DE102008009438A1 - Formed part producing method, involves forming cut surface foil according to topography of formed part, applying woven fabric and resin in cutting tool on inside of foil, and taking out finished part after precipitation hardening to tool - Google Patents

Abstract

The method involves forming a cut surface foil according to topography of a formed part. A woven fabric is applied on an inner side of the foil, where the inner side is turned towards a visible surface and is impregnated with prepolymer resin. The part is precipitation hardened, and is withdrawn. The foil is heated upto softening temperature and is formed in a cutting tool (2) according to topography of the part. The woven fabric and resin are applied in the tool on the inside of the foil. A finished formed part is taken-out after precipitation hardening to the tool. An independent claim is also included for a system for producing formed parts with an improved visible surface from fiber composite plastics, comprising a matrix holder.

Description

The The invention relates to a process for the production of molded parts from fiber composite plastics (short FVK) with a finished surface.

The The invention also relates to a plant for producing molded parts from FVK.

The The invention reduces the steps for producing molded parts from FVK and allows automation.

moldings made of fiber-reinforced plastics are especially when they as body parts in automotive engineering or as trim parts in interior and exterior of vehicles, but also of transport containers and sports equipment are used for refining and / or color design of the surfaces painted. The painting is but very expensive because the surfaces of the plastic components to be prepared for painting. Of the Reason lies in the manufacturing process, which leads to an irregular Surface texture lead.

One Another problem is that the production of molded parts from FRP previously associated with high manual effort. A problem is the currently still low automation rate.

Relative long mold occupancy times have so far caused a low output rate of molded parts made of FRP per production facility and time unit.

moldings from FVK, in which the molded part, for example by means of the resin transfer molding process (RTM), the Vacuum Injection Method (VI) or the Resin Infusion Method (RI) is made especially when used as body panels in the automotive industry or in other automotive sectors, such as motorsport and Motorcycle construction, used for finishing and / or color Design of the surfaces painted. The painting is very elaborate, because the surfaces of the moldings to be prepared for painting. Of the Reason lies in the manufacturing process, which leads to an irregular Surface texture lead. The reasons for surface defects in unrefined components are, for example, voids, holes, protruding fiber ends and chemically / mechanically induced changes of the tool surfaces, which emerge on the molding surface. In the Usually, a mechanical surface treatment is required, for example by grinding or trowelling, so that the required surface finish can only be achieved with a high manual effort. By additional Application of surface layers, such as resin-rich Nonwoven layers or IMC (Inmould Coating) is also attempted a homogenization of the surface to reach.

From the Technical Paper by Achim Grefenstein "Film Injection Instead of Painting", in Metal Surface - Coating of Plastic and Metal, Issue 10/99, Carl Hanser Verlag, Munich , it is known to use films for surface finishing in the injection molding technology. The films are preformed inserted into an injection mold. Subsequently, the cavity of the film is back-injected in a known manner with plastic to produce the finished surface in one operation. With the film back-injection technique but only smaller plastic components can be produced up to certain dimensions. With the help of the pressing method or, for example, the RTM method components in larger dimensions, such as car front or tailgates or commercial vehicle wind deflector can be made, which also meet the necessary mechanical properties by their Faserverstär effect. However, even with these methods, the surface finishes required for painting can not yet be achieved.

A method is known DE 103 09 811 A1 in which an already having the desired properties in terms of the nature and possibly the color of the surface of the component having plastic film which is preformed according to the topography of the surface of the component is inserted into a component dimensions corresponding shape that a fiber reinforced plastic, preferably with a thermoset or thermoplastic matrix is applied, with a method adapted to the composition of the semifinished product on the side of the preformed film, which is not the surface, and that after curing or cooling of the fiber-reinforced plastic, the finished molding of the mold is removed.

The Refinement of the surface of the molding can be done with the film-backing or the film resin transfer molding (film RTM). At the Back film presses are preformed on a separate line Foil on one of the forming tools of a press, in the Die or on the patrix, placed, the fiber-reinforced plastic in the form of a mat or a plasticizer on the counterpart placed the tool of the press and with a on the composition These semi-finished products matched the preformed foil connected to the mat or the plastic.

The film resin transfer molding (film RTM) is carried out in a closed mold, the closed pressing tools, die and Patrize, a press is comparable. In the mold, the preformed film and under its cavity, a fiber mat, so only the fiber reinforcement, inserted. The evacuated mold is filled in a known manner with a mixture of resin and hardener, the mat is soaked and the cavity is filled under the film. The mold remains closed until the injected resin has cured. In open processes such as hand lamination or vacuum process, this technique is also conceivable.

The Method allows both through foil-backpressing as well as by film resin transfer molding (film RTM) large format Moldings with large areas, such as luggage compartment covers or door elements, cost-effective in a surface quality produce comparable to the known film back-injection is. It can be fiber reinforced plastics and Processing methods are used, after which the generated Surfaces previously only with the high described above Finishing the effort. The slides can be colored Layers or specially prepared lacquer layers included. In particular, coextruded two- or multilayer films are suitable as films. as they are also used in film back-injection. By the Coextrusion of thin, colored plastic layers within a two- or multi-layer composite can Layers are built, the paint layers are comparable. Farther can films with a vapor-deposited metal layer as Functional layer can be used. The procedure allows refining fiber-reinforced plastics, preferably with a thermoset or thermoplastic matrix, without preparation of the Surface and without painting in a much lower Number of work steps than conventional Method. For effect colors is a downstream painting process possible with reduced painting effort.

