Method for manufacturing a fiber-reinforced plastic component

Abstract

A method for producing a fiber-reinforced plastic component by injection molding, characterized in that a fiber semi-finished product (100, 200) with at least one intentionally incorporated channel is first produced by inserting at least one insert (102, 202) into the fiber semi-finished product (100, 200) to support the at least one channel on the inside, subsequently the fiber semi-finished product (100, 200) is placed in a mold and the at least one insert (102, 202) is completely removed before injecting a matrix material, wherein the removal of the at least one insert (102, 202) exposes the at least one channel in the fiber semi-finished product (100, 200), and subsequently the matrix material is injected into the mold to infiltrate the fiber semi-finished product (100, 200), wherein infiltration of the fiber semi-finished product (100, 200) is supported by the at least one channel. becomes.

Description

[0001] The invention relates to a method for producing a fiber-reinforced plastic component using an injection method.

[0002] From WO 03 / 011576 A1 a method is known for introducing reinforcing fibers into a textile semi-finished product, in which the semi-finished product is first pierced from one side by a rotating needle (“pathway deposition probe”) and when the needle is withdrawn from the other side a reinforcing fiber is inserted into the channel created by the needle in the semi-finished product.

[0003] From DE 10 2006 025 753 A1 a method is known for introducing reinforcing fibers into a textile semi-finished product for the production of fiber composite components, wherein the reinforcing fibers are surrounded with a liquefied gas for mechanical stabilization and are driven into the textile semi-finished product in the mechanically stabilized state.

[0004] From DE 10 2012 215 189 A1, a method is known for manufacturing a fiber composite component, in particular a fiber composite component for a rotor blade of a wind turbine, comprising the following process steps: introducing fiber material for the fiber composite component into a manufacturing mold, supplying flowable matrix material for the fiber composite component via a longitudinally extending sprue of the manufacturing mold using a vacuum infusion process, so that the fiber material in the manufacturing mold is impregnated with matrix material flowing transversely to the longitudinal extension of the sprue from the sprue, wherein a first region of the fiber material is essentially impregnated with matrix material from a first section of the sprue and a second region of the fiber material is essentially impregnated with matrix material from a second section of the sprue.and specifying a first matrix material flow rate for the first section of the sprue as a function of the thickness of the fiber material in the first area, as well as specifying a second matrix material flow rate for the second section of the sprue as a function of the thickness of the fiber material in the second area.

[0005] Document DE 10 2008 055 771 A1 relates to a method for manufacturing a fiber-reinforced rib of a rotor blade of a wind turbine from a, preferably dry, fiber material, wherein the fiber material is arranged in a recess of a mold on a flow aid, the recess is sealed on the top side against the external environment by means of a cover, the sealed interior space is placed under vacuum, and resin is applied to and / or into the fiber material at at least one point on the top side, so that the resin applied to and / or into the fiber material flows to the flow aid arranged under the fiber material in the interior space when a vacuum is applied.Document DE 10 2008 055 771 A1 proposes that the resin be supplied via one or more channels formed in the fiber material, so that the resin is guided to the flow aid via the channel(s), wherein the resin dispensed from the resin sprue flows to the underside flow aid via optional channels, which are advantageously formed from a slotted or porous material (e.g. foam, balsa wood, ...).

[0006] Document EP 2 511 083 A1 relates to a method for producing a workpiece by vacuum-assisted resin transfer molding, comprising the steps of arranging fiber rovings in a mold of a closed molding system that includes a mold cavity, arranging at least one resin distribution medium between the fiber rovings, applying a vacuum to the closed molding system, and injecting resin into the mold cavity. Document EP 2 511 083 A1 proposes arranging a number of slots or flow-enhancing means or flow channels between the fiber rovings as a resin distribution medium, or using a collapsible channel as a means of distributing the resin.

