DE102011052462A1 - Method for manufacturing fiber reinforced component for motor car in automotive engineering, involves pressing manufactured composite component by closing heatable material-deforming tool, curing component, and removing component - Google Patents

Abstract

The method involves inserting a non-woven fabric (4) made of a fiber material into a tenter (1). Application of resin (7) is automated by a manipulator in a region (6) of the non-woven fabric. The resin is drawn into the non-woven fabric due to capillary forces. The resin is inserted into a heatable material-deforming tool. A manufactured fiber composite component is pressed by closing the material-deforming tool. The pressed composite component is cured and removed. The resin is applied as a thin film on an inner side (5) of the non-woven fabric. The pressed composite component is cooled.

Description

The present invention relates to a method for producing a fiber composite component according to the features in the preamble of patent claim 1.

The present invention further relates to a fiber composite component for a motor vehicle according to the features in the preamble of claim 14.

Fiber-reinforced components are increasingly used in the automotive industry. They bring the highest strength properties, at the same time low specific weight with it. This meets the rigidity and crash safety requirements of legislators and car manufacturers, while significantly reducing vehicle weight, resulting in fuel savings and low CO2 emissions.

However, fiber composite members have the property of being subject to a high dispersion of production accuracy in a manufacturing process. Thus, it is necessary that certain error rates be considered in the manufacturing processes for fiber composite components in the production process. In particular, in this case the fiber orientation and the filling with resin is of particular importance. In conventional manufacturing processes for fiber composites therefore falls on a large proportion of waste or waste products of the fiber materials themselves.

In order not now to discard these waste products entirely or else to send them to other recycling processes, methods are known from the prior art in which the fiber pieces or waste products are pressed into a nonwoven and then infiltrated with resin. For example, such a method is known from DE 35 39 006 A1 known.

The nonwoven fabric, which is pressed from pieces of fiber and waste, differs from fibers or fabrics as fiber materials in that it is formed from short pieces of fiber with a stochastically distributed orientation. As a result, it is thus possible to achieve a significantly lower strength by means of the alignment of the fibers and also due to the only respective short fiber length of the fiber pieces. The Harzinfiltration itself, in turn, is usually carried out manually, so that although sufficient resin is introduced in all areas of the web, but the conventional production and manufacturing processes are subject to strong fluctuations and high effort.

It is therefore an object of the present invention, starting from the prior art, to improve a method for processing a nonwoven made of recycled and / or reused fiber composite material.

The procedural portion of the object is achieved by a method for producing a fiber composite component for a motor vehicle according to the features in patent claim 1.

The objective part of the object is further achieved by a fiber composite component for a motor vehicle according to the features in claim 14.

Advantageous embodiments of the present invention are the subject of the dependent claims.

• – Einlegen eines Vlieses aus Faserverbundwerkstoff in einen Spannrahmen;
• – Automatisiertes Auftragen eines Harzes durch einen Manipulator in dem Bereich des Vlieses;
• – Einziehen des Harzes in das Vlies aufgrund von Kapillarkräften;
• – Einführen des Spannrahmens in ein beheizbares Umformwerkzeug;
• – Pressen des herzustellenden Faserverbundbauteils durch Schließen des Umformwerkzeuges;
• – Aushärten des gepressten Faserverbundbauteils;
• – Entnahme des gepressten Faserverbundbauteils.

The inventive method for producing a fiber composite component for a motor vehicle, wherein a nonwoven made of recycled and / or reused fiber composite material is used, is characterized by the following method steps:

• - inserting a fiber composite nonwoven fabric into a tenter frame;
• Automated application of a resin by a manipulator in the region of the web;
• - Retraction of the resin in the nonwoven due to capillary forces;
• - Introducing the clamping frame in a heated forming tool;
• - Pressing the fiber composite component to be produced by closing the forming tool;
• - curing of the pressed fiber composite component;
• - Removal of the pressed fiber composite component.

