DE4224889A1 - Prodn. of thermoplastic component with cheap tools - by depositing e.g. several coatings of polymer powder including blowing agent on core tool and blowing prod. off core inside blow mould. - Google Patents

Abstract

A plastic component (or part of one) is produced by causing a liquid or (pref) powdered polymer to adhere to a heated core tool and solidify to form a sealed by sufficiently elastic layer; this is then blown off the core in an outer mould so as to give it the required shape and surface texture. ADVANTAGE - The method is inexpensive and produces single to multi-layer constructions. It uses cheap tools. The products are readily released from the tool without any further operations and have a good finish. In an example, of the process produce components for car interiors. To make a laminate type a core is first heated and exposed to a thermoplastic powder which forms a coating on it. This is heated to plasticate it and a second layer of a thermoplastic resin plus blowing agent is similarly deposited on top. This is heated to plasticate it and activate the blowing agent and a third powder is similarly applied as a decorative layer. The product is blow moulded to shape, with its inner tool (1), foam (2), decorative layer (3) and grain (4) in the finish. The complete layer is blown off the tool and cooled in the mould.

Description

The invention relates to a method for manufacturing of a component or part of a component made of plastic.

The object of the invention is the production of a component or of components of a component in a sequence of processes made of plastic, being an inexpensive manufacture a multi-layer or single-layer component construction is possible, only low tool costs required are and mold separations without rework in sufficient surface quality on the component they are. With the procedure in sequence, So essentially in one production step, one term or multilayer components manufactured inexpensively can be.

The invention provides a method of manufacturing a Component or part of a component made of plastic before, liquid or on a heated core preferably powdered plastic material for adhesion brought and then solidified to a  closed, sufficiently stretchable layer arise to let that in a row from core to core the surrounding shape is blown off, thereby removing the contour form and surface structure.

The invention is a method in liquid or preferably powdered on a core plastic material is adhered to. This material is then solidified so that a closed, sufficiently stretchable layer is created, which are subsequently blown off from the core into a mold and thus the contouring and surface structure takes shape.

The layer is further solidified in the form that after the demolding of the layer from the mold usable part is available.

A multilayer structure is created by multiple Coating the core one after the other, usually a respective first consolidation in sequence is carried out. Then the whole Layer structure is blown off the core into the mold and receives its final strength and shape there as well Surface structure.

The materials preferably consist of thermoplastic Plastics. However, layers of other can also be used Material such as B. glass fibers, minerals, etc. and foamable plastics or the like are used. As well there is the possibility of other process steps in the Integrate process sequence, such as. B. foaming processes.  

It is also possible to shape other elements insert which when blowing off the layer or the Layer structure in the form connected to the layer and a separate later assembly is not necessary.

This is also a new type of coating for components an application of the method described. (e.g. back Coating of textiles or leather also in the ready-made Condition, e.g. B. for equipment for later rear foaming) enables.

According to the method described here, it is also possible to produce multicolored surfaces. For more complex geometries of the component can be on the visible side of the component related mold separation may be required. The resulting resulting mold parting edges on the component do not require any further rework, since the tools are well coordinated is possible, the internal pressure (blowing pressure) comparatively is low and therefore no material leakage is to be expected.

This process therefore creates, not like with Blow molding due to certain geometries of the hose on the mold separation (outer hose), which need rework and z. T. not acceptable on the component are.

It is also the process application as another use possibility provided after blowing off a layer as z. B. Decorative layer in the form of a direct rear foaming, rear injection, rear pressing or similar.

Another important aspect is the material-saving use. So z. B. frame-shaped parts without the Zwischenbe rich to be coated with feed.  

The weight of the components is low because of the very thin wall thickness can be put. Compared to decorative skins that are in powder Slush processes are also produced by the method described Process fulfills the task of producing pore-free surfaces.

In the described method, the individual steps run in sequence. Therefore, there is the possibility of continuously clocking the process steps in terms of system engineering, and thus achieving a cycle time similar to the injection molding or blow molding process when using multiple cores.
Components: e.g. B. trim parts or elements of trim parts for motor vehicles,
single-layer: e.g. B. air duct, support elements (flat), decorative skins, etc.,
multilayer: z. B. panel covers, door panels, handles, pillar panels, glove box covers, sun visors, etc.

By way of example, a possible process sequence for a multi-layer structure of a component is now to be described with reference to the drawing with FIGS. 1 to 8.

Fig. 1 shows a first heating station for heating a mold core.

Fig. 2 shows a first powder station for powdering a first hermoplastic plastic as a later carrier material.

Fig. 3 shows a second heating station for the plasticization of the first powder material.

Fig. 4 shows a second powder station for powdering a second thermoplastic with blowing agent components.

Fig. 5 shows a third heating station for plasticizing the second powder material, and to activate the intumescence.

Fig. 6 shows a third station for powder Anpulvern of a third thermoplastic resin as a later decorative layer.

Fig. 7 shows a fourth heating station for plasticizing the third powder material.

Fig. 8 shows a blowing station 5 and reveals carrier 1 Foam 2, 3 and decorative scar. 4 Process steps are provided here: inserting them into the blow mold, blowing off the layers from the core, cooling the layers in the mold and demolding the finished component.

Claims (1)

Method of manufacturing a component or part a component made of plastic, which is heated on a Liquid or preferably powdered plastic core material adhered and then solidified is a closed, sufficiently stretchable layer to be created, which in succession from the core into one the mold surrounding the core is blown off in order to Contouring and surface structure of the shape.