Title of Invention

"FIRE PROTECTIVE FABRIC FOR FIRE PROXIMITY SUIT AND A PROCESS FOR PREPARATION THEREOF"

Abstract

This invention relates to a fire protective composite fabric for fire proximity suit which enables fireman to fight fire in close proximity to site of fire, comprising an outermost layer of aluminium layer of .01 to .03 microns preferably 0.02 microns, Polyethylene terephthalate (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; second layer of Neoprene coated 'E' glass fabric which comprises 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; third layer of 65 to 75% preferably 70% carbon, 04 to 06% preferably 5% Kevlar fibre and 20 to 30% preferably 25% Fire Retardant (FR) rayon and a fourth and the innermost layer of Fire retardant (FR) cotton fabric. Further this invention relates to a process for the preparation of a composite fabric for fire proximity suit comprising the steps of preparing an outermost layer by aluminizing PET film, laminating it to 'E' glass fabric by a thermal resistant resin and curing; preparing a second layer by applying neoprene based coating on 'E' glass fabric and curing, preparing a third layer by FR batting of carbon fibre, Kevlar fibre and FR rayon, making a fourth layer from FF cotton fabric.S

Full Text

FIELD OF INVENTION This invention relates to a fire protective composite fabric for fire proximity suit and a process for preparation thereof. PRIOR ART Fire proximity suit provides protection to a fire-fighter against conductive, convective and radiant heat as produced in case of bulk flammable gas and/or bulk liquid fires or aircraft fires. The suit provides protection to whole body of fireman, from head to feet and enables a fire¬fighter to operate very close to the fire for short duration but not the direct entry into flames. A fire proximity suit consists of jacket with sleeves, trouser, gloves, over boots and hood incorporating helmet and visor assembly. The fire protective fabric used for such suits is a multi-layered fabric. One of the fire protective fabric known in the art suitable for 'fire proximity suit' comprises of two layers, where-in first layer comprises of Aluminised glass fabric and second layer is thermal barrier. The main advantage of the above mentioned type of fabric is that it is heavy weight and provides less protection up to 01 minutes only. Another disadvantage of the above-mentioned type of fabric is that it allows permeation of hot fumes and vapours to the body. Yet another disadvantage of the above-mentioned type of fabric is that it causes irritation to the wearer. Another fabric known in the art which is suitable for fire proximity suit is asbestos fabric. 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 less tearing strength, OBJECTS OF INVENTION The main object of the present invention is to provide a fire protective fabric for a fire proximity suit which pro.tects whole body of fireman and enables him to carry out fire fighting operations in close proximity to fire, for short periods Another object of the present invention is to provide a four-layered fire protective fabric for proximity suit Still another object of the present invention is to provide a fire protective fabric for fire proximity suit which incorporates an additional layer comprising kevlar fiber. FR rayon and carbon black which serves as a thermal barrier to provide thermal protection to the fireman. Further object of the present invention is to provide a fire protective fabric for fire proximity suit where-in the outermost heat reflecting layer is alummised glass fabric capable of reflecting 90-95% radiant heat. Still further object of the present invention is to provide a tire protective fabric for fire proximity suit which enables preparation of fire proximity suit with overall weight of all its components namely, jacket with sleeves, trouser, gloves, over boots and hood incorporating helmet and visor assembly in the range of 7 to 10 kg Yet further object of the present invention is to provide a fire protective fabric so that fire proximity suit made thereof when worn by the fireman does not adversely affect his audibility and fireman is able to hear beating of fire gong from a distance of 100 to 200 meters. Still further object of the present invention is to provide a fire protective fabric so that fire proximity suit made thereof when worn by the fireman does not adversely affect his mobility and fireman is able to walk or bicycle and can carry loads of about 50 kg on his shoulder and hold rubberised hose over his left or right shoulder. DESCRIPTION OF INVENTION According to this invention there is provided a fire protective composite fabric for fire proximity suit which enables fireman to fight fire in close proximity to site of fire, comprising an outermost layer of the fabric of Polyethylene terephthalate (PET) film aluminised on both sides and laminated, with a thermal resistant Fluoro-elastomeric based resin, to E-glass fabric; second layer of Neoprene coated 'E' glass fabric; .third layer of carbon, kevlar and Fire retardant (FR) rayon, and a fourth and the innermost layer of Fire retardant (FR) cotton fabric. Further according to this invention there is provided a process for the preparation of a composite fabric for fire proximity suit comprising the steps of:- (a) preparing an outermost layer by aluminising PET film, laminating it to '£' glass fabric by a thermal resistant resin and curing; (b) preparing a second layer by applying neoprene based coating on 'E' glass fabric and curing; (c) preparing a third layer by FR batting of carbon fibre, kevlar fibre and FR rayon, (d) making a fourth layer from FR cotton fabric. PROCESS FOR PREPARATION OF FABRIC According to the present invention, the fire protective fabric for fire proximity suit comprises of following layers in the sequence as below:- Outermost layer : Heat reflective glass fabric Second layer : Moisture barrier Third layer : Thermal Barrier Fourth layer : Fire Retardant (FR) cotton (Innermost layer) The process for the preparation of each of the above layer is as follows -Preparation of outermost layer The outermost layer of the fabric i.e. heat reflective glass fabric is a multi-layered composite fabric consisting of five layers namely: aluminium layer of 01 to 03 microns preferably 002 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 support layer of E-glass fabric, which is a strong fire retardant glass fabric with thickness of 420 to 440 microns preferably 430 microns For preparation of this layer, Polyethylene terephthalate (PET) film having optical density of 2 on a scale of 0-10 is metallised under high vacuum condition of the order of 10"4 to 10"" 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-obstructive movement ot aluminium vapours which get deposited on both sides the 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 svstem based on fluoro-elastomeric resin This laminate is cured at temperature around 195°C for 10 minutes. The E-glass fabric is prepared by "using glass yarn of the type EC68 Tex240 TPM x 25 160 TPM on automatic shuttle loom. The resulting fabric of 500 GSM is 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 pans by weight) and • hexamethylene diamine carbamate (1.5 parts by weight). Preparation of second laver The second layer i.e. 