DE102019121592B3 - Method for manufacturing a component and component for this - Google Patents

Abstract

The invention relates to a method for producing a component from a component material which has at least one plastic material, the method comprising the following steps:
- Providing a component substrate from which the component is to be produced;
Application of a segmented textile fabric to the component substrate in at least one application section, the segmented textile fabric having a plurality of segments;
- Consolidating the plastic material contained in the component substrate in such a way that the segmented textile fabric is connected to the consolidated plastic material in the application section; and
Peeling off the individual segments from the component substrate after the plastic material has consolidated.

Description

The invention relates to a method for producing a component from a component material which has at least one plastic material. The invention also relates to a component for this purpose.

Due to the weight-specific strength and rigidity of fiber composite components that are made from a fiber composite material, such components have become indispensable in the aerospace industry and in many other areas of application, such as the automotive sector. In the production of a fiber composite component, a matrix material embedding the fiber material is cured mostly under the application of temperature and pressure and thus forms an integral unit with the fiber material after curing. The reinforcing fibers of the fiber material are thereby forced into their specified direction and can transfer the loads that occur in the specified direction.

Fiber composite materials from which such fiber composite components are produced generally have two main components, namely on the one hand a fiber material and on the other hand a matrix material. In addition, other secondary components can be used, such as binder materials or additional functional elements that are to be integrated into the component. If dry fiber materials are provided for the production, then during the production process the matrix material of the fiber composite material is infused into the fiber material by an infusion process through which the dry fiber material is impregnated with the matrix material. This usually happens due to a pressure difference between the matrix material and the fiber material, for example by evacuating the fiber material by means of a vacuum pump. In contrast to this, fiber composite materials are also known in which the fiber material is already pre-impregnated with the matrix material (so-called prepregs).

Before the matrix material hardens, the fiber material is usually introduced into a molding tool which, with its molding tool surface, simulates the subsequent component shape. Both dry and pre-impregnated fiber materials can be placed or introduced into the molding tool.

Fiber composite components have some disadvantages compared to isotropic materials during production, since the component shape of a fiber composite component usually has to be formed by appropriate molding tools, which represent a kind of negative impression of the later component. It is therefore not uncommon for complex fiber composite components to be glued together from various components that are either made of fiber composite materials or are composed of isotropic materials in order to be able to produce the complex geometry. However, reliable bonding of the components must be guaranteed.

Such gluing of plastic components, such as fiber composite components made from a fiber composite material, is not entirely uncritical with regard to certification and validation. In the aerospace sector in particular, high standards have to be set for such an adhesive connection in order to meet the safety requirements, especially in the case of safety-critical components. The particular challenge here is that a non-destructive test of bonds or bonded joints is only possible to a limited extent.

Such fiber composite components are often refined by painting and coatings, so that such materials that are applied to such a finished fiber composite component must be applied in a process-reliable manner and must hold securely on the surface of such a fiber composite component. There is fundamentally a need for such coatings to adhere reliably to the surface of the fiber composite component even under given stress conditions.

From the post-published DE 10 2018 111 306 A1 a method for applying a material to a surface of a fiber composite component is known, wherein a monofilament fabric with matrix material is arranged on the component surface and cured in a common process step with the matrix material of the fiber composite component before the material is applied. After curing, the monofilament fabric is peeled off the component and then the material is applied. The hardening of the matrix materials creates a firm connection in the boundary area between the component and the monofilament fabric, with the matrix material being cohesively broken in the boundary area by the tearing off of the monofilament fabric.

From the US 2013/0280488 A1 a method for producing a fiber composite component is known, a bonding layer (bond ply) and a tear-off layer (peel ply) being placed on the fiber composite component in order to prepare a joining surface. After curing, the connection layer and the tear-off layer are removed from the component, whereby the joining surface of the component is activated for a further application step.

From the DE 10 2017 113 430 A1 A method for checking a joining surface of a fiber composite component is known, in which a sheet-like test textile with an adhesive primer is applied to the joining surface of the fiber composite component and cured together with it. The test textile is then pulled off the joining surface of the fiber composite component. On the basis of a qualitative assessment of the fracture pattern or a quantitative assessment of the pull-off force, the joint surface can now be checked in order to ensure process-reliable and valid bonding on this joint surface.

From the US 7 736 452 B2 a method for the non-destructive checking of an adhesive connection when repairing fiber composite components is known, the checking of the adhesive connection being carried out indirectly here. The damaged area on the fiber composite component is repaired in a first step and a corresponding glued-in repair patch is used. A test patch, which has the same properties and the same material as the repair patch, is then glued on in the immediate vicinity of the repaired point and, after the adhesive bond has hardened, it is subjected to a corresponding force. If the test patch withstands the force applied in this way, the durability of the repaired area is assumed.

From the US 2008/0011075 A1 a method for quality control of a fiber composite component and a possible adhesive connection is known, in which case a metallic structure is glued to the surface of the fiber composite component. The metallic structure has a predetermined breaking point. After the adhesive bond has hardened, a force is now applied to the metallic structure. If the predetermined breaking point breaks, the adhesive bond with the surface of the fiber composite component is effective. However, if the adhesive connection breaks instead of the predetermined breaking point, it was not free of defects.

The use of tear-off fabric as a method for surface activation and testing, however, harbors a fundamental contradiction in terms of the requirements. On the one hand, by tearing off the tissue, a clean, activated surface should be created. On the other hand, the fabric should be able to be pulled off by hand without great effort, and the component must not be damaged in the process.

