Injection molding manufacturing of parts

Abstract

To provide a method for injection molding translucent plastic parts that enables automated production and yields extremely precise results. [Solution] The present invention provides a method for manufacturing a part 500 having a front surface with n raised contours and a back surface covered with a colored film 40. An injection molding tool 100 is provided, comprising a first tool part 10 and a second tool part 20 surrounding a cavity 30 having the contours of the part. The surface of the first tool part represents the negative of the front surface of the part and has n recesses corresponding to the n contours 51 of the part. The surface of the second tool part represents the negative of the back surface of the part. The film 40 is positioned on the surface of the second tool part. After the plasticizing plastic 50 injected into the cavity has cured, the part with the film is demolded. When positioning the film, n raised portions 21 provided on the surface of the second tool part engage with n notches 43 provided in the film.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing translucent plastic parts, an injection molding tool suitable for manufacturing such parts, and injection molded parts.

Background Art

[0002] Injection molding methods for manufacturing parts made of thermoplastic or thermosetting plastics have long been known. In this case, usually each plastic is liquefied and injected into a mold formed by each injection molding tool. By cooling and / or crosslinking, the plastic transitions back to a solid state and, after opening the tool, can be removed as a finished part or demolded. The shape of the parts thus manufactured is predetermined by the shape of the injection molding tool. In this case, the cavity of the tool determines the shape and surface structure of the finished part. In this case, the cavity is usually defined by two or, in some cases, more tool parts, which are combined to form the cavity.

[0003] Combining such injection molding with film application onto parts is already known. For example, WO 93 / 04837 Al describes a method of fixing and sandwiching an embossing film between two tool halves of an injection molding tool. Through a sprue passage formed in one of the tool halves, the plastic material is injected into the cavity in the mold, and this material then cures while forming a plastic article decorated with the decoration of the stamping film and can be removed from the mold.

[0004] European Patent Publication 1 902 902 Al describes a covering member for an opening in a vehicle, the covering member having at least a partially metallized film. The film has a first plastic layer overmolded on its front side. On its rear side, the film has a second plastic covering layer injection-molded at the rear. This component, formed as a covering member, can be provided to cover a vehicle distance sensor. Furthermore, this covering member can also be formed as an emblem.

[0005] When manufacturing interior trim parts (covering panels) in automobiles that include emblems or other decorative elements, for example, transparent plastic parts can be manufactured with a color design on the back side. For this purpose, a colored film, such as a lacquer film or transfer lacquer film, can be placed on the back side of the part, and this film is applied in a manner similar to that described above during the injection molding process of the part.

[0006] In particular, the decorative structure may be a raised contour on the front side, which protrudes from the front surface of the part and thus can form the three-dimensional contour of the part.

[0007] Special visual effects can be achieved when the decorative components of a part do not have a colored layer on the back side, and as a result these areas are transparent and can be illuminated from the back. Particularly attractive effects are obtained, for example, when the surface of the decorative part is provided with a chrome layer or other opaque layer, so that the decorative part, formed as a protruding contour, is illuminated from the side by rear lighting.

[0008] For example, to manufacture such a part that allows illumination of raised contour areas, the color design on the back of the part should be matched as precisely as possible. When applying a color design to the back of the part using a colored film, such as a lacquer film or lacquer transfer film, the areas on the back of the part that correspond to the raised contour areas on the front of the part should be precisely free of color coating. In principle, this can be achieved by first covering the back of the part with a colored film during the injection molding process, and then cutting or laser-cutting the corresponding areas on the back of the part, thereby allowing the colored film or colored layer to be removed at a later stage. However, this additional step can be very costly in practice and may not lead to satisfactory results, especially if the cutting is not precise enough.

[0009] Having the colored film support layer on the outer surface side of the inside of the component, and remaining there, is advantageous for the component to be manufactured because it allows for better color design and simultaneously protects the subsequent colored layer. However, in this case, since the colored film support layer must also be cut away in addition to the colored layer, partial cutting or laser cutting at a later stage becomes more difficult. A satisfactory solution for this process that enables automated production on the one hand and yields very precise results on the other hand has not yet been proposed. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] International Publication No. 93 / 04837 Al [Patent Document 2] European Patent Publication No. 1 902 902 Al [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] In contrast, the object of the present invention is to provide a method for injection molding a translucent plastic part having contours, particularly protruding or raised contours, such as decorative contours, on the front side, and a portion of the rear side covered with a colored film for color design. The rear side of the part opposite to the front side area having n contours should not be covered with a colored film or have no color design. This method enables simple, reliable, and automatable manufacturing on the one hand, and achieves very precise results on the other hand, in which the color design on the rear side of the part is fitted to perfectly match the contours on the front side of the part. [Means for solving the problem]

[0012] This problem is solved by a method for manufacturing translucent plastic parts, as is evident from claim 1. Furthermore, this problem is solved by an injection molding tool for manufacturing plastic parts and injection-molded parts, as shown in further independent claims. Preferred configurations of this method, injection molding tool and injection-molded parts are evident from dependent claims.

