DE102010052180A1 - Injection molding tool used in manufacture of composite plastic components for motor vehicle, has tool cooling device that is arranged on mold sections and is supplied with cooling medium through conveying device - Google Patents

Abstract

The injection molding tool has cavity that is defined with two mold sections which are moved relative to each other. The inductor (4) and vibration actuator (5) are provided in one of the mold sections. The tool cooling device (6) is arranged on the mold sections and is supplied with cooling medium through conveying device (10). An injection channel in an extruder unit (7), is extended to the injector to inject melted plastic material at the cavity. A vacuum pump (9) is connected with the cavity through vent line. An independent claim is included for method for manufacture of composite plastic component.

Description

The invention relates to an injection molding tool and a method for producing fiber composite plastic components from textile inserts as well as the fiber composite plastic component itself.

Fully consolidated thermoplastic prepregs (organic sheets) are known from the prior art as planar semi-finished products. Organo sheets are understood to mean semi-finished fiber composites in the form of fiber-reinforced thermoplastic sheets. Such fiber composite component inserts (FVK depositors) are currently heated for the production of fiber composite plastic components outside the tool and preformed spatially separated. The production of such fiber composite plastic components from such fiber-reinforced thermoplastic sheets to date requires several individual processes in which the various process steps are performed.

In existing injection molding, the cavity enclosed between two tool halves of an injection molding tool or the mold regions delimiting the cavity is generally heated during the injection molding process, but partially also before the injection molding process or after completion of the injection process, in order to prevent premature solidification of an injected plastic ,

By the DE 10 2006 040 748 A1 is an injection molding process for fiber-reinforced motor vehicle parts known, with which fiber-reinforced exterior or interior parts of motor vehicles of complex geometries or alternately reinforced and unreinforced areas can be produced easily and inexpensively. For this purpose, an unconsolidated textile or structural insert made of hybrid yarn is prepared, which is then preheated at least in the edge zone to a temperature close to the melting point of the thermoplastic fibers before or during introduction into an injection mold. There, the textile insert is overmolded with a thermoplastic at a temperature above the melting temperature of the thermoplastic fibers, which are melted at least in the edge zone of the textile insert. This is followed by cooling and removal of the finished component.

DE 10 2006 039 780 A1 relates to a method and a tool for temperature control in the injection molding of molded parts by inductively heated mold areas of a cavity of an injection mold. This is to improve the molding surface quality and reduce cycle times. The method is that before filling the cavities of an injection mold by a change in position of the movable mold halves inductors that are integrated in the mold halves or alternatively external inductors are arranged in front of opposite cavity halves, so that geometrically limited areas of the walls of the cavities on both sides directed directly inductively heated. After complete heating of the cavities, the return of the tool halves takes place in their original position, so that an injection molding step can follow.

On the basis of this prior art, it is desirable to provide an improved injection molding machine or an improved tool for producing a fiber composite plastic component from a "dry" textile inserter which is not or not completely impregnated or consolidated. The tool is intended to allow a combination of the various required process steps of fiber impregnation and consolidation in order to improve the quality of the finished fiber composite plastic component.

This object is achieved by an injection molding tool with the features of claim 1.

Another object is to provide a method of manufacturing a fiber composite plastic component from a "dry" textile inlay with respect to cycle times and process costs.

A method which achieves this object is described by the features of claim 6.

Further developments of the tool and the method are carried out in the respective subclaims.

Furthermore, a fiber composite plastic component of a textile insert, which is improved in terms of mechanical properties, the surface finish and the component weight, with the features of claim 10 is disclosed.

A first embodiment of the invention relates to an injection molding tool or an injection molding machine for the production of fiber composite plastic components from textile inserts and a thermoplastic matrix material. The injection molding tool usually has two mold halves, which can be moved relative to each other and have mold areas that define a cavity into which the textile insert is inserted and the plastic melt is injected. Thus, the fiber impregnation and consolidation of the textile insert can be made possible. The injection molding tool has a vibration actuator in one of the tool halves, with which the tool or the textile inlaid in the cavity is set in vibration. One or both mold halves have internal inductors located near the mold areas and suitable for generating a high frequency alternating magnetic field. A tool cooling device, which is supplied with a cooling medium by a conveying device, is likewise arranged near the molding regions on at least one of the tool halves. In addition, the injection molding tool is equipped with an extruder unit which is arranged on one of the tool halves and from which an injection channel extends to one or more injection devices, which are arranged for injecting the plastic melt on the cavity. A vacuum pump is connected to the cavity via a vent line.