[0007] Document WO 91 / 18725 A1 relates to a method for vacuum forming large objects from synthetic resin in a demountable mold with reinforcing materials arranged therein, in which the monomer, together with the curing agent and an optional accelerator, is fed into the cavity from below and above to fill the vacuum-held cavity. Document WO 91 / 18725 A1 proposes feeding the synthetic resin to at least one point in the cavity, initially located in its lower part, and then successively moving it upwards at such a speed that this point is just below the surface of the synthetic resin as it is fed and rises in the mold.The synthetic resin shall be supplied through at least one hose, which is inserted sealingly through a wall in the upper part of the mold so deep into the cavity that its free end is located in the lower part of the cavity, and that the hose or hoses are gradually pulled upwards at such a speed that the free end or free ends of the hose or hoses are just below the surface of the synthetic resin when it is supplied and rises in the mold.

[0008] Document WO 2013 / 087599 A2 concerns a flow medium for distributing a fluid, comprising at least one flow channel and at least one layer of fibrous material. Document WO 2013 / 087599 A2 proposes that the at least one flow channel be designed to be porous and spatially enclosed within the layer of fibrous material.

[0009] The invention is based on the objective of improving a method mentioned above. In particular, the matrix material flow and / or infiltration behavior are to be improved. Specifically, the matrix material flow and / or infiltration behavior are to be locally controllable. Specifically, a fiber-reinforced plastic component is to be producible with reduced injection and / or pressing pressure. Specifically, a fiber-reinforced plastic component of increased quality is to be producible. Furthermore, a structurally and / or functionally improved fiber-reinforced plastic component is to be provided.

[0010] The problem is solved by a method for producing a fiber-reinforced plastic component using an injection process, wherein a fiber semi-finished product with at least one specifically introduced channel is first produced by inserting at least one insert into the fiber semi-finished product to support the at least one channel on the inside, subsequently the fiber semi-finished product is placed in a mold and the at least one insert is completely removed before injecting a matrix material, wherein the removal of the at least one insert releases the at least one channel in the fiber semi-finished product, and subsequently the matrix material is injected into the mold to infiltrate the fiber semi-finished product, wherein infiltration of the fiber semi-finished product is supported by the at least one channel.

[0011] The fiber-reinforced plastic component contains reinforcing fibers. The reinforcing fibers can be carbon fibers. The reinforcing fibers can be glass fibers, ceramic fibers, aramid fibers, boron fibers, basalt fibers, steel fibers, natural fibers, or nylon fibers. The reinforcing fibers can be bundled as filament yarn. The reinforcing fibers can be bundled as roving. The reinforcing fibers can be bundled into a fiber semi-finished product. The fiber semi-finished product can be a dry fiber semi-finished product. The fiber semi-finished product can be manufactured using a textile process. The fiber semi-finished product can be manufactured using a weaving, laying, knitting, embroidery, and / or braiding process. The fiber semi-finished product can contain continuous fibers, long fibers, and / or short fibers. The reinforcing fibers can be coated. The reinforcing fibers can be coated with a sizing agent.The sizing can act as an adhesion promoter between the fiber preform and the matrix material. The reinforcing fibers can be pre-impregnated. The fiber preform can be a prepreg. The fiber preform can be a fiber-matrix preform, such as BMC or SMC. The fiber preform can be a thermosetting fiber preform. The fiber preform can be a thermoplastic fiber preform.

[0012] The matrix material can be a polymer. The matrix material can be a thermoset. The matrix material can be a synthetic resin. The matrix material can be an elastomer. The matrix material can be a thermoplastic. The matrix material can be a biopolymer. The matrix material can be injected into the mold cavity as a flowable molding compound.

[0013] The fiber-reinforced plastic component can be manufactured using an autoclave process, fiber spraying, compression molding, pultrusion, injection molding, compression molding, filament winding, hand lay-up, or resin injection molding. The fiber-reinforced plastic component can also be manufactured using a vacuum-assisted process.

[0014] The mold can be multi-part. The mold can be a single piece. The mold can be openable and closable. The mold can have at least one mold cavity. The mold can have at least one sprue. The at least one sprue can be used to inject matrix material. The at least one channel specifically incorporated into the fiber semi-finished product can correspond to the at least one sprue of the mold.

