DE10244287A1 - Production of dent-free composite elements, e.g. for car roofs or engine hoods, involves forming two layers of fibre-reinforced polyurethane with an intermediate spacer on a layer of foil in a mould - Google Patents

Abstract

A method for producing composite elements by forming fibre-reinforced polyurethane on a foil in a mould involves introducing a spacer layer between two layers of polyurethane leaving a distance of 10-300 mm between the outer edge of the spacer and the edge of the resulting element. A method for the production of composite elements comprising (i) a foil and (ii) a polyurethane (PU) reinforcing layer involves (A) laying the foil in an open mould, (B1) injecting the components of the PU system onto the foil, (B2) placing a spacer layer on the PU components, (B3) injecting PU components onto the spacer, (C) closing the mould and reacting the components to form the PU and optionally (D) removing any overhanging foil. The dimensions of the spacer layer are such that its outer edge (inside the composite) is at least 10-300 mm from the edge of the resulting element. Independent claims are also included for (1) composite elements as above in which a spacer layer is embedded in the reinforcing layer with at least one horizontal distance of 10-300 mm from the edge of the element (2) roof modules containing such composite elements

Description

The invention relates to a composite element, constructed from i) a film and ü) a reinforcing layer containing polyurethane, wherein in the reinforcing layer a spacer layer is embedded, characterized in that the embedded spacer layer has at least one horizontal distance from 10 mm to 300 mm from the edge of the composite element, and a process for producing these composite elements as well as their Use as exterior body parts.

EP-A-995 667 and EP-A-1 077 225 describe the manufacture of automotive exterior components such as roof modules, hoods, etc., with deep-drawn colored thermoplastic foils or metal foils being reinforced with glass fiber reinforced polyurethane (PUR).

DE-A-100 57 365 describes the production of fiber-reinforced plastic sandwich components with an interlayer structure.

The deep-drawn foils run usually not exactly according to the contour of the mold. Thereby an air cushion is formed between the film and the mold. at full-surface GF-PUR The trapped air cannot enter during PUR foaming escape between the film and the tool. The so enclosed Air is partially compressed, the foam pressure is lower than that Air pressure between film and tool, the film bulges towards GF-PUR. This dent remains on the film surface the demolding of the component is visible.

The deep-drawn foils made of thermoplastic, aluminum Coil coating or steel coil coating can also be used after another Procedures are reinforced.

In this process, the foils into the foaming tool inserted and covered with a layer of GF-PUR using the LFI-PUR process. A cardboard honeycomb is placed in the still moist reaction mixture. (The cardboard honeycomb can be coated on both sides with glass fleece Cardboard honeycomb takes over the function of a spacer in the component. This occurs against classic LFI-PUR process a weight reduction.) Now a second layer of GF-PUR on the cardboard honeycomb using the LFI-PUR process entered. The tool is then closed and the cardboard honeycomb into the desired one with the LFI-PUR Formed.

The e.g. 12 mm thick cardboard honeycomb 7 mm in the middle area and 2 in the edge area mm pressed. Due to the high degree of compression in the edge area between the film and the foaming tool trapped air and can be in the foaming process do not escape. This creates partial air cushions which are used for Form dents in the film.

Also in this process the difficulty of thread inserts or foam inserts with screw-on points in the way to foam the high Ausreiflkräfte can be achieved.

The trim edge of the component protrudes with this construction in the installed state in the wet area of the vehicle. Due to the capillary action and hydrophilicity of the Cardboard honeycomb can become an undesirable one Water absorption of the component. The moist honeycomb can be from microbes be attacked, and / or the component can freeze up in the event of frost (Ice blasting), there is delamination of the outer coating and reinforcement. This in the worst case, the mechanical Properties.

The object of the invention was therefore to a process for the production of spacer-containing, dent-free Composite elements, in particular for use as exterior parts of the body, ready to provide.

Enclosing the air between the film and Mold could be prevented unexpectedly by the Cardboard honeycomb not inserted into the higher pressed edge area of the component protrudes. This prevents that the upper part of the tool over the Cardboard honeycomb print on the film and thus on the lower part of the tool exerts and with that emanate that prevents the air from the middle area. This border area will by an increased Material entry filled in the LFI-PUR process.