Unlike in the prior art, all the necessary processes for producing such a fiber composite plastic component combined are advantageously carried out in a single tool according to the invention. In this case, the tool surface or the textile insert contact surface is not only inductively heated, but it can also be carried out together with the tool cooling device a variothermic inductive temperature control. Due to the variothermic temperature control, the flowability of the thermoplastic is very high and thus increases the processing time. The injection molding tool according to the invention assists in the injection molding of a fiber composite plastic component, the improved impregnation and the optimal consolidation of the textile insert with a thermoplastic matrix plastic by the variotherm inductive temperature control and occurring in consequence of the vibrations occurring fiber loosening in the textile feeder and thereby enables quality improvement at reduced costs. The surface structure of the organic sheets can be maintained or even improved by the targeted heating of the tool. By combining several individual steps, the heat balance for the production of the injection-molded FRP component can be improved and thus energy and the associated costs can be saved.

Another embodiment of the injection molding tool relates to the injection device, which may further comprise a controllable needle valve nozzle. The regulation of the injection takes place by means of one or more displacement sensors for detecting the vibration performed by the tool, wherein the one or more displacement sensors and the part of an actuator is / are that actuates the needle valve nozzle. This allows injection of the melt of the thermoplastic resin matrix material coordinated with the tool / textile inler vibration. The actuator may be a hydraulic actuator which is connected via a fluid line with a pumping device.

Usually, a tool half will be a closing-side mold half and the second mold half will be a mold-side, the extruder unit being associated with the mold-side mold half.

The injection molding tool according to the present invention may further include a secondary cavity which serves to catch a melt surplus. The Nebenkavität is connected via a pressure-controlled valve with the cavity. The valve is coupled to a pressure sensor located on the cavity. In addition, the secondary cavity for drawing off the excess melt comprises a draw-off device which is connected via a withdrawal line to a delivery device.

Furthermore, it is conceivable that the tool is coupled with one or more controllable gripper devices as well as with a preheating device. The gripper device (s) is / are designed for handling the textile inserter and / or the preheating device such that they place the textile insert under the preheating device and insert it into the tool during an opening phase of the tool, or during an opening phase of the tool insert into the tool and the preheating, which may be in particular an external Induktoreneinrichtung or an infrared radiation device, arrange at the inserted into the tool textile insert.

The molding area of at least one of the mold halves, in particular of the closing side mold half, can be lined with a heat-insulating layer, in particular of a ceramic material. Thus, the entire (closing) mold half is not tempered and energy and cycle time can be saved.

The inventive method for producing fiber composite plastic components from textile inserts and a thermoplastic matrix material, which also uses an injection molding tool according to the invention, comprises the following steps: First, the textile insert is preheated to a temperature below a melting temperature of the matrix material after or before it is inserted into the tool becomes. The preheated textile inlay is preformed by pressing against a cavity defining heated mold area of one of the tool halves, whereupon the tool is closed and the textile inlaid by the inducers directly or indirectly over the heated tooling surface Temperature of the process is tempered. This is followed by injecting the thermoplastic matrix material into the cavity of the tool through the extruder unit, maintaining the process temperature above the melt temperature of the thermoplastic matrix material so that the textile inlay is impregnated with the matrix material. At the same time the cavity is vented by means of the vacuum pump and the inserted textile insert is vibrated by the vibration actuator which generates vibrations in order to achieve better penetration of the textile inserter with the matrix material and to minimize the proportion of trapped air bubbles. The consolidation of the fiber composite plastic component takes place by carrying out a pulse cooling device by means of the tool cooling device. The cycle time for impregnation and consolidation of a semi-finished product can thereby be significantly reduced. Also, the process costs can be reduced by the process-controlled temperature.

The thermoplastic matrix material may contain nanoscale particles of a ferromagnetic material, so that the high-frequency alternating magnetic field generated by the inductors not only causes the indirect heating of the halves of the tool, but also directly to a heating of the nanocomposite by the nanoscale particles excited to vibrate leads. The combination of nanoscale ferromagnetic particles, deaeration and compaction by means of the generated vibrations leads to a significantly improved consolidation of the dry textile.

According to an embodiment of the method according to the invention, it can further be provided that during the injection of the thermoplastic matrix material, a movement of the melt stream of the matrix material is tuned with the vibration generated by the vibration actuator, so that the matrix material melt is injected into the cavity intermittently or in a pulsating manner by the needle valve nozzles. The thus generated movement of the melt stream is then out of phase but rectified or simultaneous to the tool movement. Thus, the friction between the filaments of the textile inlay and the matrix melt can be minimized and the penetration of matrix material into the loosened fibers of the textile inlay can be facilitated. The synchronized movement can also reduce the porosity and reduce costs since less energy is needed to make the part.

A further embodiment of the method according to the invention relates to the implementation of a spray-molding step in the tool according to the invention. In this case, after the impregnation of the textile insert with the thermoplastic matrix material, the tool is opened and the tool halves are spaced around an embossing gap, which is advantageously in a range of 1/10 to 3/10 mm. The tool is thus kept open for a period of time in a range of a few seconds, for example 1 to 10 seconds, with contraction of the impregnated textile insert just taking place. In the next step, additional matrix material is injected into the cavity, the mold closed again, and the pressure on the additional matrix material increased to penetrate the impregnated fabric insert. The valve for Nebenkavität is opened under pressure control, there to catch an excess amount of the matrix material, which can then advantageously be recycled after appropriate treatment in the extruder unit.

