DE102015201559A1 - Wet pressing method and pressing tool for this - Google Patents

Abstract

The present invention relates to a wet pressing method for producing a fiber composite component (10), comprising the steps of: opening a pressing tool (20), introducing a first fiber material (14) with at least one insert (18) into the pressing tool (20), introducing a fiber composite ( 11) in the pressing tool (20), wherein the fiber composite comprises a second fiber material (16) and a matrix (12), closing the pressing tool (20), and performing a pressing operation for pressing the first fiber material (14) with the fiber composite (11 ). Furthermore, the invention relates to a pressing tool for performing the wet pressing process.

Description

The present invention relates to a wet pressing method for producing a fiber composite component and a pressing tool for performing the wet pressing method.

In the prior art, wet pressing methods for producing a fiber composite component are known. In known wet pressing processes, for example for the vehicle industry, a fiber material impregnated with a matrix is placed in a pressing tool and formed under high pressure into a fiber composite component and crosslinked. In the molding process, the fiber material is compressed. This results in flow processes of the matrix in the fiber material, in which still dry areas of the fiber material can be re-impregnated.

So far, only monolithic inserts without functional elements using the wet pressing process are usually made. Insert parts, such as sockets, plates or adapter parts, must generally be used or incorporated into the fiber material prior to impregnation and positioned precisely in cavities provided in the tool during the pressing process. In particular, when multiple inserts are present, an exact insertion is difficult. Since the matrix crosslinks or hardens on contact with a hot pressing tool, repositioning of the fiber material with inserts after the first depositing is not possible.

It is an object of the present invention to at least partially avoid the disadvantages described above in a wet pressing method and a pressing tool for the wet pressing method. In particular, it is an object of the present invention to provide a wet pressing method and a pressing tool for the wet pressing method for producing a fiber composite component, whereby the introduction of an insert into the fiber composite material can be simplified and specified.

The above object is achieved by a wet pressing method with the features of claim 1 and a pressing tool for performing the wet pressing method with the features of claim 9. Further features and details of the invention will become apparent from the dependent claims, the description and the drawings. In this case, features and details that are described in connection with the wet pressing method, of course, also in connection with the pressing tool according to the invention for the wet pressing process and in each case vice versa, so that with respect to the disclosure of the individual aspects of the invention always reciprocal reference is or may be.

• – Öffnen eines Presswerkzeugs,
• – Einbringen eines ersten Fasermaterials mit wenigstens einem Einlegeteil in das Presswerkzeug,
• – Einbringen eines Faserverbunds in das Presswerkzeug, wobei der Faserverbund ein zweites Fasermaterial und eine Matrix aufweist,
• – Schließen des Presswerkzeugs, und
• – Durchführen eines Pressvorgangs zum Verpressen des ersten Fasermaterials mit dem Faserverbund.

According to a first aspect of the present invention, there is provided a wet pressing method for producing a fiber composite component, comprising the steps of:

• Opening a pressing tool,
• Introducing a first fiber material with at least one insert into the press tool,
• Introducing a fiber composite into the pressing tool, wherein the fiber composite has a second fiber material and a matrix,
• - closing the pressing tool, and
• - Performing a pressing operation for pressing the first fiber material with the fiber composite.

Characterized in that the insert is first introduced only in the first, preferably at least substantially dry, fiber material in the pressing tool and is pressed only during the pressing process with the fiber composite, a precise positioning of the insert in the fiber composite component can be achieved. This makes it possible to increase the quality of fiber composite components. Furthermore, this can reduce scrap, which results from inaccurate positioning of inserts in fiber composite components. In the case of the wet pressing method according to the invention, moreover, it is not necessary for inserts to be introduced into a fiber material before the wet pressing process, which is subsequently impregnated, but before the wet pressing process. This can reduce the complexity of the pressing process. In addition, the wet pressing method according to the invention can be carried out much faster than conventional wet pressing method. Thus, working cycles of only a few minutes can be achieved in the present case for the production of the fiber composite component.

