Molded part with front and back PUR layer and method for its manufacture

Abstract

Molded part (100), comprising - an injection-molded base body (110) with a front (111) and a back (112) made of a translucent plastic material; - a front transparent PUR layer (120) applied to the front (111) of the base body (110) and produced by flooding the front (111) with a transparent PUR; - a rear colored PUR layer (130) applied to the back (112) of the base body (110) and produced by flooding the back (112) with a colored PUR; wherein the front transparent PUR layer (120) and the rear colored PUR layer (130) are bonded tightly and seamlessly together along a circumferential seam line, so that the front transparent PUR layer (120) and the rear colored PUR layer (130) tightly enclose the base body (110).

Description

[0001] The invention relates to a molded part, which is intended in particular as a decorative component for a motor vehicle. The invention further relates to a comparatively simple method for manufacturing such a molded part.

[0002] DE 10 2015 101 013 A1 describes a molded part, designed in particular as a decorative and / or trim part for a vehicle interior. The molded part comprises a decorative layer formed from a plastic film, to the back of which a carrier is arranged, in particular injection-molded. The plastic film is preferably transparent or translucent and has at least one opaque printed layer with at least one recess for light transmission. The plastic film is coated on the front side with a transparent or translucent protective and / or optical layer, which consists, for example, of polyurethane (PUR). The protective and / or optical layer is applied in particular by spray painting, injection molding, or RIM technology. A molded part of a similar type and a method for manufacturing the molded part are known from DE 10 2021 116 784 A1.

[0003] Based on this, the invention aims to provide a molded part that appears to be of particularly high quality and is comparatively easy to manufacture.

[0004] The problem is solved by the molded part according to the invention with the features of claim 1. By dependent claim 8, the invention also extends to a method for manufacturing such a molded part. Advantageous further developments and embodiments of the invention are described analogously for both subject matters of the invention in dependent claims 2 to 7 and 9, respectively, the following description of the invention (which expressly includes optional and exemplary features), and the figure.

[0005] The molded part according to the invention comprises or has: - an injection-molded base body with a front side which also forms the visible side of the molded part and a back side, wherein the base body is made of a translucent plastic material; - a transparent front PUR (polyurethane) layer applied to the front of the base body; - a rear colored PUR layer (polyurethane layer) applied to the back of the base body.

[0006] The molded part according to the invention has a spatial shape defined by the base body. The base body is preferably designed as a flat base body and preferably has a thickness of 2.5 mm to 4.0 mm, which refers to the thickness between the front and back surfaces. The front surface can be flat or curved, and in particular, also multiply curved.

[0007] The injection-molded base body is made of a light-transmitting, i.e., transparent, in particular clear, or at least translucent, plastic material. Preferably, the base body is made of a (light-transmitting) thermoplastic material, e.g., polycarbonate (PC). Due to its injection-molded base body, the molded part according to the invention can also be referred to as an injection-molded component.

[0008] The front PUR layer applied to the front of the base body is transparent, meaning that it is clear or, optionally, tinted, particularly only slightly tinted. The back PUR layer applied to the back of the base body is colored, particularly such that it is opaque. Preferably, both the front and back PUR layers are applied to the base body over its entire surface or at least substantially over its entire surface, with the back PUR layer also having recesses (su). The front PUR layer can have a thickness of 0.3 mm to 1.0 mm. The back PUR layer can have a thickness of 0.3 mm to 0.8 mm. Equivalently, polyurea (PUA) can be used instead of polyurethane (PUR) for both the front and back layers.

[0009] The molded part according to the invention can be manufactured relatively easily and cost-effectively, as explained in more detail below. In particular, painting and / or printing processes for applying a layer of paint or varnish are not required.

[0010] Preferably, the front transparent PUR layer and the rear colored PUR layer are bonded together along a seam line, in particular a circumferential seam line running around the base body, in a material-bonded and preferably also tightly sealed, i.e., moisture- and dirt-tight, manner. In particular, it is provided that the front transparent PUR layer and the rear colored PUR layer tightly enclose the base body, i.e., the base body is completely surrounded or encased in PUR. This particularly improves weather resistance.

[0011] Indentations can be arranged on the back of the base, referring specifically to indentations molded into the base (towards the front). These indentations can form a pattern, lettering, a logo, or the like. Alternatively, there can be only a single indentation, for example, forming a line or lettering. The indentations create a particularly high-quality, under-glass 3D effect.

[0012] The colored PUR backing layer can be thinner in the recesses, meaning that the PUR backing layer has a reduced thickness in these recesses, specifically by 0.1 mm to 0.2 mm. Alternatively, the colored PUR backing layer can be omitted in the recesses, meaning that no PUR layer is applied in these areas. This local thinning or omission allows for a particularly high-quality backlighting of the molded part in the recesses, creating a so-called "no-show" effect.

