AT503682A2 - METHOD AND DEVICE FOR PRODUCING COATED PLASTIC MOLDED PARTS - Google Patents

Description

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The invention relates to a method for producing composite plastic molded parts with at least one coating layer of a sheet material or decorative material (films, laminates, fabrics, generally sheet-like materials) and a plastic body. The invention further relates to a device with which the method can be exercised.

Such composite plastic moldings are nowadays used for example for furniture, household appliances, etc. and in the automotive industry for interior door trim, dashboards, trunk linings, sun visors, etc. The coated surfaces of the plastic moldings form the visible surfaces in the mounted state and are designed from an aesthetic point of view, wear decorations and / or have certain surface textures such as color design, surface texture or tactile properties such as "soft touch", i. some surface compliance, often using foamed plastic materials. In the following, such coating materials including foils, foamed plastics, decorative materials, etc. are generally referred to as sheet materials. Since such web materials are often very sensitive to deformation and heat, embossing paths of up to 150 mm are used in the injection molding of web materials in an injection molding tool in order to reduce the load on the web material.

From EP-0333198 B1 and DE-19531143 C2 so-called vertical machines for the production of composite plastic moldings are known. EP-0333198 B1 describes a method for producing a composite plastic molded part, in which the web material is placed on a mold half of an opened injection molding tool and... then the mold is closed, wherein during the closing plasticized plastic mass is introduced into the mold. This method is intended to prevent the web material is damaged by the introduced plastic compound. Another way proposes the DE-19531143 C2, which also relates to a method for injection molding of plastic moldings. According to this method, the web material is placed in the open mold, the mold is closed and deforms the web material, and during the subsequent opening process plasticized plastic mass is introduced into the opening mold; after the introduction of the plasticized plastic compound, the mold is closed and the plastic compound is pressed in the mold cavity.

From DE-OS 2548318 and EP 1115547 B1 so-called "horizontal machines" for the production of composite plastic moldings are known. According to DE-OS 2548318 heated web material is introduced between the mold halves, on one of the mold halves suppressing is applied, so that the sheet material applies to the mold half inner wall, the mold is closed except for a gap, then plasticized plastic mass is increased in something like that Mold cavity injected and finally distributed by final closure of the mold in the mold cavity. According to EP 1115547 B1, a web material is inserted between the tool mold halves of an opened injection mold, the tool is closed forming the web material, a negative pressure is applied to one side of the web material and / or overpressure to the other side of the web material, so that the web material abuts a mold half hugs, and under controlled opening of the injection mold to a predetermined position dosed plasticized plastic mass is introduced into the mold cavity of the injection mold, the injection mold is completely closed and formed the composite plastic molded part and then the finished composite plastic molded part is removed from the mold.

A disadvantage of these known methods is that the cycle time is comparatively high, because the injection molding of the preformed web material can only be started when the web material is prepositioned and optionally preformed. ····· ····· # · · · · ··· ·················································································· ·· ·· · + ·· - 3 -

Proceeding from this, the object of the invention is to specify a method for producing a composite plastic molded part, subsequently coated plastic molded part, in which more composite

Plastic moldings can be produced as with the aforementioned prior art. Another object of the invention is to provide a suitable device therefor.

The solution of the first object is achieved by a method according to claim 1. The solution of the further object is achieved by a device having the features of the independent patent claim 7. Advantageous embodiments and further developments can be found in the dependent claims.

Due to the fact that the "preliminary work" and the actual molding of the plastic mass take place in separate working levels, more composite

Plastic moldings are manufactured as in the prior art, where only a single work plane is used.

Depending on which injection molding machine is used and how the process is to be optimally designed in detail, the injection of plasticized plastic material in the second working level can be more or less simultaneous to preforming the web material in the first working plane or the preforming and the injection molding can more or less proceed sequentially to each other.

Especially with sensitive web materials, the plasticized plastic mass can be injected into a vorvergrößerten mold cavity in the second working level. The plasticized plastic mass can also be introduced into mold halves opening into the mold and then pressed together with the web material when approaching.

A granular surface on the outside of the sheet material can be achieved by providing a molding surface reflecting this surface structure. This is called the in-mold graining. • · · · · · · · · · · · · · · · · · · · · · ·· ·· ···· - 4 -

The invention will be explained in more detail by means of embodiments and with reference to the figures. Show it:

A perspective view of an injection molding machine for performing the method;

2 shows a plan view of the module with the rotating device Fig.3.1. - 3.12. the course of the method according to the invention

1 shows an injection molding machine with a plasticizing and injection unit 11, fixed platen 2, a movable platen 4 and a turning plate 6. The platen carrying molds 3a, 5a and the insert 6 further molds 3b and 5b, which in the closed state with the Forming tools 3a and 5a interact and form working levels A and B. Each of these working levels is also assigned a robot 13 and 14. With the robot 13 assigned to the working level A, a decorative material can be introduced into the first working plane A and preformed there. With the work plane B associated robot 14 finished back-injected and thus coated moldings can be removed from the injection molding machine. The movable platen 4 is moved by means of spars 8, which are guided by the fixed platen 2 to the fixed platen to or from this. For this purpose, a drive 10 is provided, which may be, for example, a piston-cylinder unit, wherein the spars 8 are provided at this end with a piston which is acted upon on both sides with a pressure medium.

