EP0258513B1 - Textile fire protection layer - Google Patents

Abstract

The textile fire-protection layer of the invention will apply, in particular, to the field of aeronautics and land or sea transportation means, as well as to clothing, furnishing and construction. According to the present invention, the textile fire-protection layer has the form of a sheet of fibres of the polyacrylate type and flexible means giving the whole a homogeneous holding of the charred framework, and also comprises carbon-precursor fibres referred to as "preox" fibres. <IMAGE>

Description

The invention relates to a textile fire barrier. It will find its application in particular in the field of security to form a protective screen and avoid any propagation of the flame. It concerns the clothing industry, furniture, construction, aeronautics and all means of land or sea transport.

A study of accidents shows that the presence of a fire represents a major factor in the severity of the disaster. The fire takes direct victims by the heat given off and the harmful gases and indirectly by the panic created and the hustle and bustle and crowds that ensue.

As a safety measure, certain precautions are taken in public places to deal with fires, this is how panic doors and emergency stairs must be put in place at different levels and the use of fire-resistant materials should be adopted wherever possible.

In terms of transport, whether they are wheelchairs for motor vehicles or railway cars, or even more so for airplane seats, manufacturers impose a certain number of constraints on the upholstery to prevent the latter cannot contribute to the action of the fire.

Current technological developments do not make it possible to offer a textile product compatible with economic imperatives and which can be used to make an external covering and internal padding, for example. Studies are therefore rather oriented towards the development of products allowing, in the event of a disaster, to gain time to facilitate the evacuation of the occupants.

The material must therefore not give off abundant harmful gases and also, must not propagate the flame.

The main difficulty encountered mainly lies in the padding. Indeed, many seats use synthetic foam as an interior lining because it has good elasticity and great comfort. Unfortunately, these synthetic foams, which are generally polyurethane, have very poor fire-fighting properties. Under the action of the flame, these foams tend to melt and spread the flame when burning.

On the other hand, with regard to the upholstery fabrics, there are currently on the market a certain number of fibers which allow the manufacture of fireproof fabrics. These fabrics give off little gas on burning and do not spread the flame.

However, it should be noted that current fabrics, if they have satisfactory intrinsic properties with regard to fire, are completely ineffective as a fire barrier. Indeed, under the action of the flame, the fabrics do not retain any uniformity or uniformity which allows them to form a screen opposing the passage of the flame.

It is known from documents US-A-4,092,752 and FR-A-2.283.201 to use, as fire protection, glass fiber fabrics or fabrics having for component cotton, polyvinyl chloride, polyamide, polyimides, these fabrics being in particular intended to form covers for mattresses or for seats. However, as noted above, such embodiments are entirely ineffective as a fire barrier and do not allow homogeneous mechanical resistance of the assembly under the action of the flame.

It is also known from American patent PARKER n ° 4.463.465 an airplane seat equipped with a fire propagation blocking system in which a barrier is provided between the seat padding and the external trim element non-fire impermeable to combustion gases generated in the event of fire. The purpose of this document is to propose a specific embodiment in which the outer coating layer is impermeable to the combustion gases generated in the event of fire. However, here again, the proposed solution does not give a satisfactory mechanical property under the action of the flame and a screen is not formed which oppose the passage of the flame, keeping a uniform resistance in the event of fire.

Consequently, to meet security requirements, it is essential to interpose between the lining fabric and the interior padding a fire barrier which is the subject of the present invention.

Flame resistance standards can be broken down into two categories depending on the nature of the tests to be performed.

First of all, with regard to land vehicles, such as railroad cars, the test is essentially thermal. This involves bringing the object to be tested to a temperature close to 450 ° C under the action of a flame for a determined time and verifying that after this action, the hearth is not maintained.

The aeronautical industry imposes a more severe test since not only the object is brought to high temperature, of the order of 1040 ° C but also it is subjected to the mechanical action of a flame spat out by a kerosene burner. Many fire barriers do not resist the blast of the burner and crack, thus losing all effectiveness.

In the specific application of the seat envisaged in the present invention, the fire barrier must also have elasticity and deformability properties compatible with the seat cushion.