In order to enable an exact positioning of the at least one insert, this is inventively introduced into a fiber material which is not impregnated prior to insertion into the pressing tool. After the introduction and the exact positioning of the at least one insert in the first fiber material, a further fiber material or second fiber material is prepared and impregnated, whereby a fiber composite is created. The second fiber material may comprise or be the same material as the first fiber material, but may also comprise or be another or further fiber material, ie a fiber material different from the first fiber material. The fiber composite is then inserted into the pressing tool and pressed together with the first fiber material and the at least one insert. By yourself resulting flow processes of the matrix and the previously inserted first fiber material is re-impregnated with the at least one insert.

The first fiber material is preferably a dry fiber material, but in a preferred development can be at least partially impregnated with a matrix. For example, it is conceivable for the at least one insert part to be introduced into the first fiber material in a region in which the first fiber material is dry or essentially dry, the first fiber material being in a region in which the at least one insert part is not introduced , at least partially impregnated with a matrix. Furthermore, it is conceivable according to a preferred development that the first fiber material is impregnated with a matrix only for coarse stabilization, for example with less than 50%, preferably less than 30% and more preferably less than 10% of the amount suitable for a full impregnation of the first fiber material is required. According to the present invention, the at least one insert part can be introduced into the first fiber material before or after the opening of the pressing tool, but can also be introduced into the pressing tool as a finished delivery part. In any case, it is possible according to the invention to use prepared blanks, which have the first fiber material with the at least one insert, in order to achieve the fastest possible processing. The matrix used preferably comprises a synthetic or semisynthetic polymer, but may also comprise a biopolymer. The matrix used is preferably a resin, in particular a synthetic resin. Particular preference is given to using a duroplastic, elastomer and / or thermoplastic. Thermosets have the effect that they are glasspröde and not plastically deform. Synthetic resins and elastomers are liquid until they cure. The advantage of thermoplastics is that they can be hot-formed after the pressing process.

When opening the pressing tool, a first or upper and a second or lower mold are moved apart. The at least one insert part is preferably introduced into the first fiber material in such a way that it is held in a defined position by the fiber material. It may be advantageous here if the at least one insert part is inserted at a corresponding recess in the first fiber material, which is formed in the first fiber material prior to introduction of the at least one insert part. However, the at least one insert part can also be introduced or pressed into the first fiber material until it has a sufficiently stable seat in the first fiber material. After introducing the first fiber material with the at least one first insert and the fiber composite with the second fiber material and the matrix, the pressing tool is closed, d. that is, the upper die is moved toward the lower die. More specifically, according to the present invention, the upper die is pressed against the lower die until the first fibrous material is crimped with the at least one insert with the fiber composite. In the context of the present invention, pressing is to be understood as meaning in particular a joining of the fiber material to the fiber composite. In particular, the matrix of the fiber composite connects to the first fiber material. In addition, the first and the second fiber material can also be connected to one another, for example by interengaging the respective fibers. According to the present invention, it is possible here to produce a fiber composite component with different fiber materials, that is to say a specific first fiber material and a specific second fiber material, which differs from the material composition of the first fiber material.

According to one embodiment of the present invention, the fiber composite can be provided supersaturated with the matrix. This has the advantage that not only is sufficient matrix provided for the second fiber material, but also matrix for the first fiber material, without adding matrix in a separate operation. As a result, the complexity in carrying out the wet pressing process can be further reduced. For the purposes of the present invention, supersaturated means that more matrix is present in the fiber material than is required for impregnation thereof. For this purpose, further matrix can be applied to the second fiber material, after it has already been completely impregnated, resulting in an excess matrix on or at the fiber composite.

