EP0299308B1 - Building element made from a velvet texture and method for its manufacture - Google Patents

Abstract

A structure based on velour fabric, having at least a first layer and a second layer and intermediate ribs connecting these layers provides a production-efficient, stable and nevertheless light-weight product. The velour fabric is made of a commercial yarn such as aramid fiber, carbon fiber, ceramic fiber or in particular glass fiber. The velour fabric is resin-hardened, wherein the intermediate ribs for rigid spacing elements between the first layer and the second layer.

Description

The invention relates to a component based on velor fabric according to the features of the preamble of claim 1. Furthermore, a method for producing a component by resinification and subsequent curing of a fabric according to the features of the preamble of claim 12.

The use of resin-hardened fiber composite materials has found a wide range of applications, be it in the form of load-bearing structural elements or for the fulfillment of insulation tasks. With the greatest possible rigidity and compressive strength, the lowest possible weight is also sought for special cases, such as flight technology.

From FR-A-1 393 269 a textile insulation element is known, which consists of spaced layers and connected by means of intermediate webs. The fabric can be made of glass fiber. It is important that a component manufactured according to this has a certain flexibility. In terms of production, it is also important that the tissue is kept under tension during resinification.

In addition to the prior art, US Pat. No. 3,481,427 is to be mentioned. From this it is known to chamber a textile component that can be produced using weaving technology. Glass fiber is also used. An element produced according to this document is a rigid component. The weaving of the intermediate webs is to be regarded as complex, since the hollow weaving process is used for this. All this brings certain difficulties with resin hardening; the fabric builds up when no special spacers are used for support. One therefore inserts support cores. However, the latter leads to extremely complex production.

On the other hand, types of weave such as weft velvet and warp velvet are known. For particularly economical manufacturing processes, two layers are used; so-called double velvet is created, in which the connecting webs between the layer-creating velor threads make a double shed formation. The length of the floating threads is adjustable so that longer or shorter web lengths are achieved. The center threads of the pile threads are then cut on a cutting bench.

Knowing this velor weaving method or Raschel plush weaving method, the present invention has set itself the task, starting from a state of the art according to US Pat. No. 3,481,427, with means simple in terms of production technology and even using existing machines, a light, yet stable to create multilayer, practically sandwich-like component.

In the subject of claim 1, this object is achieved in terms of device. The created component is characterized by the velor weaving process by intermediate webs, which form rigid spacing elements of the first and second layers and consist of helically twisted individual webs.

In the subject of claim 12 is carried out in the production such that after resinification of the fabric, a partial removal of resin is carried out by pressing, the removal of resin in one to such an extent that the restoring force is released by intermediate webs.

As a result of such an embodiment, a generic component of high bending and compressive strength is achieved, which also brings good results with regard to the weight factor. The distance between the layers is no longer bridged by woven sections, but by floating areas that support the layers to each other. Technical yarns such as aramid fiber, carbon fiber, ceramic fiber or in particular glass fiber or a mixture of the fibers mentioned are used here. Due to the binding structure in combination with the properties of such materials, the web-forming support surfaces endeavor to stand up. They brace the two layers from each other. This results in a structure which can be achieved in the weaving process and which tolerates deflections in the integration areas without damage. The even force-like restoring force saves any external support; rather, it was found that the velor fabric with hardened resinification from the many evenly distributed individual, free-standing intermediate webs so stable spacing elements creates that even the greatest loads to be expected in the course of the operation can be absorbed. There is also a high degree of sound insulation or absorption due to the high proportion of voids. Accordingly, there is again considerable material savings that are interesting today. The still given flexibility of the component allows a relatively good deformability, in particular a slightly spherical curvature of the sandwich-like body is accepted without disadvantage. In practice, the further design measure also proves to be advantageous in that the average length of the intermediate webs is greater than the distance between the layers. As a result, the intermediate webs are given a more or less steep oblique position, it proving advantageous in a further development that the intermediate webs run obliquely in a controlled manner. As a result, a load flowing over the wide area is still converted into a rectified layer displacement component. This is particularly advantageous for partial high loads, since the entire body is then included in the resistance to deformation. The corresponding regulation, ie rectification of the webs, also makes the evasive movement determinable. It has proven to be favorable that the intermediate webs enclose an angle of approximately 65 ° with a horizontal. Depending on the purpose of the component, a steeper position can be useful. In this case, the intermediate webs enclose an angle of approx. 85 ° with a horizontal line, which means that they are almost perpendicular to the horizontal line. Another means of optimizing flexibility while maintaining a high level of stability is that an intermediate web consists of two weakly twisted individual webs. As a result, there are, as it were, helically shaped spring bodies, which, however, are nevertheless axially highly resilient due to the weak twist. Only in the event of an overload does evasion occur due to further bending. In order to increase this effect even further, it is proposed that the intermediate web consist of 8-shaped twisted individual webs.