The however, all methods described above require all of the foregoing Process of film forming in a separate operation on a separate Production plant including a necessary burr removal and Edge processing of the thus formed film.

A similar procedure is in the EP 0 819 516 A2 described. There, the surface is referred to as a paint film and also consists of a preformed on a separate plant film that must be cropped, transported and stored. These processes significantly affect their quality, especially with the very thin film described here. The thin film described can further improve at best the surface quality of components in terms of color, but not their mechanical and possibly chemical resistance to external influences and other properties of the molding, such as splinter resistance in a crash. For the described production methods of the fiber-reinforced components, in particular RTM, LFT, SMC and GMT, the in EP 0 819 516 A2 due to the low strength not usable because they do not apply the necessary mechanical and thermal resistances to withstand these, usually under pressure and temperature occurring process.

Another Disadvantage is that before forming on the outside of the Foil applied lacquer layer, which hardened after forming becomes. This lacquer layer is sensitive to damage through the mold, especially at high injection pressures of the injected matrix material due to friction between Paint surface and tool can arise as the deformed Slide caused by dimensional changes due to the shrinkage behavior after thermoforming, not without problems fits into another tool.

One Another, already known method for surface finishing is a variant of the IMD process (in-mold decoration). in this connection a printed carrier film is passed over a mold. After closing the mold halves, the carrier film together with the decorative imprint by means of pneumatic pressure formed of an injected plastic. After hardening of (mostly thermoplastic) plastic and component removal the decor print adheres to the resulting component, the carrier film is detached and disposed of.

This Method allows a decoration of the surfaces of the component, but not the production of a mechanical or chemical resistant protective layer. For applications in the weathered outdoor area must in principle to be painted. Also, the components to be decorated are equipment technology conditionally use only in limited dimensions.

A combination of the already mentioned methods of IMD and film back-injection is a method in which an unshaped, decorated and elastic film is passed over a mold. After closing the mold halves, the film is transformed together with the decorative imprint by means of the pneumatic pressure of an injected plastic. After hardening of the (mostly thermoplastic) plastic and the component removal, the film adheres to the resulting component. With this method, however, only mechanically less resilient, elastic surfaces with low hardnesses (so-called softfeel surfaces) can be used for un-weathered interior areas on components be brought.

Next the benefits of omitting a complete operation and the insertion of a preformed film including the elimination of quality-reducing Storage processes can still provide the necessary process heat the transformation as process heat of the subsequent production the components are used for energy saving.

The Remain straight from thinner surface films in the mold greatly improves the quality assurance production, since the removal of one in a separate plant preformed film as well as the transport and storage due the risk of contamination and changed ambient temperatures to quality reductions and also dimensional changes (Shrinkage) leads.

In the EP 1 230 076 the process of film forming in the later shaping tool is described, but only very thin films with at most decorative properties can be used here, since the ineffective heating by means of contact heat of the heated male and the holding frame (called ring nut) takes a lot longer with thicker films as with a separate radiant heater. This type of film heating is not suitable for the production of FRP molded parts since the male and the ring nut have to be subjected to a longer cooling process again for faultless removal from the mold of the resulting FRP molded part. Furthermore, this type of foil heating does not allow any representation of sharp-contoured surfaces.

Another disadvantage of in the EP 1 230 076 used ring nut (frame) is that this (r) must have only the shape of the outer contour of the molding section and thus a flexible design for various outer contour cuts is not given. For each differently shaped molding a new, appropriately designed ring nut must be made. The product change in the system is therefore just as extensive as lengthy.

One Another disadvantage of the use of the ring nut (the frame) is the limited mobility of the ring nut (frame), since this during the production process of vacuum and Heating / cooling lines must remain connected.

About that In addition, the entire process flow of the production of moldings with a surface foil and a back-injected molding compound made of polyurethane, similar to the foil rear spraying described. However, polyurethane moldings differ significantly disadvantageous in terms of specific weight, strength and field of application compared to the FVK molded parts.

task The invention is the already known method for finishing the surfaces of molded parts made of fiber-reinforced plastics so as to simplify that at least the separate method of film forming and the associated peripheral handling is eliminated.

• – Formen der Oberflächenfolie entsprechend der Topographie des Formteiles,
• – Aufbringen eines Fasergewebes auf eine der Sichtfläche abgewandten Innenseite der geformten Oberflächenfolie und anschließendes Imprägnieren mit Präpolymerharz,
• – Formen des Formteiles und Aushärtung,
• – Entnahme des sichtseitig die Oberflächenfolie aufweisenden Formteiles,

das dadurch gekennzeichnet ist, dass

• – eine zugeschnittene Oberflächenfolie bis zur Erweichungstemperatur erwärmt wird,
• – die zugeschnittene erwärmte Oberflächenfolie im Formwerkzeug entsprechend der Topographie des herzustellenden Formteiles geformt wird,
• – ein Fasergewebe und Präpolymerharz im gleichen Formwerkzeug auf die Innenseite der Oberflächenfolie aufgebracht, entsprechend der Topographie des Formteiles geformt und ausgehärtet wird und
• – das fertige Formteil nach Aushärtung dem Formwerkzeug entnommen wird.

