Tool for the production of fiber composite components

Abstract

The present invention provides a tool for the production of fiber composite components. The tool has a surface for depositing semifinished fiber products on the surface, the surface having a number of openings for feeding a matrix to the deposited semifinished fiber products. It is consequently possible to dispense entirely or partly with a conventional flow promoter and possible to achieve a high quality of fiber composite component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a view of a section through a tool with a placed-in semifinished fiber product according to an exemplary embodiment of the invention;

FIG. 1B shows a view of a section through a tool with a placed-in semifinished fiber product according to a further exemplary embodiment of the invention;

FIG. 2 shows a plan view of a tool according to yet a further exemplary embodiment of the invention;

FIG. 3 shows a view of a section along the sectional line E-E from FIG. 2;

FIG. 4 shows a plan view of a tool according to yet a further exemplary embodiment of the invention;

FIG. 5 shows a plan view of a tool according to get a further exemplary embodiment of the invention;

FIG. 6 shows a plan view of a tool according to yet a further exemplary embodiment of the invention;

FIG. 7 shows a plan view of a tool according to yet a further exemplary embodiment of the invention; and

FIG. 8 shows a view of a section through a tool for an injection process according to yet a further exemplary embodiment of the invention.

In the figures, the same reference numerals designate components that are the same or functionally the same, unless otherwise indicated.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1A shows a view of a section through a tool 1 with a placed-in semifinished fiber product 3 according to an exemplary embodiment of the invention.

The tool 1 has a table 1a with a surface 2, the form of which defines the form of the components to be produced. The table 1a preferably consists of metal, but may also consist of plastics, ceramics or other suitable materials.

On the surface 2, the semifinished fiber product 3 is arranged. The semifinished fiber product 3 may be, for example, a laid, woven or knitted fabric, a nonwoven fabric, loose fibers or a sandwich-like structure. The thickness of the semifinished fiber product 3 may also vary over the surface 2.

A peel ply and/or a release film 4 is/are typically arranged between the surface 2 and the semifinished fiber product 3. In the same way, such a release film and/or peel ply 5 may also be arranged on the semifinished fiber product 3.

The entire construction is packed in an airtight manner by means of a vacuum film 6 and sealing strips 7. It may prove to be expedient to use a double-walled vacuum film 6, as indicated in FIG. 1. Also possible in principle are other types of vacuum bagging that are necessary for different processes (for example introducing membranes in the case of vacuum assisted processing (VAP) or inlet and outlet are identical as in the case of single line injection (SLI)). The air under the vacuum film 6 is extracted by way of pumping connections 9.

An inlet 8 is connected to a reservoir (not represented) for resin. The resin is sucked into the bagging by the pressure gradient forming. The resin flows along the surface 2 of the tool 1 and through the semifinished fiber product 3. It is of particular importance here that the semifinished fiber product 3 is uniformly impregnated with the resin. Excess resin is carried away at an outlet 9.

The inlet 8 and/or the outlet 9 may be integrated in the surface 2 of the tool 1. On the other hand, it is similarly possible to provide them in the conventional way as tubular or punctiform feeds which are packed underneath the vacuum film 6. The inlet 8 and the outlet 9 are preferably in different planes, in particular on different sides of the semifinished fiber product 3.

Grooves 12 (for the sake of overall clarity, only one of the grooves is provided with a reference numeral) in the surface 2 connect the inlet 8 to the outlet 9. The resin can consequently distribute itself uniformly over the surface 2 in the grooves 12.

The groove cross section is preferably half-round, but may also be of any other desired form. The width lies with preference in the range from 0.1 mm to 4 mm. The depth may be of the same order of magnitude. The groove cross section can also be used at the same time to set the throughput of resin. Two grooves may also differ over part of their length or over their entire length in cross section, geometry, width and/or arrangement.

The flow of the resin is schematically indicated by the flow front 10. The flow front 10 has an inclination with respect to the vertical. This is caused by the different flow rate of the resin in the grooves 12 and the semifinished fiber product 3. The flow rate in the grooves 12 should preferably be adapted to the flow rate in the semifinished fiber product 3.

With respect to FIG. 1B, only the differences in comparison with the construction from FIG. 1A are to be discussed.

On the side facing away from the tool, a conventional flow promoter 5′ has been applied to the semifinished fiber product 3, which has for example a sandwich construction. This flow promoter 5′ is connected to the inlet 8 and the outlet 9. As a result, faster impregnation of the semifinished fiber product 3 with resin can be achieved in comparison with the exemplary embodiment according to FIG. 1A. However, the side of the semifinished fiber product 3 facing the surface 2 continues as before to be subjected to resin without a flow promoter.