It is therefore the object of the present invention to provide an improved method for producing a component from at least one plastic material, in which a joining surface can be activated and checked in a process-reliable manner and the disadvantages known from the prior art can be avoided.

The object is achieved according to the invention with the method according to claim 1 for producing a component from a plastic material and the component according to claim 13. Advantageous embodiments of the invention can be found in the corresponding subclaims.

According to claim 1, a method for producing a component from a component material which has at least one plastic material is proposed, wherein first a component substrate is provided from which the component is to be produced. The component substrate can consist of the plastic material, for example, without containing further fiber materials. The component substrate can, however, also have the fiber material of a fiber composite material, but without also containing the necessary matrix material at the time of provision. This is only infused into the fiber material of the component substrate at a later point in time. The component substrate provided can, however, also contain the fiber material and the matrix material embedding the fiber material. The component substrate can be provided in such a way that the plastic material is already consolidated, preconsolidated (not yet fully consolidated) or not yet consolidated. Accordingly, a component substrate can be provided that already corresponds to the fully cured component or a preliminary stage thereof.

After the component substrate has been provided, a segmented textile fabric is applied to at least one application section (part of the surface of the component substrate) of the component substrate, the segmented textile fabric having a plurality of segments. The segmentation creates a flat textile structure that contains a plurality of individual test textiles that can be used separately and independently of the other segments for surface activation and checking of the joining surface.

After the application of the at least one segmented textile fabric, a plastic material is consolidated in order to connect the segmented textile fabric to the component substrate in the application section through the consolidated plastic material. The connection is made in particular cohesively and / or adhesively. In addition, the consolidation of the plastic material creates a cohesive and / or positive connection between the segmented textile fabric on the one hand and the component substrate on the other hand.

A distinction can be made between two basic procedures. On the one hand, the component substrate can be consolidated together with the segmented textile fabric, which can primarily be used for surface activation. The component substrate in this case has a plastic material that has not yet been fully consolidated, which is consolidated together with the plastic material for connecting the segmented textile fabric. On the other hand, the component substrate can already be fully consolidated or preconsolidated when the segmented textile fabric is applied, which is primarily used to check the surface of the component with simultaneous surface activation. In this case the textile fabric is provided with a plastic material or this is infused into the textile fabric.

The plastic material of the component substrate can at the same time also be the plastic material for connecting the segmented textile fabric, with the textile fabric being advantageously applied to the plastic material of the component substrate. It is also conceivable, however, that an additional plastic material is used in or on the textile fabric in order to connect it to the component substrate. In that case, the textile fabric itself contains a plastic material. The textile fabric can either be soaked with the plastic material before application or it is soaked with plastic material during the consolidation process, for example by applying a layer of plastic material over it or by the plastic material from the component substrate penetrating the fabric.

In the context of the present invention, the consolidation of the plastic material is understood to mean that the plastic material is at least partially cured. However, it is also conceivable that the plastic material is completely cured, i. H. the polymerisation processes of the plastic material are largely complete.

After the plastic material has been consolidated and the sheet-like structure has been firmly connected to the component substrate, the individual segments of the segmented textile sheet-like structure are peeled off the component substrate, with each individual segment being peeled off one after the other. In this case, one edge segment is preferably peeled off first, while the other segments still remain on the component substrate. Only when the first edge segment has been peeled off is the next segment peeled off the component substrate until all segments have been peeled off.

As a result of the segmentation of the textile fabric, it was surprisingly recognized that comparatively little effort is required to peel off the textile fabric in order to prepare, activate and, if necessary, also check the joining surface in the application section.

The segmentation of the textile fabric allows the surface pretreatment or adhesion test to be carried out in segments or in strips. In this way, on the one hand, low peeling forces can be implemented, since the force required for peeling is proportional to the width of the strip or the width of the segment, and on the other hand, a particularly advantageous evaluation of the peeling force can be carried out (as for example in FIG DE 10 2017 113 430 A1 described), because the force measurement is based on a defined width of the textile. The segmented textile fabric is applied as a whole to the component substrate in the application section, which significantly simplifies the application process step. At the same time, however, the advantage of individual segment strips or fabric strips can then be used for surface pretreatment or adhesion testing.

In addition, due to the segmentation of the textile fabric due to the constant width of the fabric strips, an automated peeling can be realized by means of a testing device.

The segmented flat textile structure can be individual sections with defined dimensions. However, it is also conceivable that the flat structure is present in endless roll form.

The segmented textile fabric can be provided or produced completely impregnated or partially impregnated with adhesive or a matrix material of a fiber composite material. The segmented textile fabric can, however, also be provided in dry form without pre-impregnation. In the latter case, impregnation with the adhesive or the matrix material takes place during processing.

The fabric material of the segmented textile fabric can be, for example, metal, preferably steel, particularly preferably stainless steel, which preferably forms a chromium oxide layer on contact with oxygen. However, aluminum is also conceivable as a fabric material. Furthermore, thermoplastic materials are also conceivable, such as polyester, polyethylene terephthalate, polypropylene or polyamide. In addition, materials are also conceivable from which the reinforcing fibers one Fiber composite material exist, for example glass fibers, carbon fibers, aramid. Metallized fabric materials, such as thermoplastic fibers, which have been provided with a metal layer, for example made of steel, aluminum, nickel, copper, etc., are also conceivable.

The fabric thickness for wefts is preferably 50 μm to 500 μm, particularly preferably between 80 μm and 200 μm. Thicker weave fabrics are also conceivable for special applications, in particular for very thick adhesive seams.

