KR100909599B1 - Method for manufacturing interior materials for vehicles using vacuum and low pressure injection molding - Google Patents

Abstract

The present invention relates to a method for manufacturing a vehicle interior material, and more particularly, vacuum and low pressure injection molding which can perform a low pressure injection molding of the substrate at the same time as the vacuum molding of the skin material, so that a separate bonding process is unnecessary and the manufacturing process can be shortened. It relates to a method for manufacturing a vehicle interior using.

Method for manufacturing a vehicle interior using a vacuum and low-pressure injection molding according to the present invention is the step of loading the skin material in the upper mold and preheating the skin material, forming a base protective layer on the upper surface of the lower mold, vacuum Operating a pump to discharge the inner air of the upper mold and vacuum forming the skin material and simultaneously supplying the liquid resin substrate to the upper surface of the substrate protective layer through an inlet formed in the lower mold; Lowering the mold, combining with the lower mold, and cooling to fix the shape of the molded article comprising the skin material and the substrate; and raising the upper mold, releasing the molded article from the lower mold, and then piercing the mold. It is characterized by including.

Vacuum, low pressure injection, molding, interior material, skin material, substrate, substrate protective layer

Description

MANUFACTURING METHOD OF INTERIOR FOR VEHICLE BY VACUUM AND LOW PRESSURE INJECTION MOLDING}

1 is a manufacturing process flow chart of a conventional vehicle interior material.

Figure 2 is a schematic flowchart showing a manufacturing process of the interior material by the manufacturing method of the vehicle interior material using the vacuum and low-pressure injection molding according to the present invention.

Figure 3 is a cross-sectional view of the manufacturing process of the interior material by the manufacturing method of the vehicle interior using vacuum and low pressure injection molding according to the present invention.

※ Explanation of code for main part of drawing

10: prize mold

20: lower mold

30: skin material

40: description

50: substrate protective layer

The present invention relates to a method for manufacturing a vehicle interior material, and more particularly, vacuum and low pressure injection that can be carried out in the low pressure injection molding of the base material at the same time as the vacuum molding of the skin material, so that a separate bonding process is unnecessary and the manufacturing process can be shortened. The present invention relates to a method for manufacturing a vehicle interior using molding.

In general, vacuum molding and low pressure injection molding are used as a method of manufacturing a vehicle interior, and a manufacturing process flow chart of a conventional vehicle interior is shown in FIG. 1. Specifically, the skin material is charged into a mold, preheated, and then vacuum molded, and the substrate is low-pressure injection molded in a separate mold. Then, the product is taken out through the bonding process and the piercing process of the skin material and the substrate. However, the conventional manufacturing method of the vehicle interior material has a problem in that the process of bonding the skin material and the base material is necessary and the process is long, and therefore, a separate oil-based adhesive must be used to harm the environment.

In addition, the vehicle interior sheet has been changed from PVC to olefin, and the olefin sheet is molded by vacuum and low pressure injection method by laminating polypropylene foam (PP FOAM) on TPO (Thermoplastic Olefin) SKIN, respectively. come. In the case of low-pressure injection and vacuum method, the olefin sheet of a vehicle interior has been used a TPO sheet in which PP FOAM is laminated to TPO SKIN, but the heat resistance has been mixed differently according to the method. In case of low pressure injection, TPO SKIN aims to improve the moldability by lowering the heat resistance. In the case of vacuum molding, TPO SKIN aims to improve heat resistance. PP FOAM aims to improve the heat resistance by increasing the heat resistance in the case of low pressure injection, and improves moldability by lowering the heat resistance in the case of vacuum molding. However, these two methods have advantages and disadvantages, and the method that can utilize the advantages of both methods is a method of combining vacuum and low pressure injection method, but a sheet satisfying both heat resistance and formability has not been developed until now.