[0013] The molded part according to the invention is, in particular, a decorative component for a motor vehicle, and can be either an interior or an exterior component. An interior component is, for example, a decorative trim panel. An exterior component is, for example, a radiator grille-like front panel.

[0014] The manufacturing process according to the invention comprises the following steps: - Manufacturing or producing the base body by injection molding a translucent plastic material, whereby the recesses on the back, if required, can also be produced; - Flooding the front of the base body with a transparent PUR, thereby creating the front transparent PUR layer; - Flooding the back of the base body with a colored PUR, thereby creating the rear colored PUR layer, optionally with local thinning or recessing in the depressions.

[0015] When flooding the front surface, a circumferential PUR edge (made of transparent PUR) is preferably created. During the subsequent flooding of the back surface, the colored PUR can bond with the transparent PUR along this edge, forming a circumferential and, in particular, tight seam. The flooding of the front surface and the flooding of the back surface can also be carried out in reverse order, with the aforementioned order being preferred. The inventive method is also suitable for series production, especially when using a 3-component injection mold (su). The PUR materials used (or alternatively PUA materials) are preferably very low in viscosity and, in particular, have a reaction or curing time of less than one second, enabling short cycle times.

[0016] The method according to the invention, or the aforementioned steps, are preferably carried out in a 3-component injection mold, which in particular has a front slide and a rear slide. The method according to the invention may then further comprise the following steps: - Providing the 3-component injection mold (as a preceding first step); and - Removing the manufactured and appropriately shaped part from the 3-component injection mold (as the final step).

[0017] The 3-component injection mold can have interchangeable inserts (so-called interchangeable inserts) that allow for the production of different molded part variants. These inserts can be replaced relatively quickly and easily for variant changes.

[0018] Within the scope of the invention, both the features described above and those explained below are applicable not only in the specified combination of features, but also in other combinations or individually. This also applies to the features shown in the figure.

[0019] The invention is explained in more detail below in a non-limiting manner with reference to a figure. The features shown in the figure and / or explained below can, even independently of specific combinations of features, be general features of the invention and further develop the invention accordingly. Fig. Figure 1 shows a molded part according to the invention in a schematic (not to scale) sectional view

[0020] The molded part 100 has an injection-molded, flat base body 110 made of a translucent plastic material. The base body 110 is formed with a front surface 111 and a back surface 112. Recesses 113 are arranged in the back surface 112. A transparent front PUR layer 120 is applied to the front surface 111 of the base body 110. A colored rear PUR layer 130 is applied to the back surface 112 of the base body 110. In the recesses 113, the rear PUR layer 130 is thinner or, if necessary, omitted. The front PUR layer 120 and the rear PUR layer 130 are bonded together along a circumferential seam 140 in a material-bonded and tight manner.

[0021] Further designs and variants of molded part 100 are described above. A manufacturing process for molded part 100 is also explained above.

Claims

[1] Molded part (100), comprising - an injection-molded base body (110) with a front (111) and a back (112) made of a translucent plastic material; - a front transparent PUR layer (120) applied to the front (111) of the base body (110) and produced by flooding the front (111) with a transparent PUR; - a rear colored PUR layer (130) applied to the back (112) of the base body (110) and produced by flooding the back (112) with a colored PUR; wherein the front transparent PUR layer (120) and the rear colored PUR layer (130) are bonded tightly and seamlessly together along a circumferential seam line, so that the front transparent PUR layer (120) and the rear colored PUR layer (130) tightly enclose the base body (110). [2] Molded part (100) according to claim 1, characterized by, that recesses (113) are arranged on the back (112) of the base body (110). [3] Molded part (100) according to claim 2, characterized by , that the rear colored PUR layer (130) is thinner in the recesses (113). [4] Molded part (100) according to any one of the preceding claims, characterized by , that the base body (110) is made of polycarbonate. [5] Molded part (100) according to any one of the preceding claims, characterized by , that the base body (110) has a thickness between 2.5 mm and 4.0 mm. [6] Molded part (100) according to any one of the preceding claims 1 to 5, characterized by , that this molded part (100) is an interior component for a motor vehicle. [7] Molded part (100) according to any one of the preceding claims 1 to 5, characterized by , that this molded part (100) is an exterior component for a motor vehicle. [8] Method for producing a molded part (100) according to any one of claims 1 to 7, comprising the steps: - Manufacturing the base body (110) by injection molding; - Flooding the front (111) of the base body (110) with a transparent PUR, creating a circumferential PUR edge from the transparent PUR; - Flooding the back side (112) of the base body (110) with a colored PUR, whereby the colored PUR bonds to the transparent PUR along the PUR edge, forming a continuous and tight seam. [9] Method according to claim 8, characterized by that the steps are performed in a 3-component injection mold.

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