• i) einer Folie und
• ii) einer Polyurethan enthaltenden Verstärkungsschicht, umfassend die Schritte:
• A) Einlegen einer Folie (i) in ein geöffnetes Formwerkzeug,
• B1) Einbringen von Polyurethansystemkomponenten in das Formwerkzeug auf die eingelegte Folie (i),
• B2) Einbringen einer Spacer-Schicht in das Formwerkzeug auf die eingetragenen Polyurethansystemkomponenten,
• B3) Einbringen von Polyurethansystemkomponenten in das Formwerkzeug auf die eingelegte Spacer-Schicht, und
• C) Schließen des Formwerkzeugs und Reaktion der eingebrachten Polyurethansystemkomponenten zu einem Polyurethan (ii), und
• D) gegebenenfalls Abtrennen von überstehender Folie,

wobei Abmessungen der Spacer-Schicht so gewählt werden, dass der äußere Rand der Spacer-Schicht innerhalb des Verbundelementes mindestens einen Abstand von 10 mm bis 300 Millimeter (mm), bevorzugt 15 bis 250 mm, mehr bevorzugt 25 bis 220 mm, besonders bevorzugt 40 bis 200 mm, vom Rand des resultierenden Verbundelementes aufweist.The invention therefore relates to a method for producing a composite element, constructed from

• i) a film and
• ii) a reinforcement layer containing polyurethane, comprising the steps of:
• A) inserting a film (i) into an open mold,
• B1) introducing polyurethane system components into the molding tool on the inserted film (i),
• B2) introducing a spacer layer into the molding tool on the polyurethane system components entered,
• B3) introducing polyurethane system components into the molding tool on the inserted spacer layer, and
• C) closing the mold and reaction of the introduced polyurethane system components to form a polyurethane (ii), and
• D) if necessary, cutting off any excess film,

dimensions of the spacer layer are selected such that the outer edge of the spacer layer within the composite element is at least a distance of 10 mm to 300 millimeters (mm), preferably 15 to 250 mm, more preferably 25 to 220 mm, particularly preferably 40 up to 200 mm from the edge of the resulting composite element.

• i) einer Folie und
• ii) einer Polyurethan enthaltenden Verstärkungsschicht, wobei in die Verstärkungsschicht eine Spacer-Schicht eingebettet ist,

dadurch gekennzeichnet, dass die eingebettete Spacer-Schicht mindestens einen horizontalen Abstand von 10 mm bis 300 Millimeter (mm), bevorzugt 15 bis 250 mm, mehr bevorzugt 25 bis 220 mm, besonders bevorzugt 40 bis 200 mm, vom Rand des Verbundelementes aufweist und die Verwendung des Verbundelementes zur Herstellung von dellenfreien Karosserieauflenteilen, insbesondere von dellenfreien Dachmodulen.The invention furthermore relates to a composite element composed of

• i) a film and
• ii) a reinforcement layer containing polyurethane, a spacer layer being embedded in the reinforcement layer,

characterized in that the embedded spacer layer has at least a horizontal distance of 10 mm to 300 millimeters (mm), preferably 15 to 250 mm, more preferably 25 to 220 mm, particularly preferably 40 to 200 mm, from the edge of the composite element and the Use of the composite element for the production of dent-free body panels, in particular dent-free roof modules.

Under dent-free is under this Invention understood that when looking at the manufactured Composite element no bumps, especially no bumps or indentations of the film (i) are recognizable, i.e. the foil is planar on the reinforcement layer arranged.

The composite elements obtainable by the method according to the invention are preferably used as exterior body parts, in particular as roof modules for automobiles, and preferably have a flat structure. The thickness of the composite element, in particular roof module, is preferably 2 to 100 mm, more preferably 5 to 30 mm and particularly preferably 8 to 20 mm. The area size of the two-dimensional composite elements is generally not limited, preferably the two-dimensional composite elements have an area size of 0.1 to 10 m ² , preferably 1 to 5 m ² , particularly preferably 1.2 to 3 m ² .

