a super heated steam container. (c) Preparation of Innermost Laver The inner most layer is made of Fire Retardant(FR) cotton fabric. -6- All the three layers i.e. outermost, middle and innermost layers have been integrated into composite fabric during stitching "by overlapping each other without using any chemical bonding or lamination. The invention will now be illustrated with working example which are intended to be a typical examples to illustrate the working of the invention and is not intended to be taken restrictively to imply any limitation on the scope of the present invention. WORKING EXAMPLE Polyethylene terephthalate (PET) of 12 microns having optical density of 2 was metallised under high vacuum condition of the order of 10"4 to 10° torr, till a layer of 2 microns of aluminium vapours gets deposited on both sides of the PET film. E-glass fabric was separately prepared by using the glass yarn of the type EC 68Tex240 TPMX25 160 TPM on automatic shuffle loom. The resulting fabric of 500 GSM was desized at 400CC by passing through a heating chamber for one to three minutes. An adhesive was prepared by mixing eiastomeric resin and methyl ethyl ketone in stiochiometric ratio and adding magnesium oxide (7.5 parts) and hexamethylene diamine carbamate (1.5 parts). The metallised PET film was laminated to E-glass fabric using the adhesive system prepared as above. Second layer was prepared by coating 150 GSM basic cloth with 200 GSM neoprene coating. For preparation of neoprene coating, 325 g of neoprene 75g of carbon black, 75g of antimony trioxide and 500 ml of methyl alcohol was refluxed on a steam bath for 2 hours with stirring. The resulting solution was filtered while hot and clear solution was distilled under vacuum pressure in order to get a semi-solid paste This paste was applied to the E-glass fabric and the product was cured at 145°C in a superheated steam container. The innermost layer is made of FR cotton. The fabric for fire proximity suit is composite of the above mentioned three layers It is to be understood that the process of the present invetion is susceptible to modifications, changes and-adaptations by those skilled in the art.Such modifications, changes, adaptations are intended to be within the scope of the present invention which is further set forth under the following claims:- WE CLAIM: 1. A fire protective composite fabric for fire approach suite to provide whole body protection to a fire-fighter against radiation from fire of highly flammable gas /liquid fire comprising an outermost layer of Polyethylene terephthalate (PET) film aluminised on both sides and laminated with thermal resistant adhesive to E-glass fabric, characterized in that middle layer being moisture barrier layer comprising E-glass fabric coated with neoprene based coating and innermost layer made is of Fire Retardant (FR) cotton fabric. 2. A fire protective composite fabric as claimed in claim 1 wherein the outermost layer consists of aluminium layer of .01 to .03 microns preferably 0.02 microns, PET film of 10 to 15 micron preferably 12 micron, aluminium layer of .01 to .03 microns preferably 0.02 micron, fluoro-elastomeric based resin of 40 to 45 microns preferably 43 micron and a layer of E-glass fabric of 420 to 440 microns preferably 430 microns. 3. A fire protective composite fabric as claimed in claim 1 wherein said fluoro-elastomeric resin comprises elastomeric resin and methyl ethyl ketone in stiochiometric proportions along with 7.5 parts by weight of magnesium oxide and 1.5 parts by weight of hexamethylene diamine carbamate. 4. A fire protective composite fabric as claimed in claim 1 wherein the said neoprene based coating comprises preferably of 63 to 67% preferably 65% by weight of neoprene, 14 to 16% preferably 15% by weight of carbon black powder, 14 to 16% preferably 15% by weight of antimony trioxide, 04 to 06% preferably 5% of methyl alcohol. 5. A process for the preparation of a fire protective composite fabric comprising the steps of: - (a) preparing an outermost layer by laminating metallised PET film in vacuum, with E-glass fabric, (b) preparing a middle layer by applying neoprene based coating on E-glass fabric, (c) preparing innermost layer from Fire Retardant (FR) cotton. 6. A process as claimed in claim 6 wherein metallisation of PET film is carried under vacuum of lO-4 to lO-5 torr. 7. A process as claimed in claim 6 wherein curing of outermost layer is carried out at around 195°C. 8. A process as claimed in claim 6 wherein curing of middle layer is carried out at 140-150°C. 9. A process for the preparation of a composite fire protective fabric substantially as herein described and illustrated in the examples. 10. A composite fire protective fabric suitable for a 'fire approach suit' substantially as herein described and illustrated in the examples.

Documents:

254-DEL-2002-Abstract-(24-06-2008).pdf

254-del-2002-abstract.pdf

254-DEL-2002-Claims-(24-06-2008).pdf

254-del-2002-claims.pdf

254-DEL-2002-Correspondence-Others-(24-06-2008).pdf

254-del-2002-correspondence-others.pdf

254-del-2002-correspondence-po.pdf

254-del-2002-description (complete)-24-06-2008.pdf

254-del-2002-description (complete).pdf

254-del-2002-form-1.pdf

254-del-2002-form-18.pdf

254-DEL-2002-Form-2-(24-06-2008).pdf

254-del-2002-form-2.pdf

254-DEL-2002-Form-26-(24-06-2008).pdf

254-del-2002-form-3.pdf

254-del-2002-gpa.pdf