[0013] The present invention provides for manufacturing a translucent plastic component having a front surface with n contours, particularly n raised contours, and a back surface covered with a colored film. The n contours may be decorative contours, such as one or more emblems or star-shaped protrusions, which create a three-dimensional impression.

[0014] The method according to the present invention first involves steps a to d, which are described in detail below. a. A step of providing an injection molding tool comprising a first tool component and a second tool component, wherein the first tool component and the second tool component together surround a cavity having the contour of the part to be manufactured when the tool is closed. The surface of the first tool part represents the negative of the front surface of the part and has n structural parts, in particular n recesses, corresponding to n contours. • The surface of the second tool part represents the negative of the back of the part. The process of providing, b. A step of positioning the film on the surface of the second tool component, c. The process of closing the injection molding tool and injecting plasticizer into the cavity, d. A step of demolding the part with the film attached after the plasticizer has hardened, It is characterized by the following.

[0015] Furthermore, the method according to the present invention has the following features e and f, e. Provide n raised areas on the surface of the second tool component. f. Before the positioning process described above, the film is provided with n notches, so that when the film is positioned, the n raised portions on the surface of the second tool component engage with the n notches in the film. It is characterized by the following.

[0016] This method achieves highly precise and accurate application of a colored film to the back side of a part during the injection molding process, where the colored film already has notches before being inserted into the injection molding tool, and these notches correspond to the n contoured areas on the front side of the part. Therefore, the corresponding areas on the back side of the part remain without colored film, and as a result, the color design using the colored film on the opposing back side of the part is only relevant to the areas outside the n contours. In this proposed method, the n ridges on the surface of the second tool part ensure accurate and precise positioning of the film when it is inserted into the injection molding tool. The n ridges on the surface of the second tool part engage with the n notches in the film, acting as, so to speak, hooks or positioning aids for the film. This allows the film to be placed perfectly and precisely in the desired position on the surface of the second tool part. Film slippage during the subsequent injection molding process is reliably avoided. Overall, this proposed method makes film positioning significantly easier, enabling the production of parts in which the colored film is precisely positioned and the notches in the film are precisely aligned with the n contours on the front side of the part. In this process, the n protrusions on the surface of the second tool part work in conjunction with the n precisely aligned notches in the film to serve two functions. On the one hand, the film is fixed in the injection molding tool. On the other hand, the precisely aligned notches in the film simultaneously achieve the desired color design.

[0017] Particularly preferred, the method according to the present invention has the following additional features a to c with respect to the surface configuration of the first tool part and the second tool part. a. After closing the tool, the n structural parts on the surface of the first tool part and the n protrusions on the surface of the second tool part are positioned in the cavity such that each of the n structural parts faces one of the n protrusions. b. Among the parts that have been demolded, the n cutouts of the film overlap with one of the n contours in a viewing direction perpendicular to the front and / or back surface of the part, such that the n structural parts in the surface of the first tool part and the n raised parts on the surface of the second tool part are positioned. c. The n cutouts of the film and the n contours on the front side of the part have the same outer shape in a viewing direction perpendicular to the front and / or back surface of the part. It is characterized by at least one of the above.

[0018] Preferably, the aforementioned features a and b, or a and c, or b and c, particularly preferably a, b, and c are all realized.

Advantages of the Invention

[0019] Particularly, with respect to the viewing direction perpendicular to the front and / or back surface of the part to be manufactured, in a closed injection molding tool, by accurately aligning or precisely opposing the n structural parts in the surface of the first tool part and the n raised parts on the surface of the second tool part to each other, very precise positioning of the colored film on the surface of the second tool part with respect to the n contours on the front side of the part to be manufactured is achieved. Particularly, in the application of the part to be manufactured that is illuminated through the area of the n contours or in some cases the edge area of the n contours on the part, in the area of the n cutouts of the film on the back side of the part, the light radiated vertically into the part can exit the part or illuminate this contour accurately in the area of the corresponding n contours on the front side of the part. Therefore, by these measures, a visually particularly attractive effect can be achieved in the part to be manufactured.