In the context of the invention, a nonwoven, which is made of recycled and / or reused fiber composite materials, in particular fiber composite material pieces, inserted into a tenter. The fleece itself can be clamped in the clamping frame and / or clamped or placed. Preferably, the clamping frame is dimensioned such that it is larger than the fiber composite component itself to be produced. The nonwoven itself thus has in the clamping frame on an edge region, which only has a holding function during the manufacturing process.

According to the invention, an automated application of a resin is subsequently carried out by a manipulator in the region of the nonwoven. Particularly preferably, only the area of the nonwoven is wetted with resin, which later also passes through the forming tool to the fiber composite component is transformed. As a result, the process is carried out particularly economically, since no superfluous resin must be applied, which does not subsequently account for the manufactured component, on the other hand, the clamping frame or surrounding tools is not contaminated by excess resin material, so spares expensive cleaning operations.

The automatically applied resin draws into the web due to capillary forces, so that the web is substantially homogeneously interspersed with the resin.

In a further method step, the clamping frame is introduced into a heatable forming tool. By closing the forming tool itself, the fiber composite component to be produced is shaped or pressed in the forming tool. Subsequently, the pressed fiber composite component cures in the forming tool in a hardening step. Following this, the pressed fiber composite component is removed from the forming tool and fed to further processing steps. For example, it may be a cooling or trimming the edge.

Particularly preferably, the resin is applied via a nozzle with an industrial robot, preferably in an uninterrupted application process, in particular at a temperature between 20 ° and 60 ° C., more preferably between 30 ° and 50 ° C. The order with an industrial robot ensures that a particularly homogeneous distribution of the resin takes place on the fleece itself. An exact dosage is thereby possible, which is avoided by the retracting due to the capillary effect in the nonwoven resin that air pockets or resin excesses are introduced. The effect is enhanced by a single uninterrupted application process and / or by a temperature control of resin and / or nonwoven.

In the context of the invention, a resin application can additionally take place by means of a meander-shaped pivoting movement of the nozzle. Also, this order form has been found to be particularly advantageous for a homogeneous introduction of the resin to the inhomogeneous web.

The automated application of the resin can be further supplemented by a doctor blade process. In the context of the invention, a squeegee is to be understood as a distributor strip with which the resin is additionally distributed by brushing with a squeegee during the spraying process and / or shortly after the spraying process. Depending on the intensity and contact surface of the doctor blade, massaging in of the resin into the nonwoven or impressing the resin into the nonwoven may additionally take place. In a particularly preferred embodiment of the present invention, a combined spray-on and doctor blade tool is used.

Also preferably, the resin is applied to only one side of the web as a thin film. This is especially an inside of the fleece.

Advantageously, a split clamping frame is used or two clamping frames are used, which are particularly preferably folded after the resin application, so that the inner sides are internally opposed to each other. This provides a resinized nonwoven having a sandwich construction. Above and below are each a nonwoven portion, due to the hinged clamping frame or the two collapsed clamping frame and inside is a resin film, which is composed of two applied and folded sides.

Due to the capillary action, the resin now migrates from the interior region of the sandwich component into the nonwoven or the respective nonwoven layers. At the latest during the pressing process in the forming tool itself, therefore, a complete and homogeneous penetration of the resin of the entire web takes place. Any air pockets within the web itself are expressed by the resin migrating from the inside to the outside and are not trapped in the component itself.

In a further preferred embodiment, unidirectional fibers are introduced into the nonwoven in preferred directions. These can already be introduced during the manufacturing process of the fleece itself or else be applied to the fleece, in particular also shortly before or with the spraying process of the resin, so that the unidirectional fibers are arranged in the interior of the sandwich component. As a result, the fiber composite component experiences a significant increase in strength over conventional nonwoven components, without continuous fiber reinforcement.

In a further preferred embodiment, the clamping frame is placed in a pre-heated forming tool, more preferably the forming tool is preheated to a temperature between 70 ° and 200 ° C, in particular between 80 ° and 180 ° C and most preferably between 90 ° and 170 ° C. , The clamping frame is inserted into the forming tool in such a way that at the forming tool parts of the forming tool the resin-wetted nonwoven areas come into contact with the closing of the forming tool. Due to the preheated forming tool curing of the resin takes place due to the as advantageously resulting temperature ranges. The pre-hardening or curing with closed and already pre-heated forming tool thus brings the advantage of a short cycle time with it.

