DE102016200530B4 - Process for producing a fiber-reinforced plastic component - Google Patents

Abstract

A method for producing a fiber-reinforced plastic component (100), wherein at least one fiber material (11) is arranged between at least two planarized layers (12, 13, 14) with a matrix material (10), the method comprising at least the following steps: a) Feeding the matrix material (10) into an extruder device (15); andb) heating the matrix material (10) within the extruder device (15) above a melting temperature of the matrix material (10); andc) extruding the matrix material (10) through openings, in particular nozzles, of the extruder device (15) such that the at least two layers (12, 13, 14) are formed flat with the matrix material (10); andd) arranging the fiber material (11) between the at least two planarized layers (12, 13, 14) with the matrix material (10), whereby a planar molding compound (16) of fiber-reinforced plastic is formed; unde) cutting the sheet-like molding compound (16); andf) pressing the sheet-like molding compound (16), wherein the molding compound (16) is brought into a predetermined shape for the fiber-reinforced plastic component (100), characterized in that in and / or after step c) the layers (12, 13, 14 ) are conveyed with the matrix material (10) in sections spaced apart from one another, and in step d) the fiber material (11) is arranged on a surface of at least one of the layers (12, 13, 14), the individual layers (12, 13, 14) are placed on each other and thereby the fiber material (11) between the individual layers (12, 13, 14) is arranged and fixed.

Description

Technical area

The invention relates to a method for producing a fiber-reinforced plastic component and a fiber-reinforced plastic component itself.

Due to the objective of reducing CO2 emissions, a great variety of requirements are placed on materials, in particular in automobile production. One of the most important requirements is lightweight construction. One possibility for reducing the weight of plastic components is the reinforcement of the plastic components by means of fibers, for example glass fibers. In this case, weight reductions of more than 20% can be achieved with the same property profile of the plastic components.

By combining plastics with reinforcing fibers, a large weight saving potential can be generated. However, the use of fiber-reinforced plastics is currently associated with high costs, since the manufacturing processes in which materials can be produced with very good mechanical properties are only partially automated. With fiber composites, the material is only produced during the component manufacturing process.

A material with very good mechanical properties is for example the glass mat reinforced thermoplastic (GMT). GMT is prefabricated in the form of a semi-finished product. During the production of the semi-finished product, the material must be heated. In the subsequent processing or post-processing, wherein the semi-finished product is brought into the desired shape, this is heated again for the forming.

Components based on the semifinished product GMT are thus not produced directly, but the detour via the semifinished product is always selected, as a result of which the component manufacturer first has to purchase the semifinished product. The material must be heated several times until the production of the finished component, resulting in a significant energy consumption.

State of the art

In the known in the prior art method for producing fiber-reinforced plastics fibers in the form of short fibers, long fibers or continuous fibers are usually performed together with the plastic or a matrix material through an extruder, the fibers are often severely damaged and partially shortened. This often results in poor mechanical properties of the components. Furthermore, the solutions known in the prior art are sometimes only suitable for thermosets, which means that the components are not or only very difficult to recycle.

In the DE 40 20 109 A1 a process and a plant for the production of moldings from crosslinked reaction plastics, in particular polyurethane, are described.

The DE 10 2007 028 872 A1 relates to a method for producing a planar structural composite component with a first layer, which is connected on their sides facing away from each other with another layer, each consisting of a reinforced with discontinuous reinforcing fibers in irregular distribution thermoplastic material. The reinforcing fibers are fed to at least one extruder and mixed there with the respective thermoplastic material.

In the DE 10 2006 025 280 A1 For example, a method for producing a fiber-reinforced component and a device for doing so will be described. It is provided that a bundle of continuous fiber impregnated and this fiber / matrix strand is placed by means of a handling device via a nozzle in a temperature-controlled device and consolidated.

In the DE 22 00 594 A For example, composite sheets reinforced from low molecular weight thermoplastic polymers and glass fibers are described. In doing so, these sheets are brought into a desired shape by means of a forming apparatus operating substantially at ambient temperature while the sheets are preheated to a temperature above the softening point of the polymer.

The DE 32 06 164 A1 relates to a method and an apparatus for producing multilayer sheets of extrudable plastic, wherein at least two sheets of plastic supplied by means of extruders with slot dies or the like are joined together by means of rollers, including a structure.

DESCRIPTION OF THE INVENTION: Problem, Solution, Advantages

The object of the present invention is to further improve a method for producing a fiber-reinforced plastic component such that the detour via a semifinished product can be avoided and the fiber material is not damaged or damaged as little as possible, so that the resulting fiber-reinforced plastic component has good mechanical properties.

Furthermore, the object of the present invention is to propose a fiber-reinforced plastic component with good mechanical properties, which can be made without the detour via a semi-finished product.

