EP2004886A2

EP2004886A2 - Stretchable fabric

Info

Publication number: EP2004886A2
Application number: EP07724204A
Authority: EP
Inventors: Jörg RUSCHULTE
Original assignee: Global Safety Textiles GmbH
Current assignee: Global Safety Textiles GmbH
Priority date: 2006-04-12
Filing date: 2007-04-12
Publication date: 2008-12-24
Also published as: JP2009533565A; MX2008013155A; CN101421450A; ZA200808659B; DE102006017270A1; US20090194188A1; WO2007118673A3; CA2649382A1; WO2007118673A2

Abstract

Disclosed is a fabric comprising first and second warp threads and first and second weft threads. Said fabric is characterized in that the first warp threads (11, 12) and the first weft threads (13) form a basic fabric (17) while the second warp threads (14), along with the second weft threads (15), form a covering fabric that adjoins the basic fabric (17), the second warp threads (14) also being interwoven with the first weft threads (13).

Description

Stretchy fabric

The present invention relates to a stretchable fabric having first and second warp yarns and first and second weft yarns.

There are known tissues that are used for the production of air bags for personal restraint systems, and which are installed uncoated. An airbag provided with such a fabric is abruptly inflated in the application with an inflation gas, wherein the tissue is loaded by the resulting pressure in the air bag to train with the result that the fabric structure opens, that is, by pulling apart the fabric structure, the air permeability increases the tissue, and can flow in the appropriate application inflation gas. As a result, the performance of the airbag can be severely impaired, for example by a slower deployment of the airbag, due to constantly occurring air loss, with the result that the air cushion is only later ready for use and thus only later can develop a protective effect for a passenger. In addition, the passenger may experience health damage due to leakage of the inflation gas.

Attempts have been made to counteract the higher Aufblasgasverlust by larger generators. However, this entails increased costs for the finished module. Another way to avoid the negative consequences just described is to coat or laminate the tissues for the air bags. This can actually produce a much better and with regard to the air permeability almost optimal tissue. However, the manufacturing costs for such a tissue increase immensely. Reason- In addition, the additional production step "coating or lamination" also makes the overall production more extensive and thus inevitably more critical.

The invention has for its object to propose a tissue in which the said and known from the prior art disadvantages are avoided or at least greatly reduced.

The object is achieved, firstly by a fabric according to claim 1. This fabric with first and second warp threads and first and second weft threads is characterized in that the first warp threads and the first weft threads form a base fabric and the second warp threads with the second weft threads to the Base fabric adjacent roofing fabric, wherein the second warp threads are also interwoven with the first weft threads and wherein the first warp threads and the second warp threads are arranged so that they lie after stretching of the fabric - alternately - substantially side by side, so always next to a first warp thread a second warp thread comes to rest. With the fabric according to the invention there is the advantage that, when the fabric is used to form an airbag, so that the two roof fabrics face each other, an air cushion can be produced on the respective roof fabric in the explosion case, the first application of gas through the airbag gives the generator. The construction of the fabric according to the invention causes the first warp yarns and the first weft yarns to stretch according to the load when the airbag is inflated, with the second warp yarns drawing the second weft yarns into the intermediate spaces created between the first weft yarns due to the elongation of the base fabric. As a result, as the pressure increases, they simultaneously close the same way to the formation of "gaps" or "holes" in the fabric by "stuffing" by means of the second weft threads, which could also be called sealing threads, thereby avoiding or at least greatly delaying an increase in air permeability. The result is that due to the self-sealing or tightly holding tissue under load, a flow of the inflation gas is restricted.