In general, as film (i) a thermoplastic film or a metal foil is used.

As a thermoplastic film (i) can generally known films are used, for example conventional films based on acrylonitrile butadiene styrene (ABS), polymethyl methacrylate (PMMA), acrylonitrile styrene acrylic ester (ASA), polycarbonate (PC), thermoplastic polyurethane, polypropylene, polyethylene, and / or Polyvinyl chloride (PVC). Preferred is as a thermoplastic film (i) a two-layer film, the first layer being on PMMA and the second layer based on ASA and / or PC used. You sit down Two-layer film, the polyisocyanate polyaddition product adheres preferably on ASA and / or ASA / PC.

All usual come as metal foil (i) Metal foils into consideration, an aluminum foil is preferably used or a steel foil, in particular a so-called aluminum coil coating.

Such films are commercial available and their manufacture is well known. The foils generally have a thickness of 0.1 to 5 mm, preferably 0.5 to 2 mm, particularly preferably from 0.6 to 1.0 mm.

The reinforcing layer (ii) is made made of fiber reinforced, preferably glass fiber reinforced Polyurethane and serves as a carrier, the mechanical properties advantageous to the composite component, such as for example, gives high strength. Under fiber-reinforced polyurethane is understood to be PUR, which contains fibers for reinforcement, these fibers being preferred are designed so that they do not have a conventional High pressure mixing head can be processed. The fibers can, for example by means of the LFI process (Long Fiber Injection) introduced into the polyurethane system components are and generally have a length of more than 5 mm, preferably of more than 10 mm, particularly preferably from 10 mm to 10 cm. Possibly is it also possible insert the long fibers in the form of mats in the polyurethane.

The long fibers used can it is glass fibers, natural fibers such as flax, jute or sisal, synthetic fibers, such as polyamide fibers, polyester fibers, Trade carbon fibers or polyurethane fibers. Glass fibers are preferred used.

The fibers for reinforcement are usually in an amount of 0.1 to 90 wt .-%, preferably from 1 to 50, more preferably from 5 to 40 and particularly preferably from 10 to 30% by weight, based on the total weight of layer ii) used.

Layer ii) usually has a density of 0.1 to 1.3 kg / l, preferably of 0.2 to 1.1 kg / l, particularly preferably from 0.3 to 1.0 kg / l. To achieve this density compact or cellular polyurethanes are used, preference being given to rigid polyurethane foams be used.

The thickness of layer ii) in the Composite components according to the invention is usually 0.1 to 100 mm, preferably 0.5 to 25 mm, more preferably 1 to 20 mm, particularly preferably 1 to 10 mm.

In the composite components according to the invention there is preferably adhesion between layer i) and layer ii), i.e. the adhesion between the layers is preferably greater than the cohesion within one shift.

The cover layer, ie the composite of outer layer (i) and reinforcing layer (ii) preferably has a tensile strength according to DIN EN 61 of 10 to 21 N / mm ² , a tensile modulus of elasticity according to DIN EN 61 from 800 to 4000, particularly preferably of 1500 to 3600 N / mm ² , impact strength according to DIN 53 453 from 14 to 90 kJ / m ² (or no breaking of the test specimen at room temperature), bending modulus according to DIN EN 63 from 800 to 4000 N / mm ² and / or a bending strength according to DIN EN 63 from 30 to 90 N / mm ² .

In the context of the present invention, the term polyurethane encompasses any polyisocyanate polyaddition products, such as, for example, polyurethane and / or polyisocyanurate. These are generally obtainable by reacting (a) polyisocyanates with (b) polyols, optionally in the presence of (c) catalysts, (d) blowing agents, (e) Auxiliaries and additives. In the context of this invention, polyurethane system components are understood to mean two components, the first generally comprising polyisocyanates (a), optionally in the form of polyisocyanate prepolymers (so-called isocyanate components), and the second component generally comprising polyols (b) and (c) catalysts , (d) blowing agents, (e) auxiliaries and additives (so-called polyol component). These two polyurethane components are introduced as liquids into a mold, where they react to form polyurethanes, preferably polyurethane foams.

