Method for manufacturing a molded part for a vehicle interior trim part and molded part

Abstract

Method for manufacturing a molded part (1) for a vehicle interior trim part, comprising the following steps: - Providing a forming tool with an upper tool half and a lower tool half, - Arranging a malleable planar support (9) between the upper tool half and the lower tool half, - Pressing a projection (17) of the upper tool half against a top surface (16) of the carrier (9) so that the carrier (9) is deformed and a depression (13) is formed in the carrier (9), - Creating an opening (14) in the carrier (9) in an area of ​​the depression (13), - Sealing off a space (20) formed by the recess (13) at the top by a sealing element (22), wherein a projection (23) of the sealing element (22) extends into the recess (13) and fills part of the recess (13), - Introducing a flowable and curable or self-curing plastic (11) through the opening (14) of the carrier (9) into the space (20) such that the plastic (11) at least partially fills a part of the space (20) bounded by the carrier (9) and the sealing element (22), - Curing of the plastic (11) and - Removal of the sealing element (22).

Description

[0001] The application relates to a method for producing a molded part for a vehicle interior trim part according to the preamble of claim 1. Furthermore, the application relates to a molded part.

[0002] Vehicle interior trim parts generally comprise a carrier that provides the vehicle interior trim part with a certain degree of stability, and a decorative part arranged on this carrier, which, among other things, gives the vehicle interior trim part a desired visual appearance. For example, WO 2010 / 105855 A2 discloses a manufacturing method for a vehicle interior trim part in which a decorative part is joined to a fiber-reinforced carrier. The decorative part comprises two skins, the end regions of which are inserted into a groove of a retaining profile. To connect the decorative part to the carrier, the retaining profile is inserted into an elongated recess in the carrier. Certain recess geometries are particularly suitable for securely holding the retaining profile.

[0003] For further information on the state of the art, please refer to document DE 10 2011 085 225 A1.

[0004] Furthermore, it is known to press natural fiber mats into a desired shape by compression molding in the manufacture of vehicle interior trim parts. However, this process cannot produce any desired geometries of the molded natural fiber mats. In particular, it is often not possible to create the sharp edges desired for a specific purpose, as the natural fiber mats can exhibit a certain rigidity. If, in the manufacture of a vehicle interior trim part, a retaining profile as described above is to be connected to a compression-molded natural fiber mat, additional processing steps, such as milling the natural fiber mat, are often necessary to create the desired geometry of the recess.

[0005] The object of the present application is to propose a method for producing a molded part for a vehicle interior trim part, by which a large number of different geometries of the molded part, in particular shapes with sharp edges, can be produced in a comparatively simple manner, even with rigid carrier materials. In particular, the object of the present application is to propose a method for producing a molded part that is suitable for accommodating a retaining profile of a decorative part.

[0006] These objects are achieved by a method having the features of the main claim and by a molded part having the features of a further claim. Advantageous developments arise from the features of the further dependent claims and the embodiments.

[0007] The proposed method is suitable for producing a molded part for a vehicle interior trim part. In the method, a molding tool with an upper tool half and a lower tool half is provided. In addition, a moldable flat carrier is arranged between the upper tool half and the lower tool half. In a further step, a projection of the upper tool half is pressed against an upper side of the carrier so that the carrier is deformed and a recess is formed in the carrier. In addition, an opening in the carrier is created in a region of the recess. In addition, a space formed by the recess is closed off at the top by a sealing element. In this case, a projection of the sealing element projects into the recess and fills part of the recess.A flowable and curable or self-curing plastic is then injected through the opening in the support into the space so that the plastic at least partially fills a portion of the space defined by the support and the sealing element. The plastic hardens, and the sealing element is removed.

[0008] The projection of the sealing element generally has a narrower cross-section than the recess. After the sealing element has been removed, the molded part or the plastic can have a recess. This recess is generally located on an upper side of the plastic and in the region of the recess in the carrier. The shape of the recess is typically determined largely by the shape of the projection of the sealing element. For example, the shape of the projection can be transferred completely in negative to a shape of an upper side of the plastic. The described method can be used to create recesses that are particularly suitable for accommodating a retaining profile of a decorative part. One advantage of the method described above and below is that it can be used to produce recesses with a precisely defined geometric shape. In addition, improved dimensional accuracy can be achieved.

[0009] After the molded part has been produced, a decorative part can be provided, for example, with a first and a second decorative skin and a retaining profile. The retaining profile can have a groove on its upper side into which an end section of the first decorative skin and an end section of the second decorative skin are inserted. The retaining profile can then be inserted into the recess arranged on the upper side of the plastic.

