MOLD FOR MOLDING AUTOMOTIVE TRIM PARTS

Abstract

Moulding tool, for compression moulding and or in mould foaming of automotive trim parts, comprising at least one mould having a 3D shaped cavity, characterised in that the mould part comprises a thermoset resin binder matrix with particulates bound within the matrix.

Claims

1. A molding tool, for compression molding and/or in mold foaming of automotive trim parts, comprising at least one mold having a 3D shaped cavity, wherein the mold part comprises a thermoset resin binder matrix with particulates bound within the matrix.

2. The molding tool according to claim 1, whereby the thermoset resin binder is one of an acrylic based, polyester based, furan based resin, epoxy based resin, or a phenolic based resin.

3. The molding tool according to claim 1, whereby the particulates are a granular material with an average grain size of less than 500 μm, preferably between 100 and 300 μm.

4. The molding tool according to claim 1, whereby the particulates or granular material is one of chosen from the group of quartz sand or silica sand, artificial sand, ceramic particles or metal particles or thermally conductive alloys, or a combination of the materials mentioned.

5. The molding tool according to claim 1, whereby at least the surface forming the cavity of the mold further comprises at least one surface treatment chosen from a coating and/or infusion and/or penetration with a second material.

6. The molding tool according to claim 5, whereby the surface treatment is infusion or penetration with a second material thereby closing any voids between the resin binder and the bound particles at least on the inner surface of the mold.

7. The molding tool according to claim 5, whereby the second material for the surface treatment is a thermoset material, preferably at least one of an acrylic based, polyester based, furan based, epoxy based, or phenolic based materials.

8. The molding tool according to claim 5, whereby the surface treatment resin and the binder resin are the same.

9. The molding tool according to claim 5, whereby the surface treatment material is forming a closed layer at least on part of the molding surface of at least 5% of the thickness of the mold, preferably up to 100% of the thickness of the mold, or at least 1 mm of the thickness of the mold.

10. The molding tool according to claim 1, further comprising channels integrated in the mold, preferably directed at least partially parallel to the inner mold cavity surface, to enable the temperature of the mold to be controlled.

11. A process for producing a molding tool according to claim 1, comprising at least the step of printing layers to form the mold by alternating steps of (1) layering a layer of particulates and (2) depositing binder droplets in a desired pattern to bind locally particulates and the binder material together, and whereby the alternating steps (1) and (2) are repeated until the mold is completely printed.

12. The process according to claim 11, further comprising an additional step of treating the surface, at least the surface forming the molding cavity, with a second material to fill the voids between the binder and the particulates.

13. The process according to claim 11, further comprising an additional step of coating at least the surface of the printed mold forming the molding cavity with second material to fill the voids between the binder and the particulates at least at the surface of the mold.

14. The process according to claim 11, comprising the additional step of cleaning the mold produced to remove any debris or free material that might interfere with the use of the mold or the quality of the molded part.

15. The process according to claim 11, further comprising at least one heat treatment step to either treat the printed mold, or treat the printed and surface treated mold.

16. A method of using the molding tool according to claim 1 for compression molding and/or in mold foaming automotive parts made of single or multilayer materials with at least one layer being a foam, preferably in mold foamed or slab foam, fibrous layer, nonwoven, scrim, heavy layer formed by a filled thermoplastic elastomeric layer, film or foil layer.

Description

[0062] FIG. 1 Example of compression moulding tool with mould halve according to the invention.

[0063] FIG. 2 Schematic figure of the process of producing the moulds according to the invention.

[0064] FIG. 3 Schematic figure of the material build-up of the mould

[0065] FIG. 4 Example of a 3D printing process for producing the mould according to the invention.

[0066] FIG. 1 is showing an example of compression moulding with mould halves made according to the invention. According to the figure a press mould 1 comprises a lower mould half 2 and an upper mould half 3. These moulds can have cooling channels for instance as indicated by the openings 4 and a cross section through a channel 6 as possible examples. Preferably, the channels are placed at least partially parallel and close to the surface. The two mould halves, 2 and 3 together define a mould cavity in which the automotive product will be moulded. An example of an automotive product 7 as shown might consist of a single layer, of fibrous material or foam. However multiple layers that need compression and binding within and or between the layers might also be used in the moulds.

[0067] Preferably the design of the mould halves might have spaces for inserting cutting and or sealing elements or to enable other types of inserts. The mould will close preferably under pressure of a for instance a mould press for the time necessary to mould and set the material in the final shape. After which the mould opens and the part can be removed.

[0068] The mould or mould halves might have dedicated areas for mounting the mould to the press as well as for other functions normally provided for by a mould.

[0069] The mould might further comprise a cooling or heating system comprising channels 4, 6 within the mould halves. The channel might contain a fluid, while a passive or active replacement system (not shown) for the fluid transports the fluid through the channels. The fluid can circulate within the mould and an area with lower temperatures to cool or heat when necessary, the mould during use.

[0070] FIG. 2 is showing schematically a preferred process for making the mould halves with the basic steps of printing layers to form the mould halves (100) with the desired design, Infusion of the mould halves (200) by penetrating at least the surface forming the cavity with a penetrating material that will fill the voids or pores between the printed material forming the mould and optionally cleaning (300) the mould halves to get rid of any debris or free material that might interfere with the use of the mould during the moulding process of the automotive part.

[0071] FIG. 3 shows schematically a mould halve with an infused area. The mould is formed by particles (8) bound by a thermoset binder (9) forming the mould structure, between the bound particles voids are formed (10). At least by partially penetrating a resin material (11) into the voids (10) it is possible to make the mould air and/or liquid tight for at least the surface (12) of the mould forming the moulding cavity. The thickness of the infused layer (13) is at least 5% of the overall thickness of the mould, preferably at least 10 mm and can be up to 100% of the mould thickness. During the infusion process the cooling channels should stay open, for example the surface can be made airtight by penetrating the resin material just up to the thickness where the cooling channels are situated. Alternatively, the cooling channels can be filled with a fluid or material to prevent full penetration of the channels during the penetration process. The material or fluid can be discarded after the penetration process.

[0072] FIG. 4 shows an example for a machine and process of producing the mould according to the invention. The 3D printing tool comprises a housing 20 for feeding the particle supply 21 as well as taking up the printed part 23 embedded in particles 24. In addition, a binder resin supply system, with a liquid resin feed, for instance using a pump or extruder and pump system 26 and a printing head for applying droplets of binder resin in a desired pattern.

[0073] The process of producing the printed part is a repeating process of the following steps, providing a layer of powder by the powder feed roller. As soon as a new layer of powder is placed on top of the platform or the printed part, the binder printing head will place droplets of binder resin in a desired 2D pattern on top of the particle layer. After finalising the pattern, the pistons move again as indicated with the arrows one step up or down, and a next layer of powder will be displayed on top of the thus formed part again. Layers of powder and printing the resin binder will be repeated until the full thickness of the part has been achieved. The box with the printed part with bound particles is incubated preferably in a curing oven to achieve the full binding strength of the resin. The fully bound part is cleaned, taking unbound particles away and can be used as such or in a second step at least the surface of the mould can be impregnated or penetrated with a resin material to close the voids between the bound particles.