The fabric thickness for mesh fabrics is preferably 50 to 300 μm, particularly preferably between 70 μm and 200 μm for special applications, thin or thick mesh fabrics can also be used.

The pore size of the segmented textile fabric is preferably 5 μm to 100 μm, particularly preferably between 20 μm and 50 μm, in the case of wefts.

Larger pores are also conceivable for special applications. In the case of mesh fabrics, the pore size is preferably 50 μm to 500 μm, particularly preferably between 80 μm and 200 μm. Larger pores are also conceivable for special applications, in particular for the production of thick adhesive seams.

According to one embodiment it is provided that a fiber composite material is used as the component material which has a fiber material and a matrix material embedding the fiber material as plastic material in order to produce a fiber composite component. The component substrate can be a fiber preform made of fiber material, the segmented textile fabric being applied to a fiber preform made of dry fiber materials or pre-impregnated fiber materials. When using dry fiber materials, the dry fiber materials are then infused with matrix material in an intermediate step. The matrix material makes contact with the applied textile fabric. The plastic material used for connecting the textile fabric to the component substrate can accordingly be a matrix material of a fiber composite material, in particular that which is used in the component substrate. A fiber composite component is then produced from the component substrate.

For consolidation, a vacuum build-up can be created over the component substrate after the segmented textile fabric has been applied, in order to evacuate the component substrate and, if necessary, to infuse the matrix resin. The component substrate is then cured under the vacuum build-up by temperature control and, if necessary, pressurization.

According to one embodiment it is provided that at least one material is applied in the application section after all the segments of the segmented textile fabric have been peeled off. Such a material can preferably be an adhesive, with at least one further component being glued on by means of the adhesive in the application section after the adhesive has been applied. By peeling off the segments, the component surface is activated and pretreated for the joining operation to be performed on it. The joining partner can also be a lacquer or a coating. The application of the material to be applied (e.g. adhesive, varnish, coating) should take place shortly after peeling, as the surface reactivity decreases over time.

If a component is to be joined by means of an adhesive in the application area after all segments have been peeled off, this component can be a plastic component that has already been fully consolidated, preconsolidated or not yet consolidated. The further component to be joined can be a fiber composite component made of a fiber composite material, the adhesive preferably being formed by the matrix material of the fiber composite material from which the further component is or is to be made. The application of the adhesive in the form of a matrix material can take place before the application of the further component. However, it is also conceivable that the adhesive in the form of the matrix material is introduced into the application section by infusing the matrix material into the fiber material of the component to be applied.

For an adhesion test of the surface, it is advantageous according to one embodiment if the application section after peeling off the segments by qualitative evaluation of the fracture pattern between the consolidated plastic material and at least one segment of the segmented textile fabric and / or by quantitative evaluation of at least one during peeling Segment of the segmented textile fabric determined peeling force is checked.

In the case of an inadequate or inadequate connection of the segments to the joining surface of the component substrate, the plastic material is separated from the component substrate or the component, whereby the inadequate pretreatment of the joining surface is recognized. Correct surface pretreatment results in a cohesive material separation within the boundary layer between component substrate or component and textile segment.

In the case of a pre-impregnated textile fabric, it is conceivable that adjacent segments that are aligned parallel to one another are combined to form a segmented unit as a result of the impregnation. The individual fabric strips can be arranged adjacent to one another without gaps or they can have a certain overlap area. In both cases, it is structurally ensured that the adhesive layer or the matrix material breaks up completely when the individual segments are peeled off and that no gap remains between two segments that are not broken up. Segments with a width of 100 mm to 2000 mm are advantageous for surface activation or surface preparation, while segments with a width of 10 to 100 mm, preferably 25 mm, are advantageous for checking the surface.

In the event of repairs, the adhesion test usually has to be carried out on an uneven surface. This can be, for example, a multi-curved, non-developable surface or even a stepped surface. The pre-fabricated fabrics are molded to these surface geometries before they are glued. Stabilization of the segments is provided so that the individual fabric segments do not slip relative to one another when they are molded and thus overlap more than desired or so that a gap does not form between individual fabric strips.

According to one embodiment, it is therefore provided that a segmented textile fabric is provided which has at least one linear predetermined breaking point for forming the segments, or that at least one linear predetermined breaking point is created in the textile fabric for forming the segments, the segments being cut through the linear predetermined breaking point The predetermined breaking point can be peeled off from the component substrate.

According to one embodiment, however, it can also be provided that a segmented textile fabric is provided which has a plurality of individual segments that are connected to one another by means of a common carrier material on a rear side of the segments facing away from the component substrate, or that a plurality of individual segments with a common carrier material are connected to one another on a rear side facing away from the component substrate, the segments being peeled off from the component substrate with the carrier material being severed between two segments.

According to one embodiment, the segmentation (predetermined breaking point) can also be implemented in that the tensile strength of the warp threads of the textile is (very much) lower than the tensile strength of the weft threads (e.g. at least 50%) and that the tensile strength of the warp threads is lower than the peeling force of the Textile strip is. In this way, peeling off in segments in the direction of the weft threads can take place. For this purpose, the weft threads can already be severed or severed at regular intervals in an initial section. Two adjacent incisions thus form a segment which can be peeled off, the weft threads being severed during the further peeling process along the warp threads with the specified strip width. Of course, the warp threads (in terms of material or geometry) can also be made weaker.