As polyisocyanates (a) in general known (cyclo) aliphatic and / or in particular aromatic polyisocyanates be used. For the production of the molded parts according to the invention Aromatic diisocyanates are particularly suitable, preferably diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI). The isocyanates can be in the form the pure compound or in a modified form, for example in the form of uretdiones, isocyanurates, allophanates or biurets, preferably in the form of urethane and isocyanate groups Implementation products, so-called polyisocyanate prepolymers become. If polyisocyanate prepolymers are used, point these generally have an NCO content of 8 to 25%, preferably of 12 to 20%.

In the context of this invention, (b) polyols are understood to mean all compounds having at least two hydrogen atoms reactive toward isocyanate groups, the reactive hydrogen atoms preferably being selected from OH groups, SH groups, NH groups, NH ₂ groups and CH-acidic groups such as β-diketo groups. Examples of compounds which come under component (b) are polycarbonate diols, polyether polyols and / or polyester polyols. In the following, compounds of component (b) are referred to as "polyols".

Polyols with a are preferred functionality from 2 to 8, in particular from 2 to 4, a hydroxyl number of 20 up to 1000 mg KOH / g, preferably from 25 to 500 mg KOH / g, and 10 to 100% primary Hydroxyl groups. The polyols generally have a molecular weight from 400 to 10,000 g / mol, preferably from 600 to 6000 g / mol. Are polyether polyols because of their higher hydrolytic stability particularly preferred.

In a preferred embodiment a mixture of at least two polyether polyols is used, the first polyether polyol preferably having an OH number of 20 to 50 from 25 to 40, and the second polyether polyol has an OH number of 100 to 350, preferably from 180 to 300, generally the weight ratio from the first to the second polyether polyol is 99: 1 to 80:20.

Suitable polyether polyols mostly by base-catalyzed addition of lower alkylene oxides, in particular ethylene oxide and / or propylene oxide, on 2 to 8-functional, in particular 2 to 4-functional starter substances. The content of primary Hydroxyl groups can be achieved by using the polyols to Finished with ethylene oxide.

As polyether polyols (b), so-called low unsaturated Polyetherols can be used. Taking low unsaturation In the context of this invention, polyols are especially polyether alcohols containing unsaturated compounds of less than 0.02 meq / g, preferably less than 0.01 meq / g. Such polyether alcohols are mostly produced by the addition of alkylene oxides, especially ethylene oxide, propylene oxide and mixtures thereof at least difunctional alcohols in the presence of so-called double metal cyanide catalysts manufactured.

To the compounds reactive towards isocyanates (b) can also chain extension and / or Crosslinking agents belong. For chain extenders it is predominantly around two or three functional alcohols with molecular weights from 60 to 399, for example ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol. The crosslinking agents are compounds with molecular weights from 60 to 499 and 3 or more active H atoms, preferably amines and particularly preferably alcohols, for example glycerin, trimethylolpropane and / or pentaerythritol.

Conventional compounds can be used as catalysts (c) are used, which the reaction of component (a) with the Accelerate component (b) strongly. For example, come into question tertiary Amines and / or organic metal compounds, especially tin compounds. Preferred catalysts are those which, if possible, are used low fogging, i.e. at the lowest possible levy of volatile Lead compounds from the polyisocyanate polyaddition product, for example tertiary Amines with reactive end groups and / or higher boiling amine catalysts. For example the following compounds are used as catalysts: triethylenediamine, Aminoalkyl and / or Aminophenyl imidazoles, for example 4-chloro-2, 5-dimethyl-1- (N-methylaminoethyl) imidazole, 2-aminopropyl-4, 5-dimethoxy-1-methylimidazole, 1-aminopropyl-2,4,5-tributylimidazole, 1-aminoethyl-4-hexylimidazole, 1-aminobutyl-2, 5-dimethylimidazole, 1- (3-aminopropyl) -2-ethyl-4-methylimidazole, 1- (3-aminopropyl) imidazole and / or 1- (3-aminopropyl) -2-methylimidazole, tin (II) salts of organic carboxylic acids, for example tin (II) diacetate, tin (II) dioctoate, tin (II) diethylhexoate and tin (II) dilaurate and dialkyltin (IV) salts of organic carboxylic acids, e.g. Dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and Dioctyltin diacetate.

