EP1098575A1 - Textile complex for making clothes for protection against heat - Google Patents

Abstract

A textile complex is provided including at least a fabric, a textile lap, made of inflammable material, designed to form the external surface of the complex, and a comfort and hygiene lining designed to form the complex internal surface. On the fabric internal surface and/or the lining external surface folds are provided having substantially the same orientation with respect to each other, fixed on the fabric and/or the lining, and defining between the fabric and the lining air-filled passages.

Description

 TEXTILE COMPLEX FOR THE PRODUCTION OF THERMAL PROTECTIVE CLOTHING

The present invention relates to a textile complex for the production of thermal protection clothing. The complex in question aims to provide thermal protection against heat and flame, by being used for the production of clothing for firefighters but also, more generally, in other areas of activity where there is a risk of burns due to heat or flame.

Quite old-fashioned, the firefighters used in France a leather jacket equipped with an interior lining of comfort in cotton or wool. Such a jacket does not have appropriate internal thermal protection. In other countries, the jackets used by firefighters are textile-based, either without a sealing barrier, which reduces thermal protection, or with a non-vapor permeable sealing barrier d water, which prevents evaporation of perspiration and increases the problem of heat stress. Heat stress is a physiological phenomenon resulting from the rise in the internal temperature of the body, occurring under the effect of external factors such as a hot atmosphere, or under the effect of a significant and prolonged effort. Heat stress results in a rise in the internal temperature of the body which no longer manages to thermoregulate, which can lead to discomfort, even fainting or a heart attack. We now know that when the body temperature exceeds + 1.5 ° C the normal temperature, the faculties of judgment and reaction are impaired to the point of causing accidents in dangerous environments. The last study on the deaths of firefighters in the USA announces only 8% of deaths by burns, 42% of the deaths are directly due to heat stress and the remaining 50% are accidents with no apparent cause but that specialists reconcile more and more stupid accidents related to impaired judgment related to heat stress.

There is a European directive relating to personal protective equipment used in particular by firefighters. A jacket must meet a certain number of criteria, in particular protection against radiant heat, protection against convective heat, have good thermal stability of the constituent materials, meet criteria of pure flammability, and have good waterproofing.

In addition, a jacket must allow an operator to protect it in extreme accidental conditions, in particular by providing him with a flight time. This is particularly how to protect a firefighter from a phenomenon of "flash-over". Flash-over is a very rapid transition stage in the development of an urban fire, which occurs when the gases and vapors present in a room reach a temperature of 500 to 600 ° C and suddenly ignite. In a fraction of a second, the temperature rises from 500 to 1000 ° C, corresponding to an incident heat flux of the order of 40 kW / m. An operator should be allowed to resist this sudden increase in temperature long enough to be able to move away from the fire.

It is known to produce a textile complex enabling these objectives to be achieved. Such a textile complex comprises an outer protective fabric made of a non-flammable material, for example based on aramid, meta-aramid or polyamide imide fiber. This fabric incorporates thermal protection qualities, provides mechanical performance of resistance to abrasion and tears, and has undergone a water repellent treatment to make it water and water repellent in general. Behind this protective fabric is a waterproof and breathable membrane, generally fixed on a textile surface ensuring its mechanical resistance, allowing to pass the water vapor resulting for example from the perspiration of a user, but not the water under its liquid form. In addition, this membrane provides a windproof effect, which contributes to the thermal insulation of the jacket by slowing down the penetration of heat flows. Under the membrane is disposed a thermal insulator constituted by a three-dimensional knitted mesh, as described in the document EP 0443991, or by a felt capable of trapping air, as described in the document EP 0 364 370. This thermal insulator is generally sewn on a lining.

Such a jacket has the advantage of ensuring excellent thermal protection under an extremely high heat flux of 40 kW / m ² , of very high efficiency, or even too high because, by its high insulating power, it does not allow the user to be sensitive to heat to heat fluxes of 0 to 1 kW / m ² 'corresponding to the usual working conditions of the fire brigade, and to detect a possible danger. The overprotected operator, under these conditions, may have to take risks that are not measured due to a deterioration in the perception of the heat flow. Such a jacket is also uncomfortable insofar as it is thick and heavy, and where it is charged with water, in particular at the level of the thermal insulating material, which can result, in the event of a sudden rise in temperature, by a vaporization of this water which can burn the operator.

In addition, when the jacket is wet, following an intervention in a humid environment or washing, the felt or knitted fabric absorbs a lot of water, which results in a significant drying time during which the jacket does not is not usable. Figures 1 and 2 represent two graphs which illustrate the behavior of different complexes intended to produce clothing for firefighters, taking into account the European standard EN 469.

FIG. 1 illustrates the evolution of the heat transmission factor TF% which is the ratio of the heat flow which has passed through the product over the incident heat flow Q ₀ . Incident heat flow is the heat flow generated by a thermal source to which the sample is exposed.