The object of the invention is achieved with a method for the production of molded parts made of fiber-reinforced plastics with a finished visible surface, which on the visible side have a surface film which comprises the following method steps:

• Forming the surface film according to the topography of the molding,
• Application of a fiber fabric to an inner side of the shaped surface film facing away from the visible surface and subsequent impregnation with prepolymer resin,
• - molding of the molding and curing,
• Removal of the visible side of the surface foil having molding,

which is characterized in that

• - a cut surface film is heated to the softening temperature,
• The shaped heated surface foil in the mold is shaped according to the topography of the molded part to be produced,
• - Applied a fiber fabric and prepolymer resin in the same mold on the inside of the surface film, shaped and cured according to the topography of the molded part and
• - The finished molding is removed after curing the mold.

• – eine Beladestation, aufweisend eine gehalterte Folienrolle mit einer aufgewickelten Oberflächenfolie und ein Zuschneidewerkzeug,
• – eine Heizstation zur Erwärmung der Oberflächenfolie,
• – eine Formstation, aufweisend einen Matrizenhalter mit einer Matrize, einen Patrizenhalter mit einer Patrize, wobei Matrize und Patrize die Negativ- bzw. Positivform des herzustellenden Formteiles aufweisen,
• – eine Formteilentnahmestation und
• – eine Folienhalterung für die Halterung der Oberflächenfolie.

Furthermore, the object of the invention is achieved with a system for the production of molded parts with finished visible surface made of fiber reinforced plastics, which have a surface film on the visible side, comprising

• A loading station comprising a supported film roll with a wound surface film and a cutting tool,
• A heating station for heating the surface foil,
• A forming station comprising a die holder with a die, a die holder with a male die, the die and male die having the negative or positive mold of the molded part to be produced,
• - A mold removal station and
• - A foil holder for holding the surface foil.

The film holder can be exemplified as a holding frame or as a vacuum fixation for the Transportation and processing of the surface film may be formed.

The surface film used serves, connecting with the resulting molding, as a decorative and functional surface layer, z. B.
decorative colored or transparent with a smooth or textured surface or with decorative and functional elements in or under the foil or
Functional as a protective layer against external mechanical or chemical effects on the molded part.

Of the According to the invention used holding frame takes the unshaped surface film on and transported them then to the next processing station. This can be the preheater for the surface film or the forming device be. There, the support frame carries the surface film during the forming process as well as during the forming process Injection process. After the completed injection of the resin carries out the support frame during demolding the negative mold the resulting unmachined part. He then transports if necessary, the unmachined part by a heat path for post-processing or Mold removal station.

At the Frames are the pictures of the automatic linear transport axes attached.

advantageously, the frame seals the surface film base against the pressure plate from which to generate the pneumatic forming pressure during high-pressure molding (by means of pneumatic overpressure) covers the bottom of the foil.

About that In addition, the frame takes the channels for the media guide on, here the vacuum or displaced exhaust air / excess Resin can be.

The Die and Patrizenhalter clamp on both sides sealing the reshaping Surface film.

The Die and Patrizenhalter are designed so that they during the pneumatic film forming the seal between forming tool (negative mold, die) and clamped in the holding frame Surface film produces. He also writes the Slide bottom against the pressure plate, which is used to produce the pneumatic forming pressure during high-pressure molding (by means of pneumatic overpressure) covers the underside of the film.

Of Furthermore, the lower film holder seals the underside of the film (back) to the counterform during the injection process.

By the upper mold holder is between the upper side of the film and the forming tool evacuated for forming or during high-pressure molding vented.

A Media passage through the upper and lower mold holder supports the modular design as stationary Mold carrier with interchangeable mold inserts without complex media connections and seals at these mold inserts.

The Support shell used according to the invention serves as a receptacle and transport aid for the tailored and preformed fiber material from the preforming station to the forming tool, as separating material between counter-mold (patrix) and fiber composite plastic (FVK) and supporting, depending on the version, for the FVK structure during demolding of the still in the Gelierzustand FVK molding (gelled means hardened, but not yet cured). The support shell consists of a metal with a release agent coating or one Plastic, which is an indifference to the matrix plastic used owns to avoid a chemical compound.

advantageous Further developments of the invention are in the subclaims specified.

A Embodiment of the method according to the invention provides that the heating of the clamped surface film except half of the mold and then the surface film is introduced into the mold.

A advantageous development is characterized in that the Heating of the clamped surface foil in Mold is done.

A Another embodiment of the method provides that the clamped Surface film in the mold by means of pressure and / or Vacuum is formed.

In An advantageous development is after the molding of the surface film the fiber fabric by means of a support shell on the inside the applied in the mold surface film applied and in a resulting mold gap between the inside of the surface film and the support shell the prepolymer resin in the liquid Condition injected.

In an embodiment of the method according to the invention is by means of the support shell, the dimensions of the mold gap set.

A development is characterized in that the holding frame on a transport path is moved.

A advantageous embodiment of the invention Process is characterized in that excess in the fiber fabric introduced prepolymer resin over Resin channels is discharged.

In Another embodiment of the method is the introduction supported by the prepolymer resin with vacuum.

A advantageous embodiment of the invention Appendix is characterized in that in addition a Heat post-treatment station is arranged.

In a development of the system according to the invention the film holder is designed as a holding frame.

In In another embodiment, the holding frame is designed in several parts.

In In a further development, the holding frame is integrally formed.

In a development of the system is the heating station in the forming station integrated.