Finally, the invention relates to a molded fiber composite plastic component which comprises at least one textile insert encased with a thermoplastic matrix material, wherein the thermoplastic matrix material comprises nanoscale particles of a ferromagnetic material. Such a nanocomposite advantageously allows the inductive heating of the matrix material in the alternating magnetic field. Alternatively or additionally, the textile insert may comprise electrically conductive wires, in particular metallic or carbon fiber wires, which have a defined length and a defined cross section and are integrated unidirectionally or bidirectionally into the textile insert.

Such a tissue allows "health monitoring" after an "accident" via a resistance measurement on the component produced therefrom, even in the installed state.

Improved consolidation and the incorporation of nanoparticles into the product or semi-finished product result in better mechanical properties and improved crash integrity.

Due to the variothermal tempering, surfaces of high quality can be imaged, even the formation of very fine or even filigree surface properties can be realized. The image of weld lines is avoided.

Furthermore, due to a reinforcing effect by the nanocomposite used, a weight reduction can advantageously be achieved. By saving on material, on the one hand, and on the other hand, fuel costs for operating a vehicle made with lighter materials can be reduced.

These and other advantages will become apparent from the following description with reference to FIGS accompanying figures set forth. The reference to the figures in the description is to aid in the description and understanding of the subject matter. Articles or parts of objects which are substantially the same or similar may be given the same reference numerals. The figures are merely a schematic representation of an embodiment of the invention.

Showing:

1 1 is a side sectional view of an injection molding tool according to the invention, with gripper device and infrared radiator,

2 a side sectional view of an injection molding tool according to the invention with textile insert with the tool still open,

3 a side sectional view of an injection molding tool according to the invention with textile insert with closed tool,

4 a top view of the textile inserter with gripper device,

5a . 5b . 6a . 6b schematic representations of the heating and alignment of the nanoscale particles in the textile insert by means of alternating magnetic field

7 a perspective view of an external inductor when inserted into the opened tool,

8th a perspective view of an external inductor when inserted into the open tool, with gripping device,

9 a side sectional view of the textile insert in the closed mold when tempered by the inductors, which are arranged in the casting-side mold half,

10 . 11 . 12 . 13 . 14 Side sectional views of the tool according to the invention,

15 Side sectional view of another tool according to the invention, in which a spindle drive is used as a vibration actuator.

The device according to the invention relates to an injection molding tool such as in 1 is shown. With the injection molding tool fiber composite plastic components from a textile insert 3 and a thermoplastic matrix material, wherein the injection molding tool is a closing-side mold half 1 and a casting-side tool half 2 which are movable relative to each other and have mold areas which bound the cavity K.

The term "textile inlay" is understood here to mean a blank of a non-consolidated, a partially consolidated or a consolidated fiber composite semifinished product, which is in particular a fiber-reinforced thermoplastic. This comprises at least one thermoplastic and an organic and / or inorganic reinforcing fiber portion, and may be, for example, a hybrid textile of reinforcing fibers and thermoplastic fibers or a textile of a homogeneous very finely divided hybrid roving or a hybrid yarn.

The thermoplastic matrix material may be a thermoplastic other than the thermoplastic portion of the textile insert; alternatively, the same thermoplastic material may be used.

In the present specification, a fiber composite plastic component is mentioned as overmolded textile product. This may in particular be a component for a motor vehicle, such as a front end support, a Z-strut, a rear wall, a pedal bearing block, a tailgate, a door base module, a door, an end wall, a multi-function tray, etc. It is also conceivable, the plastic fiber composite product produced according to the method according to the invention in the injection molding tool according to the invention constitutes a type of semi-finished product which is subsequently subjected to further processing steps.

In the following, the injection molding tool or the plant and the processes performed in combination will be described.

The injection molding of thermoplastic moldings per se is known. A plastic granulate is via a feeder 12 an extruder screw 13 fed. The in the extruder 7 located screw conveyor 13 compacts the granules, whereby it heats up strongly (usually up to the melting temperature of the respective plastic). Depending on the selected plastic, additional heating / cooling for the extruder may be necessary 7 required to reach or maintain the melting temperature. For this purpose, the extruder device 7 a corresponding heater 14 on. The screw conveyor 13 is here axially movable, whereby an injection of the molten viscous plastic mass (which now before the extruder screw 13 located) via the injection channel 7 ' by means of the injector 7 '' is possible. The axial movability is optional.

The now liquefied plastic is in the cavity K between the mold halves 1 . 2 introduced, the textile insert 3 penetrated and the final shape to be manufactured for the component is formed due to the injection pressure and the injection volume. The tool halves 1 . 2 become inductive by means of inductors 4 heated so that the molding process does not begin too early and the injected plastic material remains as fluid as possible. The injection process is followed by a cooling process by means of the pulse cooling device 6 to achieve a fast impression. By an ejector, the finished molded part can be ejected and the process is completed.