The main object of the present invention is the production of a fire-resistant textile barrier which has good mechanical flexibility properties which make it compatible with applications in clothing and furniture and which, moreover, in terms of safety, offer guarantees with regard to the action of a flame.

The fire-resistant textile barrier meets the standards imposed both with regard to public places and land vehicles as well as in aeronautics and marine.

In combination with the use of polyurethane foam padding, the textile barrier of the invention protects it and prevents the mouse from spreading the fire.

In addition, the manufacture of the textile barrier anti-fire can easily be carried out with traditional industrial means compatible with economic imperatives.

Other objects and advantages of the present invention will appear during the description which follows which is however given only for information and which is not intended to limit it.

• ladite nappe de fibres non tissées et non feu est du type polyacrylate et est renforcée par des moyens souples procurant à l'ensemble une tenue homogène et assurant une cohésion mécanique de l'ensemble du squelette carbonisé,
• ladite nappe de fibres étant formée d'un mélange homogène de fibres comprenant :
  • d'une part 95 à 70 % de fibres de polyacrylate,
  • et d'autre part 5 à 30 % de fibres d'aramide, polybenzimidazol (PBI) ou laine, en mélange intime avec lesdites fibres de polyacrylate pour constituer lesdits moyens souples de renfort,
  • la somme des constituants indiqués devant, dans chaque cas, être égale à 100 %.

The fire-resistant textile barrier intended in the field of security to form a protective screen and prevent any propagation of the flame, said barrier being interposed between an external lining element and an internal material, for example of padding, said barrier having the form of a sheet of nonwoven and fireproof fibers, is characterized by the fact that:

• said sheet of non-woven and flame-retardant fibers is of the polyacrylate type and is reinforced by flexible means providing the assembly with a uniform hold and ensuring mechanical cohesion of the entire charred skeleton,
• said sheet of fibers being formed of a homogeneous mixture of fibers comprising:
  • on the one hand 95 to 70% of polyacrylate fibers,
  • and on the other hand 5 to 30% of aramid fibers, polybenzimidazol (PBI) or wool, in intimate mixture with said polyacrylate fibers to constitute said flexible reinforcing means,
  • the sum of the components indicated must, in each case, be equal to 100%.

• la figure 1 illustre à titre d'exemple la composition interne d'un siège anti-feu,
• la figure 2 schématise en vue de coupe la mise en place d'une barrière textile anti-feu selon la présente invention.

The invention will be better understood on reading the following description accompanied by attached drawings, among which:

• FIG. 1 illustrates by way of example the internal composition of a fire seat,
• Figure 2 shows schematically in section the establishment of a textile fire barrier according to the present invention.

The present invention relates to a fire-resistant textile barrier intended, in the field of security, to form a protective screen and avoid any propagation of the flame. It will find its application in particular in the clothing industry, of the furnishing, in particular for the confection of the seats of vehicles and in aeronautics and the Marine.

For safety reasons, the design of public places increasingly uses fireproof products. The main concern is to use materials which, in the event of fire, do not emit harmful fumes and do not propagate the flame to give a reasonable time for evacuation.

The present invention has been more particularly developed to equip the seats of vehicles, airplanes and boats. Its use may however be extended to other equipment such as performance halls, clothing or others.

In the case of armchairs, the exterior upholstery fabric poses little problem since it can be produced using synthetic yarns having good flame behavior, that is to say giving off little gas harmful and above all not propelling the fire. On the other hand, with regard to the padding, no satisfactory and economical solution has been found at present for replacing the foam with an element having good fire-fighting properties.

The polyurethane foam generally used exhibits very poor behavior in the event of a fire because it melts and burns while maintaining the flame. It is therefore advisable to protect the foam by an enveloping screen which shelters it from the direct action of the flame, preventing it from being consumed. This is precisely the role of the textile fire barrier of the present invention which has the mission of forming a screen on the surface of the foam cushion to prevent it from propagating the flame.

To test and compare the characteristics of fire barriers, there are several series of tests that can be classified into two categories.

First of all, the tests planned for rolling stock such as railroad cars, in which the seat is subjected to the action of a simple flame releasing for a predetermined time a temperature between 600 and 1000 ° C. .