A Another embodiment provides that the stations of the system by means of a transport path are connected, on which the film holder Is arranged displaceably from station to station.

In an advantageous embodiment of the invention The unit is located between the die holder and the cartridge holder. and vacuum-tight, the film holder can be positioned.

A Another embodiment is characterized in that a pressure plate with a heating device for heating the Surface film placed on the die holder positioned film holder is, wherein the pressure plate and the heater, a compressed air supply for the formation of the surface foil in the matrix exhibit.

In a development of the system according to the invention has the die holder and the die a vent hole for applying a vacuum for forming the surface film on.

One Advantage of the invention is the provision of an automated Production of plastic parts made of fiber-reinforced plastics.

The Surface film used for surface finishing is to be used, by means of a radiant heating unit one-sided or two-sided up to forming temperature before or above the mold is heated. Then the heated Surface film in one of the topography of the surface of the to be produced molded part the same tool formed and subsequently in the same tool, the production of the molding of fiber reinforced plastics after the resin transfer molding process described above (RTM), the vacuum injection method (VI) or the resin infusion method (RI).

The Foil forming can be done by means of negative thermoforming or high-pressure forming respectively. This can be done with the help of a framework in which the is clamped film to be formed.

Of the proposed in the invention support frame is due to its Design only on the standardized external contour of the forming tool, depending on the size and contour of the mold carrier device, limited, in their fixed contours, a wide variety of molded part outer contours let represent.

The Automation of the process is critically dependent the use of a film as a surface as well as supporting or carrier film in one.

at This process is the surface film, if they are on a roll is rolled up, by means of an integrated cutting tool separated from the rest of the film. Alternatively, the surface film already be introduced cut into the plant. Now the holding frame together with the surface foil automatically between the heating elements for heating the surface film to forming temperature and then passed over the mold. Alternatively, the surface film may also be unheated over the mold are guided and there by means of movable Heating elements are heated on one or both sides. The support frame serves as a seal of the process to the mold on the one hand and, when using the pneumatic high-pressure forming for forming the surface film on the other hand, as a seal to the necessary Printing plate.

at Use of the negative thermoforming process eliminates the functions the vent.

alternative The surface film can also over the mold be guided and there on one side by means of a in the formed as a box pressure plate integrated radiant heater to be heated.

In the following next step, the correspondingly designed holding frame seals the work now occupied by the reshaped surface on the one hand and the now supplied, occupied with dry fiber material counter tool on the other hand. In another embodiment, the film holder has no sealing function but only a holding function of the surface film.

To Successful injection / introduction of the matrix material and subsequent Hardening / solidification of the component can already automatically off the negative mold are formed, since the already preformed surface the component already stabilized accordingly. The molded part remains on the counterform, which can be adaptively designed to be functional Elements such as the injection nozzles remain in the system and only the shaping, separately removable support shell the counterform remains in the component. Subsequently, the Component including the support shell and the frame, now serves as a receptacle for the transport device, further transported. Alternatively, the counter-shape with the remaining on it Component to be transported further. Likewise, the component in a closed mold until final hardening remain.

One Advantage of the invention in terms of automation of the manufacturing process of FVK molded parts is that instead of the support shell a separately produced carrier component are used, that during the manufacturing process in the mold connects with the FVK and so, for example, the molding base with required functional elements such as mounting clips or Equipment for functional components. The Counterform is designed accordingly adaptive.

ever According to the materials used, the FRP molding together with the Support shell and the support frame through a heat tunnel for temperature treatment or immediately for post-processing / edge trimming transported. Once there, the molding is ready cured, that it may be immediately post-processed or from the support shell, alternatively counterform, taken and still in the holding frame remaining on a separate holding device can be edited.

Ausgestaltend can be transparent coextruded as surface films Single-layer films are used to satisfy the desire for visualization the fiber reinforcement, especially when using technical Fabrics such as carbon fiber and dyed glass fiber fabrics to meet.

Farther favors the use of surface foils of at least 0.3 mm thickness a shortening of the cycle times: The thicker the preformed layer, the faster the finished one has Component the inherent stability that allows a molding. Slides over 0.3 mm also have over the previously used in the above-described method thin Paint films have the advantage of greater mechanical Resistance to environmental influences, as they the more functional than just a decorative surface represent. Layer thicknesses up to 5 mm are possible.

Also may partially partially colored transparent films be used, which make a visualization of the underlying Reinforcements made of plastic and possibly integrated Functional elements such as illuminated displays, digital displays and others Allow light sources. This effect is achieved by the Use of placeholders under transparent surface films, on the back then colored technical Tissue are used as reinforcement. Continue allowed the method described under the integration of solar films under a transparent surface.

The Invention will be described below with reference to drawings and application examples exemplified in more detail.

It demonstrate

1a to 1o a schematic representation of the process sequence according to the invention,

2 a schematic representation of an alternative heating of the surface film,

3a to 3c a schematic representation of a further alternative heating of the surface film,

4 a schematic representation of the deformation of the surface film by means of vacuum,

5 a schematic representation of the method according to the invention with preimpregnated fiber fabric,

6 a schematic perspective view of a system according to the invention,

7 a schematic representation of the system in plan view,

8th a schematic representation of the system in side view,

9 a detailed view of the forming station with externally arranged holding frame

10 a detailed view of the forming station with arranged between Patrizen- and die holder frame and

11 a detailed view of the forming station in teilxplodierter representation.