[0010] By pressing the projection of the upper tool half against the upper side of the carrier, the recess can be created by compression molding. The shape of the recess is generally determined by the shape of the projection of the upper tool half. It can be provided that pressing the projection of the upper tool half against the upper side of the carrier creates a downward-facing protrusion on the underside of the carrier. The shape of the downward-facing protrusion on the underside of the carrier then corresponds to the shape of the recess on the upper side of the carrier.

[0011] The plastic can be bonded to the carrier during curing to easily create a durable connection between the carrier and the plastic.

[0012] It can be provided that the plastic is introduced into the space in such a way that the plastic fills at least 80% of the volume of the space. In typical designs, the flowable plastic is injected from the lower mold half. For this purpose, the lower mold half can, for example, have an injection nozzle. To make the plastic flowable before being introduced through the opening, it can be provided that the plastic is heated. For example, the lower mold half can include hot runners for guiding a plastic melt. It can also be provided that the flowable plastic comprises two components that harden when heated.

[0013] The carrier can be a fiber mat or comprise a fiber mat. For example, the fiber mat can contain natural fibers and / or plastic fibers. Such carriers are typically characterized by recyclability and good formability, coupled with low weight. The carrier can, for example, be a composite material comprising natural fibers and / or plastic fibers, such as a so-called NFPP mat.

[0014] The plastic can be, for example, a thermoplastic elastomer, such as TPE-E.

[0015] Typically, the recess runs along a longitudinal direction. The recess can, for example, be trench-shaped and / or have a square cross-section. The recess formed on the top side of the plastic can also run along the longitudinal direction. The sealing element can, for example, be shaped such that, after the sealing element is removed, the plastic has a groove running in the longitudinal direction. This makes the molded part suitable for accommodating common retaining profiles.

[0016] In typical designs, the sealing element is shaped such that, after curing, the plastic has a rectangular, stepped, or trapezoidal cross-section. This cross-section can, if necessary, run transversely to the longitudinal direction.

[0017] The proposed process allows for the creation of geometries of the molded part's recess with sharp edges. For example, the sealing element can be shaped such that, after curing, the plastic has at least one edge with a maximum radius of curvature of 0.4 mm.

[0018] Typically, the sealing element and / or the projection of the sealing element has a surface material to which the plastic does not adhere. For example, the surface material can comprise polytetrafluoroethylene (PTFE) or suitable nanoparticles. It can also be provided that the surface material completely forms a surface of the sealing element and / or the projection facing the recess.

[0019] The opening can extend between the top side of the carrier and the bottom side of the carrier in the region of the recess. It can be provided that the opening is created without prior removal of the carrier from the mold and / or by a component of the lower mold half. The opening can be created, for example, by cutting or punching. For example, it can be provided that the opening is created by making a substantially horizontal cut with a blade. The blade can, for example, form part of the lower mold half.

[0020] The opening can be substantially round or elongated in various designs, for example. Multiple openings can be provided, spaced apart from one another along the longitudinal direction if the recess extends in the longitudinal direction. The opening can, for example, be at least 2 mm and / or at most 8 mm in diameter.

[0021] The sealing element is typically part of the upper tool half. In one possible design, the upper tool half is made up of multiple parts. A movable part forming the projection of the upper tool half can taper downwards. This part can be moved upwards before the plastic is introduced and serve as a sealing element. In this case, other movable parts of the upper tool half can be moved sideways to close off the recess at the top. For example, the upper tool half can have slides next to the projection that can be moved sideways on the upper side of the carrier and are designed to close off the space at the top together with the projection of the upper tool half.

[0022] In other designs, the upper mold half is also designed to be multi-part, but a movable part forming the projection of the upper mold half is removed after the recess is formed. The recess can then be closed off at the top with a movable insert. Using the insert allows a wide variety of different geometries for the plastic recess to be easily created.

[0023] The mold is typically convertible from an open state to a closed state. Typically, the mold is closed after the carrier is positioned. While the mold remains in the closed state, the carrier is typically deformed, the opening is created, the recess is sealed, and the plastic is introduced through the opening.

[0024] The application further relates to a molded part for a vehicle interior trim part, wherein the molded part was produced by a method as described above.

[0025] The terms above, below, upper, lower, etc. are used only to describe the relative arrangement of the described components to one another.

[0026] However, the molding tool can of course also be aligned in such a way that, for example, the upper tool half is arranged lower than or at the same height as the lower tool half.

[0027] Exemplary embodiments are described below with reference to the figures. Fig. 1 a schematic cross-section through a molded part and a decorative part, Fig. 2 a schematic plan view of the molded part, Fig. 3 a schematic view during a process step in the production of the molded part, Fig. 4 a schematic view during a further process step in the production of the molded part, Fig. 5(a) is a schematic view during a process step in the production of the molded part according to a first example and Fig. 5(b) is a schematic view during a process step in the production of the molded part according to a second example.