Particularly preferably, the forming tool is further heated during the forming process and / or during the curing process. An expensive heating and cooling of the forming tool due to the production process is thereby avoided. The tool can preferably be heated to a temperature which is then maintained over the entire shift operation of the forming tool.

In a further preferred embodiment variant of the present invention, the clamping frame is positioned between an upper tool and a lower tool of the forming tool and moved toward the lower tool during a lowering operation of the upper tool with half the lowering speed of the upper tool. This ensures that both tool halves hit the fiber composite at the same time. It thus comes simultaneously to a system of fiber composite material on the lower tool and to a system of the upper tool on the fiber composite material. Consequently, the temperature entry of both upper tool and lower tool in the component to be produced is done equally. A homogeneous heat input thus ensures good curing and thus high reproducibility of the method according to the invention.

Further preferably, the fiber composite component cures in the forming tool for 0.1 to 20 minutes, preferably 1 to 15 minutes. Following this, the fiber composite component is removed from the forming tool or removed from the mold. Already after removal of the fiber composite component cools at the ambient temperature, but preferably it can also be placed in a separate downstream cooling device. It is possible to avoid distortion during cooling, so that the accuracy of fit of the component according to the invention is particularly high. Within the scope of the invention, it would also be possible to carry out the curing process in a separate mold holding tool and then to use a cooling process or a combined mold holding and cooling tool.

The components produced in the forming tool are removed at a temperature between 120 ° and 180 ° C, in particular at a temperature between 150 ° and 170 ° C from the press. When cooled at ambient temperature or room temperature, cool the components according to the invention in about 5 to 15 minutes, preferably 10 minutes to 50 to 120 °, most preferably to 80 °.

In addition, it is conceivable to have an active cooling, which enables correspondingly much faster cooling than passive cooling at room temperature. In the context of the invention, however, it is also conceivable to design the active cooling process such that a cooling rate is achieved which is slower than the passive cooling at room temperature. Too rapid curing of the resin in the component is thereby avoided. Depending on the component geometry to be produced, this may preferably affect the material properties of the fiber composite material.

The present invention further relates to a fiber composite component for a motor vehicle, which is made of a recycled and / or a reused fiber composite non-woven material, and is characterized in that it is produced by a method with at least one of the aforementioned method steps.

The component is characterized in particular by the fact that the fleece used to produce the component is produced almost exclusively from recycled, reused fiber composite material which is obtained as a waste product in the production of other fiber composite components. The method enables particularly short cycle times, high component manufacturability and thus only a small component tolerance. The components can thus also be used in strength-relevant application areas, the production costs being particularly cost-effective and economical in terms of process and environment due to the automation of the process and the reuse of the material.

Further advantages, features, characteristics and aspects of the present invention are part of the following description. Preferred embodiments will be apparent from the schematic figures. These are for easy understanding of the invention. Show it:

1 a split tenter according to the invention with a clamped nonwoven and resin impregnated areas;

2 a folded clamping frame;

3 a tensioned on a tenter fleece in a forming tool before the forming process and

4 the fleece off 3 after the forming process.

In the drawings, the same reference numerals are used for the same or similar component, even if a repeated description is omitted for reasons of simplicity.

1 shows a split clamping frame according to the invention 1 that's from a left half 2 and a right half 3 consists. In the left half 2 and in the right half 3 is each a fleece 4 clamped from unspecified reused and / or recycled fiber material. On the fleece 4 is on an inside 5 an area 6 with resin 7 has been homogeneously wetted, wherein a non-illustrated component to be produced in the area 6 is produced by a not shown forming tool. By a subsequent folding movement K, the left half 2 and the right half 3 folded over each other, so that the insides 5 each come to rest each other.