FIG. 2 illustrates the evolution of the alert time T. ₁₂ as a function of the incident heat flow Q ₀ . The alert time is the time after which the user painfully feels the heat. We are trying to obtain a T.12 of around 15 seconds for an incident flux of 40 kW / m.

The different curves shown in Figures 1 and 2 were obtained by carrying out measurements on the following products or complexes, according to the method of standard EN 366 as described in its revision project CEN / TC162 / WG2 / N266 of 01/27/97: A = leather

B = leather + cotton lining C = leather + wool lining

D = fabric + membrane + nonwoven 90 g / m + lining 120 g / m E = fabric + membrane + mesh 220 g / m ² + lining 120 g / m ²

F ≈ fabric + membrane + felt 120 g / m ² + lining 120 g / m ² As examples, the products used are the following:

Fabric: fabric reference 4781 from the company DMC Tissus Techniques, Twill 2/1, 195 g / m ² , in Nomex Delta TA from Dupont de Nemours, blend of 75% meta aramid fibers, 23% para aramid fibers and 2% anti-static fibers.

Membrane: Reference 89/55 from the company Proline, waterproof and breathable microporous membrane in flame retardant Polyurethane of about 40 g / m ² , laminated on an Sontara Nomex SL Type E-89 nonwoven, mixture of meta and para aramid of about 90 g / m ² .

Lining: fabric ref 4948 from the company DMC Tissus Techniques, Canvas, 120 g / m ² , in Nomex / Viscose FR, mixture of 50% meta aramid fibers and 50% Viscose flame retardant fibers in the mass. Nonwoven: Sontara Nomex SL Type E-89, mixture of meta and para aramid of approximately 90 g / m ² .

Mesh: three-dimensional mesh reference AR220 from the company TTI, 220 g / m ² , in Nomex T450, 100% meta aramid.

Felt: needle felt from DUFLOT, 120 g / m ² , Nomex, 100% aramid.

These different curves perfectly summarize the advantages and disadvantages of the various known jackets which have been presented above.

The object of the invention is to provide a textile complex for making clothing, which is light and comfortable, which, under usual operating conditions (flux from 0 to 1 kW / m ² approximately), transmits heat relatively well ( which corresponds to a high TF%) and quickly alerts the operator of the presence of a danger (which corresponds to a low T. ₁₂ ), and which, under critical conditions, such as a resulting heat flux a flash-over phenomenon (flow of around 40 kW / m), ensures for a sufficient period of time and in compliance with standards, a high insulation rate (i.e. a low TF%), in order to assure the operator a reasonable leak time. In addition, this complex must allow rapid drying when wet. To this end, the textile complex that it concerns, of the type comprising at least one fabric or textile tablecloth, made of a non-flammable material, intended to form the external face of the complex and a lining of comfort and cleanliness intended to form the inner face of the complex, is characterized in that on the inner face of the fabric and / or on the outer face of the lining are arranged beads of textile material having substantially the same orientation, fixed by binding on the fabric and / or on the lining during its manufacture, to form an integral part thereof, and delimiting between the fabric and the lining of the air-filled channels. The beads define with the lining, on the one hand, and the wall of the complex opposite the lining, on the other hand, channels which are filled with air. This air is not static but can circulate, insofar as it is not trapped, by a tight mesh, as is the case for example with structures of knitted type three-dimensional mesh or net. Thus, under normal conditions of use (0 to 1 kW / m ² of thermal flux), there is no water retention in these channels, nor significant overheating of the air. Conversely, during a very sudden temperature increase (around 40 kW / m ² of thermal flux for example), the quantity of air being in the channels delimited by the beads constitutes a sufficient thermal insulation, and satisfying the standard EN 469, to allow the operator to move away from the dangerous place.

This simplicity of structure contributes to the lightness of the garment obtained, and consequently to its comfort. This is reinforced by the circulation of air in the channels, which promotes the evaporation of the sweat water absorbed by the lining. Indeed, it is known that to help thermoregulation of the body, it is absolutely essential to allow the evaporation of sweating water. When the body temperature rises, the sweating mechanism intervenes to cool the body by evaporation of sweat. If the sweat water cannot evaporate and accumulates in liquid form in the different textile layers, the thermoregulatory mechanism of sweating is neutralized and the body temperature continues to rise. These characteristics, on the one hand, improve the thermoregulation of the operator's body and reduce thermal stress and, on the other hand, facilitate the drying of the garment when it has been wet, during an intervention, or for its maintenance. Indeed, due to its very reduced structure, the water absorption and storage capacities of the invention are practically reduced to those of the lining supporting the beads, compared to those of a felt which acts like a sponge. The main disadvantage of current complexes, such as felts or three-dimensional knitted fabrics, is precisely their low propensity to allow the evaporation of perspiration. On the contrary, they tend to absorb and store it.