Fig. 1

einen Abschnitt des erfindungsgemäß ausgebildeten Bauteils in perspektivischer Darstellung, stark vergrößert,

Fig. 2

den Schnitt gemäß Linie II-II in Fig. 1,

Fig. 3

das Bauteil in Seitenansicht in Richtung A gesehen, weitestgehend schematisiert,

Fig. 4

das Bauteil in Seitenansicht in Richtung B gesehen, ebenfalls weitestgehend schematisiert,

Fig. 5

in Seitenansicht eine Verbindungszone zwischen zwei Velour-Gewebeabschnitten eines Bauteils,

Fig. 6

ein Bauteil in abgewandelter Ausbildung, und zwar in Seitenansicht in Richtung A gesehen, wiederum weitestgehend schematisiert,

Fig. 7

den Einsatz eines Zackenblattes in schematischer Darstellung,

Fig. 8

eine Variante des Gewebes gemäß Fig. 6, unterschiedliche Zwischensteg-Abstände darstellend,

Fig. 9

eine Weiterbildung dergestalt, daß zwischen die Zwischenstege gekreuzt verlaufende Zwischenstege eingeschaltet sind,

Fig. 10

eine Eckausbildung des Bauteils,

Fig. 11

das Bauteil mit auslaufender Randabflachung unter Einsatz der Gewebevariante Fig. 8 und

Fig. 12

eine solche unter Verwendung der Gewebevariante Fig. 9.

Even larger distances between the layers can be bridged without sacrificing stability by connecting the individual webs in their crossover area. So there is no weaving connection here either, but one that uses the binding resin. In this way, the total length of the spacing elements is divided into two cushioning zones which adjoin one another in the support direction and act in the same way, it also proving advantageous in this connection that the intermediate webs have base-like transition regions in the outlet region of the layers. The zones comparable to a tree stump widening towards the ground avoid any notch effect. Rather, the rotationally symmetrical, ie annular transition corner is filled to support the web. An advantageous variant of the web structure is that the intermediate webs are arranged with alternating large and small distances. In a further modification, it is then proposed that intermediate webs which are crossed with one another are interposed. An advantageous method for producing the component described by resinification and subsequent curing of a fabric, the resin being partially removed from the resin by pressing after resinification, is that when using a velor fabric which is made from a technical yarn such as aramid fiber , Carbon fiber, ceramic fiber or in particular glass fiber, the removal of resin takes place to such an extent that the restoring force is released by intermediate webs. With the removal of the squeezing forces, the resin-coated spacing elements spontaneously return to their starting position. After hardening, the overall structure is solidified. In addition, it is proposed that the weft threads be struck in a manner known per se by means of a serrated blade. This not only leads to an almost complete steep position of the intermediate webs between the layers, but above all to an exact parallel spacing of the layers of the tissue from one another. In In cases in which the component is to be composed of several fabric sections, the procedure is such that a velor fabric section is split in the connection area and the other velor fabric section is inserted into the opening thus created. If there is the intention or necessity to achieve even levels in the connection areas, then the spacing space which is already present between the layers can be used here by pressing the overlapped layer offset by the thickness of a layer. As a result, the spacing space has a further advantageous function. Also with regard to the connection itself, it proves to be favorable that the overlapping layer sections, like brush-like bodies, engage in the mesh joints of the fabric of the underlying wall sections as a result of the protruding intermediate web stubs. The layers are so to speak "locked". On the other hand, the corresponding axially compressed spring-bar-like webs yield resiliently in the transverse direction without breaking. The resin securing this bond counteracts the tendency to return to the original length, so that the connection area between the two fabric sections is also barely perceptible visually. The subject matter of the invention is explained in more detail below on the basis of an illustrative embodiment. It shows:

Fig. 1

a portion of the component designed according to the invention in a perspective view, greatly enlarged,

Fig. 2

the section along line II-II in Fig. 1,

Fig. 3

the component seen in side view in direction A, largely schematic,

Fig. 4

the component seen in side view in direction B, also largely schematized,

Fig. 5

in side view a connection zone between two velor fabric sections of a component,

Fig. 6

a component in a modified design, seen in side view in direction A, again largely schematic,

Fig. 7

the use of a serrated blade in a schematic representation,

Fig. 8

6 shows a variant of the fabric according to FIG. 6, showing different spacing between the webs,

Fig. 9

a further development in such a way that intermediate webs which cross between the intermediate webs are switched on,

Fig. 10

a corner formation of the component,

Fig. 11

the component with tapering edge flattening using the fabric variant Fig. 8 and

Fig. 12

one using the fabric variant FIG. 9.

The component 1 shown is produced on a velor weaving machine. The corresponding velor fabric or Raschel plush fabric is multi-ply, in the embodiment two-ply. A first, upper layer bears the reference number 2; a second, lower layer is denoted by 3.

Co-woven support threads, which form intermediate webs 4, hold the two layers 2, 3 together at a distance from one another. There is the uncleaved structure of a double velvet integration.

The number of support threads results from the weft density of the layers 2 and 3, also the number of support threads, measured over the weaving width and finally from the repeat size of the weave. With, for example, 2000 threads per 1 m weaving width, 12 picks / cm in the upper layer and the lower layer and 3/6 weft weave, there are 800,000 intermediate webs 4 between the two layers 2, 3.

By changing the number of web threads and weft density as well as binding, intermediate webs 4, which are several times higher or lower, can be woven. The required strength of the upper layer 2 and the lower layer 3 and bending strength are achieved by appropriate use of material from the warp and weft in the top layers. Of course, the web height is variable and can be individually adjusted to the desired height.

Technical yarns such as aramid fiber, carbon fiber, ceramic fiber or in particular glass fiber are processed.

As a result of the restoring force inherent in such high-performance fibers and also due to the connection structure, the support threads forming the intermediate webs 4 endeavor to straighten up after the weaving or to reset in a load-free state. This leads to a parallel spacing of the layers 2 and 3. The clear distance x between the two layers 2 and 3 corresponds to a multiple of a layer thickness.

The intermediate webs 4, which are comparable to the pile threads of a velor double velvet weave, are stiffened like the entire component body by hardening resin, so that the intermediate webs 4 form rigid spacing elements between the first layer 2 and the second layer 3. The resetting of the dividers 4 in its end position shown in FIG. 1 occurs even after the weaving structure has been completely compressed. Accordingly, no damage occurs during the weaving process due to the necessary deflections, which fact can be used advantageously in the manufacture of such components.

As can be seen from the figures, the average length of the intermediate webs 4 is greater than the clear distance x between the layers 2, 3. The free support thread sections forming them therefore do not change in the shortest possible way between the two adjacent layers 2, 3. Rather, as can be seen from FIG. 1, there is a slight inclination, seen from the viewing direction A in FIG. 1. This is clearer from the schematic illustration, for example according to FIG. 3. With respect to all the intermediate webs 4, an oblique bevel is used so that one can speak of a regulated bevel course.

The corresponding helix angle alpha is, according to FIG. 3, approximately 65 °, based on the horizontal support base of component 1, that is to say a horizontal.

According to variant Fig. 6, all intermediate webs 4 with the above-mentioned horizontal form an angle alpha of approximately 85 °. So there is a very steep incline here.

The variant Fig. 8 embodies a solution in that the intermediate webs 4 are arranged with alternating large and small distances. The larger distance corresponds to approximately twice the small distance between the parallel webs. 8, these intermediate webs are designed in an angular position to the horizontal as in FIG. 6.