On the other hand, the object is also achieved with a fabric according to claim 2. This fabric with first and second warp threads and first and second weft threads is characterized in that the modulus of elasticity of the first warp threads is higher than the modulus of elasticity of the second warp threads, and that the second warp threads are woven with lower warp tension than the first warp threads, and that the first weft threads lie in a ground plane and the second weft threads lie in a roof plane adjacent to the ground plane, wherein the first Warp threads and the second warp threads are arranged so that they are after stretching of the fabric alternately substantially adjacent to each other, so that always comes next to a first warp a second warp. The advantages of this fabric according to the invention are the same as those of the fabric according to claim 1. In the case of the second tissue solution, however, the behavior of the tissue according to the invention in an airbag results in a different behavior of the tissue. However, the result is basically the same as that of the first fabric, namely that the air permeability of the fabric during the use phase does not increase and, accordingly, the flow of inflation gas during deployment and the service life required for an airbag do not appreciably increase. The construction of the fabric according to the invention according to claim 2 results in a much stronger ondulation of the second warp threads, since these have a higher modulus of elasticity than the first warp threads and are interwoven with lower warp tension. If, in the case of use of the fabric in an airbag, tension is exerted on the fabric, the first warp yarns with a lower modulus of elasticity are stretched more than the second warp yarns with a higher modulus of elasticity, so that the distance between the first weft yarns increases with tensile load on the fabric is compensated by the fact that the previous lying in the roof level second weft thread more or less in the growing gaps between the first weft threads arrange, and thereby the absolute distance between two adjacent weft yarn remains approximately the same. Thus, it is advantageously possible to keep the gap and thus the air permeability between the warp and weft threads in approximately constant or individually controlled via the load profile by the gas pressure occurring in the airbag.

Throughout the description is spoken repeatedly of first and second warp and weft threads. It is emphasized that not only individual threads are meant, but also multiply laid threads or folded threads, d. H. multiple adjacent threads may be meant. In the formulation z. For example, "a first warp" is meant the word "a" functional and not numerical.

The fabric according to the invention can be provided in both solution variants as a piece, for example as a filter part or gas discharge mechanism in an airbag, both ready-made and in "one-piece-woven" air bags (OPW). The airbag may also be made entirely of such a fabric.

It should be emphasized that in a woven fabric in the warp and / or weft direction threads of different construction and / or material elongation can be used according to the invention. This - A -

is not intended exclusively for use in vehicle occupant protection systems, but can be used in many areas of technical textiles.

It is also possible according to the invention, for example, to use a heavily textured material for the first weft threads (binding threads) in the weft direction and to subject the first warp threads (sealing threads) to a very high warp tension, so that the second warp threads (sealing threads) allow production from the base fabric composite by the stretchability of the textured material, lifted out and thus placed above the fabric rather than in the ground fabric plane.

The invention will be briefly described below by way of example with the aid of a drawing for better understanding.

Fig. 1 shows schematically a fabric of the prior art in the unloaded state.

Fig. 2 shows schematically the fabric of Fig. 1 in the loaded state, as it takes place in the application of an airbag.

Fig. 3 shows schematically an embodiment of the tissue according to the invention in the unloaded state.

Fig. 4 shows schematically the tissue of FIG. 3 in the loaded state.

Fig. 5 shows schematically another embodiment of the tissue according to the invention in the unloaded state.

Fig. 6 shows schematically the tissue of Fig. 5 in the loaded state.

Fig. 1 shows greatly enlarged weft threads 3 shown as circles, which of warp threads 1 and 2 in the usual manner of a woven plain weave L 1/1 tissue, wherein the distance between two weft thread is denoted by the reference numeral 6. The upper illustration of FIG. 1 shows a section through a fabric along a first warp thread, in which a first warp thread 1 wraps around weft threads 3.

The lower illustration of a detail of a plain weave fabric known from the prior art shows a section through the fabric along a second warp knit fabric. thread 2. The distance 6 between the weft thread 3 (the behavior is the same between warp thread) is due to the design.

FIG. 2 now shows the fabric sections according to FIG. 1 in the loaded state, that is to say, for example, in the case of use of the fabric in an airbag, during or after it has been inflated. The application of gas to the airbag (not shown) by a generator (not shown) and / or the immersion of a passenger in the airbag cushion results in a tensile load on the fabric, resulting in a spacing 6 between the weft threads - in FIG for the loaded condition each with a small a provided - remove from each other. The distance 6a is greater than the distance 6, and the weft threads in the position 3a have correspondingly greater distances. The aforementioned increase in the distance 6a between the weft threads 3a causes an increase in the air permeability through the tissue. There is a construction and a substance expansion. In the course of substance expansion, the threads (warp threads and weft threads) also become thinner.