[0028] Fig. 1 shows a molded part 1 and a decorative part 2 for a vehicle interior trim part. The decorative part 2 comprises a retaining profile 3 having a groove 4 on its upper side. Furthermore, the decorative part 2 comprises a first decorative skin 5 and a second decorative skin 5'. The decorative skins 5, 5' are sewn together at end sections 6, 6' and inserted into the groove 4 of the retaining profile 3 with the end sections 6, 6'. The decorative skins 5, 5' are also sewn to the retaining profile 3 with several seams. One of these seams is identified by the reference numeral 7, for example. The decorative part 2 further comprises a pin 8, which is formed, for example, from an elastically deformable plastic.

[0029] The molded part 1 comprises a moldable, flat carrier 9. The carrier 9 can, for example, be an NFPP mat containing plastic and natural fibers. The carrier 9 can also be a "wood fiber polypropylene" carrier. The plastic fibers can, for example, comprise polyolefins, such as polypropylene. The natural fibers can, for example, contain hemp or flax. To connect the decorative part 2 to the molded part 1, the molded part 1 has a recess 10 on its upper side, into which the retaining profile 3 and the pin 8 can be inserted to produce the vehicle interior trim part.

[0030] The recess 10 is defined by a plastic 11. This plastic 11, which contains, for example, TPE-E, can have two sharp edges 12, 12' at an upper end in the illustrated example. The plastic 11 is integrally bonded to the carrier 9 in the region of a recess 13 in the carrier 9. At a lower end of the recess 13, the carrier 9 has an opening 14. The opening 14 extends in the illustrated direction, which runs transversely to a longitudinal direction, by 5 mm, for example.

[0031] In Fig. Figure 2 shows a plan view of the molded part 1. Recurring features are provided with the same reference numerals in this and the following figures. The recess 10 runs along the longitudinal direction on an upper side of the molded part 1. In some embodiments, the recess 10 can be a groove running in the longitudinal direction. In addition, the Fig. 1 shown holding profile 3 along this longitudinal direction when the decorative part 2 is inserted into the molded part 1.

[0032] A method for producing the molded part 1 is illustrated in the following figures. During production, the moldable carrier 9 is first prepared, which is initially largely planar and unopened. Subsequently, the recess 13 is created by compression molding, as shown in Fig. 3. The carrier 9 is arranged between a lower and an upper mold half. Slides 15, 15' of the upper tool half can then be arranged on an upper side 16 of the carrier 9. In a further step, a downwardly tapered projection 17 of the upper tool half is arranged between the slides 15, 15'. The projection 17 of the upper tool half is then pressed downwards against the upper side 16 of the carrier 9. This deforms the carrier 9 so that the recess 13 is formed in the carrier 9. In addition, a downwardly directed elevation 18 of the carrier 9 is formed.

[0033] Fig. 4 shows a view during a further method step for producing the molded part 1. Here, the projection 17 of the upper tool half is first moved upwards so that the projection 17 no longer completely fills the recess 13 of the carrier 9. The carrier 9 is then opened in the region of the recess 13. For this purpose, a cut is made in a horizontal direction 19 with a blade (not shown) of the lower tool half. This creates the opening 14 of the carrier 9 in the region of the recess 13. Other known methods can also be used to open the carrier 9. For example, the opening 14 can be created by punching and / or cutting.

[0034] Side walls of the carrier 9 laterally delimit a space 20 in the area of ​​the recess 13, which is closed off at the top in a further process step. According to one embodiment, the projection 17 of the upper tool half and the slides 15, 15' can be used for closing, as shown in Fig. 5(a). Here, the slides 15, 15' are pushed inward against the upwardly moved projection 17 of the upper tool half, as indicated by the arrows with the reference numerals 21 and 21'. The slides 15, 15' then touch the projection 17 of the upper tool half such that the space 20 is sealed off largely in a liquid-tight manner on an upper side. Thus, the slides 15, 15' together with the projection 17 of the upper tool half form a sealing element 22.

[0035] The sealing element 22 does not close off a top surface of the space 20 in a planar manner. In contrast, the projection 17 of the upper tool half has been moved upward only so far that a bottom surface of the projection 17 of the upper tool half forms a projection 23 of the sealing element 22 that projects downward into the space 20.

[0036] Another version for closing off the room 20 upwards is shown in Fig. 5(b). First, the projection 17 of the upper mold half is removed. Then, an insert 24 is placed between the slides 15, 15'. The insert 24 is shaped such that it closes off the space 20 at the top and thus forms the sealing element 22. A portion of the insert protrudes from above into the space 20 and thus forms the projection 23 of the sealing element 22.

[0037] In a next step, the plastic 11, which is curable or self-curing, is introduced in a flowable state through the opening 14 of the carrier 9 into the space 20. In some embodiments, the plastic 11 can comprise two components that subsequently cure under the influence of heat. To introduce the plastic 11, the lower mold half can, for example, have known hot runners for guiding a plastic melt and / or injection nozzles. In this process, the plastic 11 largely completely fills a portion of the space 20 defined by the carrier 9 and the sealing element 22.