[0015] During the production of the fiber semi-finished product, at least one insert is incorporated into the fiber semi-finished product to support the at least one channel on the inside. The at least one insert can be incorporated during the textile manufacturing process of the fiber semi-finished product. The at least one insert can be woven, laid, knitted, embroidered, and / or braided with the reinforcing fibers.

[0016] The at least one insert can fill the at least one channel at least approximately completely. The at least one insert is completely removed before the matrix material is injected. The at least one insert can be pulled out of the fiber preform before the matrix material is injected. Removing the at least one insert releases the at least one channel in the fiber preform.

[0017] In an embodiment not covered by the scope of protection, the at least one insert can remain at least partially in the fiber semi-finished product. The at least one insert can be a single piece. The at least one insert can be multi-part. A portion of a multi-part insert can be removed at least approximately completely before the matrix material is injected. A portion of a multi-part insert can remain at least partially in the fiber semi-finished product. The portion of the multi-part insert remaining in the fiber semi-finished product can define or partially define the at least one channel.

[0018] The at least one insert can have a wire. The wire can have a linear shape. The wire can be straight or have only slight curvatures. The wire can form a one-piece insert. The at least one insert can have a spiral. The spiral can be wound around a longitudinal axis. The spiral can have a helical spring-like shape. The spiral can form a one-piece insert. The spiral can form part of a multi-piece insert. The wire can form part of a multi-piece insert. The wire can form a removable part of a multi-piece insert. The wire can be arranged inside the spiral. The at least one insert can have, at least partially, a surface with good sliding properties, in particular made of polytetrafluoroethylene. The at least one insert can consist at least approximately entirely of polytetrafluoroethylene.At least one insert may have a surface coating or covering of polytetrafluoroethylene and a core made of another material.

[0019] In an embodiment not covered by the scope of protection, a fiber-reinforced plastic component may be provided, comprising a fiber material and a matrix material, wherein the fiber material is infiltrated with the matrix material by an injection process, and wherein the plastic component is manufactured according to such a process. The fiber-reinforced plastic component may be a vehicle component. The fiber-reinforced plastic component may be a motor vehicle component. The fiber-reinforced plastic component may be a body component. The fiber-reinforced plastic component may be an underbody component. The fiber-reinforced plastic component may be an interior trim component. The fiber-reinforced plastic component may be a trim component.

[0020] In summary, and in other words, the invention provides, among other things, control of resin flow by creating sprue channels. Sprue channels can be created by embedding a cable or wire in a supported area during the production of a semi-finished product. The wire material can be polytetrafluoroethylene or another material with a smooth surface. After forming / preforming, this wire can be drawn out of the semi-finished product to create an integrated sprue channel. Sprue channels can also be created by embedding a spiral, for example made of polyethylene terephthalate or steel, instead of a wire or cable during the production of the semi-finished product for targeted infiltration in specific areas. If necessary for the forming process, the spiral can be pre-positioned on a wire, which is then removed after preforming.The two options can be selected as needed.

[0021] The term "may" is used to denote, in particular, optional features of the invention. Accordingly, there is an embodiment of the invention that includes the respective feature or features.

[0022] The invention improves matrix material flow and / or infiltration behavior. Matrix material flow and / or infiltration behavior can be controlled locally. A fiber-reinforced plastic component can be manufactured with reduced injection and / or pressing pressure. A fiber-reinforced plastic component can be manufactured with increased quality. Furthermore, a structurally and / or functionally improved fiber-reinforced plastic component is provided.

[0023] Exemplary embodiments of the invention are described in more detail below with reference to the figures. Further features and advantages will become apparent from this description. Specific features of these exemplary embodiments may represent general features of the invention. Features of these exemplary embodiments combined with other features may also represent individual features of the invention.

[0024] They show schematically and by example: Fig. 1. A fiber semi-finished product with wire inserts for the targeted introduction of channels and Fig. 2 a fiber semi-finished product with spiral inserts for the targeted introduction of channels.