According to the invention, a method for producing a fiber-reinforced plastic component is proposed for this purpose, wherein at least one fiber material is arranged between at least two flat layers with a matrix material. The matrix material may consist of thermosets and / or thermoplastics or have these. It is preferably provided that the matrix material comprises or consists of thermoplastics. The fiber material may comprise or consist of glass fibers, carbon fibers and / or aramid fibers.

1. a) Zuführen des Matrixwerkstoffs in eine Extrudervorrichtung; und
2. b) Erwärmen des Matrixwerkstoffs innerhalb der Extrudervorrichtung bis über eine Schmelztemperatur des Matrixwerkstoffs; und
3. c) Extrudieren des Matrixwerkstoffs durch Öffnungen, insbesondere durch Düsen, der Extrudervorrichtung, derart, dass die mindestens zwei Lagen mit dem Matrixwerkstoff flächig ausgebildet werden; und
4. d) Anordnen des Faserwerkstoffs zwischen den mindestens zwei flächig ausgebildeten Lagen mit dem Matrixwerkstoff, wodurch eine flächige Formmasse aus faserverstärktem Kunststoff ausgebildet wird; und
5. e) Zuschneiden der flächigen Formmasse in einzelne Formmassenteile; und
6. f) Pressen der zugeschnittenen Formmassenteile, wobei diese in eine vorgegebene Form für das faserverstärkte Kunststoffbauteil gebracht werden.

The method according to the invention has at least the following steps in the predetermined order:

1. a) feeding the matrix material into an extruder device; and
2. b) heating the matrix material within the extruder device to above a melting temperature of the matrix material; and
3. c) extruding the matrix material through openings, in particular through nozzles, of the extruder device, such that the at least two layers are formed flat with the matrix material; and
4. d) arranging the fiber material between the at least two planar layers with the matrix material, whereby a flat molding compound of fiber-reinforced plastic is formed; and
5. e) cutting the sheet-like molding compound into individual molded parts; and
6. f) pressing the cut molding mass parts, wherein these are brought into a predetermined shape for the fiber-reinforced plastic component.

The above-described manufacturing process can be carried out with the steps a) to d) as a continuous process. By cutting the sheet-like molding compound into molded parts and then pressing the cut molding compound parts, the continuous process is converted into a discontinuous process. The extruder device can be designed, for example, as a screw extruder or screw extruder. Preferably, the extruder device is designed as a single-screw extruder or twin-screw extruder. As an extrudate, the extruder device, the matrix material and optional additional additives are supplied. In the extruder device, the added extrudate is melted and homogenized. For this purpose, heat is supplied to the matrix material in the extruder device.

The extruder device has at least two openings, in particular nozzles (for example slot dies) for pushing through or pushing through the matrix material. In this case, the matrix material is extruded, such that at least two layers are formed flat with the matrix material.

In the method according to the invention described above is a kind of direct process for the production of a fiber-reinforced plastic component. The detour via a semi-finished product, for example a glass mat reinforced thermoplastic (GMT) is not necessary. The fact that all raw materials are processed directly in the manufacturing process, costs can be saved. The material know-how also remains with the manufacturer, as this becomes independent of semi-finished manufacturers with the proposed method.

Characterized in that the fiber material is not supplied to the extruder device, but only then (after the extrusion of the matrix material) is arranged on the sheet-formed layers with the extruded matrix material, long fibers can be obtained, resulting in improved mechanical properties.

The proposed manufacturing method is suitable for mass production and can be carried out in a particularly preferred productive and very fast. Furthermore, the use of low cost thermoplastics, such as polypropylene (PP), is possible because chemical curing reactions do not have to wait. Furthermore, the recyclability of the fiber-reinforced plastic components produced therewith is ensured.

In and / or after step c), the individual layers are conveyed with the matrix material in sections spaced apart from one another, and in step d) the fiber material is arranged on a surface of at least one of the layers. In this case, the individual layers are in step c) following the extruder device substantially one above the other, but spaced apart, conveyed or promoted. After arranging the fiber material on a surface of at least one of the layers, the individual layers are placed one on top of the other, thereby arranging and fixing the fiber material between the individual layers.

The steps a) to d) can be carried out in a particularly suitable manner in a continuous process sequence.

The fiber material is preferably arranged in the form of long fibers and / or continuous fibers, in particular in the form of rovings, between the at least two planar layers with the matrix material. For example, the fiber material can be supplied via a roving station with a plurality of roving rollers.

Furthermore, it is preferably provided that in step d) of the fiber material together with a semi-finished textile, in particular a fabric or scrim, between the at least two planar layers is arranged with the matrix material.