2 shows the split tenter 1 , where the right half 3 and the left half 2 were folded over each other, so that the fleece 4 the left half 2 and the fleece 4 the right half 3 lie one above the other or parallel to each other. The insides 5 Thus, they lie against one another and have a homogeneous resin layer, which is proportionally exaggerated here, lying between them. The resin 7 penetrates via capillary forces 8th in the fleece 4 one.

3 shows a forming tool 9 for producing a fiber composite component according to the invention 13 , being between an upper tool 10 and a lower tool 11 a tenter 12 is positioned. In the tenter frame 12 is a fleece 4 arranged that was acted upon by the method according to the invention with a resin not shown here. By lowering the upper tool 10 becomes the fleece 4 to a fiber composite component 13 according to 4 reshaped. It is possible that the clamping frame 12 in a balancing direction 14 yields, so that it does not lead to a demolition or cracking within the fleece 4 comes during the forming process.

LIST OF REFERENCE NUMBERS

1

divided clamping frame

2

left half

3

right half

4

fleece

5

inside

6

Area

7

resin

8th

capillary forces

9

forming tool

10

upper tool

11

lower tool

12

tenter

13

Fiber composite component

14

compensation direction

K

folding movement

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3539006 A1 [0005]

Claims (14)

Method for producing a fiber composite component for a motor vehicle, wherein a nonwoven ( 4 ) is used from recycled and / or reused fiber material, characterized by the following process steps: - inserting a nonwoven fabric ( 4 ) made of fiber material in a tenter frame ( 1 ); - Automated application of a resin ( 7 ) by a manipulator in the region of the web ( 4 ); - drawing in the resin ( 7 ) in the fleece ( 4 ) due to capillary forces; - insertion of the clamping frame ( 1 ) in a heated forming tool; - Pressing the fiber composite component to be produced by closing the forming tool; - curing of the pressed fiber composite component; - Removal of the pressed fiber composite component. Process according to claim 1, characterized in that the resin ( 7 ) is applied via a nozzle with an industrial robot, preferably in an uninterrupted application process, in particular at a temperature between 20 and 60 ° C, more preferably between 30 and 50 ° C. A method according to claim 2, characterized in that the resin is applied by a meandering pivotal movement of the nozzle. Method according to claim 2 or 3, characterized in that the sprayed-on resin ( 7 ) is spread with a doctor blade, preferably by a combined spray and doctor tool. Method according to one of claims 1 to 4, characterized in that the resin ( 7 ) on an inside ( 5 ) of the nonwoven ( 4 ) is applied as a thin film. Method according to one of claims 1 to 5, characterized in that a split clamping frame ( 1 ) or that two clamping frames ( 1 ) be used. Method according to claim 5 or 6, characterized in that the clamping frame ( 1 ) is folded after the resin application, so that the insides ( 5 ) come into contact with each other internally. Method according to one of claims 1 to 7, characterized in that the clamping frame ( 1 ) in a pre-heated forming tool ( 9 ) is inserted, preferably the forming tool ( 9 ) preheated to a temperature between 70 and 200 ° C, in particular between 80 and 180 ° C and more preferably between 90 and 170 ° C. Method according to one of claims 1 to 8, characterized in that the forming tool ( 9 ) is heated during the forming process and / or during the curing process. Method according to one of claims 1 to 9, characterized in that the clamping frame ( 1 ) between an upper tool ( 10 ) and a lower tool ( 11 ) of the forming tool ( 9 ) is positioned and during a lowering operation of the upper tool ( 10 ) with half the lowering speed of the upper tool ( 10 ) on the lower tool ( 11 ) is moved. Method according to one of claims 1 to 10, characterized in that the fiber composite component ( 13 ) in the forming tool ( 9 ) is cured for 0.1 to 20 minutes, preferably 1 to 15 minutes. Method according to one of claims 1 to 11, characterized in that the fiber composite component ( 13 ) is removed from the mold. Method according to one of claims 1 to 12, characterized in that the removed fiber composite component ( 13 ) is cooled, preferably in a cooling device. Fiber composite component for a motor vehicle, which consists of a recycled and / or reused fleece ( 4 ) is made of fiber composite material, characterized in that it is produced by a process according to at least one of claims 1 to 13.

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