It is also conceivable that a segmented textile fabric is provided which has at least one predetermined breaking point for the formation of the segments, which is formed by a reduced tear strength of one or more warp threads or weft threads, the segments being peeled off from the component substrate by severing the predetermined breaking point.

• - Verbinden benachbarter Segmente durch ein oder mehrere Filamente bzw. Garne, z.B. durch Nähen oder Wirken
• - Verbinden benachbarter Segmente durch Schweißen (Verschweißen der Kanten der Prüftextilsegmente)
• - Verbinden benachbarter Segmente durch Kleben (Zusammenkleben der Kanten der Prüftextilsegmente)
• - Verbinden benachbarter Segmente durch gemeinsames Imprägnieren mit einem Trägermaterial (gemeinsames Imprägnieren oder durch gemeinsames Imprägnieren mit einem zusätzlichen Trägermaterial)
• - durch einzelnen Fäden aus einem Polymer (Verschweißen bzw. Verkleben mittels einzelner Fäden aus einem Polymer)
• - Verbinden benachbarter Segmente durch Erzeugung einer Sollbruchstelle (durch Verschweißen bzw. Verkleben mittels eines Flächengebildes/Trägermaterials)

These embodiments are particularly useful in the case of dry and non-pre-impregnated fabrics in order to achieve safe handling when the segmented textile fabric is applied. The following measures can therefore be applied to stabilize individual segments (individually or in combination):

• - Connecting adjacent segments by one or more filaments or yarns, for example by sewing or knitting
• - Connecting neighboring segments by welding (welding the edges of the test textile segments)
• - Connecting adjacent segments by gluing (gluing the edges of the test textile segments together)
• - Connection of adjacent segments by joint impregnation with a carrier material (joint impregnation or by joint impregnation with an additional carrier material)
• - by individual threads made of a polymer (welding or gluing by means of individual threads made of a polymer)
• - Connection of adjacent segments by creating a predetermined breaking point (by welding or gluing using a flat structure / carrier material)

When stabilizing adjacent segments by jointly impregnating them with a carrier material, the carrier material is arranged above the fabric, on the side facing away from the substrate, and is also embedded in adhesive / matrix material. The carrier material is applied as a whole and can thus hold the segments together during handling. The carrier material has a thin or light design and thus tears when the individual segments are peeled off later without itself showing a weak point along the strip boundaries. The carrier material is a flat, porous fabric such as a spunbond, a knitted, knitted, woven or knitted net, or for example a very fine mesh fabric. The weight per unit area of the carrier material is preferably 5-50 g / m2.

The segments can be glued using individual threads made of a polymer (e.g. polyamide, polyester) or, preferably, with a flat, porous carrier material made of a polymer. As before, the carrier material can be a flat, porous sheet-like structure such as a spunbond, a knitted, knitted, woven or knitted net, or for example a very fine mesh fabric. The weight per unit area of the carrier material is preferably 5-50 g / m2. To connect the segments to the carrier material or polymer thread, the polymer is heated, if necessary up to the softening area or melting area, and applied to the adjacent segments. After cooling, the polymer is glued or welded to the flat structure so that the individual polymer threads or the polymer flat structure hold the individual segments together and thus stabilize them. As a result of the very thin design of the polymer threads or the polymeric sheet-like structure, the segments can be pulled off in strips after application to the substrate, the polymeric stabilizing material tearing. A particularly advantageous production variant is to connect the segments to a flat carrier material by means of a rolling process, with the carrier material being heated e.g. can be implemented by temperature-controlled rollers or ultrasound.

The flat textile structure can be present as a whole, the segmentation being introduced into the fabric as a predetermined breaking point along equidistant parallel lines. The predetermined breaking point can be introduced mechanically or thermally, for example. In this way, the fabric holds together, but after the impregnated adhesive has cured it can be pulled off in strips, the fabric tearing at the predefined predetermined breaking points. In particular, the segmentation can be carried out by welding (in particular by resistance or ultrasonic welding) with roller-shaped tools. In this way, the tissue is segmented and a predetermined breaking point is introduced, while the edges of the segments are sealed at the same time.

According to one embodiment, it is therefore provided that the segmented textile fabric is provided as a mesh fabric, square mesh fabric, leno fabric, triaxial fabric or as a braid fabric, each in monofilament or multifilament design, in a plain weave, twill weave and / or satin weave. In particular, smooth wefts in the high-performance variant (with increased flow capacity) have proven to be advantageous.

For use on surfaces with double-curved or otherwise complex geometry, knitted fabrics in twill weave and twill weave in particular have proven to be advantageous, since they have a higher drapability than fabrics in plain weave.

According to one embodiment it is provided that the segmented textile fabric is provided in such a way that the sum of all open areas of meshes of the segmented textile fabric is at least 30%, preferably at least 50%, particularly preferably between 50% and 70% of the total base area of the segmented textile Corresponds to the flat structure. The area fraction of the cohesive fracture of the fracture surface produced in the plan view (projected surface) preferably corresponds to at least 30%, preferably more than 50%.

According to one embodiment it is provided that a segmented textile fabric is provided, which is calendered by means of a plastic material. By calendering, the textile fabric can be calendered to a predetermined uniform thickness. In particular with monofilament mesh fabrics, calendering can bring about greater fabric stability. At the same time, calendering can be used to achieve a lower pull-off force, a higher defect detection capability, a reduced layer thickness of the broken adhesive and / or a special fracture surface morphology. In particular, when the sheet is cured together with a fiber composite component and the peeling of the sheet is used purely for surface pretreatment, calendering reduces the risk of damage to the fiber composite substrate by the peeling process.