The process sequence according to the invention is described in a flowchart with reference to the in the 1a to 1o explained schematically process steps.

In the step after 1a becomes a surface film suitable for the process according to the invention 4 from a roll of film 1 deducted and the required size by means of cutting tool 2 tailored.

This surface film 4 becomes in the step after 1b in a holding frame 3 clamped (loading station A).

According to 1c is the in the frame 3 clamped surface foil 4 between heating elements of a heating device 5 heated (heating station B), and then, as in 1d shown under a template 6 in a die holder 7 is held, guided (negative mold), the topography of the surface of a molded part to be produced 16 made of fiber composite plastic (forming station C).

Alternatively, the film can also be positioned directly under the mold and there by means of a movable heater 5 ( 2 ) or by means of the then box-shaped pressure plate 8th in 3a let in heating elements. This is possible with particularly thin film thicknesses.

After that, the matrix is 6 by means of the pressure plate 8th locked ( 1e ), with the holding frame 3 with the surface film 4 by the applied pressure against the die holder 7 with the inner die 6 against the support frame 3 seals.

Alternatively, as in 3b shown, the counter tool from the pressure plate 8th that with an internal heating device 5 is provided during the forming process on the printing plate 8th remains and optionally also during the forming process can be switched on or off.

Through a pneumatic overpressure, via the compressed air supply 9 supplied, pictured in 1f and 3c , or by a pneumatic negative pressure, shown in 4 , the surface film becomes 4 deformed during Folienpreforming so that a surface film 4 with the topography of the surface of the molded part to be produced 16 arises ( 1f ).

The foil forming with a on the printing plate 8th overlying heating element 5 for film forming by means of vacuum is also possible and not shown here. All of the above-mentioned types of forming are also possible without any heating of the film, depending on the film thickness and the geometry of the mold. In the step after 1g becomes a fiber tissue 11 under the resulting cavity of the surface film 4 on one over the patrix 14 positioned support shell 10 placed so that the preformed surface film 4 the visible surface of the molding 16 forms ( 1h ). The depth and contour of the patrix 14 takes into account the wall thickness of the molded part to be produced 16 , In the process step 1i Now it is done on the semi-finished, in this case, the fiber fabric 11 Coordinated forming process in which the resin matrix in the form of liquid prepolymer through a Harzeinfüllkanal 15 in one with dry fiber tissue 11 (or fiber mat or scrim) filled mold gap 17 is injected. All types of fibers are suitable for the process according to the invention, such as synthetic fibers (glass, carbon, aramid, polyester fibers), natural fibers, metal fibers in every form of processing (mat, endless mat, fabric, scrims, nonwovens).

As an alternative to the described dry fiber materials can also, as in 5 represented, already impregnated with a reaction plastic fiber fabric 11 on the support shell 10 or the patrix 14 be spent. The injection process described above is omitted. By moving together of the mold, so the male 14 and the matrix 6 becomes the already impregnated fiber fabric 11 with the surface film 4 to a molding 16 pressed.

After curing of the fiber-reinforced plastic or cooling, as in 1j shown, the mold open and the finished molding 16 remains on the support shell 10 over the patrix 14 , The support shell 10 is from the patrix 14 removed and now serves together with the support frame 3 for further transport of the molding 16 , The shaping out of the matrix 6 can already be done before the curing of the matrix material, since the surface is already hardened, so that the molding 16 is sufficiently fixed to this side. The matrix can currently be in a hardened state (gelled).

The other side of the molding 16 is due to the remaining support shell 10 or the patrix 14 fixed.

The described forming process can also without support shell 10 respectively. The molding tool of the molding station C remains closed until the curing of the prepolymer resin. Compared to conventional methods, there is still a high time advantage here, since the waiting times for one only made of reaction resin surface omitted.

In conventional methods is a retention of the molding 16 necessary until after curing for damage-free demoulding.

The resulting molding 16 is by means of the holding frame 3 on the transport track 37 possibly automatically by a Nachhei zer 29 ( 1k ) of the heat post-treatment station E and cured there dimensionally stabilized by the remaining support shell 10 and the support frame 3 due to heat supply via the reheating 29 out.

at Use of highly reactive materials can this post-treatment omitted.

At the end of reheating 29 can the molding 16 from the support shell 10 demolded ( 11 ) and, in the frame 3 remaining, on a post-processing device ( 1m ) and by post-processing tools 18 be trimmed.

Alternatively, the molding 16 represented in 1n , even before trimming the frame 3 and support shell 10 removed and then, as in 1o be represented, trimmed. After trimming and possibly cleaning the edges of burrs of the plastic, the molded part can 16 be used. Alternatively, the molding 16 already before trimming from the frame 3 be removed and trimmed on a separate device.

The molding 16 gets through the surface film 4 a ready to use

Surface, which no longer requires post-processing or painting. For Effect colors is a downstream coating process with reduced Painting costs possible.

On the basis of in the 6 . 7 and 8th By way of example in perspective, in plan view and in side view of the inventive plant shown production line, the method described above is shown schematically summarized.

