Method for forming of a tubular semi-finished product from fibre-reinforced plastic material

Abstract

Disclosed is a method for producing a profiled semi-finished plastic product from flexible web material, including: providing a plurality of webs of flexible material, continuously and simultaneously feeding the webs of material to and along a plurality of shaping pieces arranged next to each other, folding each web of material around a respective shaping piece to form a body and an edge strip which projects transversely with respect to the body,causing the edge strips of different webs of material to at least partly cover each other, impregnating the webs of flexible material provided or the assembly of webs of material with folded-over edge strips covering each other with a hardenable unit, causing the hardenable unit to harden to form the profiled semi-finished plastic product, wherein open spaces remain between two neighbouring bodies and edge strips.

Claims

1. A method for producing a profiled semi-finished plastic product from web material, comprising: providing a plurality of webs of material; continuously and simultaneously feeding the plurality of webs of material to and along a plurality of shaping pieces arranged next to each other, having a greatest transverse dimension which is smaller than a width of the plurality of webs of material; folding each of the plurality of webs of material around a shaping piece to form a body and an edge strip which projects transversely with respect to the body; causing the edge strip of each of the plurality of webs of material to at least partly cover each other; impregnating the plurality of webs of material with folded-over edge strips covering each other with a hardenable means; causing the hardenable means to harden to form a profiled semi-finished plastic product, in such a manner that hollow or open spaces remain, each defined between two neighbouring bodies and edge strips in the profiled semi-finished plastic product.

2. The method according to claim 1, wherein gaps are formed between the shaping pieces and wherein the continuous and simultaneous feeding of the plurality of webs of material to and along the shaping pieces comprises: continuously and simultaneously feeding the plurality of webs of material via the gaps to and along the plurality of shaping pieces which are arranged next to each other.

3. The method according to claim 2, wherein the continuous and simultaneous feeding of the plurality webs of material to and along the shaping pieces comprises: allowing the edge strips to project with respect to the shaping pieces on either side of the gaps, in which case the body is situated in the area of the gaps and between the edge strips.

4. The method according to claim 1, comprising: folding each of the plurality of webs of material around a first side of the respective shaping piece to form a plurality of first edge strips; folding each of the plurality of webs of material around a second side of the respective shaping piece to form a plurality of second edge strips; causing the plurality of first edge strips on the first side of the respective shaping piece to cover each other; causing the plurality of second edge strips on the second side of the respective shaping pieces to cover each other.

5. The method according to claim 4, comprising forming the edge strip on opposite sides of the respective shaping piece.

6. The method according to claim 5, comprising causing the edge strip of the plurality of webs of material to project in opposite directions with respect to the body.

7. The method according to claim 6, comprising folding the edge strip by using a shaping element which moves in a peripheral direction around a common contour defined by the shaping pieces, wherein an axis of the shaping element is directed in a same direction as a longitudinal direction of the shaping pieces.

8. The method according to claim 1, wherein the edge strips cover each other in a manner of roof tiles.

9. The method according to claim 1, comprising: providing at least one auxiliary strip; fitting the at least one auxiliary strip so that it contacts at least one edge strip, and impregnating the at least one auxiliary strip together with the plurality of webs of material comprising folded edge strips covering each other with a hardenable means.

10. The method according to claim 1, comprising: separating a completed semi-finished product into several end products.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Below, exemplary embodiments of the invention will be described, solely by way of example and with reference to the accompanying diagrammatic drawings, in which identical parts are denoted by the same reference numerals.

(2) FIG. 1 shows a principle view of a device for carrying out the method according to the invention.

(3) FIG. 2a shows a view in perspective of a first embodiment of the device.

(4) FIG. 2b shows a view in perspective of a second embodiment of the device.

(5) FIGS. 3a-c show different stages of the shaping of a semi-finished product in the device.

(6) FIG. 4 shows a part of the completed semi-finished product obtained according to FIGS. 2a and 3a-c.

(7) FIG. 5 shows a part of the completed semi-finished product obtained according to FIG. 2b.

(8) FIG. 6 shows a part of a variant of the completed semi-finished product.

(9) The drawings are only intended for illustrative purposes, and do not serve to limit the scope of protection which is defined by the claims.

DESCRIPTION OF EMBODIMENTS

(10) The principle view illustrated in FIG. 1 shows the different steps related to the method according to the invention. According to this view, the direction of the production process is from the left to the right in FIG. 1. In this case, a number of webs of flexible fibre-reinforced material 1 are used, originating from the rollers 2. The webs of material 1 are impregnated with a resin 3 (or another suitable impregnating means), which is situated in the container 4. Subsequently, they are passed through the shaping device 5, in which the webs of material are given the desired shape. When they exit the shaping device 5, the webs of material 1 have been hardened and shaped to form a coherent semi-finished product 6. The inner parts 8 of the endless conveyor belts 7 engage with this semi-finished product, in such a way that a driving action is achieved on the webs of fibre-reinforced material 1 which are still connected thereto. By means of the sawing device 9, the finished products 10 are finally sawn off from the semi-finished product 6.