Advantageously, the beads are made of a material which is not very compressible under the effect of an increase in heat. This maintains a sufficient volume of insulating air to provide protection, including under the effect of large heat flows (around 40 kW / m ² for example).

According to a first embodiment of this complex, each bead is made from thermostable fibers, such as para-aramid.

Advantageously in this case each bead is constituted by a bundle of wires assembled to each other, for example two twists of Nm 8/2 twisted together. Such a structure is less compressible than an equivalent title yarn composed of one end. According to one possibility, still in the case of this type of bead, each bead is fixed to the lining by binding with the threads of this lining, during the manufacture of the latter.

In order to ensure the provision of a sufficient volume of air between the beads, the thickness of each bead is greater than 0.3 mm, and preferably between 1 and 10 mm, and the spacing of the beads is greater at 2 mm, and preferably between 2 and 15 mm.

In order to promote the circulation of air, in the case of a garment produced from a textile complex, such as that which has just been defined, the beads and the channels which they delimit have a general longitudinal orientation clothing, especially vertical in the case of a jacket, promoting air circulation by a natural phenomenon of convection.

It is possible to provide between the outer protective fabric and the lining an impermeable and breathable membrane allowing water vapor to pass but not water in liquid form, this membrane also having a windproof effect, favorable for protection. thermal.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawings showing, by way of nonlimiting examples, an embodiment of this textile complex and an embodiment of a jacket obtained using this complex:

Figure 1 represents a series of curves showing the evolution of the heat transmission factor TF% as a function of the incident heat flow φ ₀ ;

Figure 2 represents a series of curves showing the evolution of the warning time T12 as a function of the incident heat flow φ ₀ ;

Figure 3 is an exploded perspective view of the various constituent layers of the complex; Figure 4 is a sectional view of this complex, transversely to the beads which comprises it;

Figure 5 is a partially cutaway perspective view of a jacket part made from the complex of Figures 1 and 2.

The complex shown in the drawing comprises an outer protective fabric 2 made of a non-flammable material, consisting of a fabric reference 4781 from the company DMC Tissus Techniques, Twill 2/1, 195 g / m ² , in Nomex Delta TA from Dupont de Nemours, blend of 75% meta aramid fibers, 23% para aramid fibers and 2% antistatic fibers. Against this outer fabric is arranged a waterproof and breathable membrane, consisting of the reference 89/55 from the company Proline, microporous waterproof and breathable membrane in flame retardant polyurethane of about 40 g / m ² , laminated on a non woven Sontara Nomex SL Type E-89, mixture of meta and para aramid of approximately 90 g / m ² . The complex finally comprises a lining 4 consisting for example of a fabric reference 4948 from the company DMC Tissus Techniques, Canvas 120 g / m ² , in Nomexp / Viscose FR, mixture of 50% meta aramid fibers and 50% viscose fibers Flame retardant in the mass. On the lining 4 is fixed, on the side facing the membrane 3, a series of continuous parallel beads 5 representing a surface mass of 70/80 g / m ² , constituted in the present case of yarn of fibers made of 100% para aramid Nm 8/2/2 (twist of 2 ends of Nm 8/2). Insofar as the lining is constituted by a fabric, the connection of the beads with the fabric is obtained during weaving, by a particular evolution of certain bottom threads of said fabric.

It should be noted that, in the complex shown in Figures 3 to 5, layers 2, 3 and 4 are generally not assembled, but simply juxtaposed. However it is quite possible that some of these layers are assembled by gluing for example, in the case of specific needs.

The thickness of each bead is of the order of 1 mm, and the spacing of the beads is of the order of 10 mm.

FIG. 5 represents a jacket 6 produced from the textile complex which has just been defined, and in which the beads 5 are oriented vertically.

The curves of FIGS. 1 and 2 illustrate the behavior of a complex I according to the invention.

This complex has the advantage, compared to certain existing complexes, of being lighter and more flexible, the beads 5 advantageously replacing a felt intended to trap air. These beads are lighter and more flexible than such a felt or a three-dimensional knitted fabric.

The water absorption capacity of these beads is very reduced compared to such a felt or a three-dimensional mesh, which greatly limits the phenomenon of pumping and storage of sweating water in the garment.

Thus, the pumping and water storage capacities of the insulating complex of the invention are practically reduced to those of the lining used as support for the beads, which in its form of embodiment as described above represents 2.5 times its dry weight. In comparison, that of complex F using a felt, which acts like a sponge, is 10 times its dry weight.

Maintained at a distance from the membrane by the beads, the lining serving as support for the complex of the invention is transformed into an exchange surface for the sweating water (which it absorbs) with the air circulating in the channels formed. by these so-called beads, accelerating evaporation and allowing the body to thermoregulate much faster. The appearance of thermal stress is thus delayed or even eliminated, in particular under the usual working conditions 0-1 kW / m ² .