[0020] Preferably, the shape of the n cutouts of the colored film coincides with the shape of the n contours on the front side of the part. This shape may be, for example, a star shape, other decorative shapes, or an emblem, etc.

[0021] The translucent plastic used to manufacture the parts may be a conventional thermoplastic used in the corresponding parts, or it may be a thermosetting plastic, particularly a plastic used in the automotive sector. Polymethyl methacrylate (PMMA), polycarbonate (PC), polyamide (PA), such as PA12, or blends of such plastics are particularly suitable.

[0022] Preferably, the plastic does not contain pigments or other components that adversely affect the light transmittance of the plastic. It is particularly preferable that the plastic be transparent in its cured state.

[0023] Furthermore, it is preferable that this plastic, in its cured state, does not contain crystalline regions that may cause undesirable light refraction.

[0024] In a particularly preferred configuration of the method according to the present invention, the method has the following additional features a or b: a. The n protrusions on the surface of the second tool component are formed to be retractable. b. Before the demolding process of the part, particularly during the injection process of the plasticizer, the n protrusions of the second tool part are indented, and in particular, the surface of the second tool part is made completely flat in the area of ​​the indented protrusions. The system features at least one of the above, and it is particularly preferable that both features a and b are realized.

[0025] Therefore, with this configuration of the present method, it is possible to optionally insert n ridges on the surface of the second part into the tool during injection molding in order to obtain a smooth back surface of the part.

[0026] In this configuration of the method, first, a colored film with notches is precisely positioned on the surface of a second tool part and remains in place during the injection of the plasticizer. The n ridges have already receded during injection, resulting in the back of the part forming a substantially flat surface.

[0027] Furthermore, the indentation of the n protrusions on the surface of the second tool component facilitates the subsequent demolding of the component from the injection molding tool.

[0028] The film may be, for example, a thermoplastic film, which is colored using organic dyes, or organic and / or inorganic pigments. The colored film is then preferably composed of a single layer and preferably has a thickness in the range of 50 μm to 1500 μm. However, there are also preferred embodiments in which the colored film is formed of at least two layers.

[0029] Therefore, in a particularly preferred configuration, the method according to the present invention relating to a colored film has the following additional features a or b: a. The film is a lacquer film or a transfer lacquer film, and has a lacquer layer on a carrier layer. b. The lacquer film or transfer lacquer film is positioned so that the carrier layer is first positioned on the surface of the second tool portion. It is characterized by at least one of the above, and in this case, a combination of both characteristics is particularly preferred.

[0030] In these configurations, a carrier that does not necessarily need to be colored forms the first layer, and a lacquer layer forms the second layer of the colored film.

[0031] Generally, color design of parts using colored films offers special advantages in manufacturing. In particular, uniform color application can be achieved at low cost with consistently good quality. The use of transfer lacquer films and lacquer films is already well known, and both comprise a carrier layer or carrier film and a colored layer, especially a lacquer layer. The difference between transfer lacquer films and lacquer films is that the carrier, especially the carrier layer or carrier film, is removed after the color is applied. In the case of lacquer films, the carrier layer or carrier film remains on the part, more specifically on the back of the part, even after the injection molding process.

[0032] By first placing the lacquer film with a carrier layer on the surface of the second tool part, the finished part achieves a configuration where the lacquer layer is present first on the back side of the part, followed by the carrier layer. This provides special protection for the lacquer layer, as it is protected by the carrier layer on the rear-outward side of the part. Furthermore, placing the lacquer layer between the plastic part or transparent injection-molded material and the carrier film is advantageous for achieving visually optimal results.

[0033] In a preferred configuration, the lacquer layer may include a matrix consisting of a conventional coloring pigment and a conventional binder. The coloring pigment may be any organic and / or inorganic pigment commonly used as automotive lacquer.

[0034] In a particularly preferred configuration, the coloring of the lacquer layer, and therefore the color design of the part to be manufactured, is further matched to the color design of the surrounding area of ​​the part to be installed, for example, the vehicle color of each vehicle body on which the part will be used.

[0035] In a preferred embodiment, a lacquer layer can be used to coat the back side of a component with an opaque layer that blocks light in the visible wavelength range. This allows the component, which is otherwise made of transparent plastic, to appear in a corresponding color due to the color design of the back side using a colored film.