FIG. 3 now shows an embodiment of a new fabric in which first weft threads 13 and second weft thread 15 lying above (so-called sealing threads) are arranged. Analogous to the representation according to FIGS. 1 and 2, the weft insertion of the first 13 and second 15 weft threads in conjunction with the warp threads 11 and 14 is again shown in the upper part of FIG. Wherein the first weft threads 13, as it were, form a base fabric 17, above which a not really "adjacent" roofing fabric 19 is arranged. 3 shows warp threads 12 and 14. As can be clearly seen from FIG. 3, the first warp threads 11 and 12 only undulate around the first weft threads 13, whereas the second warp thread 14, here, as it were in function of a binding thread, forms the first warp thread second weft threads 15 to form a roof fabric 19 to the base fabric 17 binds. The second weft thread 15, so the sealing thread are not here, but rather arranged on the base fabric 17 and form a "roof fabric" 19. In fact, the roof fabric 19 is not its own tissue, but a resting on the base fabric 17 fabric area 19, represented by the Weft threads 15 and the second warp threads (binding threads) 14. While the tissue according to FIG. 3 is shown in the unloaded state, FIG. 4 now shows the tissue from FIG. 3 in the loaded state. The first and second warp yarns 11, 12 have stretched under the load extending to the left and right in FIG. The distance between the weft yarns 13a has increased to the dimension 16a, and in the space between the weft yarns 13a, the second weft yarns 15a (sealing yarns) are drawn into the interstices 16a by the binding yarns (second warp yarns 14a). hereby It is possible to keep the gap between the threads constant and thus to keep the air permeability through the tissue even in the load state almost constant.

With the special construction of the fabric according to the invention it is now possible by presetting the run length of the second warp thread (binding thread 14) to the weft threads 13 and 15, the intermediate space 16 resulting from the drawing under stress, and thus also the air permeability between the threads of the fabric to keep constant, to reduce with increasing load, or to increase the requirements accordingly, or to steer individually over the course of the load. For example, it is possible to set the narrowest spacing between two sealing weft threads (in FIG. 3 distance 16 and in FIG. 4 distance 16b) in FIGS. 3 and 4. In this exemplary embodiment shown here, the distance in FIG. 3 between two weft threads 13 (= distance 16) remains equal to the distance 16b in FIG. 4 between two weft threads 13a and 15a. In this case, one assumes a constant air permeability. If the running length of the second warp thread 14 (binding thread) is selected to be greater than in the variant shown in FIG. 3, then, when the fabric is loaded analogously to the representation according to FIG. 4, a distance 16b which is greater than the distance 16 according to FIG 3. In the woven construction according to Fig. 3, the distance between the fabric layers 17 and 19 would then be greater. Conversely, you could make the distance between the fabric layers 17 and 19 smaller, which would lead to that under load of the fabric analogous to FIG. 4, the distance 16b would be smaller than the distance 16 of FIG. 3 and thus the air permeability with increasing load would be reduced.

The described fabric construction according to FIGS. 3 and 4, of course, also vice versa, that is, interchangeable with warp and weft threads applicable. In the weft direction, for example, one could use a heavily textured material for the binding threads and apply a very high warp tension to the analogous sealing thread, so that the sealing threads are lifted out of the base fabric composite during production, made possible by the stretchability of the textured material and thus above the fabric. Roofing fabric) than in the tissue.

Fig. 5 shows a second embodiment of a fabric according to the invention in the unloaded state, with similar behavior as in the first embodiment, but without separate binding and sealing thread. 5, two different yarn materials are used in the warp, namely first warp yarns 21 and second warp yarns 24, the second warp yarns 24 having a relation to the modulus of elasticity of the first warp yarns 21 have higher modulus of elasticity. As is already apparent from the illustration according to FIG. 5, the second warp threads 24 are interwoven with a lower warp tension than the first warp threads 21. The fabric layer results in such a way that the first weft threads 23 are located in a ground plane 27 and the second weft threads 25 are located in a roof level 29. The first warp yarns 21 with a lower modulus of elasticity compared to the second warp yarns 24 are presented with a warp tension for fabric production, and the second warp yarns 24 with an modulus of elasticity which is higher than the modulus of elasticity of the first warp yarns 21 are provided with an im Compared to the first warp threads 21 submitted lower warp tension. This results in the state of the fabric shown in FIG. 5, in which the second weft threads 25 rest, as it were, on the first weft thread 23 and results in a roof plane 29 lying on a ground plane 27.