[0025] Fig. Figure 1 shows a fiber semi-finished product 100 with wire inserts, such as 102, for the targeted introduction of channels. The fiber semi-finished product 100 comprises carbon fibers. The fiber semi-finished product 100 has several textile-like layers or sections. The layers or sections are joined together or fixed to one another by a stitching process. The layers or sections are joined together or fixed to one another by drawing threads through them. The wire inserts 102 are incorporated during the production of the textile-like layers or sections and / or during the joining or fixing of the layers or sections. The wire inserts 102 are arranged at predetermined positions and with predetermined orientations.

[0026] The wire inserts 102 each have a surface made of polytetrafluoroethylene. The wire inserts 102 are each flexible. The wire inserts 102 extend from a surface of the fiber semi-finished product 100 into the interior of the fiber semi-finished product 100 or through the interior of the fiber semi-finished product 100. The wire inserts 102 protrude at one end or at both ends beyond a surface of the fiber semi-finished product 100. This allows the wire inserts 102 to be gripped and pulled out of the fiber semi-finished product 100.

[0027] The fiber preform 100 is intended to be subsequently infiltrated with a matrix material. For this purpose, the fiber preform 100 is placed in a mold. The wire inserts 102 are withdrawn to create channels in the fiber preform 100. The wire inserts 102 can be withdrawn before or after the fiber preform 100 is placed in the mold. The wire inserts 102 can be withdrawn after the fiber preform 100 has been produced, as soon as it is sufficiently stabilized so that internal support for the channels to be created is no longer necessary. The channels created in the fiber preform 100 can correspond to the sprue channels of the mold when the fiber preform 100 is placed in the mold. Matrix material flowing in through the sprue channels of the mold then infiltrates the fiber preform 100 and flows into or through the created channels.

[0028] Fig. Figure 2 shows a fiber semi-finished product 200 with spiral inserts, such as 202, for the targeted introduction of channels. The spiral inserts 202 are incorporated during the production of the textile-like layers or sections and / or during the joining or fixing of the layers or sections. Optionally, the spiral inserts 202 are each part of a multi-part insert, in which wires are arranged as further insert components within the spiral inserts 202 to enable or facilitate their insertion into the fiber semi-finished product 200. If the spiral inserts 202 have internal wires, these wires can be pulled out of the fiber semi-finished product 200 to create channels. The spiral inserts 202 are themselves pulled out of the fiber semi-finished product 200 to create spiral channels. Further details are provided in particular on Fig. 1 and the associated description are referenced. Reference sign 100 fiber semi-finished products 102 wire insert 200 fiber semi-finished products 202 spiral insert

Claims

A method for producing a fiber-reinforced plastic component by injection molding, characterized in that a fiber semi-finished product (100, 200) with at least one intentionally incorporated channel is first produced by inserting at least one insert (102, 202) into the fiber semi-finished product (100, 200) to support the at least one channel on the inside, subsequently the fiber semi-finished product (100, 200) is placed in a mold and the at least one insert (102, 202) is completely removed before injecting a matrix material, wherein the removal of the at least one insert (102, 202) releases the at least one channel in the fiber semi-finished product (100, 200), and subsequently the matrix material is injected into the mold to infiltrate the fiber semi-finished product (100, 200), wherein infiltration of the fiber semi-finished product (100, 200) is facilitated by means of the at least one channel is supported. Method according to claim 1, characterized in that at least one one-piece or multi-piece insert (102, 202) is introduced. Method according to at least one of claims 1 to 2, characterized in that at least one insert (102) comprising a wire is introduced. Method according to at least one of claims 1 to 3, characterized in that at least one insert (202) having a spiral is introduced. Method according to at least one of claims 1 to 4, characterized in that at least one insert (102, 202) is introduced which has at least sectionally a surface with good sliding properties, in particular made of polytetrafluoroethylene. Method according to at least one of claims 1 to 5, characterized in that the fiber semi-finished product (100, 200) is produced in a textile engineering process and the at least one insert (102, 202) is incorporated during the production of the fiber semi-finished product (100, 200) in the textile engineering process.

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