With the polyurethanes used, it can are compact or cellular polyurethane. It is preferably cellular polyurethane, the production of cellular polyurethane being carried out by adding blowing agents. Well-known chemically or physically active compounds can be used as blowing agents (d). Water can preferably be used as the chemical blowing agent. Examples of physical blowing agents are, for example, (cyclo) aliphatic hydrocarbons, preferably those having 4 to 8, particularly preferably 4 to 6 and in particular 5 carbon atoms, partially halogenated hydrocarbons or ethers, ketones or acetates. The different blowing agents can be used individually or in any mixtures with one another. Only water is particularly preferably used as the blowing agent. If physical blowing agents are used, it is preferred that they are used in an amount of <0.5% by weight, based on the weight of component (b).

The amount of blowing agent used depends on the desired density of the foams.

The implementation takes place if necessary in the presence of auxiliaries and / or additives, e.g. fillers, Cell regulators, mold release agents, pigments, surface-active compounds and / or stabilizers against oxidative, thermal or microbial degradation or aging.

For the production of the polyurethanes generally the polyurethane system components, i.e. the Polyisocyanates (a) and the polyols (b) are reacted in such amounts brought that equivalence ratio of NCO groups of (a) to the sum of the reactive hydrogen atoms of (b) preferably 0.7 to 1.5: 1, particularly preferably 0.9 to 1.2: 1 and in particular 1 to 1.15: 1.

In a preferred embodiment the polyurethane system is adjusted so that a closed cell or only slightly forms open-cell foam as a polyurethane matrix because the spacer layer, especially in the case of a cardboard honeycomb, against environmental influences, such as Water vapor, microbe infestation to be sealed. Preferably points the polyurethane foam used has an open cell of less than 50%, more preferably less than 30%, particularly preferred from 0 to 10%, in particular from 0 to 5%, measured according to DIN EN ISO 7231, on.

The molding according to the invention is generally found for the production of exterior body parts for means of transport, such as motor vehicles, Airplanes, ships, and rail vehicles, use, for example for the manufacture of roof modules, fenders, end edge flaps and trunk lids. Preference is given to using the moldings according to the invention for the production of roof modules.

• A) Einlegen einer Folie (i) in ein geöffnetes Formwerkzeug,
• B1) Einbringen von Polyurethansystemkomponenten in das Formwerkzeug auf die eingelegte Folie (i),
• B2) Einbringen einer Spacer-Schicht in das Formwerkzeug auf die eingetragenen Polyurethansystemkomponenten,
• B3) Einbringen von Polyurethansystemkomponenten in das Formwerkzeug auf die eingelegte Spacer-Schicht, und
• C) Schließen des Formwerkzeugs und Reaktion der eingebrachten Polyurethansystemkomponenten zu einem Polyurethan (ii), und
• D) gegebenenfalls Abtrennen von überstehender Folie,

wobei Abmessungen der Spacer-Schicht so gewählt werden, dass der äußere Rand der Spacer-Schicht innerhalb des Verbundelementes mindestens einen Abstand von 10 mm bis 300 mm vom Rand des resultierenden Verbundelementes aufweist.The methods for producing the composite elements according to the invention include the following steps:

• A) inserting a film (i) into an open mold,
• B1) introducing polyurethane system components into the molding tool on the inserted film (i),
• B2) introducing a spacer layer into the molding tool on the polyurethane system components entered,
• B3) introducing polyurethane system components into the molding tool on the inserted spacer layer, and
• C) closing the mold and reaction of the introduced polyurethane system components to form a polyurethane (ii), and
• D) if necessary, cutting off any excess film,

dimensions of the spacer layer are selected such that the outer edge of the spacer layer within the composite element is at least a distance of 10 mm to 300 mm from the edge of the resulting composite element.

