Plastic component and method for its manufacture

Abstract

The invention relates to a plastic component (1) formed in one piece from at least two different plastics, wherein at least a first plastic in the form of a thermoplastic with a Shore D hardness of at least 70 (according to ISO 868:2003-03) and at least a second plastic in the form of a thermoplastic elastomer with a Shore A hardness in the range of 55 to 95 (according to DIN ISO 48-4:2021-02) are joined together by additive manufacturing such that the at least one second plastic forms a rubber-like deformable second region (1b) of the plastic component (1) and the at least one first plastic forms a stiffer and less flexible first region (1a) of the plastic component (1). The invention further relates to a method for manufacturing the plastic component (1).

Description

[0001] The invention relates to a plastic component which is formed in one piece from at least two different plastics, and to a method for its manufacture.

[0002] Plastic components made from at least two different plastics are known. For example, DE 10 2020 119 413 A1 discloses a method for manufacturing a multi-component composite component with at least two plastic bodies made of different thermoplastic materials that are bonded together. The plastic bodies are joined via an adhesive interlayer made of another thermoplastic material. Injection molding, spraying, extrusion, or compression molding processes are used to manufacture the composite component.

[0003] The object of the invention is to provide a plastic component and a method for its manufacture, wherein at least two plastics with different mechanical properties are joined together directly, i.e. without using an adhesive layer for joining.

[0004] The problem is solved for the plastic component, which is formed in one piece from at least two different plastics, by combining at least one first plastic in the form of a thermoplastic plastic with a Shore D hardness of at least 70 (according to ISO 868:2003-03) and at least one second plastic in the form of a thermoplastic elastomeric plastic with a Shore A hardness in the range of 55 to 95 (according to DIN ISO 48-4:2021-02) by means of additive manufacturing in such a way that the at least one second plastic forms a rubber-like deformable second area of ​​the plastic component and the at least one first plastic forms a stiffer and less flexible first area of ​​the plastic component.

[0005] The plastic component possesses considerable flexibility in its geometry, thus enabling a wide range of applications. This allows for a mechanically strong yet low-stress connection between the first and second areas of the plastic component.

[0006] The at least one first plastic is preferably predominantly made of polyamide, in particular PA 22. PA 22 has a hardness of approximately 75 Shore B and is stiff and mechanically inflexible. Alternatively, a material marketed under the trade name Iglidur i3 with a hardness of 70 Shore B or PA 12 can be used as the first plastic.

[0007] The at least one second plastic is preferably predominantly made of a polyurethane, in particular TPU 1301. TPU 1301 has a hardness of approximately 86 Shore A and exhibits rubber-like elastic mechanical properties.

[0008] In principle, the same thermoplastic material can be used as the basis for the first plastic and the second plastic, as long as the required different Shore hardnesses and different mechanical properties are achieved through different additives and / or aggregates.

[0009] The plastic component is preferably an engine mount, a bearing component, or a robot gripper. However, other applications in the automotive or electronics industries are also conceivable. The bearing component is particularly preferably at least part of a bearing seal. In this case, the second plastic preferably forms a seal or a sealing lip assembly, and the first plastic forms a reinforcing section for the seal or the sealing lip assembly.

[0010] The problem is solved for the method of manufacturing the plastic component according to the invention by additively manufacturing the plastic component using a selective laser sintering process, wherein the at least one first plastic and the at least one second plastic are used in powder form. Selective laser sintering, abbreviated SLS, is a known process from the group of additive manufacturing processes. This enables a mechanically strong and low-stress bond between the different plastics. The plastic component thus possesses considerable flexibility in its component geometry, allowing for a multitude of applications and enabling iterative component and product development.

[0011] Preferably, a transition area between the at least one first plastic, i.e. the first area, and the at least one second plastic, i.e. the second area, is formed by a powder mixture of the at least one first plastic and the at least one second plastic.

[0012] In particular, the concentration of at least one first plastic in the powder mixture is gradually reduced from the first region of the plastic component, while the concentration of at least one second plastic in the powder mixture is gradually increased towards the second region of the plastic component. Alternatively, it has proven effective to continuously decrease the concentration of at least one first plastic in the powder mixture from the first region of the plastic component and continuously increase the concentration of at least one second plastic in the powder mixture towards the second region of the plastic component (graduation). Both methods enable a material transition between the first and second plastics, or between the first and second regions of the plastic component, in such a way that stresses are minimized and a mechanically strong bond is achieved.