The inductive heating of the tool serves to increase the flowability of the thermoplastic to be processed. As a result, Bindenahtkerben be avoided, also are hardly achieved until no sink marks. The shear of the plastic melt as it flows through the cavity is minimized. Residual stress and shrinkage are also minimized, premature solidification of the melt is prevented, an improved microstructure is achieved and an improved molding surface is achieved and a reduction of the cycle times is made possible.

The process-controlled pulse cooling device makes rapid molding possible and the cycle time is further reduced. The impulse cooling device has the task during the heating process to take over the cooling (protection against overheating, control of the process temperature) of the tool or the cavity K. Upon completion of the injection molding process, the controlled pulse cooling device provides for rapid molding of the structural member by rapid cooling of the cavity.

According to the method according to the invention, the processes for the impregnation / consolidation of the FRP textiles are combined by injection molding. The "dry" textile (eg preconsolidated hybrid roving) or the "dry" inlay 3 are preheated to the required forming temperature for all subsequent steps. This is in 1 such as 7 to 9 shown, wherein the preheating of the textile insert 3 outside of and / or takes place in the tool.

In 1 and 8th is by a gripper device 17 an infrared radiator 23 introduced into the open tool, where the already inserted textile insert 3 preheated by the infrared radiation IR. In 9 a thermally insulated tempering of the textile insert takes place 3 in the closed mold through the inductors 4 that are in the casting-side tool half 2 are arranged while the molding area of the closing side mold half 1 with a heat insulating layer 24 is lined. 7 shows the preheating of the textile insert 3 by means of an external inductor 4 ' , which is also introduced by a gripper device, not shown in the open tool. In some circumstances, the textile insert 3 also only in the forming area, so only locally and partially heated. Finally, it is also conceivable that the preheating by the present in the tool inductors 4 he follows.

By preheating in the tool, the surface, the structure and the structure of the textile insert are not damaged by too high and possibly unnecessary (an excessive temperature is often used because the organo sheet cools down quickly) heat input.

This is how the textile inlay becomes 3 heated or held to the ideal temperature for cohesive connection. This may possibly only in the contact zone or contact surface between the injection molding tool and the insert 3 done as local partial warming.

The thermoplastic content of the insert 3 is melted in the tool.

The inductive variothermic mold temperature control, the application of a high frequency alternating magnetic field for nanocomposite heating, the vibration opening of the textile inlay fibers, a synchronous injection embossing (overmolding by melt flow control) and a mold temperature control using thermal insulation are mentioned and described below.

In general, in the described method, a process-controlled pulse cooling device by means of the tool cooling device 6 and a vacuum suction by means of the vacuum pump 9 carried out.

The injection molding tool according to the invention shown in the figures consists of two mold halves 1 . 2 with one of the two halves moving relative to the other. The one tool half 1 in this case forms the cavity K. Further tool components are the vibration actuator 5 , the inductors 4 with the associated generator 8th for tool heating, tool cooling 6 and the associated pump 10 , and the extruder unit 7 coming from the extruder screw 13 and the feeder unit 12 exists, as well as the vacuum pump 9 ,

The first step is a prefabricated textile 3 that's about a gripper device 17 (see. 4 ), from this for preheating under an infrared radiator 23 (please refer 1 and 8th ) or an external inductor 4 ' (please refer 7 ) guided. For this purpose, the closing-side mold half is opened in accordance with arrow a. Under the infrared radiator 23 / external inductor 4 ' becomes the textile 3 heated to just below the melting temperature of the contained thermoplastic polymer. The thermoplastics contained in the textile inlay can be, for example, polyamide (PA), polyphthalamide (PPA) or polyetheretherketone (PEEK), in the case of PA the textile inlay can be preheated to 200.degree. The preheated textile 3 is now from the gripper 17 inserted into the tool with a slight pressure on the casting-side mold half 2 pressed. This achieves preforming of the later product. The semi-finished product is made by pressing on the tool half 2 and in addition by slide 15 fixed. In the 4 to see) locking 18 of the clamping frame 19 can be opened and moved out of the tool (see 2 ). It is also conceivable inserting an already consolidated (and heated in the previous process step) semi-finished product, which also by the gripper 17 is preformed and by slide 15 and the gripper 17 is fixed.

2 shows the preheated textile inlaid in the tool 3 with the tool still open. 3 shows the textile insert 3 in the closed tool.

The next process step is now followed by the injection molding or injection-compression molding process. Before and during injection molding or injection-compression molding, the textile inlay is used 3 variotherm inductively brought to process temperature.