Thereafter, various embodiments of the tool 1 are respectively shown in a plan view or sectional view. These can be combined with one another in various ways.

FIG. 2 shows parallel running grooves 12, which connect an inlet 8 to an outlet 9. The grooves 12 are upwardly open, as shown in the cross section along the sectional line E-E in FIG. 3.

In FIG. 2, the density per unit area of the grooves 12 is, for example, greater in the region C than in the region D. As a result, the greater throughput of resin is achieved in the region C than in the region D. Moreover, more uniform wetting of the surface 2 can be achieved.

FIG. 4 shows parallel running grooves 12, which connect an inlet 8 to an outlet 9. In a region A near the inlet 8, the grooves 12 are wider than in a region B near the outlet 9. Consequently, more resin can be taken up by a placed-in semifinished fiber product in the region A than in the region B, in particular since the resin flows more slowly in the region A.

FIG. 5 shows an inlet 8 and an outlet 9. A network of crossing grooves 12 connects the inlet 8 and the outlet 9. The mean flow direction is substantially from the inlet 8 to the outlet 9, as indicated by the arrow 11.

The grooves 12 have an inclination or an angle 22, 23 with respect to the mean flow direction 11. The resin consequently does not flow from the inlet 8 to the outlet 9 by a direct path. The lengthening of the path has the effect that the resin stays longer in contact with placed-in semifinished fiber products.

The angles 22, 23 may lie in the range from 0° to 90°, preferably 40° to 50°.

In a further exemplary embodiment of the tool 1 according to the invention, as shown in FIG. 6, parallel grooves 12 may connect an inlet 8 to an outlet 9. The grooves 12 may in turn be inclined with respect to the mean flow direction.

Grooves 12 in FIG. 7 are arranged in an approximately zigzag form and thereby likewise inclined in relation to the mean flow direction.

FIG. 8 shows a section through a tool 1 for an injection process according to yet a further exemplary embodiment of the invention. The tool 1 is in this case formed such that it can be closed in a pressure-tight manner. Resin is fed in and carried away by way of an inlet 8 and outlet 9, respectively. The distribution of the resin takes place by way of grooves 12 in the surface 2 of the tool 1. Semifinished fiber products arranged in the cavity 13 can consequently be impregnated uniformly.

After the production of a fiber composite component, the tool 1 can in principle, if required, be freed of any remains of resin or cleaned. As a result, repeated use of the tool 1 is ensured.

In the figures, the surface 2 is represented in a planar form. However, this is not to be considered as restrictive. The surface 2 may have any desired curved forms. The grooves, however, continue to run in the surface.

Although the present invention has been described here on the basis of preferred exemplary embodiments, it is not restricted to these but can be modified in various ways.

The present invention provides a tool for the production of fiber composite components. The tool has a surface for depositing semifinished fiber products on the surface, the surface having a number of openings for feeding a matrix to the deposited semifinished fiber products. It is consequently possible to dispense entirely or partly with a conventional flow promoter and possible to achieve a high quality of fiber composite component.

Claims

1. A tool for the production-of fiber composite components, the tool comprising a surface for depositing semifinished fiber products thereon, the surface having a number of openings for feeding a matrix to the deposited semifinished fiber products.

2. The tool according to claim 1, wherein the openings are constituted by grooves in the surface.

3. The tool according to claim 2, wherein at least one of a density per unit area, a width, a depth, an arrangement, an orientation, a routing and a cross-sectional form of the grooves is adapted to a predetermined impregnating property of the semifinished fiber products.

4. The tool according to claim 2, wherein the grooves are provided with a first density per unit area in a first region of the surface and the grooves are provided with a second density per unit area in a second region of the surface.

5. The tool according to claim 1, wherein the grooves are inclined by an angle in relation to a line joining an inlet and an outlet in a third region of the surface, the angle being in a range from 0° to 90°0.

6. The tool according to claim 2, wherein the grooves have a first width in a fourth region of the surface and the grooves have a second width in a fifth region of the surface, the first width being greater than the second width.

7. The tool according to claim 2, wherein the width of the grooves lies in the range from 0.1 mm to 4 mm.

8. The tool according to claim 1, wherein an auxiliary material is arranged on the surface, the auxiliary material being permeable to the matrix.

9. The tool according to claim 1, wherein the tool has an inlet for feeding in the matrix and an outlet for carrying away the matrix, the inlet and the outlet being arranged in different planes.