[0036] The translucent plastic allows for the formation of transparent components within the substrate, which also offers the special advantage of allowing illumination through areas without colored film.

[0037] Furthermore, by forming the components transparently within the substrate, there is the advantage that the same component can be used for vehicle bodies of different car colors, except for the selection of each colored film.

[0038] The colored film may be manufactured, for example, as a web-like product and wound in a roll, and can be appropriately cut before being inserted into an injection molding tool. The n notches in the colored film can be cut out, for example, by punching or laser cutting.

[0039] The support for the lacquer film or transfer lacquer film may be a plastic film commonly used for this type of purpose, with a uniform thickness, for example, in the range of 10 to 300 μm, particularly in the range of 100 to 150 μm, for example, 120 μm. In this case, the support layer can be formed from non-polar plastics, such as polypropylenes or phenolic resins.

[0040] The lacquer layer on the carrier preferably has a uniform thickness, for example, in the range of 10 μm to 150 μm, preferably 10 μm to 100 μm, and particularly preferably 10 μm to 50 μm. For example, this thickness may be in the range of 15 μm to 20 μm. The lacquer layer can be made, for example, from a plastic dispersion base, and can be made using polyurethane, polyethylene and / or polycarbonate in particular.

[0041] For the purpose, the colored film used, and in particular the pigment-colored layer or lacquer layer of the colored film, should be compatible with each transparent injection-molded plastic used.

[0042] The lacquer layer on the carrier is preferably already cured. Preferably, it is not necessary to perform a separate process such as UV irradiation to crosslink the uncrosslinked lacquer components.

[0043] However, in order to improve the adhesion of the plasticizer injected onto the film, it is also possible to provide a colored film positioned on the surface of a second tool part, coated with an adhesion promoter. This adhesion promoter can be configured, for example, to be UV-curable and / or thermosetting.

[0044] In the method according to the present invention, a colored film, particularly one formed as a lacquer film comprising a lacquer layer on a carrier layer, is placed on the surface of a second tool part representing the negative of the back of the part during the injection molding process. In some particularly preferred embodiments, the carrier layer of the lacquer film remains on the part. To obtain a visually valuable appearance, it is desirable to place the lacquer layer between the transparent injection molding material and the carrier layer. In the process according to the present invention, the colored film, particularly a lacquer film or transfer lacquer film including a carrier, is already completely cut out in corresponding areas before injection molding, for example, by laser or punching. To precisely position the areas to be cut out in the injection molding tool, the present invention provides the aforementioned raised portions in the second tool portion, which function as positioning aids and engage with the cutouts in the colored film. These raised portions preferably precisely correspond to the outline of the front side of the part to be manufactured. The cutouts in the flat film are formed accordingly, and as a result, precise color design of the back surface of the part with the cutout becomes possible in the area facing the contour of the front side of the part.

[0045] Therefore, preferably, the pigment-colored layer of the colored film, particularly the colored lacquer layer, is directly overmolded with a transparent thermoplastic, in which case the contour region is already a cutout in the colored film before the injection molding process.

[0046] A particularly preferred configuration of the method according to the present invention includes the following additional features: a. At least one light source shall be assigned to the back of the component. A system is in place.

[0047] A particularly attractive visual effect can be achieved by illuminating the parts to be manufactured from the rear. In particular, in this regard, special shapes can be provided on the surfaces of n raised contours, especially on the n raised contours on the front side of the part, for example by chrome plating or other opaque lacquer coating, so that the outlines of the n contours can be illuminated by rear lighting.

[0048] A more preferred configuration of the method according to the present invention includes the following additional features a to d with respect to the configuration of the part to be manufactured: a. The part is an interior trim part for the vehicle body. b. The part is a covering panel for the vehicle body. c. Except for the area with n contours on the front side, the part shall have a substantially uniform thickness. d. Except for the area on the front side that has n contours, the front and back surfaces of the part are substantially parallel to each other. At least one of these is provided.

[0049] In particular, features a and b, and features c and d, described above, are implemented in combination with each other in preferred embodiments. In some embodiments, all features a to d are implemented in combination.

[0050] Furthermore, preferably, the following additional features a and b, a. The front surface of the part shall be partially or completely covered, and in particular lacquered, preferably clear lacquered. b. The surfaces of the n contours on the front side of the part are coated with an opaque material, in particular lacquered and / or chrome plated, preferably hot stamped with a chrome film. At least one of these may be provided.