FIG. 6 now shows the tissue according to FIG. 5 in the loaded state. With the same absolute load on the fabric, the first warp yarns 21a with a lower modulus of elasticity are stretched more than the second warp yarns 24a with a higher modulus of elasticity, so that the increasing distance (26 becomes 26a) between the first weft yarns 23a under tensile load the fabric is compensated by the fact that the previously overlying weft thread 25 depending on the load more or less in the increasing gaps 26a and arrange the absolute distance 28 between two adjacent weft yarn 23 a, 25 a remains the same. Thus, it is possible to keep the gap 26/28 and thus also the air permeability between the weft thread constant.

In an advantageous embodiment of the invention, a tissue, for. Example, as shown in Fig. 6, woven, which is characterized in that it is woven in the unloaded state same ondulation of the first warp 21 and the second warp 24, wherein the material elongation of the second warp 24, 24a is higher than the material extensibility the first warp yarns 21, 21a. Advantageously, in this fabric, second weft threads (sealing threads 25), due to the different material elongation capacity of the warp threads in the loaded state, can be lifted out of the plane of the first weft threads.

The distance can also be increased or reduced compared to the relieved tissue Fig. 5. The construction according to the invention allows the air permeability to increase disproportionately when weaving a fabric similar to the fabric of Fig. 6, that is, with the same undulation of the warp yarns 21 and 24, now in the unloaded state. However, the second weft yarns (sealing yarn 25), due to different material elongation (the material elongation of the second warp 24, 24a is higher and the material extensibility of the first warp 21, 21a is lower) are lifted out of the plane of the first weft yarns 23 in the loaded state (analogous to the representation of FIG. 5, but with an even greater distance between the levels 27 and 29, but in the loaded Status).

In another advantageous embodiment of the invention, a fabric is proposed in which the course of the expansion curve is set individually, which is characterized in that it in predetermined areas warp threads and weft threads with selectively selected parameters such as moduli E, or in a specifically selected sequence having. With fabric constructions made from the described fabrics according to the invention, other technical parameters such as, for example, the course of the expansion curve can be set individually, which subsequently also influences, for example, the unfolding behavior of the air sacs by more or less or individually expanding tissue sections. Thus, in the future, these intelligent tissue can be used to independently adjust the tissue parameters, which are today dependent on one another, independently of one another.

REFERENCE NUMBERS

, Ia first warp, 2a first warp, 3a weft, 6a distance

1, I 1a first warp thread 2, 12a first warp thread 3, 13a first weft thread 4, 14a second warp thread (binding thread) 5, 15a second weft thread (sealing thread) 6, 16a distance 6b distance 7 base fabric 9 roofing fabric

1, 21a first warp yarn 3, 23a first weft yarn 4, 24a second warp yarn 5, 25a second weft yarn (sealing thread) 6, 26a distance 7 ground plane 8 distance 9 roof level

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Claims

PATENT CLAIMS

A stretchable fabric having first and second warp yarns and first and second weft yarns, characterized in that the first warp yarns (11, 12) and the first weft yarns (13) constitute a base fabric (17) and the second warp yarns (14) form the second warp yarns (14) Weft threads (15) form a roof fabric (19) adjacent to the base fabric (17), the second warp threads (14) also being interwoven with the first weft threads (13), and wherein the first warp threads (11, 12) and the second warp threads (14 ) are arranged so that they lie after stretching of the fabric - alternately - substantially side by side, so always next to a first warp thread (11, 12), a second warp thread (14) comes to rest.

2. Stretchable fabric with first and second warp threads and first and second weft threads, characterized in that the modulus of elasticity of the first warp threads (21) is lower than the modulus of elasticity of the second warp threads (24) and that the second warp threads (24) are interwoven with lower warp tension than the first warp threads (21) and that the first weft threads (23) lie in a ground plane (27) and the second weft threads (25) lie in a roof plane (29) adjacent to the ground plane (27) first warp threads (21) and the second warp threads (24) are arranged so that they are after stretching of the fabric alternately substantially adjacent to each other, so always next to a first warp thread (21), a second warp thread (24) comes to rest.

3. fabric, in particular according to claim 1 or 2, characterized in that it is woven in the unloaded state same ondulation of the first warp threads (21) and the second warp threads (24), wherein the material elongation of the second warp threads (24, 24a) is higher as the material stretchability of the first warp yarns (21, 21a).

4. fabric, in particular according to claim 1, 2 or 3, characterized in that it has in predetermined areas warp threads and weft threads with selectively selected parameters such as moduli E, or in a specifically selected sequence.

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