The same also applies to the variant in FIG. 9, with the difference, however, that intermediate webs 8, which run crosswise to one another, are provided between two intermediate webs 4 are. The latter are located in the larger distance between two intermediate webs 4. The crossing angle beta is 50 ° to the horizontal. The pile threads of the fabric forming the intermediate webs 8 are rooted at a distance from the adjacent row of intermediate webs which corresponds to approximately one fifth of the length of an intermediate web 8.

On the other hand, the viewing direction B in FIG. 1 results in a vertical orientation (compare FIG. 4) to the base mentioned in all cases.

The term "medium length" is chosen because the intermediate webs 4 each consist of weakly twisted individual webs 4 ', 4˝, the real length turns out to be greater. The weakly helical rise results from the perspective illustration, FIG. 1. A single web, viewed in the direction of arrow B, changes from the back to the front in the direction of inclination, specifically in relation to the exit area on the layer side.

The intermediate web 4 is thus drilled into an eight (comparable to an oval ring rotated by 180 degrees about its longitudinal axis), the individual webs 4 ', 4' being connected to one another in their crossover area 5. Such intersection-like crossover areas 5 are achieved by touching the loop sections of the intermediate webs 4 forming the eight.

In the layer-side exit area and, of course, also in the entry area, the intermediate webs 4, 8 have socle-like transition areas 6, comparable to above-ground roots of trees, etc. This leads to a practically frustoconical transition between the inside of the layers and the spacing elements. The Kebelstumpfbasis corresponds to several times the cross section of a single web 4 'or 4˝. The circular fields recognizable on the top in FIG. 1 are intended to represent the layer entry area of the intermediate webs 4 symbolize. It is based on a W integration.

The intermediate web 4 designed as an eight creates after binding in the crossover area 5 two teardrop-shaped or chain link-like sections, the cavity of which is denoted by a, b, and which, depending on the vicinity of the individual webs 4 ', 4', can also be completely or partially filled with resin .

In this way or when the individual webs 4 ', 4' 'are always free, there is always a high-strength, columnar or strut-like, nevertheless a certain flexibility also in the axial direction having spacers.

Partial loads on the wide surfaces of component 1 also involve the intermediate webs located in the wider area, since, due to the slight inclination position, which is also the same, an opposing displacement movement (arrows z, z 'in FIG. 1) of layers 2 and 3 occurs. In addition to this good load distribution, the described shape of the intermediate webs 4 also has a force-consuming effect.

A constant parallelism of the layers 2 and 3 is obtained by striking the weft thread 9 of the upper and lower fabric layer by means of a serrated blade 10 (see FIG. 7). The reed bars of the serrated sheet 10 have notches 11 on the goods side, the bottom of which defines the center distance y of the layers 2 and 3, that is to say the upper and lower goods. The distance can be 8 mm, for example. The serrated blade also allows the weft threads 9 to be struck exactly in terms of height.

The warp threads are designated 12 throughout and form the intermediate webs 4, 8.

The uneven distribution of the intermediate webs leads to relatively large spaces. This reduces resin absorption. The parts are lighter in weight. The cross-shaped blocking of the rooms also increases the strength.

The application examples according to FIGS. 10 to 12 show, based on the exemplary embodiment in FIG. 10, a corner configuration in which the upper layer 2 folds into the inner corner of the angularly shaped component. This constellation can be blocked by an additional layer 13 placed on the inside. The additional layer 13 takes an essentially parallel curve to the apex zone 14 of the profile.

Component laminates are shown in FIGS. 11 and 12. These are bordered. The edge zone 15 is reduced to a minimum of the total thickness. This is done by bundling the layers 2, 3 of each component 1. Another advantage is the opposite inclined orientation of the individual components 1. This leads to an internal blockage and a very high strength of the overall component.