[0051] Preferably, features a and b described above are realized together, and as a result, the surfaces of the n contours on the front side of the part, i.e., the surfaces of the decorative parts, are opaquely coated with chrome plating or other methods, and the remaining front surface is coated with, for example, clear lacquer. In this case, clear lacquer may also be applied to the surfaces of the n contours. This protects the surface of the part on the one hand, and provides a visually very attractive effect on the other hand.

[0052] In particular, by applying a special color design to the n contours on the front side of the part, especially by lacquering and / or chrome plating, these contours, which have decorative features, are visually emphasized and made stand out. Furthermore, this configuration makes lighting from the rear of the part particularly effective, because the contours are especially emphasized from their external shape.

[0053] Therefore, using the proposed method, it is possible to manufacture a part in which the contour of the front side of the part can be precisely defined and illuminated, particularly by visually illuminating the outer shape of the surrounding edges or contours.

[0054] In particular, the back of the part can be made to match the vehicle's color by integrating or applying a corresponding colored film with appropriate coloring during the injection molding process. By using a colored film, the color design can be easily formed up to the edges of the part. Depending on the desired visual effect, the surface of the front contour of the part can be coated and / or, for example, chrome plated, which is done particularly by hot stamping a chrome film. This is preferably done at a point after the injection molding of the part. Special lighting effects possible with parts manufactured according to the present invention are achieved, among other things, by the colored film being partially cut out in the rear region of the part corresponding to the front contour of the part. If the surface of the front contour is coated with chrome or by other means, the edge region or outline of each contour becomes directly visible to a rear light source.

[0055] Furthermore, the present invention includes an injection molding tool for manufacturing parts from plastic, particularly transparent, more specifically translucent, plastic. The part to be manufactured has a front surface having n contours, particularly n raised contours, and a back surface covered with a colored film. In this case, the injection molding tool according to the present invention has the following features: a. The injection molding tool comprises a first tool component and a second tool component, which together enclose a cavity having the contour of the part to be manufactured when the tool is closed. The surface of the first tool part represents the negative of the front surface of the part and has n structural parts corresponding to n contours. • The surface of the second tool part represents the negative of the back of the part. b. The surface of the second tool component has n raised portions that function to facilitate the positioning of the film, which has corresponding n notches. c. After closing the tool, the n structural parts on the surface of the first tool part and the n protrusions on the surface of the second tool part are positioned in the cavity such that each of the n structural parts faces one of the n protrusions. It is characterized by the following.

[0056] Further details and advantages of the injection molding tool according to the present invention have already been disclosed in connection with the description of the method according to the present invention in which this type of injection molding tool is preferably employed. Therefore, please refer to the above description for further features and advantages of the injection molding tool.

[0057] In particular, using the injection molding tool according to the present invention, it is possible to accurately and precisely position a colored film with corresponding notches on the surface of a second tool component, in which case the raised portion on the surface of the second tool component engages with the notches in the film. Through this method, it is possible to manufacture a part with a color design on the rear using a colored film, in which case the area on the rear side of the part corresponding to the n contours on the front side of the part does not have a color design. In this case, the positioning of the film becomes critically easier with the second tool component equipped with n raised portions, and as a result, a precise result can be obtained.

[0058] In a particularly preferred configuration of the injection molding tool according to the present invention, the injection molding tool has the following additional features: a. The n protrusions on the surface of the second tool component are formed to be retractable. It is characterized by the following.

[0059] The special advantages of having n protrusions that can be recessed into the second tool portion have already been discussed in detail in connection with the description of the method according to the present invention, and will be referred to here.

[0060] Finally, the present invention includes an injection-molded part made of translucent plastic, wherein the part has a front surface having n contours, particularly raised contours, and a back surface covered with a colored film. The film has n notches, in which areas the part is not covered with the film. Each of these n notches overlaps with one of the n contours on the front side of the part in a viewing direction perpendicular to the front and / or back surface of the part. It is particularly preferable that the part is manufactured in the manner described above.

[0061] Particularly preferably, the back surface of the part is provided to have a flat surface. This is achieved, in particular, by sinking n ridges on the surface of a second tool part that engages with n notches in the colored film during the injection molding process, so that plasticizer plastic can be poured into the traces created by the n ridges on the back surface of the part, thereby forming a flat surface.

[0062] The colored film is preferably a lacquer film formed by a lacquer layer on a carrier layer. Preferably, the carrier layer remains on the part. In injection-molded parts, particularly preferably, the lacquer film is first positioned on the back side of the part, so that the carrier layer is on the outside and provides protection for the lacquer layer.