Further, it is advantageous if the fiber composite is provided supersaturated with the matrix, that more matrix is present when connecting the first fiber material to the fiber composite in the pressing tool, as by the fiber composite and the first fiber material is receivable. In this way it can be ensured that in any case sufficient matrix can be provided for the entire fiber material without adding additional matrix in a further working step. By virtue of such an excess of matrix, the first fiber material can be reliably and easily re-impregnated. The excess matrix of the fiber composite can be transferred to the first fiber material in a particularly simple and effective manner. The supersaturation according to this development means that the fiber composite is provided with such a matrix excess that during the pressing operation in the pressing tool sufficient matrix for a complete impregnation of the first and the second fiber material is present.

In addition, according to the wet pressing method according to the invention, the fiber composite can be introduced into contact with the first fiber material and / or the at least one insert part introduced therein into the pressing tool. This can ensure that the first fiber material can be impregnated in a particularly simple manner with the excess matrix of the fiber composite, since the matrix can pass from one fiber material directly to the other fiber material. The fact that the fiber composite is brought into contact with the first fiber material and / or the at least one insert introduced therein means that the fiber composite contacts or is brought into direct mechanical contact with the first fiber material. According to this development, it is further preferred if excess matrix, after the first and the second fiber material have been completely impregnated, is removed from the pressing tool, for example by discharge channels. It is further advantageous if the fiber composite is brought into contact with the first fiber material and / or the at least one insert introduced therein in the pressing tool, that the fiber composite surrounds the fiber material and / or the at least one insert or his top side facing away from the pressing tool covered.

According to the present invention, the insert may comprise metal. As a result, for example, advantageous metal-plastic compounds can be produced. It is particularly preferred if the insert is made entirely of metal, wherein it is not limited to a particular metal.

In addition, for the at least one insert part in the pressing tool, a corresponding cavity may be formed, wherein the fiber composite is introduced with the insert in such a way in the pressing tool that the insert is introduced into the cavity. In this way, a particularly high quality of the fiber composite component can be achieved, since the insert can be positioned extremely precisely and can not slip in its position in the first fiber material. Correspondingly means in the context of the present invention that the insert can fit accurately, so with little or no play can be introduced into the cavity. The cavity is preferably formed in a lower mold, d. h., in one of two dies arranged gravitationally under the other die.

According to a development of the present invention, carbon, glass and / or aramid is used for the first fiber material and / or the second fiber material. As a result, a fiber composite component with a high thermal stability and a high mechanical strength and stability can be created. Preferably, the same material composition as for the second fiber material is used for the first fiber material. However, it may also be advantageous to use a different material composition for the first fiber material than for the second fiber material. For example, carbon may be used for the first fiber material and glass and / or aramid for the second fiber material, or vice versa.

Moreover, in the wet pressing method of the invention, the pressing operation may be performed at a temperature of the pressing tool or a part of the pressing tool of 100 ° C to 150 ° C, preferably 120 ° C to 130 ° C. As a result, particularly good results with respect to the component quality of the fiber composite material can be achieved.

According to a further aspect of the present invention, a pressing tool for carrying out the above-described wet pressing method is provided, which in particular has the necessary cavities for receiving and securing the position of the first fiber material and the fiber composite. Thus, the pressing tool according to the invention brings about the same advantages as have been described in detail with reference to the wet pressing method according to the invention.

Further, measures improving the invention will become apparent from the following description of an embodiment of the invention, which is shown schematically in the figures. All of the claims, description or drawings resulting features and / or advantages, including constructive details and spatial arrangements may be essential to the invention both in itself and in the various combinations.

They show schematically:

1 an open pressing tool for the wet pressing method according to the present invention,

2 an open pressing tool with a first fiber material with an insert and a fiber composite according to the present invention, and

3 a closed pressing tool with a fiber composite component according to the present invention.

Elements with the same function and mode of action are in the 1 to 3 each provided with the same reference numerals.

1 shows an inventive pressing tool 20 with an upper mold 22 and a lower die 24 in an open state. In the lower mold 24 are according to the in 1 illustrated embodiment, a first cavity 26 and a second cavity 28 educated.

