Method for producing a fiber-reinforced plastic component

Abstract

A method is provided for producing a fiber-reinforced plastic component, in particular for use in a motor vehicle. The method includes the acts of: providing a blow-molded hollow core, forming the fiber-reinforced plastic component on the hollow core; inserting an end of the hollow core between a first roller and a first counter element, and drawing the hollow core from the plastic component by rotationally driving the first roller.

Claims

1. A method for producing a fiber-reinforced plastic component, the method comprising the acts of: providing a hollow core; molding the fiber-reinforced plastic component on the hollow core; inserting one end of the hollow core between a first roller and a first counter element; and drawing the hollow core out of the fiber-reinforced plastic component by rotationally driving the first roller.

2. The method according to claim 1, wherein, before the hollow core is drawn out of the fiber-reinforced plastic component, the hollow core is stretched by: inserting at least one further end of the hollow core into a holding apparatus; and stretching the hollow core by rotationally driving the first roller and/or by moving the further end by way of the holding apparatus for releasing the hollow core from the fiber-reinforced plastic component.

3. The method according to claim 2, wherein the holding apparatus comprises a second roller and a second counter element, wherein the first roller and/or the second roller are rotationally driven for stretching purposes.

4. The method according to claim 3, wherein the first counter element and/or the second counter element are in the form of further rollers, wherein the further rollers are rotationally drivable or are freely rotatable.

5. The method according to claim 1, wherein the drawn hollow core, which is composed of thermoplastic, is melted and processed to form a new hollow core.

6. The method according to claim 5, wherein, before the hollow core is melted, at least one of the ends of the hollow core is removed and is not processed to form the new hollow core.

7. The method according to claim 1, wherein the hollow core is filled with a liquid medium during molding of the fiber-reinforced plastic component, wherein the liquid medium is drained before the hollow core is drawn.

8. The method according to claim 1, wherein the hollow core is molded by resin transfer molding in a mold or wherein the hollow core is a blow-molded hollow core.

9. The method according to claim 1, wherein the fiber-reinforced plastic component is seated in the mold or in a mold cooling apparatus while drawing the hollow core.

10. The method according to claim 1, wherein negative pressure is generated in the hollow core, as a result of which the hollow core collapses and detaches from the fiber-reinforced plastic component.

11. The method according to claim 1, wherein the method produces a motor vehicle fiber-reinforced plastic component.

12. An apparatus for producing a fiber-reinforced plastic component, comprising: a first roller and a first counter element; a hollow core with a produced fiber-reinforced plastic component disposed on the hollow core; a drive, wherein the first roller is drivable in a first direction by the drive; wherein a first end of the hollow core that extends beyond a first end of the produced fiber-reinforced plastic component is clampable between the first roller and the first counter element; and a second roller and a second counter element, wherein the second roller is rotationally drivable in a second direction which is opposite the first direction, wherein a second end of the hollow core that extends beyond a second end of the produced fiber-reinforced plastic component is clampable between the second roller and the second counter element, and wherein the second end is opposite the first end; wherein the hollow core is stretchable when the first and the second rollers are rotationally driven in the opposite first and second directions.

13. The apparatus according to claim 12, wherein the first counter element and the second counter element are in a form of further rollers, wherein the further rollers are rotationally drivable or are freely rotatable.

14. The apparatus according to claim 12, wherein the first counter element is a sliding surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a flow diagram illustrating the first actions steps of the method according to an exemplary embodiment of the invention.

(2) FIGS. 2-6 each illustrate a method act for removing the hollow core from the plastic component according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(3) An exemplary embodiment of the method according to the invention will be described using the accompanying drawings and the text which follows.

(4) Using a plurality of schematic illustrations, FIG. 1 shows the processes of providing a blow-molded hollow core 1 and molding a fiber-reinforced plastic component 7 on the hollow core 1 by resin transfer molding.

(5) Firstly, a hollow core 1 which is produced from a thermoplastic by blow molding is provided. The hollow core 1 forms the inner contour for the plastic component 7 which is to be produced.

(6) For reasons of cost, the hollow core 1 has very thin walls. The hollow core 1 is dimensionally stable in the unstressed state. However, at the latest when the resin is injected, the hollow core 1 is filled with a liquid medium, in particular water. After the hollow core 1 is filled, it is closed.

