DE102011010683A1 - Tool for producing fiber reinforced material component of motor vehicle, has negative mold equipped with microwave-permeable sections, so that curing process of impregnation material is performed by guiding microwave radiation - Google Patents

Abstract

The tool has a negative mold (27) in which impregnation process of an impregnation material is performed. The fibers obtained by the curing process of the impregnation material are more malleable. The negative mold is partially equipped with microwave-permeable sections, so that the curing process of the impregnation material is performed by guiding the microwave radiation through negative mold. The negative mold is made of ceramic, polymer material and metallic material. An independent claim is included for manufacturing method of tool for producing fiber reinforced material component.

Description

The invention relates to a tool for producing a component from a fiber-reinforced material according to the preamble of patent claim 1. The invention further relates to a method for producing a negative mold for such a tool according to the preamble of patent claim 11 and a method for producing a component from a fiber-reinforced material according to the preamble of patent claim 14.

For the production of fiber-reinforced components, continuous strand-drawing methods and discontinuous pressing methods are known from the prior art. Strangziehverfahren are also referred to as pultrusion.

The procedure known from the prior art in the pultrusion of fiber-reinforced components results from 1 , So shows 1 that in a first step 10 on spools 11 held fibers 12 from the coils 11 deducted and in a subsequent step 13 with an impregnating material 14 , z. B. with resin, are impregnated. The impregnated fibers 15 be in one step 16 with a preforming tool 17 preceded and in a subsequent step 18 by means of a negative forming die for the components to be produced extrusion tool 19 finally formed, namely while curing the impregnating material.

For this purpose, according to the prior art, the negative form of the Strangziehwerkzeugs 19 according to 1 preferably in two zones, namely in a first zone in which a temperature T1 prevails, and in a second zone in which there is a temperature T2. In the first zone, in which the temperature T1 prevails, the impregnated and pre-oriented fibers are finally shaped and in the second zone, in which the temperature T2 prevails, the impregnating material of the end-formed fibers is cured.

A profile made in this way 21 becomes according to the step 20 using a pulling device 22 through the processing stations of the preceding process steps 10 . 13 . 16 and 18 pulled and a cutting tool 23 fed to in a subsequent step 24 from the extruded profile 21 by cutting segments 25 separate.

According to the prior art, the hardening of the impregnating material takes place during pultrusion using a heatable pultrusion tool or a heatable metallic negative mold of the same. For this purpose, the metallic negative mold is heated to a defined temperature, for which according to the prior art, a high energy input is required. This is a disadvantage.

A further disadvantage of the heating of a metallic negative mold for curing the impregnating material is that the hardening of the impregnating material is relatively slow, whereby relatively long processing times are effected. This is due to the fact that according to the prior art, the heating of the impregnating material for curing the same takes place exclusively via the surface contact to the heated negative mold and thus flat, so that the heating and curing of inner regions of the impregnating, which are spaced from the surface of the heated negative mold and not have immediate contact with the same, requires longer time.

Similar disadvantages arise when fiber-reinforced components are produced by a pressing process, since, according to the prior art, heated, metallic negative molds are also used in pressing processes for curing the impregnating material of the impregnated fibers.

On this basis, the present invention based on the object to provide a novel tool for producing a component made of a fiber-reinforced material, a method for producing a negative mold for such a tool and a method for producing a component made of a fiber-reinforced material.

This object is achieved by a tool according to claim 1. According to the invention, the negative mold is designed to be microwave-permeable at least in sections, so that microwave radiation can be conducted through the negative mold in order to cure the impregnating material.

With the present invention, it is proposed for the first time to form a negative mold, which is used for producing fiber-reinforced components by pultrusion or pressing, at least partially microwave-permeable, so that microwave radiation can be conducted through the negative mold to cure the impregnating material. The curing of the material is therefore not or not exclusively by heating a metallic negative mold, but rather at least partially by utilizing microwave radiation, which is passed through the or each microwave-permeable portion of the female mold into the component to be cured.

The use of microwave radiation for curing the impregnating material that is made possible by this means has the advantage that a low energy input is required, as a result of which the energy efficiency of methods for the production of fiber reinforced components can be increased. Furthermore, the curing by microwave irradiation is not only flat but volumetric and thus relatively fast, whereby relatively short process times can be ensured.