In general, this test is carried out using one hundred grams of parboiled paper at 140 ° C rolled into a ball. This paper is placed on the seat then lit. After the paper has gone out, for the test to be conclusive, a natural and rapid extinction of the flame on the surface of the seat must be observed.

The fire barrier must therefore prevent the flames from communicating with the ground or disintegrating the product.

The second type of test relates to aeronautics where a burner supplied with kerosene is used having a nozzle of twenty centimeters of cone and placed at a distance of ten centimeters from the seat. The latter is subjected to the action of the flame brought to 1040 ° C for two minutes.

Up to now, the aeronautical special polyurethane foam cushion and the fabrics give off harmful gases. The manufacturers want the seats to be able to withstand the action of the fire for two minutes.

This test is most severe because, in addition to the action of heat, the burner exerts mechanical pressure on the seat upholstery, this pressure resulting mainly from the action of the nozzle, the fuel pressure and the amount of air from the breath. The burner develops about sixty thousand kilo-calories per hour.

Figure 1 shows a seat (1) having a cutout of the wafer (2) to illustrate the different internal elements. This seat has an outer fabric (3) of upholstery made with a fire-retardant thread known to those skilled in the art.

The interior padding (4) is made of polyurethane foam with poor fire-fighting properties.

A fire-resistant textile barrier (5) is interposed between the padding foam (4) and the lining fabric (3) to protect said foam (4) from the external action of a flame.

This arrangement is taken up in FIG. 2 illustrating in section view an exterior lining fabric (3), an intermediate fire-resistant textile barrier (5) and an interior polyurethane padding foam (4).

The textile fire barrier of the present invention calls for the use of polyacrylate fibers. It is a material having excellent fire-fighting characteristics but which cannot be spun to date and which consequently is in the form of quilted, polymerized or needled plies after carding.

Polyacrylate fibers resist the action of heat and that of chemicals. In addition, in the event of a fire, their degradation is minimal, which prevents the formation of smoke and gas.

The first attempts to use, as textile fire barrier, a sheet formed one hundred percent of polyacrylate fibers turned out to be failures.

In fact, the fibers exhibit good intrinsic behavior in the event of a fire, but the sheet produced suffers from cracking problems which create gaps revealing the polyurethane foam which, through these cracks, is subjected to the direct action of the flame. with the consequences that flow from it.

The polyacrylate sheet chars without flame and falls to dust after a certain time, the product turns yellow then blackens and chars in about fifteen minutes.

It should be noted that in normal use, the product must also follow the deformations of the seat and remain comfortable.

According to the main characteristic of the present invention, the fire-resistant textile barrier (5) consists of a sheet of non-woven and fire-resistant fibers of the polyacrylate type reinforced by flexible means providing the whole with a uniform hold of the skeleton. charred.

These flexible means make it possible to avoid cracking phenomena and therefore to protect the lining everywhere from the direct action of the flame.

By way of example, a core of glass threads is incorporated to contain the sheet and thus keep a homogeneous network of fabric. The glass strands make it possible to avoid the formation of cracks by spreading the polyacrylate fibers. This solution is satisfactory with regard to the first category of tests, that is to say when the flame does not exert a mechanical blast action.

It should be emphasized that a simple network of glass strands does not allow to resist the action of the flame which, on the contrary, very quickly loses its properties with the increase in temperature. On the other hand, the combination of a sheet of polyacrylate fibers and a network of glass threads allows the unit to temporarily resist and withstand the action of the flame.

According to another preferred embodiment of the fire-resistant textile barrier of the present invention, it consists in particular of flexible means which ensure mechanical cohesion of the entire charred skeleton of the textile barrier. This mechanical cohesion allows the barrier to also resist the blast of the flame.

These means are in the form of a component which, by virtue of its structure and its mixture with the polyacrylate fiber, will avoid the phenomenon of cracking and give good mechanical cohesion of the entire charred skeleton.

The uniform distribution throughout the thickness of this second component of the barrier allows it to benefit from homogeneous fire resistance properties.

Despite the action of the flame, the shape given to the padding (4) is retained at the start of the fire and throughout it, cracks and punctures are avoided so that the flame cannot penetrate inside. padding (4). The cushion is only subjected to the action of heat, which makes it partially melt, but the foam does not ignite. Tests at 1040 ° C for two minutes showed that the cushions had a weight difference of less than 10% after the test.