It is also preferably provided that between the steps e) and f) the cut molding compounds or cut molding mass parts are stored in an oven, in particular a continuous furnace. From step e), the previously continuously performed process is transferred to a discontinuous process. In order to design the continuous process or the process steps a) to d) as independently as possible from the subsequent process steps, the cut shaped mass parts can be stored or put into a waiting position.

Furthermore or alternatively, it is provided that a conveying speed of the matrix material is configured variably by the extruder device. Also, the speed of feeding the fiber material could be made variable. Furthermore, a conveying speed of the at least two layers with the matrix material could be variable. By providing variable or adjustable and variable conveying speeds or feed rates, an intermediate storage or waiting position and a continuous furnace can be dispensed with. The conveyor speeds or feed rates can be adapted to the speed of the press and / or the number of presses. Furthermore, the conveying speeds or feeding speeds could be adapted and changed depending on the desired shape of the resulting fiber-reinforced plastic component.

Preferably, a heat supply is provided only in step b). This is to be understood that during the production process, only the extrudate, in particular the matrix material and optionally additionally supplied additives, heat in the extruder is supplied. A heat supply to another location or during a later process step is preferably not provided. Thus, a multiple warm-up, as it is necessary, for example, when using semi-finished products, is avoided. Heat is applied to the matrix material in the extruder device so that the fiber material can be arranged on the extruded heated layers with the matrix material outside the extruder. Further heating of the individual layers outside the extruder device or heating of the resulting molding compound and the cut molding mass parts is preferably not provided.

Furthermore, the extruder device is preferably not supplied with fiber material. Particularly preferably, the extruder device is fed no long fibers and no continuous fibers. Thus, fibers in the extruder device are not destroyed or shortened, which leads to better mechanical component properties. However, it is thus not excluded that fibers, in particular short fibers, are already supplied to the matrix material in the extruder device. These are then only very short, but may be needed for the ribs, as there no long fibers can flow in (without a fiber breakage). For the purposes of this invention are short fibers with a length of up to 1 mm, long fibers fibers with a length between 1 mm and 50 mm and continuous fibers with a length of more than 50 mm.

Furthermore, it is preferably provided that in step c) more than two layers are formed flat with the matrix material. In particular, an upper side and a lower side of the molding compound are each formed by a layer with the matrix material and the fiber material is arranged exclusively between individual layers with the matrix material. The top and bottom of the molding compound thus preferably consists of the matrix material and not of the fiber material. As a result, a particularly favorable component surface quality can be achieved.

According to the invention, a fiber-reinforced plastic component, comprising a matrix material and a fiber material, is furthermore provided. The fiber-reinforced plastic component is produced by a method described above.

The matrix material comprises polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene-ethylene-propylene-diene rubber (PP-EPDM), acrylonitrile-butadiene-styrene (ABS), polymethylmethacrylate (PMMA), styrene-acrylonitrile (SAN), polystyrene (PS), polyphthalamide (PPA), polycarbonate (PC), polyetheretherketone (PEEK), thermoplastic polyurethane elastomers (PPU) and / or polyethersulfone (PES) or consists thereof. Thermoplastic polyamides (PA) or polyesters which are polymerized from lactam are particularly preferably suitable as the matrix material. In this case, a long processing time can be ensured until after pressing, if the lactam is held during processing below the starting temperature at which the lactam begins to polymerize to the polyamide.

Furthermore, it is preferably provided that the fiber material comprises or consists of glass fibers, in particular based on E glass, S glass and / or hollow glass. Furthermore, the fiber material could comprise or consist of carbon fibers, in particular high-strength (HT), intermediate module (IM), high modulus (HM), ultra-high modulus (UHM), PYROFIL and / or AKSACA. Furthermore, the fiber material could comprise or consist of aramid fibers and / or natural fibers. Natural fibers could for example be based on cork, flax and / or sisal.

Particularly preferably, the matrix material is fed to a single-screw extruder. The supply of the fiber material may be provided by roving rollers, wherein the fiber material is arranged in the form of continuous fibers between the individual layers with the matrix material. Polypropylene (PP) is particularly preferred as the matrix material, and glass fiber (based on S glass) is particularly preferably provided as the fiber material. The fiber volume fraction of the fiber-reinforced plastic component is particularly preferably between 40% and 60%.

list of figures

The invention is explained below by way of example with reference to a preferred embodiment.

• 1: den Verfahrensablauf zur Herstellung faserverstärkter Kunststoffbauteile in einem Direktverfahren.

It shows schematically:

• 1 : the procedure for the production of fiber-reinforced plastic components in a direct process.

Preferred embodiments of the invention

1 shows an apparatus for producing a fiber-reinforced plastic component 100 with several, consecutively arranged stations. The matrix material 10 as well as optional additional additives 17 become an extruder device 15 fed. The matrix material 10 as well as the optionally added additives 17 is in the extruder device 15 Heat above a melting temperature of the matrix material 10 add out.