According to a first advantageous embodiment of the invention, the negative mold is completely mikrowellenpermeabel, in particular ceramic, formed. Such a negative mold, which is completely microwave-permeable, can be used both in extrusion-drawing processes and in pressing processes for producing a component from a fiber-reinforced material, in particular for the production of structural components of a motor vehicle whose surface finish is not functionally important.

According to a second alternative advantageous development of the invention, a first segment, in particular an upper half, of the negative mold is microwave-permeable, in particular ceramic, whereas a second segment, in particular a lower half, of the negative mold is not microwave-permeable, in particular metallic. A partially microwave permeable negative mold is particularly suitable for use in a pressing process in the manufacture of a fiber reinforced material component. Hereby, in particular, exterior components of a motor vehicle can be produced whose surface finish is important for optical reasons. A metallic segment of the negative mold enables the provision of component surfaces in so-called Class A quality.

Preferably, the tool is designed as a tool closed against microwaves and has an outer, not mikrowellenpermeables, in particular metallic, housing. Then, when the tool has a non-microwave permeable housing, it can be ensured that no microwave radiation is emitted to the outside when producing a component from a fiber reinforced material. This is preferred for security reasons.

According to a further advantageous development of the invention, the or each microwave generator is thermally decoupled from the respective microwave-permeable section of the negative mold. Then, when the respective microwave-permeable portion of the negative mold is thermally decoupled from the respective microwave generator, it can be ensured that the respective microwave generator is not exposed to unacceptably high temperatures. As a result, overheating of the respective microwave generator can be avoided, which is particularly advantageous in continuous extrusion drawing process.

The inventive method for producing a negative mold for a tool, which serves to produce a component made of a fiber-reinforced material is defined in claim 11.

The inventive method for producing a component made of a fiber-reinforced material is defined in claim 14.

Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

1 the known from the prior art procedure for producing fiber-reinforced components in the pultrusion process;

2 a schematic representation of a first, insertable during pultrusion tool according to the invention for producing a component made of a fiber-reinforced material;

3 a schematic approach in producing a negative mold for a tool, which is used to produce a component made of a fiber-reinforced material;

4 a schematic representation of a second insertable when pressing tool according to the invention for producing a component made of a fiber-reinforced material; and

5 a schematic representation of a third, also used in the pressing tool according to the invention for producing a component made of a fiber-reinforced material.

The present invention relates to a tool for producing a component from a fiber-reinforced material, which can be used in particular during pultrusion or pressing. Such a tool has a negative mold for the component to be produced, in which a material of the component, for example resin-impregnated fibers such as glass fibers or carbon fibers, are malleable under curing of the impregnating material.

For the purposes of the invention, the negative mold of such a tool for producing a component from a fiber-reinforced material is at least partially microwave-permeable, so that microwave radiation through the negative mold can be conducted to cure the impregnating material to volumetrically heat the impregnating material by microwave irradiation and so on cure. The curing of the impregnating material of a component to be produced from a fiber-reinforced material by microwave radiation has the advantage that relatively little energy is required to cure the impregnating material and that the hardening of the impregnating material takes place relatively quickly. Accordingly, with the tool according to the invention, the energy efficiency in the production of a component made from a fiber-reinforced material can be increased; furthermore, process times can be shortened.

2 shows a highly schematic representation of a tool according to the invention 26 for producing a component from a fiber-reinforced material according to a first embodiment of the invention, wherein the in 2 shown tool 26 around the extrusion tool 19 of the 1 can therefore be used, which can be used for producing a component made of a fiber-reinforced material via a continuous extrusion drawing process.

According to 2 includes the tool 26 a negative form 27 , which in the embodiment of the 2 is completely mikrowellenpermeabel, with the outside then the microwave permeable negative mold 27 microwave generators 28 are positioned. About the microwave generators 28 Microwave radiation is generated by the microwave permeable negative mold 27 through in the direction of the profile to be produced 21 can be directed so as to be within the range of the tool 26 To heat the impregnating material volumetrically and to harden it.

The in 1 shown temperature zones T1 and T2 in the tool 26 be realized that over the axial extent of the negative mold 27 Seen microwave radiation is provided with different power.

To a heating or overheating of the microwave generators 28 In operation, avoid the generators 28 from the negative mold 27 thermally decoupled, preferably the microwave generators 28 be actively cooled, z. B. via air cooling or water cooling.