(7) The hollow core 1 is braided with reinforcement fibers 3, in particular fibers which are composed of carbon. Particularly when reinforcement fibers 3 are wrapped around the hollow core 1 with a relatively high tensile stress, it is useful to fill the hollow core 1 with the liquid medium before the wrapping operation.

(8) The braided hollow core 1 is then placed into a mold 4 for the resin transfer molding process. The cavity of the mold 4 corresponds to the outer contour of the plastic component 7 which is to be produced. After the mold 4 is closed, a system comprising epoxy resin and curing agent is injected into the intermediate space between the hollow core 1 and the mold 4 under a pressure of, for example, 80 bar by means of a filling system 5.

(9) As a result of the mold 4 being heated, by a correspondingly heated liquid being conducted through heating tubes 6, the plastic matrix is finally cured. After the plastic matrix is cured, the liquid medium is drained from the hollow core 1.

(10) This is followed by the hollow core 1 being removed from the plastic component 7. The plastic component 7 either remains in the mold 4 or is inserted into a mold-like cooling apparatus in the process.

(11) FIGS. 2-6 show the corresponding steps for removing the hollow core 1. The figures show the method steps in a purely schematic manner. In particular, the plastic component 7 is illustrated in simplified form in these figures and represents plastic components 7 with a wide variety of geometries, in particular relatively long plastic components 7.

(12) An apparatus for carrying out the method includes a first roller 8 with an associated first counter (mating) element 11. The first counter element 11 is likewise in the form of a roller in the exemplary embodiment. At least the first roller 8, and preferably the first counter element 11, can be rotationally driven.

(13) As indicated by the corresponding arrows in FIG. 2, the first roller 8 and the first counter element 11 can be moved toward one another. As a result, one end 10 of the hollow core 1 can be inserted between the first roller 8 and the first counter element 11.

(14) FIG. 2 further shows a second roller 9 with a second counter (mating) element 13 at an opposite further end 12 of the hollow core 1. The second counter element 13 is also in the form of a roller here. The second roller 9 and preferably also the second counter element 13 can be rotationally driven. The further end 12 can be clamped by moving the second roller 9 and the second counter element 13.

(15) As an alternative to forming the two counter elements 11, 13 as rollers, these counter elements 11, 13 can also be in the form of sliding surfaces. Therefore, it is respectively sufficient for at least one roller 8, 9 to be provided at the two ends 10, 12 for the purposes of clamping and moving the hollow core 1.

(16) FIGS. 3 and 4 show the process of stretching the hollow core 1. According to FIG. 3, the two ends 10, 12 are clamped between the pairs of rollers. According to FIG. 4, the two rollers 8, 9 and preferably also the counter elements 11, 13 are driven in such a way that the two ends 10, 12 are drawn in different, preferably in opposite, directions. As a result, the hollow core 1 stretches and at the same time detaches from the plastic component 7.

(17) Instead of the second roller 9 and the second counter element 13, only one single holding apparatus could be used for fixing the further end 12. It is possible for the hollow core 1 to stretch and at the same time detach in this case too. However, particularly for very long components, it is useful, in line with FIG. 4, to draw on both ends 10, 12 for stretching purposes.

(18) FIG. 5 shows the process of drawing the hollow core 1 out of the plastic component 7. To this end, the further end 12 is released from the fixing arrangement between the second roller 9 and the second counter element 13 and withdrawn from the plastic component 7 by way of the first roller 8 and the first counter element 11.

(19) FIG. 6 shows the plastic component 7 without the hollow core 1.

(20) The hollow core 1 can be comminuted and recycled directly after being withdrawn in line with FIG. 5. In particular, the ends 10, 12 are not used for producing new hollow cores 1 in this case on account of the ends being contaminated.

LIST OF REFERENCE SYMBOLS

(21) 1. Hollow core 2. Liquid medium 3. Reinforcement fibers 4. Mold 5. Filling system 6. Heating tubes 7. Plastic component 8. First roller 9. Second roller 10. End 11. First counter element 12. Further end 13. Second counter element

(22) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.