This low water absorption capacity of the complex according to the invention also has the advantage of limiting the risk of burning by vaporization of the water trapped in the jacket in the event of exposure to a brutal flow of heat.

It also prevents weight gain of the garment in operation, an aggravating factor of thermal stress. Indeed, recent physiological studies have shown that the weight of the firefighters' textile intervention jackets has a direct influence on the thermal stress generated.

In terms of protection, the volume of air maintained in the channels ensures satisfactory thermal insulation by limiting rapid heat transmission under critical conditions (flow of the order of 40 kW / m ² ). The structure of this complex also ensures good sensitivity to heat under normal conditions of use, and therefore a low alert time T. ₁₂ , due to its low areal mass, as shown in Figure 2. This time alert under normal conditions approaches that of leather + lining complexes, recognized as being more reassuring than that of traditional textile complexes that are too insulating (curves E and F).

It appears from FIG. 1, that in terms of thermal conduction and non-confinement of heat, the complex according to the invention provides good comfort at low energy, 0 to 1 kW / m ² (usual working conditions) comparable to that of the leather + lining complexes recognized as posing few thermal stress problems, which results in a relatively high TF% (good heat transmission). On the contrary, it has, for high incident heat flows (around 40 kW / m ² ), a heat transmission factor TF%, low (good insulation), comparable to that of much heavier complexes, less comfortable and retaining much more the water.

The comfort of this complex in terms of reduction of thermal stress, is also expressed by a Ret (evaporative resistance) particularly low compared to existing products on the market.

The more the jacket complex allows good evaporation of sweat, which means that it will have a low resistance to evaporation, the better the body will be able to thermoregulate and avoid accidents.

The table below gives the Ret of the different complexes in fig 1 (measured according to standard EN31092)

- C: 85.0 m ² .Pa / W - D: 26.7

- E: 28.5

- F: 31.0

- I: 25.6

This classification evolves in parallel with the T. ₁₂ which illustrates the thermal sensitivity of the complex. We therefore have the double advantage in terms of comfort of combining low thermal insulation (low heat storage) under normal conditions and good evaporation, hence significant progress in terms of reducing the risk of thermal stress.

As it goes without saying, the invention is not limited to the sole embodiment of this textile complex nor to its sole application to the production of a jacket, on the contrary it embraces all variants. Thus, in particular, the lining could be made of a material other than fabric, it could be associated with a membrane or a film, the beads could be discontinuous and / or could be made of another material, such as silicone, or fixed by other means such as by gluing or stitching on the lining, or that the complex could be constituted by two layers not linked together, such as pants and overpants on the face interior of which are arranged beads, without departing from the scope of the invention.

Claims

1) textile complex for the production of thermal protection clothing, of the type comprising at least one fabric (2), or a textile web, made of a non-flammable material, intended to form the external face of the complex, and a lining (4) comfort and cleanliness, intended to form the inner face of the complex, characterized in that on the inner face of the fabric and / or on the outer face of the lining (4) are arranged beads (5) of textile material having substantially the same orientation, fixed by binding on the fabric and / or on the lining during its manufacture, to form an integral part thereof, and delimiting between the fabric and the lining of the channels filled with air.

2) Textile complex according to claim 1, characterized in that the beads (5) are continuous.

3) Textile complex according to claim 1, characterized in that the beads are discontinuous.

4) Complex according to one of claims 1 to 3, characterized in that the lining (4) comprises, on its face turned towards the outside of the complex, beads (5) having substantially the same orientation, and delimiting with the facing wall of the complex, air-filled channels.

5) Complex according to any one of claims 1 to 4, characterized in that the beads (5) are made of a material which is not very compressible under the effect of an increase in heat.

6) Complex according to claim 5, characterized in that each bead (5) is made of thermostable fibers such as para-aramid.

7) Complex according to any one of claims 1 to 6, characterized in that each bead (5) is constituted by a bundle of son assembled to each other, such as two twists of Nm 8/2 twisted together.

8) Complex according to any one of claims 1 to 7, characterized in that each bead (5) is fixed to the lining by binding with son of this lining, during the manufacture thereof. 9) Complex according to any one of claims 1 to 8, characterized in that the thickness of each bead (5) is greater than 0.3 mm, and preferably between 1 and 10 mm.

10) Complex according to any one of claims 1 to 9, characterized in that the spacing of the beads (5) is greater than 2 mm, and preferably between 2 and 15 mm.

1 1) Garment made from a textile complex according to one of claims 1 to 10, characterized in that the beads (5) and the channels which they delimit have a general longitudinal orientation to the garment, and in particular vertical in the case of a jacket.