Usually In step (A), a film is placed in the lower mold half of a mold. It is preferred that this is a preformed film is. i.e. the film already has the shape of the mold on. The preforming can be done by conventional Preforming processes, for example by deep drawing, in particular Vacuum deep drawing, carried out become.

In step B1), polyurethane system components are first placed in the mold on the inserted film (i). The The polyurethane system components can be introduced, for example by hand casting, by high pressure or low pressure machines in open Molds performed become. Suitable PU processing machines are commercially available (e.g. Elastogran, Isotherm, Hennecke, Krauss Maffei and others). The polyurethane system components are applied to the already inserted film.

In a preferred embodiment, the PUR dosing systems generally adhere to the following parameters:
Discharge rate polyol component:
10 g / s to 400 g / s, particularly preferably 20 to 250 g / s;
especially 30 to 70 g / s.
Discharge rate isocyanate:
10 g / s to 400 g / s, particularly preferably 20 g / s to
250 g / s; especially 30 to 70 g / s
Component pressures in the high pressure circuit:
Isocyanate: 120 to 200 bar;
Polyol: 120 to 200 bar;
Component pressure in the storage containers: 1.5 to 4.5 bar;
Temperature of the polyol component in the storage container:
15 ° C to 50 ° C, preferably 20 ° C to 35 ° C;
Temperature of the isocyanate component in the template container:
15 ° C to 50 ° C, preferably 20 ° C to 35 ° C.

When processing with polyurethane machines it is also beneficial if during the processing of the storage containers are under reduced pressure.

After step (B1) is in step (B2) a spacer layer in the mold on top of the one already entered Introduced polyurethane system components. As a spacer layer generally suitable any layer that has a distance between the two polyurethane layers guaranteed. Preferably points the spacer layer a density that is less than the density of the fiber-reinforced polyurethane layer as such. Furthermore, the spacer layer should be constructed in this way be that the above mechanical values of the resulting Composite element are observed.

Usually the spacer layer has a thickness of 1 mm to 20 mm, preferably from 2 mm to 15 mm, particularly preferably from 5 mm to 15 mm.

In general, the spacer layer is each layer suitable, the distance between the polyurethane layers guaranteed thus the spacer layer can also be referred to as a separating layer. The spacer layer should advantageously be of such a construction have that stability the resulting composite element, e.g. the compressive strength, in Compared to composite elements without a spacer layer is not impaired. It is also advantageous if the spacer layer is such Have construction that the density of the resulting composite element is reduced compared to composite elements without a spacer layer.

In a preferred embodiment the spacer layer is chosen such that the density of the resulting Composite element in comparison to corresponding composite elements without spacer layer at least 10%, particularly preferably by at least 15%, in particular is reduced by at least $ 20. It is also preferred embodiment the spacer layer is selected in such a way that the tensile strength and / or the tensile modulus and / or the flexural modulus of the resulting composite element, in comparison to the corresponding Composite elements without spacer layer, decreases by a maximum of 10%, especially preferably increases by at least 10%, in particular by at least 20% increases. The physical characteristics are as above described standards.

Examples of suitable spacer layers are Layers of expandable plastics such as EPP, EPC, EPS, as well Layers of metals such as aluminum or magnesium or layers of natural materials, like wood cardboard or paper. The substances mentioned above are to increase of stability preferably in a non-smooth form, for example in corrugated sheet form or honeycomb shape. Cardboard honeycombs are preferably used as the spacer layer. preferred Honeycomb layers are made of cardboard and have an average Honeycomb size of approx. 5 mm diameter.

In a preferred embodiment a cardboard honeycomb layer is used as the spacer layer, which is coated on both sides with a layer of glass fibers. The glass fiber layer prevents the penetration of polyurethane system components into the individual cardboard honeycombs and generally has a thickness of 0.01 mm to 2 mm, preferably from 0.1 mm to 1 mm.

After inserting the spacer layer in the method according to the invention in step (B3) again polyurethane system components in the mold placed on the inserted spacer layer and then in step (C) closed the mold and the reaction of the introduced Polyurethane system components to the reinforcing layer (ii) carried out, wherein the reinforcement layer two fiber reinforced Contains polyurethane, in which the spacer layer is embedded.