The plant comprises a loading station A, a heating station B, a forming station C, a molded part removal station D, a heat post-treatment station E and a film holder F. In the area of the loading station A is a film roll 1 a surface film 4 cut and placed in a foil holder F. The foil holder F is here as a holding frame 3 trained, on a transport path 37 is transported to the other processing stations. In the heating station B, the holding frame 3 with the surface film 4 heated to softening and then transferred to the forming station C. In the forming station C is in the holding frame 3 clamped heated surface foil 4 between the die holder 7 and the patrix holder 13 arranged. The printing plate 8th causes the formation of the surface film 4 through the in the Patrizenhalter 13 located patrix 14 and those in the die holder 7 located die 6 , After forming the surface film 4 according to the required topography of the molding 16 becomes a fiber tissue 11 , the supporting shell 10 and then introducing the prepolymer resin as described above. After curing of the resin, a further curing of the resin takes place in the heat post-treatment station E until a sufficient strength is achieved. In the mold removal station D, the finished molding 16 taken. The advantage of the system in connection with the method according to the invention is that the surface film 4 by means of the film holder F can be transported through all processing stations and after the pressing and forming process with the resulting molded part 16 can be transported to the mold removal station D, without any removal of the film before the final completion of the molding 16 would be required.

9 . 10 and 11 show exemplary embodiments of the forming tool of the forming station C. This is in 9 and 11 the support frame 3 outside the die holder 7 and the patrix holder 13 arranged as shown in FIG 10 between die holder 7 and Patrizenhalter 13 the support frame 3 is inserted. Here is an additional lower frame seal 38 intended.

The forming tool of the forming station C consists essentially of the die holder 7 that is firm or movable with the pressure plate 8th connected and the die 6 receives. The die holder 7 may be provided with a heater (not shown here, eg internal lines for a water or oil tempering), so as to form the die 6 to temper. Another function of the die holder 7 consists in the sealing of the holding frame according to the invention 3 , This seal is done outside the die 6 , By a lock 21 becomes the support frame 3 held in a temporarily required position and can be mechanically solved if necessary (not shown here).

During the forming process of the surface film 4 becomes the support frame 3 with the help of the pressure plate 8th against the die holder 7 pressed. This is the holding frame 3 by means of the upper seal 27 against the die holder 7 sealed. Through the die holder 7 is via vent holes 23 and connector 22 Discharge air tet or vacuum applied through the slot 24 running around the matrix 6 and through the vent hole 19 is guided into the mold. The vacuum supports the shaping of the cut surface film 4 during the forming or can also for exclusive vacuum forming of the surface film 4 be used.

The described vent holes 19 in the mold 6 are outside the later cutting edge of the finished molding 16 ,

The use of the die holder 7 with the described functions allows a simplification of the die 6 and thus supports a quick change of mold during product changes.

The Patrizenhalter 13 serves to receive the patrix 14 and can also be tempered. The Patrizenhalter 13 is movable on the plunger 12 attached, allowing a lateral retraction and easy covering with fibrous tissue 11 , resting on the support shell 10 is possible. Through the Patrizenhalter 13 becomes an injection channel 26 led for reaction resin injection.

About one in the edge of the Patrizenhalters 13 located resin channel 25 can drain off excess injection resin, possibly assisted by vacuum.

On top of the rim of the patrix 14 there is a circumferential seal 20 , which is an intrusion of the injected reaction resin between male 14 and support shell 10 avoided.

The use of the male holder 13 allows, as with the die holder 7 described a rapid change of shape and product, since essential functional elements such as tempering and sealing no longer from the male 14 but from the fixed to the forming system Patrizenhalter 13 be taken over. A lower seal 28 prevents the escape of reaction resin during the injection phase as well as the penetration of outside air during the evacuation phase during a vacuum injection.

9 shows this with reshaped surface foil 4 , Fibrous tissue 11 and support shell 10 occupied forming tool before the injection phase (as already in the 1i described). The tool is completely closed, the mold gap 17 between die 6 and support shell 10 defines the later strength of the molding 16 ,

After the injection phase and the time of hardening of the reaction resin, the lock becomes 21 solved. The Patrizenhalter 13 comes complete with the patrix 14 and the FVK molding thereon 16 and the support shell 10 lowered. This is the molding 16 , connected by the surface film 4 still clamped in the frame 3 , The support frame 3 comes on laterally mounted, not shown here leadership roles on the track of a transport path 37 to a halt. This is located in a plane above the lowest position of the track of the Patrizenhalters 13 , Due to the further downward movement of the male holder 13 and the patrons on it 14 it comes to the demolding of the FRP molding 16 from the patrix 14 , where the support shell 10 on the molding 16 remains, as this without any attachment to the male 14 rests and by adhesion forces on the molding 16 adheres.

The further procedures are schematically in 1k to 1m described. The support frame 3 serves until complete demolding of the molded part 16 as a stabilizer and transport device.

In the 11 Parts exploding representation of the mold of the molding station C illustrates the basic structure of the invention.

Method example of the automated Procedure by making a motorcycle wheel cover

A Motorcycle wheel cover is said to be made of a material combination of a high-tensile thermoplastic, here PETG, manufactured as a surface and a carbon fiber laminate as a support layer become. The carbon fibers should be visible for design reasons remain, the component should be light, stiff and unbreakable. Therefore is a construction of a transparent film of PETG (1 mm) and a 2-ply carbon fiber fabric laminate (0.4 mm) chosen.

The PETG provides the fracture and shatterer safety and required Flexibility of the molding ensures that carbonla minat for the required stiffness, to result in a lightweight Get component.