[0038] Subsequently, the plastic 11 hardens and is bonded to the carrier 9. To prevent the plastic 11 from adhering to the sealing element 22, the sealing element 22 has a suitable surface material, which contains, for example, PTFE or suitable nanoparticles, particularly in the region of the projection 23 of the sealing element 22.

[0039] In a further step, the sealing element 22 is removed. In addition, the now finished molded part 1 is removed from a mold formed from the lower and the upper tool halves. The shape of the recess 10 of the finished molded part 1 is determined significantly by the shape of the projection 23 of the sealing element 22. It is possible that the recess 10, in a section transverse to the longitudinal direction, has, for example, a rectangular, a stepped or a trapezoidal shape. Furthermore, it is possible that the plastic 11, as in Fig. 1 is open at the bottom. However, it is also possible that the plastic 11 is closed at the bottom and is continuous in the section transverse to the longitudinal direction.

[0040] In all embodiments, the plastic 11 typically comprises at least one sharp edge which has a small radius of curvature in a cross-section of, for example, less than 0.2 mm.

[0041] Only features of the various embodiments disclosed in the exemplary embodiments can be combined with one another and claimed individually.

Claims

[1] Method for producing a molded part (1) for a vehicle interior trim part, comprising the following steps: - Providing a mold with an upper mold half and a lower mold half, - arranging a formable flat support (9) between the upper tool half and the lower tool half, - pressing a projection (17) of the upper tool half against an upper side (16) of the carrier (9) so that the carrier (9) is deformed and a recess (13) is formed in the carrier (9), - creating an opening (14) of the carrier (9) in a region of the recess (13), - closing off a space (20) formed by the recess (13) at the top by a sealing element (22), wherein a projection (23) of the sealing element (22) projects into the recess (13) and fills a part of the recess (13), - introducing a flowable and curable or self-curing plastic (11) through the opening (14) of the carrier (9) into the space (20) such that the plastic (11) at least partially fills a part of the space (20) delimited by the carrier (9) and the sealing element (22), - Curing of the plastic (11) and - Remove the sealing element (22). [2] Method according to claim 1, characterized by that the plastic (11) is bonded to the carrier (9) during curing. [3] Method according to one of claims 1 or 2, characterized by that the flowable plastic (11) is introduced by injection from the lower tool half. [4] Method according to one of claims 1 to 3, characterized by that the carrier (9) is or comprises a fiber mat. [5] Method according to claim 4, characterized by that the fiber mat contains natural fibers and / or synthetic fibers. [6] Method according to one of claims 1 to 5, characterized by that the recess (13) runs along a longitudinal direction. [7] Method according to claim 6, characterized by that the sealing element (22) is shaped such that the plastic (11) has a groove running in the longitudinal direction after removal of the sealing element (22). [8] Method according to one of claims 1 to 7, characterized by that the sealing element (22) is shaped such that the plastic (11) has a recess (10) which is rectangular, stepped or trapezoidal in cross section after curing. [9] Method according to one of claims 1 to 8, characterized by that the sealing element (22) is shaped such that the plastic (11) has at least one edge (12, 12') after curing, the radius of curvature of which is a maximum of 0.4 mm. [10] Method according to one of claims 1 to 9, characterized bythat the sealing element (22) and / or the projection (23) of the sealing element (22) has a surface material to which the plastic (11) does not adhere. [11] Method according to one of claims 1 to 10, characterized by that the opening (14) is created by cutting or punching. [12] Method according to one of claims 1 to 11, characterized by that the upper tool half is made up of several parts and a movable part forming the projection (17) of the upper tool half tapers downwards and is displaced upwards before the plastic (11) is introduced and serves as a sealing element (22), wherein further movable parts of the upper tool half are displaced laterally in order to close off the recess (13) at the top. [13] Method according to one of claims 1 to 11, characterized bythat the upper tool half is made up of several parts, wherein a movable part forming the projection (17) of the upper tool half is removed after the formation of the recess (13) and the recess (13) is closed off at the top by a movable insert (24). [14] Method for producing a vehicle interior trim part comprising the steps of a method according to one of claims 1 to 13, characterized by following steps: - Providing a decorative part (2) with a first and a second decorative skin (5, 5') and a holding profile (3), wherein the holding profile (3) has a groove (4) on an upper side, into which an end section (6) of the first decorative skin (5) and an end section (6') of the second decorative skin (6) are introduced, - Inserting the holding profile (3) into a recess (10) arranged on an upper side of the plastic (11). [15] Moulded part (1) for a vehicle interior trim part, produced by a method according to one of the preceding claims.

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