[0063] Furthermore, in a preferred embodiment, the component has the following features a to d: a. The part is an interior trim part for the vehicle body. b. The part is a covering panel for the vehicle body. c. The surfaces of the n contours on the front side of the part are lacquered, preferably opaquely lacquered and / or chrome plated. d. At least one light source is assigned to the back of the component. It is characterized by at least one of the following.

[0064] For further details on these features, please refer to the explanation above.

[0065] In principle, the configuration of injection-molded parts that can be manufactured according to the present invention is not limited in any way, particularly with respect to the n contours on the front side of the part. Therefore, the shaping of these contours can be formed according to functional, visual, and / or design considerations. In this regard, it is not necessary that these contours protrude from the rest of the front surface of the part. Therefore, these contours can also be formed as recesses in the front surface of the part.

[0066] The number n of contours is preferably freely selectable. In a particularly preferred embodiment, the number n is in the range of 1 to 1000, preferably in the range of 10 to 500. Within these ranges, n = 100 to 300 contours is even more preferred. When the number of raised contours is such that, and by forming a corresponding number of tool parts of the injection molding tool accordingly, and by forming structural parts on the surface of the first tool part and raised parts on the surface of the second tool part, a visually very attractive result is achieved in the manufacture of the part. Furthermore, these proposed measures enable problem-free and failure-resistant manufacturing.

[0067] Further features and advantages of the present invention are shown in the following description of embodiments in conjunction with the drawings. Each feature can be realized individually or in combination with others. [Brief explanation of the drawing]

[0068] [Figure 1] This is a schematic diagram of the longitudinal cross-section of the first tool component and the second tool component of the injection molding tool according to the present invention. [Figure 2] This is a schematic diagram of a first tool component and a second tool component of an injection molding tool according to the present invention, having a positioned colored film. [Figure 3] This is a schematic diagram of a first tool component and a second tool component of an injection molding tool according to the present invention, having injected plastic. [Figure 4] This is a schematic diagram of the first and second tool parts of an injection molding tool according to the present invention, having an injected plastic and a recessed protrusion in the second tool part. [Figure 5] This is a schematic cross-sectional view of an injection-molded part manufactured according to the present invention. [Figure 6] This is a schematic cross-sectional view of an injection-molded part manufactured according to the present invention, which has rear illumination. [Figure 7] This figure shows a visual impression of an injection-molded part manufactured according to the present invention, illuminated from the rear. [Modes for carrying out the invention]

[0069] Figure 1 is a schematic longitudinal section view of the first tool part 10 and the second tool part 20, which together form or surround the cavity 30 of the injection molding tool 100. This cavity 30 defines the contour of the injection molded part to be manufactured. In this case, the surface of the first tool part 10 facing the cavity 30 forms the negative of the front of the part and has several structural parts 11, in particular recesses, which define the contour of the front side of the part to be manufactured. The surface of the second tool part 20 facing the cavity 30 represents the negative of the back side of the part and this surface of the second tool part 20 is equipped with several protrusions 21. These protrusions 21 can be recessed into the second tool part 20, and as a result, the surface of the tool part 20 facing the cavity 30 can form a flat surface.

[0070] As shown in Figure 2, a colored film 40 is placed on the surface of the second tool part 20 before the plasticizing plastic is injected into the cavity 30 of the tool 100. The colored film 40 includes a carrier layer 41, in particular a plastic film, and a pigment-containing or colored layer, in particular a lacquer layer 42, placed thereon. The colored film 40 has notches 43 whose shape, in particular its outline, corresponds to the front side contour of the part to be manufactured. In the process of the method according to the present invention, these notches 43 are positioned on the back side of the part to be manufactured so as to precisely face the front side contour of the part to be manufactured, so that the area or outline of the part contour is left without color design on the back side. The raised portion 21 on the surface of the second tool part 20 functions to precisely position the colored film 40 on the back side of the part to be manufactured. For this purpose, these protrusions 21 engage with the notches 43 of the colored film 40, thereby enabling precise positioning of the colored film on the surface of the second tool part 20. Furthermore, the film 40 is prevented from slipping off.

[0071] Figure 3 shows the injection of plasticizable plastic 50 into the cavity of the injection molding tool 100, defined by the first tool part 10 and the second tool part 20. During the injection process, the colored film 40 is precisely held in place by the raised portion 21 of the second tool part 20. To improve the adhesion of the plasticizable plastic 50 to the colored film 40, the colored film 40 may have adhesive on the side facing the plastic 50. On the front side of the part, a raised contour 51 is formed during the injection molding process, corresponding to the recess 11 of the first tool part 10.