According to a further advantageous embodiment of the invention it is provided that the tool 26 a non-microwave permeable housing 29 so as to be closed to microwave radiation tool 26 train. About the or each microwave generator 28 Microwave radiation generated accordingly attains only inward in the direction of the impregnating material to be cured of the profile to be produced by pultrusion 21 and not outside in the environment.

The housing 29 is preferably closed on all sides and has only one inlet during pultrusion 30 for a profile to be cured 21 and an outlet 31 for the already cured profile 21 ,

The microwave permeable negative mold 27 or the or each microwave permeable section of the negative mold 27 is preferably ceramic based or high temperature polymer based. The negative form 27 is therefore on the one hand microwave permeable and on the other hand resistant to high temperatures. Further, it is subject to only a minimum shrinkage or a minimum expansion with temperature changes.

Preferably, a ceramic matrix or the polymer matrix of the or each microwave permeable portion of the negative mold is 27 Reinforcing fibers and / or nanoparticles embedded.

Particularly preferred is an embodiment of the tool in which the or each microwave permeable portion of the negative mold 27 consists of a ceramic matrix. Wollastonite may preferably be used as the ceramic material.

In the ceramic matrix, preferably wollastonite matrix, fibers such as glass fibers, carbon fibers, aramid fibers or boron fibers are embedded to reinforce the mechanical stability of the or each microwave permeable portion of the negative mold 27 to increase.

As nanoparticles, nanosize sodium silicate particles are preferably embedded in the ceramic matrix, whereby the structure of the ceramic, microwave-permeable negative mold via the nanoparticles 27 or the or each microwave permeable portion thereof can be improved. Thus, by adding or embedding nanosize sodium silicate particles into the ceramic matrix, a homogeneous and nonporous structure of the or each microwave permeable portion of the negative mold can be formed 27 be guaranteed, whereby the compressive strength thereof can be improved. At the same time, this can cause the roughness of the surface of the negative mold 27 or the or each microwave permeable portion thereof are minimized, whereby the mold release of a component to be manufactured from the negative mold 27 can be improved.

Instead of or in addition to the nanoscale sodium silicate particles, it is also possible for nanoscale carbon particles, iron oxide particles, lithium oxide particles, aluminum oxide particles, silicon particles or silicon nitride particles to be embedded in the wollastonite ceramic matrix.

In particular, when nanoscale aluminum oxide particles in the microwave permeable negative mold 27 embedded, can by the microwave irradiation, the negative mold 27 also be heated yourself. In this case, a volumetric heating and curing of the impregnating material then takes place via the microwave radiation and, in addition, a surface heating and curing of the impregnating material takes place via contact with the surface of the heated negative mold. Such an embodiment of the negative mold 27 in which it is itself microwave active, is particularly preferred.

In a specific embodiment, the ceramic, microwave-permeable negative mold 27 or the or each microwave permeable section thereof has the following composition: 50 vol% to 95 vol%, preferably 70 vol%, wollastonite ceramic matrix with embedded nanoscale alumina particles; 50% by volume to 5% by volume, preferably 30% by volume, glass fibers.

3 schematically illustrates an inventive method for producing a negative mold for a tool, which is used to produce a component made of a fiber-reinforced material, namely a method for producing a microwave-permeable negative mold or a microwave-permeable portion of a negative mold.

In the production of a microwave-permeable negative mold 27 or the production of a microwave permeable portion of a negative mold are first according to the steps 32 . 33 . 34 and 35 provided the different components of the negative mold to be produced, wherein in a subsequent step 36 the in the steps 32 to 35 provided ingredients are mixed.

In a concrete embodiment, it was assumed that in step 32 powdery wollastonite is provided as the first constituent for the negative form to be produced.

In step 33 is the second part of the negative form phosphoric acid and in the step 34 as the third component thereof provided a nanosize sodium silicate solution.

In step 35 can be provided as a component of the produced, microwave-permeable negative mold as reinforcing fibers glass fibers.

As mentioned earlier, those in the steps 32 to 35 provided components in step 36 mixed, with in step 37 the liquid, pourable mixture is filled into a mold and cured in the mold. Preferably, the mixing is done in step 36 , filling the mold and curing the mixture in step 37 under vacuum to avoid any air trapping in the tool material.

The mixing in step 36 is preferably carried out under vacuum in a vacuum mixer for a period of between 1 to 5 minutes.

