Method for producing a plastic component, plastic component, and use thereof

Abstract

The invention relates to a method for producing a plastic component (1) comprising at least two panel-shaped sub-bodies (2.1, 2.2, 2.3) which are arranged one over the other in a layered manner and the mutually facing faces of which have at least one respective recess (3), wherein the recesses (3) together delimit a channel (4), and each of the sub-bodies (2.1, 2.2, 2.3) is produced in a thermoplastic foam injection molding method and are subsequently connected together in a layered manner in order to form the plastic component (1).

Description

[0001] Method for producing a plastic component, plastic component and its use

[0002] Description

[0003] Technical area

[0004] The invention relates to a method for producing a plastic component, the plastic component produced by the method and its use.

[0005] State of the art

[0006] The production of plastic components is well known.

[0007] Injection molding, for example, is used to manufacture plastic components. In injection molding, the plastic is first plasticized and then injected under pressure into the cavity of the injection mold. After the material has solidified in the cavity, the injection mold is opened and the finished plastic component is removed. This process allows for large quantities to be produced cost-effectively.

[0008] However, it is important to ensure that the melt flows as laminarly as possible during injection to obtain plastic components with the most accurate dimensions. For this, and to ensure the most uniform cooling and shrinkage possible, it is crucial that the plastic components produced by this process have the most uniform wall thickness possible.

[0009] To improve the dimensional accuracy and surface quality of the plastic component, it is possible to allow material to flow into the mold cavity through a process known as post-pressing, thereby improving shrinkage and the surface quality of the plastic component. Post-pressing is an additional step and therefore lengthens and increases the cost of the manufacturing process.

[0010] A thermoplastic foam injection molding process is also known.

[0011] In this process, the plasticized plastic is foamed in the cavity of the injection mold using a blowing agent. This causes the foaming plastic to expand and reliably fill the mold cavity completely.

[0012] The advantage of this process is that sink marks are avoided and even thicker-walled molded parts can be produced. The plastic components produced using this process are also lightweight and have a low susceptibility to warping, making them particularly dimensionally stable.

[0013] Conventional re-pressing, as previously described, is not required when using this method.

[0014] Description of the invention

[0015] The invention is based on the object of demonstrating a process by which plastic components can be manufactured easily and reliably from plate-shaped parts of varying wall thicknesses with dimensionally accurate results. The plastic components should exhibit low tolerances and be particularly durable.

[0016] In addition, the use of a plastic component manufactured in this way should be mentioned.

[0017] This object is achieved according to the invention by a method according to claim 1. The claims directly or indirectly referring back to claim 1 refer to advantageous developments of the method. Furthermore, the object is achieved by a plastic component according to claim 5.

[0018] The use of such a plastic component is mentioned in claim 6.

[0019] To achieve the object, a method for producing a plastic component is provided, comprising at least two plate-shaped partial bodies which are arranged layer by layer on top of one another and each have at least one recess on their mutually facing sides, wherein the recesses together delimit a channel and wherein the partial bodies are each produced in a thermoplastic foam injection molding process and are then connected to one another layer by layer to form the plastic component.

[0020] Particularly for plastic components that are constructed layer by layer from several plate-shaped sub-assemblies, high dimensional accuracy of the sub-assemblies is particularly important. Due to the layered construction, manufacturing-related tolerances of the individual sub-assemblies add up, so the tolerances of the sub-assemblies must be very small in order to achieve a dimensionally accurate, layered plastic component. The thermoplastic foam injection molding process is well suited for this.

[0021] The greater the variation in the thickness of the individual components, the better the thermoplastic foam injection molding process is suited for producing layered plastic components. These varying thicknesses can be caused by recesses in the components. These recesses can be formed by depressions or perforations. By producing the components using the thermoplastic foam injection molding process, such varying wall thicknesses along the flow path are virtually irrelevant in the production of the components, in contrast to the manufacturing processes previously used, such as the conventional injection molding mentioned above.

[0022] The dimensionally accurate partial bodies produced by the thermoplastic foam injection molding process each have connecting surfaces that are also particularly dimensionally accurate and have a good level of flatness, whereby the connecting surfaces do not have any sink marks or defects due to the manufacturing process.

[0023] The process, particularly the simple and precise manufacture of the resulting components, provides the designer with considerable design freedom in the wall thickness of the respective parts and a free choice of injection point. Shrinkage that typically occurs in the mold cavity is automatically compensated for by foaming the material during the cooling phase, without the need for additional pressure. This results in consistent shrinkage values ​​throughout the entire part despite different wall thicknesses. The parts produced in this way and the plastic component manufactured from the stacked parts thus achieve the highest achievable precision.

[0024] The thermoplastic foam injection molding process has previously been used to achieve material savings in the component to be manufactured.

[0025] In contrast, this process has not been used to produce stack-like plastic parts comprising at least two plate-shaped sub-bodies arranged one above the other in layers and connected to one another, with the sub-bodies together defining a channel. For such plastic parts, it is necessary that the channel structures of the sub-bodies be congruent. This places high demands on the injection moldability of significant wall thickness changes within the supporting bodies and on the shape / position tolerances of the surface structures of adjacent sub-bodies in the layered structure.