According to one embodiment it is provided that a segmented textile fabric is provided that at least one of the Component substrate facing application side has a functional coating, or that a functional coating is applied to an application side of the segmented textile fabric facing the component substrate. In a special embodiment for this purpose, it can be provided that the coating remains at least partially on the component substrate after the segments have been peeled off and assumes further functions. However, coating on both sides is also conceivable.

The coating can, for example, be an adhesion-promoting substance which, when the segments are peeled off, causes a break in the plastic material, for example in the matrix material of the fiber composite material. However, it can also be a coating that remains wholly or partially on the component substrate and the later component, i.e. H. the coating can break cohesively when it is peeled off or it can completely detach from the segments. The color of the coating can be designed in such a way that it contrasts with the color of the component substrate or the subsequent component. This is advantageous for the following joining operations in order to identify the joining zone. At the same time, the coating material remaining on the component substrate can take on special functions. For example, the material heterogeneity of the coating can produce crack-stopping properties in a bond made on it.

The coating material can be designed in such a way that a particularly good connection is achieved between the fabric filaments and the surrounding adhesive or matrix material, so that a completely cohesively broken surface is created when the sheet is peeled off from the cured adhesive / matrix material.

The coating material can, however, also remain in the application section. If the application section is then glued over, the coating material becomes an integral part of the glue joint and can take on functional tasks. For example, an improvement in the adhesion between the adhesive break surface in the application section and the adhesive applied to it is conceivable. However, the coating material can also lead to a local modification of the properties of the adhesive joint after application of a second adhesive. For example, the coating material can have a high elongation at break and low stiffness compared to the surrounding adhesive / matrix material. This local change in the stiffness of the adhesive joint enables crack-stopping properties and a high damage tolerance of an adhesive joint to be achieved.

The coating material can also be made of a material which interacts with the surrounding adhesive / matrix material during curing. In particular, the coating material can dissolve in the surrounding adhesive and undergo a precipitation reaction when it cures, so that the coating material precipitates in the area around the flat textile structure. These precipitations can cause special property modifications. These properties can represent, for example, increased fracture toughness or damage tolerance of the adhesive joint created later, or else enable the fracture surface to be bonded with adhesives of a different type. Particularly suitable coating materials for this are PEI (polyetherimide), PSU (polyethersulfone), phenoxy (polyhydrodyether), rubber with hydroxyl groups on the free molecule ends (e.g. HTPB or CTBN, ATBN).

In one embodiment it is provided that a segmented textile fabric is provided, which is roughened and / or microstructured on at least one application side facing the component substrate, or that an application side of the segmented textile fabric facing the component substrate is roughened and / or microstructured. But it is also conceivable that both sides are microstructured.

The mechanical roughening creates stress peaks in the adhesive / matrix material when it is pulled off. A lower peeling force can thus be achieved. Tests have shown that coarse roughening by means of blasting processes (e.g. sandblasting) of steel fabrics causes deformations of the filament surface with edges, which generate such stress peaks when the fabric is peeled off. The result observed is a particularly lower peel force. A type of positive fit (micro-positive fit) can be created with the plastic material through microstructuring, which creates a cohesive fracture portion on the surface of the plastic material when it is peeled off. A fine microstructuring can also result in a higher peeling force and, as a result, a higher ability to detect adhesion defects.

The segmented textile planar structure can contain further point, line, or flat structures. Such structures are, for example, spheres (for example made of a polymer), polymer threads or polymeric flat structures such as the aforementioned carrier materials. As a rule, these further structures are arranged on the side facing away from the component substrate. These structures can support compliance with a defined layer thickness, avoid unwanted drainage of adhesive or matrix resin during processing or the Modify the rigidity of the textile fabric after hardening. A spacer fabric carrier material applied to the textile fabric restricts the compaction of the adhesive or matrix resin located above the textile fabric. so that a minimum thickness of adhesive or matrix resin can be guaranteed above the fabric. Last but not least, technical manufacturing reasons can also justify the use of such additional materials in the cross-sectional structure of the textile fabric. For example, in the processing sequences it may be necessary to provide an adhesive film with a carrier material before the adhesive film is rolled onto the textile fabric.

As point, line, or sheet-like structures, as described above, materials are also conceivable which consist of reinforcing fibers of a fiber composite material, e.g. Carbon fiber, glass fiber or aramid. In addition to the functions already mentioned, these structures can also serve as spacers between the substrate or the reinforcing fibers of the substrate and the segmented flat textile structure. In particular, when the flat structure is cured together with a fiber composite component and the removal of the flat structure is used purely for surface pretreatment. It was recognized that the risk of damage to the fiber composite component during the removal process due to the reinforcement fibers and fabric being rejected can be reduced.

If the fabric is impregnated with adhesive or matrix material, it can be, for example, thermosetting (premixed) 1-component systems based on epoxy. Impregnation with other types of thermosets and thermoplastic adhesives as well as with thermoplastics is also conceivable, which solidify according to the mechanisms of chemical hardening, physical setting or a combined mechanism. Possible methods of impregnating the fabric with 1K epoxy adhesives are, for example, rolling on an adhesive film or matrix resin film, rolling on heated and therefore viscous adhesive or matrix material or production using the impregnation method, whereby the fabric is drawn through a bath of liquid adhesive or matrix material and then onto a A defined thickness is rolled, with excess impregnation material being deposited.