[0072] The plastic 50 of the parts to be manufactured is a particularly transparent thermoplastic, such as polymethyl methacrylate, polycarbonate, or polyamide, especially PA12.

[0073] Figure 4 shows that the raised portion 21 sinks into the second tool part 20 during the injection molding process. This approach ensures that the imprint formed by the raised portion 21 in the part to be manufactured is completely filled with plasticizer plastic, resulting in a flat surface on the back of the part to be manufactured.

[0074] A cross-sectional view of the part 500 that can be manufactured in this manner is shown in Figure 5. The part 500 has a base made of plastic 50 and a colored film 40 on the back side of the part, which has a notch 43 in the region facing the contour 51 on the front side of the part.

[0075] In this embodiment of the part, the surface of the contour 51 is covered with a chrome film 52 by hot stamping or other means. Furthermore, two connection points 53 are added to the back side of the part for further assembly of the part 500. The connection points 53 were manufactured by a further injection molding process in a manner known to itself. The connection points 53 may be manufactured, for example, from PC / ABS (polycarbonate / acrylonitrile butadiene styrene).

[0076] In some cases, a further coating, such as a clear lacquer coating, can be provided on the front surface of the part 500, thereby providing protection and scratch resistance to the front surface of the part. This may be particularly useful, for example, when polycarbonate is used as the thermoplastic material.

[0077] Figure 6 illustrates rear illumination of an injection-molded part 500. In this configuration, light sources 200 are positioned on the back side of the part 500, and these light sources illuminate the transparent substrate of the part 500 in the area of ​​the cutout 43 in the colored film 40. The remaining area of ​​the colored film 40 forms an opaque layer that does not transmit visible light. The chrome film coating 52 on the surface of the contour 51 is also opaque to light rays, and as a result, light rays exit from the substrate of the part 500 in the outer area of ​​the contour 51, achieving an illumination effect that illuminates only the outer shape of the contour 51.

[0078] Figure 7 illustrates this visual effect when part 500 is illuminated from the rear. The raised contour 51 on the front side of part 500 forms a star shape, and the rear illumination precisely defines the outline of the star-shaped contour 51 and illuminates the surrounding area.

[0079] Overall, the manufacturing process of the part 500 according to the present invention using the injection molding tool 100 according to the present invention makes it possible to manufacture a part 500 having a color design on the back side using a colored film 40, and in doing so, the area with the contour 51 on the front side of the part 500, for example, a star that appears three-dimensional, can be illuminated with positional accuracy as intended. At the same time, by applying the colored film 40 to the back side, the color design can be reliably applied to the edges of the part.

Claims

1. A method for manufacturing a part (500) made of translucent plastic (50), wherein the part (500) has a front surface having n contours (51), particularly n raised contours, and a back surface covered with a colored film (40), a. A step of providing an injection molding tool (100) comprising a first tool component (10) and a second tool component (20), wherein, when the tool is closed, the first tool component (10) and the second tool component (20) together surround a cavity (30) having the contour of the part to be manufactured (500), - The surface of the first tool part (10) represents the negative of the front surface of the part (500) and has n structural parts (11), in particular n recesses, corresponding to the n contours (51). - The surface of the second tool part (20) represents the negative of the back surface of the part (500). The process of providing, b. A step of positioning the film (40) on the surface of the second tool part (20), c. The step of closing the injection molding tool (100) and injecting the plasticizable plastic (50) into the cavity (30), d. A step of demolding the part (500) on which the film (40) is provided after the plasticizing plastic (50) has hardened, In a method having, e. Provide n raised portions (21) on the surface of the second tool part (20), f. Before the positioning step, n notches (43) are provided in the film (40), so that when the film (40) is positioned, the n raised portions (21) on the surface of the second tool component (20) engage with the n notches (43) of the film. method.

2. The following additional features: a. After closing the tool (100), the n structural parts (11) on the surface of the first tool part (10) and the n raised parts (21) on the surface of the second tool part (20) are positioned in the cavity (30) such that each of the n structural parts (11) faces one of the n raised parts (21). b. In the demolded part (500), the n structural parts (11) on the surface of the first tool part (10) and the n raised parts (21) on the surface of the second tool part (20) are positioned such that each of the n notches (43) of the film (40) overlaps with one of the n contours (51) in a viewing direction perpendicular to the front and / or back of the part (500). c. The n notches (43) of the film (40) and the n contours (51) on the front side of the part (500) have the same outer shape in a viewing direction perpendicular to the front and / or back of the part. The method according to claim 1, comprising at least one of the following.