Flexible means ensuring mechanical cohesion of the whole are in the form of aramid, aromatic polyamide, polybenzimidazol (PBI) or wool fibers. These fibers are intimately mixed with the polyacrylate fibers to form a homogeneous composition.

Aramid fibers have excellent mechanical resistance thanks to an important molecular orientation. Despite their loss of resistance with the rise in temperature, the aramid fibers, which do not burn, allow the carbonized skeleton to retain a mechanical cohesion preventing the formation of cracks even under the action of the burner at 1040 ° C.

Aramid carbonizes but turns less to dust than polyacrylate, which allows it to keep the structure of the fiber network.

Tests have shown, with regard to the composition of the mixture, that a proportion of less than 15% of aramid fibers no longer makes it possible to avoid cracking phenomena which reappear.

On the other hand, a composition comprising more than 30% of aramid fibers is very difficult to work in a mixture which becomes less intimate and risks of heterogeneous mechanical resistance exist.

A minimum threshold of 5% of aramid fibers must be reached for the mixture to be able to effectively act as a fire barrier.

• d'une part 95 à 70 % de fibres de polyacrylate,
• et d'autre part 5 à 30 % de fibres d'aramide, polybenzimidazol (PBI) ou laine, en mélange intime avec lesdites fibres de polyacrylate pour constituer lesdits moyens souples de renfort,
• la somme des constituants indiqués devant dans chaque cas être égale à 100 %.

However, according to the invention, said sheet of fibers will advantageously be formed from a homogeneous mixture of fibers comprising:

• on the one hand 95 to 70% of polyacrylate fibers,
• and on the other hand 5 to 30% of aramid fibers, polybenzimidazol (PBI) or wool, in intimate mixture with said polyacrylate fibers to constitute said flexible reinforcing means,
• the sum of the constituents indicated must in each case be equal to 100%.

The following example, given as an indication, made it possible to develop a fire-resistant textile barrier making it possible to withstand all the standard tests practiced in aeronautics.

EXAMPLE 1

The polyacrylate fibers used are sold by the company COURTAULDS under the name of "INIDEX". The aramid fibers used are sold by the company DU PONT DE NEMOURS under the name of "KEVLAR".

An intimate and homogeneous mixture of these nonwoven fibers is produced from 80% polyacrylate fibers and 20% aramid fibers. The manufacturing comprises a first carding step which makes it possible to obtain a veil which is then coated by superposition to form a barrier with a thickness of approximately four millimeters. The homogeneity of the whole is achieved by needling.

The use of a sheet having a density of three hundred grams per square meter gave good results for all of the tests.

Other materials, with similar properties, and other proportions could also have been used without departing from the scope of the present invention as defined in claims 1 to 4.

Claims (4)

1. Fire-proof textile screen for forming, in the field of safety measures, a protective screen and to avoid any flame propagation, said screen being interposed between an external cloth component (3) and an internal, for instance stuffing, material (4), said screen being made as a non-woven and fire-proof fibre sheet, characterized in that:

   - said non-woven and fire-proof fibre sheet is of the polyacrylate type and is reinforced by flexible means providing the aggregate with a homogeneous holding and ensuring a mechanical cohesion of the whole carbonized skeleton,

   - said fibre sheet being made of a homogeneous mixture of fibres comprising:

   - on the one hand, 95 to 70% of polyacrylate fibres,

   - on the other hand, 5 to 30% of aramide, polybenzimidazol (PBI) or wool fibres, intimately mixed with said polyacrylate fibres to form said flexible reinforcing means,

   - the sum of the mentioned components having to be, in each case, equal to 100%.
2. Fire-proof textile screen according to claim 1, characterized in that it is made of a homogeneous mixture of non-woven fibres comprising 80% of polyacrylate fibres and 20% of aramide fibres.
3. Fire-proof textile screen according to claim 2, characterized in that the sheet has a four millileter thickness.
4. Fire-proof textile screen according to claim 2, characterized in that the sheet has a density of three hundred grams per square meter.

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