The process sequence in the method according to the invention is shown in a flow chart with reference to the in the 1a to 1o explained schematically process steps. In the step after 1a becomes a tailored surface film suitable for the in-line film RTM process 4 made of 2 mm thick, transparent PETG pulled from a roll and the required size by means of a cutting tool 2 tailored. This surface film 4 becomes in the step after 1b in the described holding frame 3 clamped. In 1c is the in the frame 3 clamped surface foil 4 in the heater 5 heated and then, as in 1d shown on a die 5 that led the Topography of the surface of the molded part to be produced 16 having.

Thereafter, the shaping by means of the pressure plate 8th , where the holding frame 3 with the surface film 4 by the applied pressure against the die holder 7 and the Patrizenhalter 13 seals.

By pneumatic overpressure, via the compressed air supply 9 is generated, the surface film 4 deformed during Folienpreforming so that a surface film 4 with the topography of the surface of the molded part to be produced 16 arises ( 1g ).

In the step after 1g becomes a 2-ply fiber fabric 11 under the resulting cavity of the surface film 4 on one over the patrix 14 positioned support shell 10 placed so that the preformed surface film 4 the visible surface, so the exposed side of the molded part of the environment 16 forms. In the process step 1i takes place on the PETG film adapted forming process, in the resin matrix in the form of liquid reaction plastic, here vinyl ester resin on a Harzeinfüllkanal 15 in the molding gap covered with dry carbon fiber fabric 17 is injected. After curing the carbon fiber reinforced plastic, as in 1j shown, the forming station C is opened. The finished molding 16 (here a wheel cover) remains on the support shell 10 over the patrix 14 , The support shell 10 is from the patrix 14 removed and now serves together with the support frame 3 as workpiece carrier for further transport. The shaping out of the matrix 6 can already be done before the curing of the matrix material, since the surface is already hardened and the molding 16 fixed to this side. The matrix may still partially be in a hardened state (gelled).

This side of the molding 16 is due to the remaining support shell 10 or the patrix 14 stabilized.

The molding 16 is now using the holding frame 3 on a transport track 37 automatically by a heat path ( 1k ) and hardened there dimensionally stabilized by the remaining support shell 10 out. At the end of the heat post-treatment station E is the molding 16 from the support shell 10 demolded ( 1l ) and, in the frame 3 remaining, on a post-processing device ( 1m ) and by post-processing tools 18 trimmed. After trimming and possibly cleaning the edges of burrs of plastic, the wheel cover can be used. The wheel cover has through the surface foil 4 a ready-to-use transparent surface that does not require any finishing or painting.

The time savings in the production of the FRP molding 16 is enormous in this case, because not only the procedure of forming about 3 times as fast as in conventional methods can be done, but the costly and time-consuming process of subsequent painting is completely eliminated.

applications

Produce a trunk half shell made of FRP by forming a 2 mm thick transparent plastic film made of highly tear-resistant PETG, a subsequent interior decoration on the back the formed film by means of a glued logo and the subsequent introduction of 3 0.2 mm thick reinforcing layers made of carbon fiber fabric and liquid synthetic resin by means of described sheet RTM method. You get so dynamically loadable fiber-reinforced lightweight component with a Class A surface, which as a decoration the visible carbon fiber structure shows and an identification by a glued in logo, inaccessible and thus indestructible on the back of the transparent Surface layer, includes.

The combination of highly tear-resistant described in this application thermoplastic as surface film and highly rigid Carbon laminate as a support layer is similar to a new material combination the safety glass. The highly tear-resistant plastic is without reinforcement very flexible and less rigid. The stiffness to be achieved can only be achieved by appropriate material thickness and the disadvantage of high weight. The carbon laminate alone would be without the combination with the highly tear-resistant surface film due to its low shear strength in a fracture splinter and sharp-edged Have broken edges. The combination of both materials presents a specific light, stiff material that at break kinks at best, but does not have sharp break edges.

Vehicle interior components made of FRP, such. As a Armaturenenträgerblende with shock absorbing effect, can be prepared as follows:
A 1 mm thick transparent plastic film is formed by means of high-pressure process, a 0.2 mm thick layer of colored glass fiber fabric and a thermosetting plastic matrix are applied by RTM method on the back of the film and then the back of the resulting cup-shaped component in the same tool foamed by means of appropriate device. It can turn decorative elements on the back of the film such. For example, the manufacturer's logo or placeholder for the subsequent A set of electrical bulbs / displays are introduced. The fiber-reinforced surface in Class A quality in combination with the foam allows the absorption of impact energy with subsequent recovery without damage to the component and reduces the risk of injury inside the vehicle. Here, too, the already described positive effect with respect to the fragmentation behavior of the material combination, similar to a safety glass, occurs.

Car body lightweight parts from FVK can, by means of an already colored in body color, in the mold preformed plastic film and a subsequent fiber reinforced sandwich produced by RTM process Made of plastics and prefabricated hard foam elements become.

The otherwise necessary costly painting is eliminated. The obtained moldings are light, stiff and shatterproof.

Furniture elements with shiny transparent surface and fiber optic as decoration

A transparent plastic sheet of thickness 3 mm is used in the mold transformed, covered with a resin-impregnated fibrous tissue and then with a MDF or multiplex board Standard thickness 19 mm (for furniture) in the same Tool pressed into a complex component.