(11) Although FIG. 1 shows that impregnating can take place in the container 4, impregnating may alternatively take place in the shaping device 5 by means of the injection device 3.

(12) In the view in perspective from FIG. 2a, the shaping device is illustrated in more detail. The shaping device 5 contains a number of shaping pieces 11 which are arranged one above the other. In the illustrated exemplary embodiment, each of these shaping pieces 11 has the shape of a prismatic beam with a rectangular cross section. A small distance is left open each time between the shaping pieces 11 to form a gap 12. The webs of material 1 are fed to these gaps 12, due to the pulling power which is exerted by the inner parts 8 of the conveyor belts 7 on the semi-finished product 6 made from these webs of material 1.

(13) Because the width of each web of material 1 is greater than the width of the gap 12 and the width of the shaping pieces 11, and each of the webs of material 1 is supplied to the gaps 12 in a precisely centred manner, edge strips 13, 14 project from the gaps 12 on either side. The portion of the webs of material 1 which is situated in the region of the gaps 12 between both edge strips 13, 14 forms a so-called body 15.

(14) In the shaping device of FIG. 2b, auxiliary strips 23 may also be supplied between in each case two overlapping edge strips 13 or 14. The auxiliary strips 23 are taken from the reels 24, and deflected via guides 25 in such a manner that they are arranged next to and between two successive edge strips 13 or 14. Preferably, the auxiliary strips have a unidirectional fibre orientation, so that the strength and stiffness properties of the product can be influenced.

(15) As is illustrated in FIGS. 2, 3a and 3b, an edge strip 13 which is on the right-hand side, viewed in the conveying direction, is folded downwards. Subsequently, as is illustrated in FIG. 3c, the opposite edge strip 14 is folded upwards. The illustrated orientation of the edge strips 13, 14 can be obtained in a simple manner by means of the folding element 16 which is configured as a roller. This folding element 16 is displaceable along the path formed by the guides 17. This path runs around the series of shaping pieces 11 in such a manner that the roller 16 touches the shaping pieces 11, in particular the sides 18 thereof, or is at a small distance from these shaping pieces 11. Of course, it is also possible for the edge strips on the right-hand side to point upwards and those on the left-hand side to point downwards, or for both to point upwards or for both to point downwards.

(16) In this folded position, the edge strips 13 cover each other in the manner of roof tiles; the same applies to the edge strips 14. In this position, the unit comprising folded webs of material 1 is fed to the hardening device 19, for example a heating device or other device by means of which the impregnating means can be hardened. There, the resin with which the webs of material 1 have been impregnated is hardened. The edge strips 13 and 14, respectively, covering each other in the manner of roof tiles are in this case securely connected to each other, in such a way that a self-supporting unit is produced in the form of the semi-finished product 6 which ultimately emerges from the hardening device 19, again on account of the driving action of the endless belts 7. A portion of the resulting semi-finished product is shown in FIG. 4.

(17) When auxiliary strips 23 are used, these come to lie between in each case two successive edge strips 13 or 14. The auxiliary strips 23 may be as wide as an edge strip, but narrower or wider embodiments are also possible. A section of this semi-finished product is shown in FIG. 5.

(18) As has been described above, a product 10 can eventually be sawn off from the semi-finished product 6 by means of the sawing device 9. In this way, a continuous way of producing products 10 is achieved. As illustrated in FIGS. 2a, 2b, 4, 5 and 6, said product 10 has parallel surfaces 20, 21 which consist of edge strips 13 and 14, respectively, which overlap in the manner of roof tiles. The bodies 15 extend between these surfaces 20, 21, with hollow spaces 22 being present between these bodies 15. Such a product is highly suitable for use as a panel for many different purposes. By way of example, a bridge deck, flood gate and the like are mentioned. It is also suitable as a strong sheet material for containers and modular construction and the like. The tile-like overlapping of the edge strips 13 of which the surfaces 20, 21 are made has a very high resistance to local loads and is very tolerant with regard to, for example, local damage, such as can be caused by traffic which drives across a bridge deck formed in this manner.

(19) It will be clear that the above-described embodiments have only been described by way of example and not in any limiting sense, and that different modifications and adaptations are possible without departing from the scope of the invention and that the scope is only defined by the attached claims.

LIST OF REFERENCE NUMERALS

(20) 1 Web of fibre-reinforced material 2 Reel 3 Impregnating means (e.g. resin bath) 3 Injection device 4 Container 5 Shaping device 6 Semi-finished product 7 Conveyor belt 8 inner part of conveyor belt 9 Co-rotating sawing device 10 Finished product 11 Shaping piece 12 Gap between shaping pieces 13 Edge strip 14 Further edge strip 15 Body 16 Folding element 17 Guide folding element 18 Side of shaping piece 19 Hardening device (e.g. heating device) 20 Product surface 21 Further product surface 22 Cavity in product 23 Auxiliary strip 24 Reel 25 Guide