The inductive variothermic mold temperature control uses the so-called skin effect. Here, during the injection molding or injection-compression phase, the tool by means of the inductors 4 heated and during the ejection phase by the pulse cooling device 6 cooled. The tool halves 1 . 2 are heated by taking advantage of the skin effect. The effect is based on the fact that a conductor through which a high-frequency alternating current flows has only one electron flow (current density) at the surface ("skin") of the conductor. This can be explained by the fact that a magnetic field is formed around a conductor through which current flows, which generates eddy currents in an alternating current which are directed counter to the generator current flowing in the interior. The result is that the electrons are forced to the outside of the conductor (increased current density) and increases the effective resistance of the conductor. The increase of the conductor resistance is noticeable by a strong heating of the conductor. This effect depends on the frequency with which the magnetic field is generated. The heating is "transported" by convection to the surface of the mold halves. The tool surface can thus be heated or cooled in seconds.

Furthermore, a high-frequency alternating magnetic field is used for nanocomposite heating. Here, as in 5a . 5b . 6a . 6b sketched, by means of a high frequency alternating magnetic field 20 on the one hand the tool halves 1 . 2 and on the other hand simultaneously the thermoplastic polymer composite 22 , the nanoscale paramagnetic particles 21 contains, heated. The inductors 4 (see, for example. 3 ) are arranged in the tool so that the generated magnetic field is formed in the resulting cavity K of the tool. As a result of the alternating magnetic field, this is also due to the paramagnetically behaving nanoparticles 21 a magnetic field in the polymer composite 22 induced. ( 6a . 6b ) Here, the so-called superparamagnetism occurs. This effect describes the behavior of nanoparticles of a ferromagnetic material, which also very far below the Curie temperature (above this material-dependent temperature show ferromagnetic materials only paramagnetic properties) no magnetic properties obtained, ie in these very fine particles arrange the individual atomic magnetic Moments parallel to each other, as this is usually cheaper for the particles already at room temperature.

A collection of such particles 21 behaves macroscopically paramagnetic. However, with the property that the magnetic moments do not occur individually but in blocks. The magnetic field induced in the polymer composite (a conductor, the ferromagnetic particles, in a time-varying magnetic field) induces a voltage and a current (eddy current) in the conductor. The eddy current generates its own magnetic field, this is the cause of the induction directed against and moves the particles in motion (vibration), which leads by the finite resistance of the particle to a heating (due to the magnetic field generated by the eddy current). The particles contained in the matrix composite 21 are, as previously described, by the high frequency alternating magnetic field 20 vibrated. The generated vibrations of the particles 21 and the heat generated are applied to the matrix material or the polymer composite 22 transferred, which increases its fluidity as a result of heating. Through the introduced nanoscale particles 21 Improve the mechanical properties of the composite 22 and, for example, improved strength values can be achieved. This advantage allows further material reduction, which previously had to be applied to the fabric in the form of ribbing for reinforcement. This also leads to a weight reduction of the component.

According to the invention in the tool by the integrated vibration actuator 5 a vibration loosening of the inserted thermoplastic hybrid textile 3 achieved. Vibrations are generated that affect the flow and consolidation process of the inserted dry hybrid textile 3 accelerate and improve. Generally there is the hybrid textile 3 from several rovings which in turn consist of many individual filaments. In the rovings are or several different filament materials such. As glass fiber filaments, PA (PPA, PEEK) filaments, textile filaments or metal wire filaments are summarized. These rovings become the textile insert 3 woven with a fiber direction of, for example, 0 °, 90 ° or ± 45 °. By means of the vibration actuator 5 generated vibrations are loosened the fibers, which are due to the manufacturing process very close to each other, since when producing a roving the filaments are stretched and thereby have a rectilinear alignment. The melted thermoplastic matrix can now by the vibrations of the tissue 3 penetrate better and this then leads to improved consolidation of the tissue 3 , The complete consolidation of the tissue 3 improves the mechanical properties of molded parts as well as the surface shape of the molded part or component.

During the entire injection phase of the matrix polymer is by the vibration actuator 5 , which is a piezoelectric actuator 5 may be, the tool, in particular the Werkzeugkavitätbereich, vibrated. The piezo actuator 5 works after the piezoelectric effect, the deformation of a piezocrystal (stack) when applying a voltage. By applying a low-frequency AC voltage to the crystal, a sound wave is generated. This is applied by the direct coupling to the tool in the tool as vibration. The excited oscillation, which allows optimal consolidation of the fibers, should be set in the range 5-30 Hz. This is used in the present tool to provide an injection molding / injection molding process and the component to be manufactured (taking into account the matrix polymer used and its constituents, as well as the textile used 3 be it a fabric, scrim or knit) to create a tuned frequency. The vibrations are used to make the fibers of the dry textile inlay 3 loosen or respectively open at this stage of the process and, with the resulting improved impregnation with the matrix material, leads to improved consolidation of the textile inlay 3 is achieved at the same time reduced pore content.

In combination with the nanocomposite heating produced by the high-frequency alternating magnetic field described above, penetration of the matrix material melt between the individual filaments of the roving in the dry tissue 3 significantly improved. Furthermore, mechanical, pneumatic or electrical or hydraulic vibration generators are conceivable for generating the vibration.