'Moisture barrier' layer consists of the neoprene coated glass composite and comprises preferably 150 GSM basic cloth '£' glass fabric and 200 GSM neoprene coating. The neoprene coating further comprises 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%. as solvent Neoprene coating is prepared by refluxing neoprene, carbon black, antimony trioxide and methyl alcohol on a steam bath for 02 hours with stirring. The resulting solution is filtered while hot and the clear solution is filtered under vacuum in order to get a semi-solid paste This paste is applied to glass fabric and the resulting product is then cured at 140-150CC in a superheated steam container. Preparation of third laver Third layer i.e. Thermal barrier layer is made up of FR batting of carbon 65 to 75%, preferably 70%, 04 to 06% preferably 05% of kevlar fibre and 20 to 30% preferably 25% of Fire Retardant (FR) rayon. For preparation of this layer, carbon fibre of uniform quality is taken in stiochiometric ratio and spread on the ground. Kevlar fibre and FR rayon is spread on the layer of carbon fibre and kept for about 24 hours. The resulting layers are cut vertically and fed into hopper bale breaker to form the lap In order to make the web. the lap is fed into the multi-cylinder carding engine. The prepared web is then taken to needle beds to prepare the non-woven fabric i.e. thermal barrier. Preparation of innermost layer The fourth layer, which is the innermost layer, is made of Fire Retardant (FR) cotton fabric to provide comfort to the fireman. The invention will now be illustrated with a working example which is intended to be a typical example 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 68Te.\240 TPMX25 160 TPM on automatic shuttle loom. The resulting fabric of 500 GSM was desized at 400°C by passing through a heating chamber for one to three minutes An adhesive was prepared by mixing elastomeric resin and methyl ethyl ketone in stiochiometric ratio and adding magnesium oxide (7.5 parts) and hexamethylene diamine carbamate (15 pans) 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 were 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 containers. The third layer was prepared by spreading a layer of Keviar tlbre and 1:R rayon over a layer of carbon fiber and kept for 24 hours The fourth layer which is the innermost layer, is made of Fire Retardant cotton The fire proximity suit prepared using the fabric of this invention, consists of (a) jacket with sleeves (b) trousers (c) gloves (d) over boots (e) and hood incorporating helmet and visor. The overall suit has weight between 07 to 10 kg The wearing of this suit does not hinder, in any way, the mobility, audibility and operational capability of the fireman It is to be understood that the process of the present invention 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 proximity suit which enables fireman to fight fire in close proximity to site of fire, comprising an outermost layer of aluminium layer of .01 to .03 microns preferably 0.02 microns, Polyethylene terephthalate (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; second layer of Neoprene coated 'E' glass fabric which comprises 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; third layer of 65 to 75% preferably 70% carbon, 04 to 06% preferably 5% Kevlar fibre and 20 to 30% preferably 25% Fire Retardant (FR) rayon and a fourth and the innermost layer of Fire retardant (FR) cotton fabric. 2. A fire protective fabric for fire proximity suit 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. 3. A process for the preparation of a composite fabric for fire proximity suit comprising the steps of: - a. preparing an outermost layer by aluminizing PET film, laminating it to 'E' glass fabric by a thermal resistant resin and curing; b. preparing a second layer by applying neoprene based coating on 'E' glass fabric and curing, c. preparing a third layer by FR batting of carbon fibre, Kevlar fibre and FR rayon, d. making a fourth layer from FR cotton fabric. 4. A process for preparation of fire protective fabric for fire proximity suit as claimed in claim 7 wherein said aluminisation of PET film is carried out by metallisation under vacuum of 10-4 to 10-5 torr. 5. A process for preparation of fire protective fabric for fire proximity suit as claimed in claim 7 wherein the said curing of outermost layer is carried out around 195°C for 10 minutes. 6. A process for preparation of fire protective fabric for fire proximity suit as claimed in claim 7 wherein second layer is prepared by applying neoprene coating, preferably of 200 GSM on 'E' glass fabric of preferably 150 GSM. 7. A process for preparation of fire protective fabric for fire proximity suit as claimed in claim 7 wherein said curing of second layer is carried out at 140-150°C. 8. A process for preparation of fire protective fabric for fire proximity suit as claimed in claim 7 wherein third layer is prepared by spreading Kevlar fibre and FR rayon on carbon fiber and allowing it for 24 hours.

Documents:

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

253-del-2002-abstract.pdf

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

253-del-2002-claims.pdf

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

253-del-2002-correspondence-others.pdf

253-del-2002-correspondence-po.pdf

253-DEL-2002-Description (Complete)-24-06-2008.pdf

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

253-del-2002-form-1.pdf

253-del-2002-form-18.pdf

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

253-del-2002-form-2.pdf

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

253-del-2002-form-3.pdf