The extruder device 15 has three openings in the form of slot dies, whereby the matrix material 10 extruded or pressed and thereby three flat layers 12 . 13 . 14 with the matrix material 10 be formed. Following the extruder device 15 become the three flat layers 12 . 13 . 14 with the matrix material 10 spaced apart from each other and conveyed on top of each other. On the surface of the lowest layer 12 and on the surface of the middle layer 13 becomes the fiber material 11 arranged. For this purpose, the apparatus for producing the fiber-reinforced plastic components 100 a fiber supply unit 18 with 12 roving rolls on. After placing the fiber material 11 on the surfaces of the two layers 12 . 13 become all three layers 12 . 13 . 14 placed on top of each other, creating a molding compound 16 is trained.

In a cutting unit 19 becomes the molding material 16 cut into individual molded parts and a press 20 fed.

In 1 are the individual stages of the pressing process within the press 20 shown side by side as an example. In the press 20 each of the individual shaped mass parts is the desired shape for the fiber-reinforced plastic component 100 imprinted. After the pressed component 100 cooled in the cavity and solidified, the component can 100 be demoulded and then deburred if necessary or edited by means of water jet cutting.

LIST OF REFERENCE NUMBERS

100

Fiber-reinforced plastic component

200

Device for producing a fiber-reinforced plastic component

10

Matrix material

11

Fiber material

12

First layer with the matrix material

13

Second layer with the matrix material

14

Third layer with the matrix material

15

extruder device

16

molding compound

16a

Molding material part

17

additives

18

fiber feeding

19

cutting unit

20

Press

Claims (9)

Method for producing a fiber-reinforced plastic component (100), wherein between at least two surface-formed layers (12, 13, 14) with a matrix material (10) at least one fiber material (11) is arranged, wherein the method comprises at least the following steps: a) feeding the matrix material (10) in an extruder device (15); and b) heating the matrix material (10) inside the extruder device (15) above a melting temperature of the matrix material (10); and c) extruding the matrix material (10) through openings, in particular nozzles, of the extruder device (15) such that the at least two layers (12, 13, 14) are formed flat with the matrix material (10); and d) arranging the fiber material (11) between the at least two flatly formed layers (12, 13, 14) with the matrix material (10), whereby a flat molding compound (16) made of fiber-reinforced plastic is formed; and e) cutting the sheet molding compound (16); and f) pressing the flat molding compound (16), wherein the molding compound (16) is brought into a predetermined shape for the fiber-reinforced plastic component (100), characterized in that in and / or after step c) the layers (12, 13, 14) with the matrix material (10) are conveyed in sections spaced from each other, and in step d) the fiber material (11) on a surface of at least one of the layers (12, 13, 14) is arranged, wherein subsequently the individual layers (12, 13 , 14) are deposited on each other and thereby the fiber material (11) between the individual layers (12, 13, 14) is arranged and fixed. Method according to Claim 1 characterized in that the fiber material (11) in the form of long fibers and / or continuous fibers, in particular in the form of rovings, between the at least two planar layers (12, 13, 14) with the matrix material (10) is arranged. Method according to one of Claims 1 or 2 , characterized in that in step d) of the fiber material (11) together with a textile semifinished product, in particular a fabric or scrim, between the at least two planar layers (12, 13, 14) with the matrix material (10) is arranged. Method according to one of the preceding claims, characterized in that between the steps e) and f) the cut molding compounds (16) are stored in an oven, in particular a continuous furnace. Method according to one of the preceding claims, characterized in that a conveying speed of the matrix material (10) through the extruder device (15) is variable, and / or that a feed rate of the fiber material (11) is variable, and / or that a conveying speed of the at least two Layers (12, 13, 14) with the matrix material (10) is variable. Method according to one of the preceding claims, characterized in that heat is supplied only in step b). Method according to one of the preceding claims, characterized in that in step c) more than two layers (12, 13, 14) are formed flat with the matrix material (10), wherein a top and bottom of the molding compound (16) in each case by a layer (12, 13, 14) with the matrix material (10) is formed and the fiber material (11) exclusively between individual layers (12, 13, 14) with the matrix material (10) is arranged. Fiber-reinforced plastic component (100), comprising a matrix material (10) and a fiber material (11), characterized in that the fiber-reinforced plastic component (100) was produced by a method according to one of the preceding claims. Fiber-reinforced plastic component (100) according to Claim 8 , characterized in that the matrix material (10) comprises or consists of PP, PA, PET, PBT, PP-EPDM, ABS, PMMA, SAN, PS, PPA, PC, PEEK, PPU and / or PES; and / or that the fiber material (11) comprises or consists of glass fibers, carbon fibers, aramid fibers and / or natural fibers.

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