The fabric structure explained is soaked with marker-containing resin plus hardener. The excess amount of resin is squeezed or rolled out, so that the inner structure is resin-free except for the wetted, web-forming support threads and the two impregnated fabric layers. The entry positions of the individual webs 4 ', 4'', which are somewhat displaced in each case, lead to a sliding movement on the leg sections up to the maximum reset zone. Sufficient resin is dragged along so that the crossover areas 5 are well saturated with resin; reference is made to FIG. 2, from which such a resin accumulation zone can be seen. The corresponding evacuation to resin takes place to such an extent that the restoring force of the intermediate webs 4 is released until, as already indicated, they reach their basic or final position. After the drying process there are hardened ones Components of high rigidity and pressure resistance. The good deformability of the velor fabric or Raschel plush fabric also allows the production of slightly spherically curved components.

Local and different compression of the impregnated tissue also enables different component thicknesses to be realized from one tissue.

The realized sandwich-like structure counteracts any delamination tendency, for example in the sense of a layer peeling off, due to a single coherent structure.

In the case of larger components that exceed the weaving width, such a component 1 is composed of a plurality of fabric sections 1 ', 1' '. For this purpose, a velor fabric section 1 'is split in the connection area to the other velor fabric section 1' '. This measure can be seen from the schematic illustration in FIG. 5. The gap is designated 7 there and is generated by a center cut in accordance with the desired overlap depth. The corresponding edge zone of the subsequent tissue section 1 '' is inserted into the opening thus created. While maintaining a constant overall thickness of the component 1, the edge layers near the connection area are pressed together in the direction of the spacing space. Then follows the described soaking with resin and squeezing. The tissue resets in the manner described. The corresponding provision can be limited by back support in the connection area V, so that the thickness of the component 1 is the same throughout. The more flattened edge zone disappears in the existing space. The brush-like web stubble, which is free-standing due to the split cut, is buried anchoring in the outside of the overlapped edge of the fabric section 1 ''. The latter leads to an intimate, durable bond.

Claims (14)

1. Pile fabric-based component, with at least one first (2) and second (3) layer and intermediate webs connecting these layers (2, 3), wherein the pile fabric consists of a commercial yarn such as aramide fibre, carbon fibre, ceramic fibre or in particular glass fibre, and wherein the pile fabric is resinified to the point of hardening, wherein the intermediate webs (4) form rigid spacer elements of the first layer (2) and second layer (3) and consist of helically twisted single webs (4', 4'').
2. Component according to claim 1, characterised in that the mean length of the intermediate webs (4) is greater than the distance (x) between the layers (2, 3).
3. Component according to one or more of the preceding claims, characterised in that the intermediate webs (4) are adjusted to extend at an angle.
4. Component according to one or more of the preceding claims, characterised in that the intermediate webs (4) form an angle (alpha) of about 65° with a horizontal.
5. Component according to one or more of the preceding claims, characterised in that the intermediate webs (4) form an angle (alpha) of about 95° with a horizontal.
6. Component according to one or more of the preceding claims, characterised in that an intermediate web (4) consists of two slightly twisted single webs (4', 4'').
7. Component according to one or more of the preceding claims, characterised in that the intermediate web (4) consists of single webs (4', 4'') twisted in a figure of eight.
8. Component according to one or more of the preceding claims, characterised in that the single webs (4', 4'') are connected to each other in their region of crossing over (5).
9. Component according to one or more of the preceding claims, characterised in that the intermediate webs (4) comprise pedestal-like junction zones (6) in the exit region of the layers (2, 3).
10. Component according to one or more of the preceding claims, characterised in that the intermediate webs (4) are arranged alternately at longer and shorter intervals.
11. Component according to one or more of the preceding claims, characterised in that intermediate webs (8) crossed with each other are interposed.
12. Method for the manufacture of a component, in particular according to any of claims 1 to 11, by resinification and subsequent hardening of a fabric, wherein after resinification of the fabric, partial removal of resin is performed by squeezing, characterised in that where a pile fabric which forms intermediate webs as rigid spacer elements between the first and second layers is used, resin is removed to such an extent that the return force of intermediate webs (4 or 8) is released.
13. Method according to claim 12, characterised in that during the weaving process, looping of the weft threads (9) by hand is carried out in a manner known in the art by means of a toothed sheet (10).
14. Method according to claim 12, wherein the component is composed of several fabric sections, characterised in that one pile fabric section (1') is split in the junction zone (V) and the other pile fabric section (1'') is laid in the opening formed in this way.

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