The vibrations generated are according to the invention of the vibration of the inflowing matrix material rectified, but phase-shifted. This ensures that the individual filaments of the roving move relative to each other, due to the different filament materials (eg glass filament, PA filament) in a roving. The vibration entered into the closed tool is synchronized by the resulting amplitude to the movement of the melt stream, ie the movement of the melt is due to the movement of the tool and thus of the textile 3 Voted. It minimizes the friction between the filament and the matrix that exists during the melt flow. For this purpose, a precise coordination of the melt movement to the tool movement (in the millisecond range) is necessary. In order to achieve a control within such narrow limits, for injecting the matrix material into the cavity K in the tool ( 10 to 14 ) hydraulically operated needle valve nozzles 26 used. The needle valve nozzles ( 26 ) allow to control the exact inflow time and period over which injection is made. Furthermore, via these nozzles 26 applied a vibration in the matrix material. This is done via a hydraulic actuator with displacement sensors 27 generates an intermittent motion. About the nozzles 26 The molten matrix material in the corresponding or in the depending on the used polymer and textile 3 required oscillation be offset. By this stimulation of the matrix material, it is possible to realize a phase-shifted simultaneous movement between the tool and the melt stream. In this state is the fiber of the textile insert 3 loosened and a facilitated penetration of the matrix material is made possible. In addition, a pore reduction can be achieved by the vibrated matrix.

10 to 14 refer to the synchronous injection-compression molding by means of the tool according to the invention. In this process, the injection compression tool ( 10 ) and the injection process of the matrix material begins. The high-pressure matrix penetrates into the textile inlay 3 and impregnate the filaments ( 11 ). Utilizing the contraction of the filaments, the injection compression tool is then reopened ( 12 ), but only by a small axial amount (eg 1 / 10-3 / 10 mm) and lingers in this position for a short moment, for example 1 to 5 s. The soaked textile 3 it contracts and it will be in the now subsequent phase excess matrix material injected into the tool ( 13 ) and thus reaches a melt overfilling in the tool. In the next phase, the embossing process ( 14 ). The recently injected under high pressure matrix material will now continue under increasing pressure in the fibers of the textile insert 3 crowded. The air bubbles introduced by the injection process and by the small opening phase are transported away due to the high pressure and the melt excess due to a prolonged embossing phase. The excess melt is in a Nebenkavität during the embossing process 28 collected. The excess amount is regulated by pressure. This is done via a solenoid valve 29 Access to the secondary cavity 28 released and the excess material can escape. When falling below a defined pressure, via a piezoelectric pressure sensor 30 is measured, in turn, via the solenoid valve 29 Access to the secondary cavity 28 closed. The melt excess is via a take-off device 31 from the Nebenkavität 28 discharged, crushed into granules and recycled the process or the extruder unit 7 fed again. This injection molding step makes it possible to reduce the pore content to less than 1%.

In the used "dry" textile 3 or multifunctional textile, electrically conductive wires, in particular metallic as well as carbon fiber wires, can be introduced. These then offer the possibility of health monitoring with which you can check in the "installed" state, whether a component was damaged by a crash or even destroyed.

In this application, wires with a defined resistance (eg Konstantan ^® ) and length-dependent resistance change are used. The conductors used have a defined length and a defined cross section. Depending on the "diagnostic concept", the wires are inserted unidirectionally or bidirectionally into the tissue. The diagnostic concepts differ in that either component-based (eg unidirectional) or non-contact (eg bidirectional) the component crash test is performed. If an FRP component has been deformed or even destroyed in the event of a crash, this can be diagnosed by the diagnostic system based on the resistance change (which is caused by the extension and the associated change in length of the conductor) or by the magnetic field change caused by the enlargement of the conductor loop. Thus, it can be determined quite quickly and reliably whether a FRP component is to be replaced after a crash or similar load.

The inventively integrated in the process vacuum suction is used to extract the remaining air in the tool. This serves to prevent the so-called diesel effect and a likewise improved penetration of the textile structure with the injected plastic. This is done with the vacuum pump 9 , as a rotary valve (vane), liquid ring or z. B. may be designed as a Roots, in a manner known in the art generates a negative pressure.

During this suction phase prevents a membrane 16 that the liquid plastic in the vacuum pump 9 can get. Only when reaching a defined pressure, z. B. between 0.5 and 0.9 bar, the vacuum generation is switched off. Then it is assumed that the tissue 3 sufficiently impregnated and consolidated and the possibly sprayed surfaces or matrix is / are air-free.

The mold temperature control according to the invention utilizing thermal insulation is based on the fact that a heat-insulating layer 24 is introduced into the tool. The layer 24 located on the surface of the ejector side cavity; it is made of a ceramic material (eg zirconium oxide), which prevents the heat input of the on-cast cavity from being transmitted via convection into the ejector-side cavity. As a result, the tool mass to be heated is greatly reduced, with the result that advantageously a small amount of energy for the mold temperature control is required. This lowers the process costs for the production of a semi-finished product or product. Shorter cycle times can be realized and productivity can be increased. Further, by the ceramic layer 24 avoiding contact of the textile insert with a metallic tool surface.