Around will produce a car exterior mirror housing one already coated in the desired color on the inside, transparent plastic film by means of high-pressure molding in the Molded tool and then the inner contour included the necessary shots of the built-in parts by means of injection molding introduced in the same tool. The otherwise necessary costly Painting is eliminated.

1

film roll

2

Crop

3

holding frame

4

surface sheet

5

heater

6

die

7

die holder

8th

printing plate

9

Compressed air supply

10

supporting shell

11

fiber fabric

12

plunger

13

male keeper

14

punch

15

Harzeinfüllkanal

16

molding

17

forming gap

18

post-processing tool

19

vent hole

20

poetry

21

lock

22

Union joint

23

vent hole

24

slot

25

resin passage

26

injection channel

27

upper poetry

28

lower poetry

29

reheating

30

31

32

33

34

35

inner space

36

37

transport path

38

lower Holding frame seal

A

loading

B

heating station

C

forming station

D

Mold removal station

e

Heat treatment station

F

film holder

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10309811 A1 [0009]
• - EP 0819516 A2 [0014, 0014]
• - EP 1230076 [0021, 0022]

Cited non-patent literature

• - Technical Paper by Achim Grefenstein "Film Injection Instead of Painting", in Metal Surface - Coating of Plastic and Metal, Issue 10/99, Carl Hanser Verlag, Munich [0008]

Claims (19)

Process for the production of molded parts from fiber-reinforced plastics having a finished visible surface, which have a surface film on the visible side, comprising the following process steps: forming the surface film according to the topography of the molded part, applying a fiber fabric to an inside of the formed surface film facing away from the visible surface and then impregnating with prepolymer resin , - molding of the molded part and curing, - removal of the visible side of the surface film having molding, characterized in that - a cut surface film ( 4 ) is heated to the softening temperature, - the cut heated surface foil ( 4 ) in the mold according to the topography of the molded part to be produced ( 16 ), - a fiber fabric and prepolymer resin in the same mold on the inside of the surface film ( 4 ) is applied, shaped according to the topography of the molding and cured and - the finished molding is removed after curing the mold. A method according to claim 1, characterized in that the heating of the clamped surface film ( 4 ) takes place outside the mold and then the surface film ( 4 ) is introduced into the mold. A method according to claim 1, characterized in that the heating of the clamped surface film ( 4 ) takes place in the mold. Method according to one of claims 1 to 3, characterized in that the clamped surface film ( 4 ) is formed in the mold by means of pressure and / or vacuum. Method according to one of claims 1 to 4, characterized in that after molding of the surface film ( 4 ) the fibrous tissue ( 11 ) by means of a support shell ( 10 ) on the inside of the surface of the mold in the mold ( 4 ) is applied and in an emerging mold gap ( 17 ) between inside of the surface film ( 4 ) and the support shell ( 10 ) the prepolymer resin is injected in the liquid state. Method according to one of claims 1 to 5, characterized in that by means of the support shell ( 10 ) the dimensions of the mold gap ( 17 ) is set. Method according to one of claims 1 to 6, characterized in that the holding frame ( 3 ) on a transport path ( 37 ) is moved. Method according to one of claims 1 to 7, characterized in that excess in the fiber fabric ( 11 ) introduced prepolymer resin via resin channels ( 25 ) is discharged. Method according to one of claims 1 to 8, characterized in that the introduction of the prepolymer resin is supported with vacuum. Plant for the production of molded parts with a finished visible surface made of fiber-reinforced plastics, the visible side of a surface film ( 4 ), comprising - a loading station (A), comprising a held film roll ( 1 ) with a wound-up surface film ( 4 ) and a cutting tool ( 2 ), - a heating station (B) for heating the surface film ( 4 ), - a forming station (C), comprising a die holder ( 7 ) with a die ( 6 ), a Patrizenhalter ( 13 ) with a patrix ( 14 ), where die ( 6 ) and patrix ( 14 ) the negative or positive form of the molded part ( 16 ), - a mold removal station (D) and - a film holder (F) for holding the surface film ( 4 ). Plant according to claim 10, characterized that in addition a heat aftertreatment station (E) is arranged. Plant according to claim 10, characterized in that the film holder (F) as a holding frame ( 3 ) is trained. Plant according to claim 12, characterized in that the holding frame ( 3 ) is formed in several parts. Plant according to claim 12, characterized in that the holding frame ( 3 ) is formed in one piece. Plant according to one of claims 10 to 14, characterized in that the heating station (B) in the forming station (C) is integrated. Installation according to one of claims 10 to 15, characterized in that the stations (A, B, C, D, E) by means of a transport path ( 37 ) are connected, on which the film holder (F) is arranged from station to station displaced. Installation according to one of claims 10 to 16, characterized in that between die holder ( 7 ) and male holder ( 13 ) liquid-tight and vacuum-tight, the film holder (F) can be positioned. Installation according to one of claims 10 to 17, characterized in that a pressure plate ( 8th ) with a heating device ( 5 ) for the heating of the surface film ( 4 ) on the die holder ( 7 ) positioned film holder (F) can be placed, wherein the pressure plate ( 8th ) and the heating device ( 5 ) a compressed air supply ( 9 ) for the formation of the surface film ( 4 ) in the die ( 6 ) exhibit. Plant according to one of claims 10 to 16, characterized in that the die holder ( 7 ) and the die ( 6 ) a vent hole ( 23 ) for applying a vacuum for forming the surface film ( 4 ) having.