It is essential to the invention that The spacer layer is introduced in step (B2) in such a way that the outer edge the spacer layer within the composite element at least a distance of 10 mm to 300 millimeters (mm), preferably 15 to 250 mm, more preferably 25 to 220 mm, particularly preferably 40 to 200 mm, from the edge of the resulting Has composite element.

It is further preferred that in addition to above dimensions of the outer edge of the spacer layer is chosen within the composite element so that it is not in protrudes the highly compressed edge area of the composite component. The highly compressed edge area is understood to mean the area where in the finished composite component the degree of compression of the spacer layer is more than 20% (i.e. a reduction in the thickness of the spacer layer by more than 20%), particularly preferably a degree of compression of more than 40%, in particular a degree of compression of more than 55%.

This step, which is essential to the invention, is illustrated by the 1 and 2 , 1 represents a method arrangement according to the invention, 2 illustrates the process which has been customary in the prior art. 3 illustrates a preferred embodiment described below.

• 1 Folie (i)
• 2 Polyurethansystemkomponenten, enthaltend Fasern
• 3 Spacer-Schicht
• 4 Formwerkzeug (Unterteil)
• 5 Formwerkzeug Oberteil
• 6 Schnittstelle, an der die überstehenden Folie des im Verfahrensschritt (C) entnommenen Verbundelementes abgetrennt wird (Schritt D)
• 7 Randstreifen ohne Spacer-Schicht
• 8 Gewinde-Insert.

In the 1 to 3 means:

• 1 Slide (i)
• 2 Polyurethane system components containing fibers
• 3 Spacer layer
• 4 Molding tool (lower part)
• 5 Mold upper part
• 6 Interface at which the protruding film of the the composite element removed in process step (C) is separated (step D)
• 7 Edge strips without spacer layer
• 8th Threaded insert.

From a procedural perspective it is often desirable when the slide (i) over the dimensions of the (= resulting) Composite element extends. In this case it is preferred in a step (D) the protruding film separated from the resulting composite element.

The distance of the spacer layer of 10 to 300 mm from the edge to be observed in step (B2) consequently relates to the distance from the edge of the resulting component to the edge of the inserted spacer layer. For example, in 1 the edge of the resulting component by cutting off the protruding film in place of 4 marked.

In a preferred embodiment in steps (B1) and (B2) with the introduction of the polyurethane system components started in the middle of the mold (start of shot) to Edge of the shape ceased (End of shot), this ensures a particularly advantageous displacement of the air under the film to the edge.

By the method according to the invention an advantageous homogeneous density distribution in the component is achieved, since it is not the compression that usually occurs in the prior art the foam to the edge of the cavity takes place. In a preferred embodiment, the from method according to the invention resulting composite elements on a density distribution, wherein the difference between the location within the composite element with the greatest density to the point with the lowest density a maximum of 250 g / l, preferred less than 150 g / l, more preferably less than 100 g / l and especially preferably has less than 50 g / l.

In a preferred embodiment, the reinforcement layer (ii) contains in the edge regions in which the polyurethane does not comprise an embedded spacer layer (for example illustrated by 7 in 1 ), Inserts or thread inserts.

Inlays are to be understood Sheet metal inserts caused by foaming possibilities give, for fixing handles, sun visors, lamps, antennas and other parts installed in the roof module.

Thread inserts are threaded bushings, the possibilities for fixation by integration into the polymer matrix Handles, sun visors, lamps, antennas and others in the roof module offer attached parts.

There is also the possibility Form domes that contain no inserts or threaded inserts. This can then be done with conventional drywall screws screwed and thereby already mentioned parts are attached.

As molds for manufacturing of the products can be usual and commercially available tools are used, the surface of which, for example made of steel, aluminum, enamel, teflon, epoxy resin or another polymeric material. The molds should be preferred temperable to be able to set the preferred temperatures, closable and preferred for exercise be equipped with a pressure on the product. The temperature of the Mold is preferably 30 to 80 ° C, more preferably 40 to 60 ° C. When implementing polyisocyanate polyaddition products a temperature of the starting components of preferably 15 to 50 ° C, particularly preferably 20 to 35 ° C preferred. The curing the polyisocyanate polyadducts (step F) are preferably carried out at a time of usual 0.5 to 10 minutes, particularly preferably 1.5 to 4 minutes.