The angusseitige cavity is by means of a flat internal inductor 4 heated to homogeneous heat distribution in the tool, this could be in a matrix material such as polyamide z. B. 220 ° C be. In this case, the tool is brought to a basic temperature by means of an additional variothermal two-circuit tempering device. Only shortly before and during the injection molding process is by means of the inductor 4 brought the temperature at the tool surface to the melting temperature of the polymer to be processed. In the injection molding phase, the second circle of cooling is active and also heats the die-side mold half 2 at melting temperature with. Due to the induction heating and the heat-insulated ejector side very short heating cycles are possible. The angus-side cavity is cooled to the basic temperature only by means of the first circle of the temperature control in order to allow optimum molding.

This in 9 shown thermally insulated tool shows in the ejector side cavity additional cooling device 6 , which allows a quick impression and ensures an approximately constant temperature of this mold half.

Another alternative embodiment of the injection molding tool according to the invention is shown in FIG 15 and relates to the use of a spindle drive 5 as a vibration actuator 5 in order to maintain the tool cavity area or the textile insert located therein during the entire injection phase of the matrix polymer 3 to vibrate. This is the spindle drive 5 behind the ejector-side tool half 1 is positioned over one or more webs 5 '' through the ejector plate 35 through with a steel insert 5 ' connected, which is arranged in the Werkzeugkavitätbereich. There can also be the steel insert 5 ' axially in the direction of the injection device 7 '' be moved to realize a stamping process. Due to the low rotational inertia of the spindle drive provides a great deal of dynamism, which he can transfer to the sluggish injection mold. The resulting push-pull effect generates vibrations in the range of 3-20 Hz. An embossing stroke can be applied with 1-2 mm travel.

The spindle drive connected behind the tool 5 allows, on the one hand, the minimal vibrations caused by the spindle drive 5 in the steel insert 5 ' initiates the fibers of the textile insert 3 relaxed and vibrated. The resulting space is used for impregnation, whereby the frictional forces between fiber and matrix plastic melt are reduced by two-thirds or even more, so that the impregnation process is improved and closed voids between the fibers are better penetrated.

The with the help of the spindle drive 5 After the impregnation has been completed, the spray-injection step carried out comprises forming the embossing gap P by means of the spindle drive 5 coupled steel insert 5 ' in the cavity, injecting the additional matrix material into the cavity and the process of steel insert 5 ' in the direction of the injection device, whereby the material is embossed. Here can be dispensed with the opening of the tool for creating the embossing gap after impregnation of the textile insert.

Thus, the spindle drive also allows the formation of stress-free molded parts with good surface quality by the embossing following embossing during the solidification process of the melt.

LIST OF REFERENCE NUMBERS

1

Closing tool half

2

Gutter-side mold half

3

Textile / Insert / Dry Fabric / Hygienic Fabric

4, 4 '

Inductors, external inductor

5, 5 ', 5' '

Vibrating unit, spindle drive, bar, steel insert

6

Pulse cooler

7, 7 ', 7' '

Extruder unit, injection channel, injection device

8th

generator

9, 9 '

Vacuum pump, vent line

10

Pump for pulse cooling device

11

poetry

12

feed

13

extruder screw

14

extruder heating

15

pusher

16

membrane

17

Gripper (robot)

18

Locking / unlocking unit clamping frame

19

tenter

20

magnetic field line

21

paramagnetic nanoparticles

22, 22 '

Polymer composite with nanoparticles

23

infrared Heaters

24

thermal insulating layer

25

ribbing

26

needle valve nozzle

27

hydraulic actuator with displacement sensor

28

secondary cavity

29, 29 '

Solenoid valve, actuation cable

30, 30 '

Pressure sensor, measuring line

31

off device

32, 32 '

Pump for extraction device, drain line

33, 33 '

Needle valve nozzle pump, fluid line

35

ejector

a, b, c

Movement closing tool half

K, P, W

Cavity, embossing gap, heat

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006040748 A1 [0004]
• DE 102006039780 A1 [0005]

Claims (10)