The 1K epoxy adhesive or the epoxy base matrix material applied to the flat structure is tough at room temperature and has a certain tack. To slow down the curing reaction, storage takes place at a low temperature (e.g. -20 ° C). The curing can then take place by increasing the temperature in the oven, the adhesive becoming liquid before the onset of the curing reaction and closing existing cavities within the fabric or between the fabric and the component.

At least as much adhesive / matrix material must be applied to the weave fabric that the fabric is completely saturated after curing. That is, after curing, an adhesive layer with embedded braid fabric is created, the thickness of which corresponds to the thickness of the dry braid fabric. Since the pores run obliquely through the fabric in woven fabrics, a proper break-up of the surrounding adhesive or matrix material can be guaranteed even with this minimum amount of adhesive, since the peeling direction of the fabric does not correspond to the orientation of the pores and the break within the lower half of the fabric cross-section he follows. From a technological point of view, however, it makes sense to provide a higher amount of adhesive or matrix resin, so that after curing there is additional resin or additional adhesive over the weave. The total layer thickness including embedded braid and any auxiliary materials can generally be between 100% and 800% of the thickness of the dry braid.

So much adhesive or matrix material must be applied to the mesh fabric that the layer produced from cured adhesive or matrix material with embedded mesh fabric exceeds the thickness of the unimpregnated mesh fabric. This is necessary because the pores in these tissues are essentially orthogonal to the plane of the tissue. If the adhesive layer is too thin, when the tissue is peeled off, the adhesive or matrix resin is not completely broken open in the area of the pores and thus in insufficient surface pretreatment and also in reduced load introduction or stress generation. The layer thickness required for complete break-up or for proper surface activation depends on the tissue thickness and the percentage open area of the tissue. Advantageously, a pre-impregnated fabric with a mesh fabric is to be provided with so much adhesive that the hardened fabric has a thickness which is at least 30% greater than the thickness of the dry mesh fabric. Advantageously, the mesh fabric prepreg hardened against a smooth base is 50% to 500% thicker than the dry mesh fabric.

The porous fabrics are either completely embedded in the uncured adhesive or only partially so that part of the porous fabric protrudes from the uncured adhesive. So air inclusions in the bond can be effectively avoided. Of course, it is also conceivable that the adhesive or the matrix resin only rests on the flat textile structure or only contacts or infuses the carrier material located on the flat textile structure. By evacuating the cavities before the curing reaction begins, air inclusions in the bond can be effectively avoided.

An impregnated textile fabric can have a defined weight per unit area and a defined thickness with a small scatter, so that a defined layer thickness can be maintained after curing.

Regardless of whether it is dry or pre-impregnated, the textile fabric can be provided with a protective film or protective paper on one or both sides, which is removed immediately before application. In the case of an impregnated fabric, this protection prevents the rolled-up filter fabric from sticking to one another and reduces the possibility of the product degrading due to environmental influences (especially moisture). Both dry and infused flat structures are protected from contamination by the films. The protection of the fabric or fabric prepreg by means of foils or paper is advantageously implemented in such a way that the user can clearly identify the application side. For this purpose, for example, a paper can be applied on one side and a foil on the other, or foils or papers with different colors.

The fabric webs or fabric strips can have unsealed (open) cut edges, but also selvedges, thermally or otherwise sealed edges. Braid fabrics in particular get by without edge sealing, as they have a particularly stable construction compared to mesh fabrics. Mesh fabrics are expediently stabilized by calendering, welded together at the junctions (i.e. the crossing warp and weft threads) or sealed at the edges so that tearing during the peeling process is avoided.

When wefts are used to detect defects, a peeling direction in the direction of the thicker, non-undulating filaments is selected. In the case of smooth wefts (plain weave), this is, for example, the warp direction or production direction. Tests have shown that, particularly when peeling in this direction, a high test voltage can be generated at the interface to the component, which is suitable for showing adhesion defects. Correspondingly, the cut edges of adjacent fabric strips are to be designed along this peeling direction. If wefts are peeled in the longitudinal direction of the thinner, undulating filaments, this requires a significantly lower force, but does not generate a high test voltage either. This variant is therefore particularly favorable for pure surface pretreatment or surface activation.

In the case of mesh fabrics, a peeling direction (= longitudinal direction of the stripes) in the warp or weft direction of the fabric is generally selected. Although experiments have shown. that with square mesh fabrics with similar warp and weft threads, the peeling direction has no influence on the peeling force. I.e. peeling at any angle relative to the direction in which the fabric is produced has no effect on the peeling force. However, the tests have also shown that mesh fabrics fail particularly easily if the edges of the fabric strips are produced at an angle that deviates from the weft or warp direction.

Before impregnation with adhesive / matrix material or, in the case of dry tissue, before application of a protective film or welding (or other preservation), the tissue can be subjected to a special cleaning step so that the tissue can be ensured that it is free of contamination. Possible methods for this are, for example, steam degreasing or running through a cleaning bath (wet chemical, solvent, etc.), possibly supported by ultrasonic cleaning.

The filaments of the sheet-like structure can be specially surface-treated in order to be able to enter into particularly good adhesion with the adhesive or matrix resin. After the tissue has been pulled off, the application area can be roughened, a partial cohesive break in the application area or a complete cohesive break can be achieved. An electrochemical or wet chemical pretreatment (etching, pickling, etc.) is particularly suitable for steel mesh. For polymeric fabrics, the usual processes for improving the adhesion of plastics can be used. Examples of this are wet chemical treatment, gas phase fluorination, plasma treatment (at atmospheric pressure and also low-pressure plasma), corona treatment. Flame treatment, activation with UV light (vacuum ultraviolet light excimer activation) etc.