[0013] The figure is intended to illustrate a plastic component and the process for its manufacture by way of example. It depicts a ring-shaped plastic component 1, shown here only in cross-sectional view, which forms a bearing component 2 in the form of a sealing arrangement for a bearing. The plastic component 1 is formed in one piece from at least two different plastics, wherein a first plastic in the form of PA 22 forms a ring-shaped rigid first region 1a as a stiffening ring 2a of the sealing arrangement. A second plastic in the form of TPU 1301 forms the rubber-like deformable second region 1b of the plastic body 1 and simultaneously a sealing lip arrangement 2b.

[0014] The ring-shaped plastic body 1 is built up layer by layer from powders of the first and second plastics using a selective laser sintering process. Starting from a platform, thin layers of powder are successively applied in the direction R (or in the opposite direction) and selectively solidified. A 3D printing device according to WO 2018 / 059 833 A1 or WO 2019 / 185 466 A1 can be advantageously used for this purpose. Different plastic powders can be arranged next to and on top of each other with pixel-level precision. In a transition zone U between the first and second plastics, a stepwise or graded, i.e., continuous, transition can be present to form a connection that is as stress-free as possible yet mechanically strong.

[0015] It should be emphasized here that the plastic component 1 shown in the figure serves only to illustrate the concept of the invention and that a large number of plastic components of various designs, made from a wide variety of plastics with an unlimited number and combination of plastic materials, can be formed, which can be used for a large number of applications. Reference symbol list 1 plastic component 1a first area 1b second area 2 Bearing component 2a Stiffening ring 2b Sealing lip arrangement R direction U transition area QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 119 413 A1

[0002] WO 2018 / 059 833 A1

[0014] WO 2019 / 185 466 A1

[0014] Cited non-patent literature

[0000] ISO 868:2003-03

[0004] DIN ISO 48-4:2021-02

[0004]

Claims

[1] Plastic component (1) which is formed in one piece from at least two different plastics, wherein at least one first plastic in the form of a thermoplastic plastic with a Shore D hardness of at least 70 (according to ISO 868:2003-03) and at least one second plastic in the form of a thermoplastic elastomeric plastic with a Shore A hardness in the range of 55 to 95 (according to DIN ISO 48-4:2021-02) are joined together by additive manufacturing in such a way that the at least one second plastic forms a rubber-like deformable second area (1b) of the plastic component (1) and the at least one first plastic forms a stiffer and less flexible first area (1a) of the plastic component (1). [2] Plastic component (1) according to claim 1, wherein the at least one first plastic is predominantly made of polyamide, in particular PA 22, or of PA 12. [3] Plastic component (1) according to claim 1 or 2, wherein the at least one second plastic is predominantly made of a polyurethane, in particular TPU 1301. [4] Plastic component (1) according to any one of claims 1 to 3, wherein it is a motor bearing or a bearing component or a robot gripper. [5] Plastic component (1) according to claim 4, wherein the bearing component is at least part of a bearing seal. [6] Method for producing a plastic component (1) according to any one of claims 1 to 5, wherein the plastic component (1) is additively produced by means of a selective laser sintering process, wherein the at least one first plastic and the at least one second plastic are used in powder form. [7] Method according to claim 6, wherein a transition zone between the at least one first plastic and the at least one second plastic is formed by a powder mixture of the at least one first plastic and the at least one second plastic. [8] Method according to claim 7, wherein the content of the at least one first plastic in the powder mixture is gradually reduced starting from the first region (1a) of the plastic component (1) and the content of the at least one second plastic in the powder mixture is gradually increased towards the second region (1b) of the plastic component (1). [9] Method according to claim 7, wherein the content of the at least one first plastic in the powder mixture is continuously reduced starting from the first region (1a) of the plastic component (1) and the content of the at least one second plastic in the powder mixture is continuously increased in the direction of the second region (1b) of the plastic component (1).

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