[0026] Depending on the specific circumstances of the application, it may be provided that the partial bodies produced with particularly high dimension accuracy using the process described above are subjected to further processing after their production and before the layer-by-layer joining to form the plastic component.

[0027] Following their production, the components can be provided with an electrically conductive coating. Such a coating is necessary, for example, to conduct electromagnetic waves.

[0028] For this purpose, the partial bodies can be metallized after their production.

[0029] To connect the sub-bodies arranged in layers on top of each other, the metallized sub-bodies can be soldered together to form the plastic component.

[0030] The coating may be different and have special properties, such as good sealing properties, high surface quality or good wear resistance against abrasive media.

[0031] The coated partial bodies can be connected to one another in a suitable manner, for example by gluing, welding, riveting, or snap-on connections. Furthermore, the invention relates to a plastic component produced by the thermoplastic foam injection molding process described above, comprising at least two plate-shaped partial bodies arranged one above the other in layers and each having at least one recess on their mutually facing sides, wherein the recesses together define a channel.

[0032] Such a channel can be used, for example, to direct and control any media, material and energy flows.

[0033] In particular, the channel can be used to conduct electromagnetic waves. The plastic component is then designed as a waveguide antenna.

[0034] In such cases, the duct must be particularly dimensionally accurate. Even minor dimensional deviations in the mutual alignment of the facing recesses, such as a very slight offset, can cause the duct system and the associated mass and energy flows to no longer function satisfactorily.

[0035] The plastic component can thus be used as a transport and control system for material, energy and information flows, in particular as a waveguide antenna.

[0036] The plastic component can also be used as a cell element in an electrolyzer. In such a case, the plastic component has comparatively large dimensions, so high dimensional accuracy due to its manufacturing process is particularly advantageous.

[0037] The plastic component can alternatively be used as a control block for hydraulic fluids. Brief description of the drawing

[0038] Two embodiments of the plastic component according to the invention are explained in more detail below with reference to Figures 1 and 2.

[0039] These show in schematic representation:

[0040] Figure 1 shows a first embodiment of a plastic component with three plate-shaped partial bodies arranged one above the other in layers,

[0041] Figure 2 shows a second embodiment.

[0042] Implementation of the invention

[0043] Figures 1 and 2 each show a schematic representation of a plastic component 1.

[0044] In Figures 1 and 2, the plastic component 1 comprises three plate-shaped partial bodies 2.1, 2.2, 2.3, which are arranged in layers one above the other.

[0045] The partial bodies 2.1, 2.2, 2.3 not only have different overall thicknesses, but they are also designed differently, with recesses 3 of varying depths. The recesses 3 of adjacent partial bodies 2.1, 2.2; 2.2, 2.3 together form channels 4. The recesses 3 are designed as depressions or openings. Due to the differently designed and differently deep recesses, the respective partial bodies 2.1, 2.2, 2.3 have significantly different wall thicknesses along their length.

[0046] Thanks to the thermoplastic foam injection molding process, these geometrical features of the respective sub-bodies 2.1, 2.2, and 2.3 are virtually irrelevant during their production. This process allows the respective plate-shaped sub-bodies 2.1, 2.2, and 2.3 to be designed as required for their function, without having to consider specific injection molding features.

[0047] This process prevents sink marks and undesirable distortion; the parts exhibit the greatest possible precision with the smallest tolerances. This also results in particularly accurate plastic component 1.

[0048] Another advantage of the process is that it results in highly precise channel structures with surfaces that are free of sink marks and other defects typical of conventional injection molding, thus ensuring particularly low-loss transport through the channel.

[0049] In these exemplary embodiments, the partial bodies 2.1, 2.2, 2.3 are metallized with an electrically conductive coating 5. This allows the plastic component 1 to be used as a waveguide antenna, with the electromagnetic waves propagating within the channels 4.

Claims

Patent claims 1. A method for producing a plastic component (1), comprising at least two plate-shaped partial bodies (2.1, 2.2, 2.3) which are arranged one above the other in layers and each have at least one recess (3) on their mutually facing sides, wherein the recesses (3) together delimit a channel (4) and wherein the partial bodies (2.1, 2.2, 2.3) are each produced in a thermoplastic foam injection molding process and are then connected to one another in layers to form the plastic component (1).

2. Method according to claim 1, characterized in that the partial bodies (2.1, 2.2, 2.3) are provided with a coating (5) following their production.

3. Method according to claim 2, characterized in that the coating (5) is electrically conductive.

4. Method according to one of claims 1 to 3, characterized in that the partial bodies (2.1, 2.2, 2.3) are metallized following their production.

5. Method according to claim 4, characterized in that the metallized partial bodies (2.1, 2.2, 2.3) are soldered together to form the plastic component (1).

6. Plastic component, manufactured according to one of claims 1 to 5, comprising at least two plate-shaped partial bodies (2.1, 2.2, 2.3), which are arranged in layers one above the other and each have at least one recess (3) on their mutually facing sides, wherein the recesses (3) together delimit a channel (4).

7. Use of a plastic component (1) according to claim 6 as a transport and control system for material, energy and information flows.

8. Use of a plastic component (1) according to claim 7 as a waveguide antenna.

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