• - Kettfäden pro Zoll (25,4mm) Gewebebreite: 30 bis 150, besonders vorteilhaft 30 bis 200
• - Schussfäden pro Zoll (25,4) Gewebelänge: 150 bis 700, besonders vorteilhaft 280 bis 1800
• - Verhältnis von Schussfäden zu Kettfäden pro Zoll: 4 bis 7 besonders vorteilhaft 7 bis 12 oder mehr als 12 in Ausnahmefällen

In particular, smooth wefts (for example wefts with a plain weave) have proven to be advantageous. The following parameters are to be regarded as advantageous:

• - Warp threads per inch (25.4 mm) fabric width: 30 to 150, particularly advantageously 30 to 200
• Weft threads per inch (25.4) fabric length: 150 to 700, particularly advantageously 280 to 1800
• - Ratio of weft threads to warp threads per inch: 4 to 7, particularly advantageously 7 to 12 or more than 12 in exceptional cases

It is also conceivable that the segmented textile fabric is already impregnated with adhesive or matrix material.

• 1a-c schematische Darstellung des grundsätzlichen Verfahrensablaufes;
• 2 schematische Darstellung einer Draufsicht auf das segmentierte textile Flächengebilde;
• 3 beispielhafte Darstellung eines segmentierten textilen Flächengebildes mit einem Trägermaterial
• 4 schematische Darstellung eines Querschnitts eines segmentierten textilen Flächengebildes in einer ersten Ausführungsform;
• 5 schematische Darstellung eines Querschnitts eines segmentierten textilen Flächengebildes in einer zweiten Ausführungsform;

The invention is explained in more detail by way of example with reference to the accompanying figures:

• 1a-c schematic representation of the basic process sequence;
• 2 schematic representation of a plan view of the segmented textile fabric;
• 3 exemplary representation of a segmented textile fabric with a carrier material
• 4th schematic representation of a cross section of a segmented textile fabric in a first embodiment;
• 5 schematic representation of a cross section of a segmented textile fabric in a second embodiment;

In the 1a to 1c the process sequence of the present invention is shown schematically. 1a shows a component substrate 10 , which in the embodiment of the shown 1a for example, it can be a fiber composite component that has not yet been fully consolidated. However, in the case of the adhesion test, it should be consolidated. As a result, the component substrate 10 act to a fiber preform, which is formed either from dry fiber material or from pre-impregnated fiber material.

On the provided component substrate 10 became a segmented textile fabric 20th within an application section 12 of the component substrate 10 applied to the surface of the application section 12 to prepare for a later joining operation.

Now that the segmented textile fabric 20th on the application section 12 of the component substrate 10 was applied, it will be in the component substrate 10 plastic material contained 14th consolidated or hardened. Became the component substrate 10 provided in the form of dry fiber materials, the plastic material can in an infusion process (not shown) 14th in the form of a matrix material in the component substrate 10 be infused, the application side during the infusion 22nd of the segmented textile fabric 20th wetted and contacted. In the case of pre-impregnated fiber materials, the segmented textile fabric would be 20th with its application side 22nd directly onto the plastic material already contained in the fiber material 14th can be placed and contacted.

After the plastic material has consolidated 14th what an at least partial hardening of the plastic material 14th or complete curing of the plastic material 14th can mean, the fabric 20th , as in 1b shown from the application section 12 of the component substrate 10 peeled off. The peeling off of the segmented textile fabric 20th takes place segment by segment, that is, segment by segment is removed from the component substrate one after the other 10 peeled off.

After all segments of the textile fabric have been peeled off completely 20th from the component substrate 10 can now, as in 1c is shown on the so activated surface of the application portion 12 another component 40 by means of an adhesive layer 41 be glued on. However, it is also conceivable that an unconsolidated fiber composite component is applied and that the adhesive connection is produced by the matrix resin of the second component.

2 shows the component substrate 10 in a plan view with the segmented textile fabric 20th . In the embodiment of 2 exhibits the segmented textile fabric 20th a total of four segments 20a to 20d on, with a predetermined breaking point between the segments 24 is provided. There is a release film in one area 30th connecting the fabric 20th with the plastic material of the component substrate 10 to prevent, so that a pull tab for each segment individually 32 can be formed. As a result, each segment can be removed from the component substrate one after the other 10 Peel off the sheet 20th at the predetermined breaking points 24 rips.

3 shows schematically and by way of example a segmented textile fabric 20th without impregnation in a plan view. The illustration shows the individual neighboring segments 20a - 20e , which in this embodiment by means of polymer threads applied in the liquid state 26th are fixed in their position to each other. The polymer threads 26th are on the side that faces away from the component substrate during application. In this embodiment, the individual segments 20a - 20e not necessarily be connected to one another at their predetermined breaking point, since the stabilization of the segments to one another via the polymer threads 26th is realized.

4th shows schematically in cross section a segmented textile fabric 20th that is a first segment 20a and a second segment 20b shows. To connect the two segments 20a , 20b the filaments are welded together in the edge area of the adjacent segments, which is indicated by the reference symbol 23 is marked. In these welded filaments 23 is now a predetermined breaking point 24 introduced in the form of a notch so that when one of the segments is peeled off, the connection between the two segments is at the predetermined breaking point 24 rips. There is a protective film on both the top and the bottom 28 .