According to 3 Followed by the curing in step 37 in one step 38 sintering or tempering the negative mold to improve the microstructure by fusing over the fine grain boundaries in the structure of the negative mold 27 to ensure. A possible sintering shrinkage can be adjusted by varying the proportion of nanosize sodium silicate.

With the method according to the invention can be easily and inexpensively temperature-resistant and pressure-resistant negative forms 27 be provided with high microwave permeability.

This in 2 shown tool 26 with a completely microwave permeable negative mold 27 is preferably used in pultrusion, with the principles of pultrusion already having reference to 1 have been described. To produce a component from a fiber-reinforced material, a volumetric hardening of the impregnating material in the tool accordingly takes place during pultrusion 26 under microwave radiation through the negative mold 27 through, wherein optionally additionally a surface hardening of the impregnating material by contact with the heated negative mold 27 he follows.

4 shows an embodiment of a tool 39 for producing a component from a fiber-reinforced material, which is used in a pressing process. According to 4 includes the tool 39 a negative form 40 of two segments, namely an upper half 41 the negative form 40 providing segment and a lower half 42 the negative form 40 providing segment, being in 4 both segments or halves 41 . 42 the negative form 40 are microwave permeable. Accordingly, outside is on both sides of the two halves 41 . 42 the negative form 40 each a microwave generator 43 positioned, which serves to generate or supply of microwave radiation passing through the negative mold 40 through in the direction of curing a impregnating material of a component to be produced 44 can be directed or directed. The halves 41 and 42 the negative form 40 together with the respective microwave generator 43 are from conventional tool carriers 45 recorded, where the trained as a press tool 39 again via a non-microwave permeable housing 46 has, so as to avoid that Microwave radiation reaches the outside. When pressing the component to be manufactured from a fiber-reinforced material, the hardening of the impregnating material in the tool accordingly takes place 39 under microwave irradiation or in 1 Press forces by arrows 47 are shown.

5 shows a schematic representation of another tool 48 which is preferably used in the manufacture of a component made of a fiber-reinforced material by pressing. In 5 is in contrast to the embodiment of 1 a negative form 49 of the tool 48 not completely mikrowellenpermeabel executed, but rather only partially formed microwave permeable, wherein a segment 50 the negative form 49 which according to 5 an upper half of which is microwave permeable, whereas a segment 51 the negative form 49 which forms a lower half thereof, is not formed microwave permeable. In the non-microwave permeable segment 51 the negative form 49 of the tool 48 of the 5 it is preferably a metallic half of the negative mold 49 , Accordingly, in 5 exclusively adjacent to the microwave permeable half 50 a microwave generator 52 arranged, the non-microwave permeable segment 51 the negative form 59 is not such a microwave generator 52 assigned.

Both segments or halves 50 . 51 the negative form 49 are in turn on a conventional tool carrier 53 a trained as a press tool 48 taken, the tool 48 again a non-microwave permeable housing 54 having.

The microwave permeable segments 41 and 42 the negative form 40 of the embodiment of 4 and the microwave permeable segment 50 the negative form 49 of the embodiment of 5 are in accordance to the negative form 27 of the embodiment of 2 assembled and manufactured.

In the non-microwave permeable segment 51 the negative form 49 of the embodiment of 5 it is preferably a metallic segment. With such a metallic segment 51 the negative form 49 For example, top quality surface properties, such as class A quality, may be provided to produce components that may be used in automotive engineering, for example, as exterior components.

The metallic segment 51 the negative form 49 of the embodiment of 5 can be heated in a conventional manner. In this case, volumetric heating and curing of the impregnating material of the component to be produced then take place on the one hand 44 by microwave radiation and on the other hand a surface heating and curing of the impregnating material via contact with the metallic segment 51 the negative form 49 ,

As already mentioned, the negative form is subject 27 respectively. 40 respectively. 49 of the respective tool 26 respectively. 39 respectively. 48 preferably even a heating, wherein the surface of the component to be produced or to be cured is heated by the heating of the negative mold. The interior of the component to be produced or cured is heated volumetrically by the microwave radiation.

As microwave radiation in particular linearly polarized microwave radiation is used. Such microwave beams propagate the structure to be cured of the component to be produced.

Pulsed microwave radiation can be used with a pulse duration between 5 seconds and 10 minutes.

As impregnating material of the component to be produced, in particular a microwave-active impregnating material such. B. Imidazole come to the Eisatz.