3. The following additional features: a. The n protrusions (21) on the surface of the second tool part (20) are formed to be retractable. b. Before the step of demolding the part (500), and especially during the step of injecting the plasticizable plastic (50), the n protrusions (21) of the second tool part (20) are indented, and in particular, the surface of the second tool part (20) is made to be completely flat in the area of ​​the indented protrusions. The method according to claim 1 or 2, comprising at least one of the following.

4. The following additional features: a. The film (40) is a lacquer film or a transfer lacquer film, and has a lacquer layer (42) on a carrier layer (41). b. The lacquer film or the transfer lacquer film is positioned such that the carrier layer (41) is first positioned on the surface of the second tool portion (20). The method according to any one of claims 1 to 3, comprising at least one of the above.

5. The following additional features: a. At least one light source (200) is assigned to the back surface of the component (500). The method according to any one of claims 1 to 4, comprising at least one of the following.

6. The following additional features: a. The part (500) is an interior trim part for the vehicle body. b. The part (500) is a covering panel for a vehicle body. c. Except for the area on the front side having the n contours (51), the part (500) has a substantially uniform thickness. d. Except for the area on the front side having the n contours (51), the front and back surfaces of the part (500) are substantially aligned parallel to each other. The method according to any one of claims 1 to 5, comprising at least one of the following.

7. The following additional features: a. The front surface of the part (500) is partially or completely covered, and in particular lacquered, preferably clear lacquered. b. The surfaces of the n contours (51) on the front side of the part are opaquely coated, in particular painted and / or chrome plated, preferably with a chrome film (52) hot stamped on them. The method according to any one of claims 1 to 6, comprising at least one of the following.

8. An injection molding tool (100) for manufacturing a plastic part (500), wherein the part to be manufactured (500) has a front surface having n contours (51), particularly n raised contours, and a back surface covered with a colored film (40), and has the following features: a. The injection molding tool comprises a first tool component (10) and a second tool component (20), and when the tool is closed, the first tool component and the second tool component together surround a cavity (30) having the contour of the part to be manufactured (500). - The surface of the first tool part (10) represents the negative of the front surface of the part (500) and has n structural parts (11), in particular n recesses, corresponding to the n contours (51). - The surface of the second tool part (20) represents the negative of the back surface of the part (500). b. The surface of the second tool component (20) has n raised portions (21) that function to facilitate the positioning of the film (40), c. After closing the tool, the n structural parts (11) on the surface of the first tool part (10) and the n raised parts (21) on the surface of the second tool part (20) are positioned in the cavity such that each of the n structural parts (11) faces one of the n raised parts (21). An injection molding tool (100) having the following.

9. The following additional features: a. The n protrusions (21) on the surface of the second tool part (20) are formed to be retractable. An injection molding tool according to claim 8, having the following:

10. An injection-molded part (500) made of translucent plastic (50), the part (500) having a front surface having n contours (51), particularly n raised contours, and a back surface covered with a colored film (40), the film (40) having n notches (43), in the area of ​​the notches (43) the part is not covered with the film, and each of the n notches (43) overlaps with one of the n contours (51) on the front side of the part in a viewing direction perpendicular to the front surface and / or the back surface of the part (500).

11. The injection-molded part according to claim 10, characterized in that the part is manufactured by the method described in any one of claims 1 to 7.

12. The following additional features: a. The back surface of the part (500) has a flat surface. An injection-molded part according to claim 10 or 11, having the following:

13. The following additional features: a. The film (40) is a lacquer film having a lacquer layer (42) on a carrier layer (41), b. The lacquer film is positioned such that the lacquer layer (42) is first positioned on the back side of the part (500). An injection-molded part according to any one of claims 10 to 12, having at least one of the above.

14. The following additional features: a. The part (500) is an interior trim part for the vehicle body. b. The part (500) is a covering panel for a vehicle body. c. The surfaces of the n contours (51) on the front side of the part are lacquered, preferably opaquely lacquered and / or chrome plated. d. At least one light source (200) is assigned to the back surface of the component (500), An injection-molded part according to any one of claims 10 to 13, having at least one of the above.

15. The following additional features: a. n is a number between 1 and 1000, especially a number between 10 and 500. An injection-molded part according to any one of claims 10 to 14, having the following:

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