2 shows a first fiber material 14 with an insert inserted therein 18 , wherein the fiber material 14 with the insert 18 so in the lower mold 24 is inserted or inserted, that the insert fits exactly in the corresponding second cavity 28 is arranged. In 2 is also a supersaturated fiber composite 11 represented, which a second fiber material 16 and a matrix 12 having.

3 shows the pressing tool according to the invention 20 in a closed state as well as a fiber composite component pressed therein 10 ,

With reference to the 1 to 3 Now, the wet pressing method according to the invention will be described. In a first step we, as in 1 shown, the pressing tool 20 open. This is the upper mold 22 from the lower mold 24 spaced. Subsequently, the first fiber material 14 with the insert 18 so in the lower mold 24 Inserted that insert in the second cavity 28 is fitted. Subsequently, the one with the matrix 12 supersaturated fiber composite 11 in the lower mold 24 brought in. As in 3 shown, now the pressing tool 20 closed, ie, the upper mold 22 on the lower mold 24 pressed. Here is a pressing process for pressing the first fiber material 14 with the fiber composite 11 performed, in which the excess matrix 12 from the fiber composite 11 on the first fiber material 14 goes over and reimpresses it. The pressing operation becomes, for example, at a temperature of the pressing tool 20 or a part of the pressing tool 10 carried out from about 120 ° C to 130 ° C. After the pressing process and the temperature supply, the pressing tool is opened again and the finished fiber composite component 10 can be removed.

LIST OF REFERENCE NUMBERS

10

Fiber composite component

11

fiber composite

12

matrix

14

first fiber material

16

second fiber material

18

insert

20

press tool

22

upper mold

24

lower die

26

first cavity

28

second cavity

Claims (9)

Wet pressing process for producing a fiber composite component ( 10 ), comprising the steps: - opening a pressing tool ( 20 ), - introducing a first fiber material ( 14 ) with at least one insert ( 18 ) in the pressing tool ( 20 ), - introducing a fiber composite ( 11 ) in the pressing tool ( 20 ), wherein the fiber composite a second fiber material ( 16 ) and a matrix ( 12 ), - closing the pressing tool ( 20 ), and - performing a pressing operation for pressing the first fiber material ( 14 ) with the fiber composite ( 11 ). Wet pressing method according to claim 1, characterized in that the fiber composite ( 11 ) with the matrix ( 12 ) is supersaturated. Wet pressing method according to claim 1 or 2, characterized in that the fiber composite ( 11 ) in such a way with the matrix ( 12 ) is provided supersaturated, that when connecting the first fiber material ( 14 ) with the fiber composite ( 11 ) in the pressing tool ( 20 ) more matrix is present than by the fiber composite ( 11 ) and the first fiber material ( 14 ) is receivable. Wet pressing method according to at least one of the preceding claims, characterized in that the fiber composite ( 11 ) in contact with the first fibrous material ( 14 ) and / or the at least one insert ( 18 ) in the pressing tool ( 20 ) is introduced. Wet pressing method according to at least one of the preceding claims, characterized in that the insert part ( 18 ) Metal. Wet pressing method according to at least one of the preceding claims, characterized in that for the at least one insert ( 18 ) in the pressing tool ( 20 ) a corresponding cavity ( 28 ) is formed and the fiber composite ( 11 ) with the insert ( 18 ) in such a way Pressing tool ( 20 ) is inserted, that the insert ( 18 ) into the cavity ( 28 ) is introduced. Wet pressing method according to at least one of the preceding claims, characterized in that that for the first fiber material ( 14 ) and / or the second fiber material ( 16 ) Carbon, glass and / or aramid is used. A wet pressing method according to at least one of the preceding claims, characterized in that the pressing operation is performed at a temperature of the pressing tool or a part of the pressing tool of 100 ° C to 150 ° C degrees. A pressing tool for performing a wet pressing method according to at least one of the preceding claims.

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