Abstract
The invention relates to a process for the production of multishell composite-material components, comprising the following steps: a) insertion of at least one first component (1) into an injection mold and optionally subjecting the first component (1) to a forming process, b) injection of at least one fixing element (4) onto at least one side (5) of the first component (1), c) insertion of at least one second component (2) into the injection mold and optionally subjecting the second component (2) to a forming process, d) bonding of the first component (1) to the second component (2) by way of the side (5) which has the fixing element (4), where a matrix material (6) is injected through the second component (2) onto and/or into the fixing element (4).
Claims
1-15. (canceled)
16: A process for the production of multishell composite-material components, comprising: a) insertion of at least one first component into an injection mold and optionally subjecting the first component to a forming process, b) injection of at least one fixing element onto at least one side of the first component, c) insertion of at least one second component into the injection mold and optionally subjecting the second component to a forming process, d) bonding of the first component to the second component by way of the side which has the fixing element, wherein a matrix material is injected through the second component onto and/or into the fixing element.
17: The process according to claim 16, wherein the fixing element has at least one cavity.
18: The process according to claim 17, wherein the aspect ratio of the cavity is in the range from 1:1 to 1:100.
19: The process according to claim 17, wherein during the bonding of the first component and second component a matrix material is injected into the cavity of the fixing element.
20: The process according to claim 16, wherein the first component and/or the second component comprises a reinforcing-fiber arrangement and a thermoplastic matrix.
21: The process according to claim 20, wherein the material of the matrix is the same as the material of the thermoplastic matrix.
22: The process according to claim 17, wherein, during bonding of the first component and second component, material is injected into the cavity of the fixing element, and the surface of the cavity melts at least to some extent.
23: The process according to claim 16, wherein the forming process to which the first component and/or second component is/are subjected in each case produces a single-shell fiber-plastics composite.
24: The process according to claim 16, wherein the fixing element is selected from the group consisting of ribs, convex areas, beads, grooves, fillets, and combinations thereof.
25: The process according to claim 16, wherein the first component and/or the second component is a long-fiber-reinforced thermoplastic, a continuous-fiber-reinforced thermoplastic, and/or a unidirectional, reinforced tape.
26: The process according to claim 16, wherein the first component and/or the second component is an organopanel.
27: The process according to claim 16, wherein, before bonding to the first component, the second component is brought to a temperature which is from up to 50° C. below to up to 50° C. above the melting point or the glass transition temperature.
28: The process according to claim 16, wherein, after and/or during bonding of the first component and second component, the edge areas of the second component are pressed onto the first component.
29: A multishell composite-material component produced by the process according to claim 16.
30: A molding, comprising: at least one first component and one second component, wherein the first component has a fixing element on at least one side, and the second component has been bonded coherently to the fixing element.
Description
[0079] The invention and the prior art will be illustrated below with reference to the figures:
[0080] FIG. 1 is a diagram of the sequence for a combination of in-mold forming and overmolding (CIFO) processes (prior art).
[0081] FIG. 2 is a diagram of the sequence of the process of the invention.
[0082] FIG. 3 shows the first and second component.
[0083] FIG. 4 is a section of a fixing element with a cavity.
[0084] FIG. 4a is a plan view of a fixing element with a cavity.
[0085] FIG. 5 shows a stage during the production of a double-shell composite-material component composed of a first and a second component during the procedure for injection of the matrix material.
[0086] FIG. 5a shows a stage during the production of a double-shell composite-material component composed of a first and a second component after the procedure for injection of the matrix material.
[0087] FIG. 1 is a diagram of the sequence of a CIFO process. For this, in step S1 a prefabricated semifinished product which can be either a laminate or a tape is optionally clamped into a clamping frame. Transport to an oven then takes place, so that the clamping frame with the semifinished product can be heated. This oven can by way of example be a radiant IR system. This is followed by insertion of material into the mold of the injection-molding machine. In the in-mold-forming process step S2 the mold is closed and the semifinished product is subjected to a forming process. After the forming process, in the overmolding step S3 the ribs, using an injection-molding composition, are injected. In further steps SX, the mold is then opened, and an optional demolding step and an optional trimming step then take place in order to obtain the final component.