Injection molding tool for the production of fiber composite plastic components from textile inserts ( 3 ) and a thermoplastic matrix material, wherein the injection mold a first tool half ( 1 ) and a second mold half ( 2 ) which are movable relative to one another and have mold regions which delimit a cavity (K), the injection mold - a vibration actuator ( 5 ), one of the tool halves ( 1 . 2 ), near the molding areas on at least one of the first and second tool halves ( 1 . 2 ) arranged inductors ( 4 ), One near the molding areas on at least one of the first and second mold halves ( 1 . 2 ) arranged tool cooling device ( 6 ) conveyed by a conveyor ( 10 ) is supplied with a cooling medium, - one on the first or the second mold half ( 1 . 2 ) arranged extruder unit ( 7 ), from which an injection channel ( 7 ' ) to at least one injection device ( 7 '' ), which is arranged for injection at the cavity (K), extends, - a vacuum pump ( 9 ), which via a vent line ( 9 ' ) is connected to the cavity (K) has. Tool according to claim 1, characterized in that the injection device ( 7 '' ) a controllable needle valve nozzle ( 26 ) provided by an actuator ( 27 ), which comprises at least one displacement sensor, wherein the actuator ( 27 ), in particular a hydraulic actuator ( 27 ), which via a fluid line ( 33 ' ) with a pumping device ( 33 ) connected is. Tool according to claim 1 or 2, characterized in that the first mold half ( 1 ) a closing tool half ( 1 ) and the second tool half ( 2 ) a die-side mold half ( 2 ), the extruder unit ( 7 ) of the casting-side mold half ( 2 ) assigned; and wherein the tool is a secondary cavity ( 28 ) for collecting a melt excess, which via a pressure-controlled valve ( 29 ) is connected to the cavity (K) connected to a pressure sensor ( 30 ), which is arranged on the cavity (K), wherein the secondary cavity ( 28 ) a trigger device ( 31 ) via a withdrawal pipe ( 32 ' ) with a conveying device ( 32 ) connected is. Tool according to at least one of claims 1 to 3, characterized in that the tool with at least one controllable gripper device ( 17 ) and a preheating device ( 4 ' . 23 ), wherein the at least one gripper device ( 17 ), - the textile inlay ( 3 ) under the preheating device ( 4 . 23 ) and place in the tool during an opening phase of the tool, or - the textile inlay ( 3 ) during an opening phase of the tool in the tool and the preheating device ( 4 ' . 23 ), in particular an external inductor device ( 4 ' ) or an infrared radiation device ( 23 ), on the textile inlaid in the tool ( 3 ). Tool according to at least one of claims 1 to 4, characterized in that the molding area of at least one of the tool halves ( 1 . 2 ), preferably the closing side mold half ( 1 ), with a heat-insulating layer ( 24 ), in particular of a ceramic material, is lined. Process for the production of fiber composite plastic components from textile inserts ( 3 ) and a thermoplastic matrix material using an injection molding tool according to at least one of claims 1 to 5, comprising the steps: - preheating the textile inserter ( 3 ) to a temperature below a melting temperature of the matrix material, - inserting the textile inserter ( 3 ) into the mold, - preforming the preheated textile inlay ( 3 ) by pressing against a cavity defining the molding area of one of the tool halves ( 1 . 2 ), - closing the tool and tempering the textile inserter ( 3 ) to a process temperature through the inductors ( 4 ), - injecting the thermoplastic matrix material into the cavity of the tool through the extruder unit ( 7 ) while keeping the process temperature, and impregnating the textile inserter ( 3 ) with the matrix material, thereby - venting the cavity by means of the vacuum pump ( 9 ), - generating vibrations of the textile inlaid inserter ( 3 ) by the vibration actuator ( 5 ), - consolidation of the fiber composite plastic component by carrying out a pulse cooling device by means of the tool cooling device ( 6 ). A method according to claim 6, characterized in that the thermoplastic matrix material nanoscale particles ( 21 ) of a ferromagnetic material. A method according to claim 6 or 7, comprising the step of injecting the thermoplastic matrix material - adjusting a movement of a melt stream of the matrix material with that through the Vibration actuator ( 5 ), wherein the matrix material melt intermittently or pulsating through the needle valve nozzles ( 26 ) is injected into the cavity (K) in a controlled manner, and wherein the generated movement of the melt stream is out of phase but rectified or simultaneous with the tool movement. Method according to at least one of claims 6 to 8, comprising the steps: after impregnation of the textile inserter ( 3 ) with the thermoplastic matrix material - opening the tool and spacing the tool halves ( 1 . 2 ) by holding an embossing nip (P) in the range of 1/10 to 3/10 mm, - keeping the tool open for a period of time in the range of 5 to 10 seconds, thereby allowing the textile insert to be impregnated and consolidated to contract ( 3 ), - injecting additional matrix material into the cavity (K), - closing the tool again and increasing the pressure on the additional matrix material, - pressure-controlled opening of the valve ( 29 ) and collecting an excess amount of the matrix material in the secondary cavity ( 28 ), and recycling the excess matrix material into the extruder unit ( 7 ). Shaped fiber composite plastic component, comprising at least one textile inlaid with a thermoplastic matrix material ( 3 ), characterized in that - the thermoplastic matrix material nanoscale particles ( 21 ) comprises a ferromagnetic material, and / or - the textile insert ( 3 ) electrically conductive wires, in particular metallic or carbon fiber wires, which have a defined length and a defined cross-section and unidirectional or bidirectional in the textile insert ( 3 ) are integrated.

Images