The welded filaments 23 They also provide an edge sealing of the two segments, since weft and warp threads of the fabric are welded together in this area. Such a weld seam can be produced, for example, in the case of a fabric made of a plastic by means of ultrasonic welding using a roller sonotrode. Furthermore, the flat structure shown is 20th completely infused with an adhesive or a matrix material, the total thickness being about twice that of the dry tissue.

5 shows the face of a made-up and impregnated braid as a flat structure 20th in cross section. It is a smooth filter weave that is segmented into two strips in the direction of the warp threads by an open cut edge. The incision can run completely through the tissue section or it can only be present in an edge area. However, it is also conceivable that the weft threads are made much weaker than the warp threads so that the incision continues when a segment is peeled off, in that the intact weft threads tear along the cut edge. In the variant shown, the direction of the warp threads is the peeling direction, which is particularly advantageous for checking the surface. The two tissue segments are through the infused adhesive and in particular through the flat carrier material 25th fixed. The flat carrier material was applied hot to the segments, so that a material connection between the braid and the polymeric carrier material was formed. Due to a small gap width between the two segments, the overlying carrier material and the corresponding adhesive layer thickness, a complete breakdown of the adhesive is achieved even in the area of the cut edge when peeling off the individual segments. A protective film is applied to the top and a protective paper or carrier paper is applied to the underside (application side). Foils or carrier paper can also be applied on both sides, but it must be possible to differentiate between them in terms of color or other features. in order to be able to clearly identify the application side of the filter fabric prepreg.

List of reference symbols

10

Component substrate

12

Application section

14th

Plastic material

20th

segmented textile fabric

20a-e

Segments of the fabric

21st

Filaments of the fabric

21a

Warp threads

21b

Weft threads

22nd

Application page

23

welded filaments

24

Predetermined breaking point / dividing line

25th

Carrier material

26th

Polymer threads for stabilization

28

Protective film / backing paper

30th

Release film

32

Pull tab

40

additional component

41

adhesive

Claims (13)

A method for producing a component from a component material which has at least one plastic material (14), the method comprising the following steps: - Providing a component substrate (10) from which the component is to be produced; - Applying a segmented textile fabric (20) to the component substrate (10) in at least one application section (12), the segmented textile fabric (20) having a plurality of segments (20a-e); - Consolidation of a plastic material (14) in such a way that the segmented textile fabric (20) is connected to the component substrate in the application section (12) by the consolidated plastic material (14); and - Peeling off the individual segments (20a-e) from the component substrate (10) after the plastic material (14) has consolidated. Procedure according to Claim 1 , characterized in that a fiber composite material is used as the component material which has a fiber material and a matrix material embedding the fiber material as plastic material (14) in order to produce a fiber composite component. Procedure according to Claim 1 or 2 , characterized in that at least one material is applied in the application section (12) after the segments (20a-e) of the segmented textile fabric (20) have been peeled off. Procedure according to Claim 3 , characterized in that the applied material is an adhesive (41), at least one further component being glued on by means of the adhesive (41) in the application section (12). Method according to one of the preceding claims, characterized in that the application section (12) after peeling off the segments (20a-e) by qualitative evaluation of the fracture pattern between the consolidated plastic material (14) and at least one segment (20a-e) of the segmented textile fabric (20) and / or through a quantitative assessment of the peeling force determined when peeling off at least one segment (20a-e) of the segmented textile fabric (20). Method according to one of the preceding claims, characterized in that a segmented textile fabric (20) is provided which has at least one linear predetermined breaking point (24) for forming the segments (20a-e), or that in the textile fabric (20) at least a line-shaped predetermined breaking point (24) for forming the segments (20a-e) is produced, the segments (20a-e) being peeled off from the component substrate (10) while cutting through the linear predetermined breaking point (24). The method according to any one of the preceding claims, characterized in that a segmented textile fabric (20) is provided which has a plurality of individual segments (20a-e), which by means of a common carrier material (25) on a component substrate (10) facing away from the component Rear side of the segments (20a-e) are connected to one another, or that a plurality of individual segments (20a-e) are connected to one another with a common carrier material (25) on a rear side facing away from the component substrate (10), the segments (20a- e) are peeled off from the component substrate (10) by severing the carrier material (25) between two segments (20a-e). Method according to one of the preceding claims, characterized in that the segmented textile fabric (20) is provided as a mesh fabric, square mesh fabric, leno fabric, triaxial fabric or as a braid fabric, each in monofilament or multifilament design, in a plain weave, twill weave and / or satin weave Method according to one of the preceding claims, characterized in that the segmented textile fabric (20) is provided in such a way that the sum of all open areas of meshes of the segmented textile fabric (20) is at least 30%, preferably at least 50%, particularly preferably between 50% % and 70% of the total base area of the segmented textile fabric (20) corresponds. Method according to one of the preceding claims, characterized in that a segmented flat textile structure (20) is provided which is calendered. Method according to one of the preceding claims, characterized in that a segmented textile fabric (20) is provided which has a functional coating at least on an application side (22) facing the component substrate (10), or on one facing the component substrate (10) Application side (22) of the segmented textile fabric (20) a functional coating is applied. Method according to one of the preceding claims, characterized in that a segmented textile fabric (20) is provided which is roughened and / or microstructured at least on an application side (22) facing the component substrate (10), or that one of the component substrate (10) facing application side (22) of the segmented textile fabric (20) is roughened and / or microstructured. Component (40) comprising at least one plastic material (14), the component (40) using the method according to one of the Claims 1 to 12 is made.

Images