Then, when pressing is used to manufacture a component made of a fiber-reinforced material, the tool becomes 39 respectively. 48 , in particular the negative mold 40 respectively. 49 the same, with a preferably dry, not yet impregnated fiber bundle, a so-called fiber roving, occupied and closed the tool. The negative form 40 respectively. 49 is then preferably brought to a defined temperature, preferably by microwave irradiation and / or conventional heating, and at this temperature the impregnating material is injected into the fiber bundle. Subsequently, the impregnating material is hardened volumetrically heated by microwave irradiation.

LIST OF REFERENCE NUMBERS

10

step

11

Kitchen sink

12

fiber

13

step

14

Imprägnierwerkstoff

15

impregnated fiber

16

step

17

preforming tool

18

step

19

Continuous drawing tool

20

step

21

profile

22

drawbar

23

cutting tool

24

step

25

segment

26

Tool

27

negative form

28

microwave generator

29

casing

30

inlet

31

outlet

32

step

33

step

34

step

35

step

36

step

37

step

38

step

39

Tool

40

negative form

41

half

42

half

43

microwave generator

44

component

45

tool carrier

46

casing

47

pressing force

48

Tool

49

negative form

50

half

51

half

52

microwave generator

53

tool carrier

54

casing

Claims (15)

Tool for producing a component from a fiber-reinforced material, with a negative mold, in which fibers impregnated with an impregnating material are malleable while curing the impregnating material, characterized in that the negative mold ( 27 ; 40 ; 49 ) is formed at least partially microwave permeable, so that for curing the impregnating material microwave radiation through the negative mold ( 27 ; 40 ; 49 ) is conductive. Tool according to claim 1, characterized in that the negative mold ( 27 ; 40 ) completely mikrowellenpermeabel, in particular ceramic, is formed. Tool according to claim 2, characterized in that it is designed as a pultrusion tool for producing such a component by pultrusion. Tool according to claim 1, characterized in that a first segment ( 50 ), in particular an upper half, the negative mold ( 49 ) microwave permeable, in particular ceramic, is formed, and that a second segment ( 51 ), in particular a lower half, the negative mold ( 49 ) is not microwave permeable, in particular metallic, is formed. Tool according to claim 2 or 4, characterized in that it is designed as a pressing tool for producing such a component by pressing. Tool according to one of claims 1 to 5, characterized in that the or each section of the negative mold ( 27 ; 40 ; 49 ), the microwave permeable is formed between one of the negative mold ( 27 ; 40 ; 49 ) defined cavity and a microwave generator ( 28 ; 43 ; 52 ) is positioned. Tool according to claim 6, characterized in that the or each microwave generator ( 28 ; 43 ; 52 ) is thermally decoupled from the respective microwave permeable portion of the negative mold. Tool according to one of claims 1 to 7, characterized in that it is designed as a microwave closed mold and an outer, not mikrowellenpermeables, in particular metallic, housing ( 29 ; 46 ; 54 ) having. Tool according to one of claims 1 to 8, characterized in that the or each section of the negative mold ( 27 ; 40 ; 49 ) formed microwave permeable is formed on a ceramic or polymer basis. Tool according to claim 9, characterized in that the or each section of the negative mold ( 27 ; 40 ; 49 ), which is microwave permeable, is formed of a ceramic matrix or a high temperature resistant polymer matrix having reinforcing fibers embedded in the ceramic matrix or polymer matrix and / or nanoparticles embedded in the ceramic or polymer matrix. Method for producing a negative mold for a tool, which is used to produce a component from a fiber-reinforced material, wherein sections of the negative mold are produced by casting, characterized in that at least one microwave-permeable portion of the negative mold is produced by mixing components thereof, and that the liquid or pourable mixture is filled into a mold and cured in the mold. A method according to claim 11, characterized in that the mixing, the filling and the curing is carried out under vacuum. A method according to claim 11 or 12, characterized in that the or each cured portion of the negative mold is subsequently subjected to thermal sintering. A method for producing a component from a fiber-reinforced material, wherein initially impregnated fibers with a impregnating material and then the impregnated fibers are formed in a tool while curing the impregnating material to be produced component, characterized in that the impregnating material is cured in the tool under microwave radiation. A method according to claim 14, characterized in that the same is carried out using a tool according to one of claims 1 to 10.

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