A preferred embodiment of the method according to the invention provides for the starting components or the reaction mixture for the foam core with a robot-guided Insert the mixing head into the mold. This procedure brings the advantage that the starting components for the foam are reproducibly introduced into the mold, which is the case with an introduction by hand is not always guaranteed. A very even and especially large-scale entry the starting components or the reaction mixture in the form can be achieved by using a fan nozzle to introduce the starting components is used in the mold. Through a large-scale entry of the liquid reaction mixture can reduce the entry time and thus the total cycle time become.

The invention is intended to be accomplished by the following Example.

Examples

A thermoformed, two-layer, coextruded, thermoplastic film made of PMMA and ASA / PC was used as film (i). The side of the film to be back-foamed was flamed before being placed in the mold. The flamed film was then placed in an open mold in the lower part of the LFI system, the lower part being heated to approx. 36 to 45 ° C. Then polyurethane system components were entered using the LFI method. The glass fibers wetted with PUR were entered in programmed path curves by a robot with an LFI mixing head and associated fiber cutting unit. Then a cardboard honeycomb layer (thickness 12 mm) coated on both sides was inserted. A new layer of glass fiber reinforced polyurethane was then inserted using the LFI process described above wear.

In example 1, the entry was made the cardboard honeycomb such that the edge of the cardboard honeycomb is a distance from the Edge of the resulting composite component of 40 mm.

In Comparative Example 2 d the entry of the cardboard honeycomb such that the edge of the cardboard honeycomb one The distance to the edge of the resulting composite component was 5 mm.

Elastoflex ^® E 3509 (Elastogran GmbH) and the resulting development systems containing 10 to 40% by weight of glass fibers were used as the PUR system. The entry time was between 15 and 30 seconds (sec) per reinforcement layer on both sides of the cardboard honeycomb. After the entry of the PUR-wetted glass fiber had ended, the tool was closed for a period of 300 to 1000 seconds. After the reaction time had expired, the tool was opened and the component produced was removed from the mold and the excess film was removed.

An optical inspection of the resulting composite elements showed no dents in Example 1 and clear dents in Comparative Example 2, about 25 dents per m ² with a size of approximately 50 mm in diameter having emerged.

Claims (7)

Process for producing a composite element built up from i) a film and ii) a polyurethane reinforcing layer containing, comprising the steps: A) Insert a film (i) in a open Mold B1) Introduction of polyurethane system components in the molding tool on the inserted film (i), B2) Contribution a spacer layer in the mold on the inserted polyurethane system components, B3) Introducing polyurethane system components into the mold on the inserted spacer layer, and C) Closing the Mold and reaction of the introduced polyurethane system components to a polyurethane (ii), and D) if necessary, separate from protruding Foil, dimensions of the spacer layer are selected so that the outer edge the spacer layer within the composite element at least one distance from 10 mm to 300 mm from the edge of the resulting composite element having. A method according to claim 1, characterized in that the spacer layer is a layer of cardboard honeycomb acts, if necessary on one or both sides a glass fiber layer is covered. A method according to claim 1 or 2, characterized in that that in step (B) the polyurethane system components together with Glass fibers according to the LFI process (Long fiber injection). Composite element made up of i) a film and ii) a reinforcement layer containing polyurethane, in which into the reinforcement layer a spacer layer is embedded, characterized in that the embedded spacer layer has at least one horizontal distance from 10 mm to 300 mm from the edge of the composite element. Composite element according to claim 4, characterized in that the spacer layer is a layer of cardboard honeycomb acts, if necessary on one or both sides a glass fiber layer is covered. Roof module containing a composite element according to claim 4 or 5. Roof module according to claim 6, characterized in that the reinforcement layer in the edge areas where the polyurethane is not embedded Spacer layer includes inserts or thread inserts.