The entire structure of drive and platens is mounted on a module frame 20, which in turn is mounted on a machine bed 35 of the injection molding machine. FIG. 2 shows a perspective top view of details of the module frame. Accordingly, in the module frame 20, a base plate 26 slidably mounted in linear guides 22, wherein the base plate 26 can be moved via hydraulic cylinders 24 or spindles or the like in the machine longitudinal direction. The base plate 26 carries a turntable 36, on which the insert 6 can be fixed. Furthermore, the module frame on its upper side sliding guides 28 for guiding the movable platen 4. A strut 30 serves to receive the fixed platen 2 struts 32 and ···· »· ··· · · · ····························· # - 5 - 34 close the module frame to the outside and serve, for example, the support of a plate of the drive 10th

The course of the method according to the invention will be explained in more detail below with reference to FIGS. 3.1-3.12.

Figure 3.1 shows the initial situation with the closing unit open, i. the molds 3a, b and 5a, b are in the open state and the working planes A and B are freely accessible to the robots 13 and 14. In the mold half 5a are one or more compressed air channels 9 and in the mold halves 5b and 3b on the insert 6, one or more vacuum channels 12 are provided.

According to FIG. 3.2, a preferably preheated decorative material 7 is introduced into the working plane A by the robot 13 and pre-positioned there. Subsequently (FIG. 3.3), the closing unit is closed and the decorative material 7 is preformed by deep-drawing, it also being possible for punching to be carried out. The preforming may, if required, be assisted by means of compressed air via the channels 9 and / or negative pressure in the vacuum channels 12. In this thermoforming also any existing in a mold halves structure, such as a grain, on the decorative material is molded (so-called in-mold graining).

Subsequently, the mold halves 3a, b and 5a, b are moved apart (Fig. 3.4) and subsequently the insert 6 rotated by 180 ° about the vertical axis (Fig. 3.5), so that now the preformed decorative material 7 'is in the working plane B. , In work plane A, a new decorative material 7 is now positioned (FIG. 3.6). Subsequently, the closing unit is closed (Fig. 3.7), wherein the new decorative material is preformed in the working plane A, optionally with the addition of compressed air in the channels 9 and / or suppression in the channels 12th

In the subsequent cycle section (FIG. 3.8), the working plane B is raised and plastic melt is injected into the opening mold on the preformed decorative material 7 '. From a predeterminable opening travel, the opening movement is stopped and the mold is closed again, the melt being distributed in the cavity and the composite plastic molded part being shaped (Fig. 3.9). After a predeterminable cooling time, the mold halves are moved apart again (FIG. 3.10); now located on the insert 6 on the one hand, a finished composite plastic molded part 17 (in the mold half 5b) and on the other hand, a preformed decorative material 7 '(in the mold half 3b). Now (Figure 3.11), the finished composite plastic molding 17 may be removed from the working plane B by the robot 14 and the insert 6 may be rotated 180 ° again so that the cycle can begin again from the beginning, i.e., at the end. in the working level A, a new decorative material 7 is provided and the previously preformed decorative material is located in the working plane B, where it can be back-injected with plastic melt as described above.

Claims (7)

Patent Attorneys Dipl.-Ing. Helmut Hübscher Dipl.-Ing. Karl Winfried Hellmlch Spittelwiese 7, A-4020 Linz, Germany • · · · · · · · · · · · · · · · · · · · · · · · · · ······································································· A method for producing a composite plastic molded part from at least one layer of a web material and a plastic body having at least four tool mold halves, wherein between each two mold halves a working plane is formed, comprising the steps: a) Inserting a web material between the tool mold halves in the first work plane, b) moving the mold halves of the first work plane deforming the web material, c) opening the tool mold halves of the first work plane, d) placing the preformed web material in the second work plane, e) molding plasticized plastic mass in the second working plane to the sheet material preformed in the first working plane, f) removal of the composite plastic molded part , 2. The method according to claim 1, characterized in that the injection molding of plasticized plastic material in the second working plane takes place simultaneously or sequentially for preforming of the web material in the first working plane. 3. The method according to claim 1 or 2, characterized in that in step e) the plasticized plastic mass is introduced into a vorvergrößerten mold cavity and the tool mold halves are fed in after or before the completion of the introduction. 4. The method according to claim 1 or 2, characterized in that in step e) the mold halves are first fed, that the plasticized plastic material is introduced into the mold halves opening and that the mold halves are retracted before or after the end of the introduction of the plastic material , I • · »· · 2 2 2 2 2 2 2 2 2. 2 5. The method according to any one of claims 1 to 4, characterized in that in step b) on the outside of the web material, a surface structure is generated by a surface surface pattern image forming surface is provided. 6. The method according to any one of claims 1 to 5, characterized in that in step b) the web material is subjected to compressed air and / or negative pressure. 7. Injection molding machine for carrying out the method according to one of claims 1 to 6, comprising a clamping unit, which has a first tool clamping plate and a second tool clamping plate and an intermediate and rotatable about a vertical axis of rotation center plate (insert), so that two working planes (A, B) are formed, with a device for introducing and positioning web material in the first working plane (A), with a plasticizing unit for plasticizing and injecting plastic material in the second working plane (B), as well as means for rotating the insert. Injection molding machine according to claim 7, characterized in that a fixed and a movable platen are provided and that the insert is displaceable in the direction of the machine longitudinal axis, wherein the insert and the movable platen are independently displaceable, so that in a working plane an injection-compression molding process can be performed. Linz, May 25, 2007 Krauss-Maffei Plaids