[0088] FIG. 2 is a diagram of the sequence of the process of the invention. For this, in step S1′ a prefabricated semifinished sheet product made of a thermoplastic matrix and of a reinforcing-fiber arrangement is optionally clamped onto a clamping device. It is then possible either to heat the semifinished sheet product in the mold or to insert material into the mold. In the step S2′ the mold is closed and the semifinished product is subjected to a forming process. The steps S1′ and S2′ thus correspond to the first step a) in the process of the invention. Then in step S3′ fixing elements are appropriately injected. The fixing elements are injected only on one side, or on two opposite sides, of the semifinished product. The step S3′ thus corresponds to the step b) in the process of the invention. The fixing elements are accordingly injected in the form of injection-molding composition which is the same as the thermoplastic matrix. Then in step S4′ the mold is opened and again either material is inserted into the mold or the second semifinished sheet product is heated, this being followed by either the heating of the second semifinished sheet product or insertion of material into the mold. The step S4′ corresponds to step c) in the process of the invention. After the mold has been closed, the second semifinished product is optionally subjected to a forming process in step S4′. Then in step S5′ an injection-molding composition is injected through the second semifinished product into the cavity of the fixing elements. This results in coherent bonding of the two semifinished products. After the opening of the mold in step SX′ and any demolding, the product is a multishell component or the final component.
[0089] FIG. 3 shows a first component 1 and a second component 2. In the first component 1 the edge areas 12 and the fixing elements 4 and the cavity 7 can be seen. The second component 2 is accordingly applied to the first component 1. FIG. 3 illustrates a particular section of the process of the invention, but does not show the injection mold. After the first component 1 has been placed in the injection mold and subjected to a forming process, it has the shape illustrated in FIG. 3 with the edge areas 12. The fixing elements 4 injected in step b) of the process of the invention are likewise illustrated. In FIG. 3 there are in total four fixing elements 4, and the arrangement here of each pair of these is such that they have, between them, a cavity 7 into which the matrix material is subsequently injected. The arrangement of the fixing elements 4 here is such that they are flush in a plane with the upper side of the edge areas 12 of the first component 1. The second component 2, shown here in the form of flat component 2, can thus come into contact not only with the edge areas 12 of the first component 1 but also with an area of the fixing elements 4. FIG. 3 illustrates the situation before bonding of the first component 1 to the second component 2 by way of the side 5 which has the fixing element 4. Both the first component 1 and the second component 2 are composed of a reinforcing-fiber arrangement and of a thermoplastic matrix. The fixing element 4 is likewise composed of a thermoplastic matrix.
[0090] FIG. 4 is a section of a fixing element 4 with a cavity 7 on a first component 1. FIG. 4 shows the situation of the first component 1 after the injection of at least one fixing element 4 on at least one side 5 of the first component 1 as in step b). There is therefore not yet any matrix material in the cavity 7. The fixing elements 4 that form the cavity 7 have the shape of a rectangle.
[0091] FIG. 4a is a plan view of a first component 1 which has a fixing element 4. In plan view, the shape of the fixing element 4 is a square. The overall effect therefore is that a hollow cube-shaped molding provides the fixing element 4, but that side of the cube that faces away from the side 5 of the first component 1 is absent, and a cavity 7 is therefore present. The first component 1 is composed of a thermoplastic matrix in which there is a reinforcing-fiber arrangement. The fixing element 4 is equally composed of a thermoplastic matrix.
[0092] FIG. 5 shows a stage in the production of a double-shell composite-material component composed of a first component 1 and of a second component 2, during the injection procedure. The coherent bonding procedure can be seen in FIG. 5. The injection of the matrix material 6 through the second component 2 into the cavity 7 of the fixing element 4 is depicted here. For this, the component 2 is heated locally at the points through which the matrix material 6 is injected through the second component 2 as in step d) of the process of the invention. It is also possible to pass a metal broach through the second component 2 in order to permit passage for injection of the matrix material 6.
[0093] FIG. 5a shows a stage during the production of a double-shell composite-material component composed of a first component 1 and of a second component 2, after the step d) of the present process of the invention has been carried out. The coherent bond between the component 1 and the component 2 can be seen in FIG. 5a. FIG. 5a therefore corresponds to the stage after the step d) of the process of the invention. The matrix material 6 is the same as the material of the thermoplastic matrix of the first component 1 and of the second component 2, and also the same as the material of the fixing element 4. After the step d) a coherent, interlocking, and frictional bond has therefore been produced.
KEY
[0094] 1 First component [0095] 2 Second component [0096] 4 Fixing element [0097] 5 Side of first component [0098] 6 Matrix material [0099] 7 Cavity [0100] 12 Edge areas