Accordingly, an object of the present invention is to provide a method for manufacturing interior materials for a vehicle using vacuum and low pressure injection molding which can perform a low pressure injection molding of a base material at the same time as the vacuum molding of the skin material, so that a separate bonding process is unnecessary and the manufacturing process can be shortened. Is in.

Another object of the present invention to provide a method for manufacturing a vehicle interior material that can ensure the heat resistance and moldability required in the simultaneous vacuum and low pressure injection method.

The above object of the present invention,

Inserting the skin material into the upper mold and preheating the skin material; forming a base protective layer on the upper surface of the lower mold; and operating a vacuum pump to discharge the internal air of the upper mold to remove the skin material. At the same time, the step of supplying a liquid resin substrate to the upper surface of the substrate protective layer through an injection hole formed in the lower mold, and the upper mold is lowered to be combined with the lower mold to cool the skin and A method of manufacturing a vehicle interior using vacuum and low pressure injection molding, comprising: holding and fixing a shape of a molded article made of a substrate, and piercing the upper mold and releasing the molded article from the lower mold. By providing a method.

According to a preferred feature of the invention, the skin material comprises polypropylene, polyethylene, thermoplastic vulcanizates and high melt strength polypropylene.

According to a further preferred feature of the invention, the substrate comprises an olefin resin, a foaming agent, a crosslinking agent, a crosslinking aid and an antioxidant.

According to a further preferred feature of the invention, the substrate further comprises an ethylene propylene diene monomer for electron beam crosslinking.

According to a further preferred feature of the present invention, the base protective layer is a film made of any one of polyethylene and polypropylene.

According to a further preferred feature of the invention, the substrate protective layer is a fiber woven with any one of polypropylene, polyethylene terephthalate and nylon.

According to a further preferred feature of the invention, the substrate protective layer is a coating layer made of polypropylene and having a thickness of 50 ~ 200㎛.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, this is only to describe in detail enough to be able to easily carry out the invention by those skilled in the art, which does not mean that the technical spirit and scope of the present invention is limited.

Figure 2 is a schematic flow chart showing the manufacturing process of the interior material by the manufacturing method of the vehicle interior material using the vacuum and low pressure injection molding according to the present invention, Figure 3 is a manufacturing of the vehicle interior material using the vacuum and low pressure injection molding according to the present invention It is sectional drawing of the manufacturing process of the interior material by the method.

As shown in Figure 2 and 3, the manufacturing method of the vehicle interior material using the vacuum and low-pressure injection molding according to the present invention is a skin material loading and preheating step, substrate protective layer forming step, vacuum molding and injection molding step, piercing step It includes, the vacuum molding and injection molding step is made of a skin material vacuum pressing and substrate supply step, mold molding and cooling step, as shown in Figure 3, vacuum according to the present invention with reference to Figures 2 and 3 And the manufacturing process of the interior material by the manufacturing method of the vehicle interior material using low pressure injection molding will be described.

First, the skin material 30 is charged into the upper mold 10 and the skin material 30 is preheated. Here, the skin 30 is made of thermoplastic olefin (TPO), preferably polypropylene (PP), polyethylene (PE), thermoplastic vulcanizate (TPV), high melt strength polypropylene (HMS-PP ) Specifically, the polypropylene (PP), polyethylene (PE), thermoplastic vulcanizate (TPV), high melt strength polypropylene (HMS-PP) is blended and manufactured by calendering. Here, the high melt strength polypropylene (HMS-PP) is added to the appropriate amount serves to secure the elongation and maintain the emboss shape by heat in the preheating process during vacuum molding.

Next, the base protective layer 50 is formed on the upper surface of the lower die 20. The substrate protective layer 50 serves to prevent the shape of the substrate 40 from being difficult or damaged at a deep part by applying pressure due to heat by vacuum molding and heat by low pressure injection molding. Here, the substrate protective layer 50 may be a film, a fiber or a coating layer, the film is preferably made of any one of polyethylene (PE), polypropylene (PP) or a mixture thereof. In addition, the fibers are preferably woven with any one of polypropylene (PP), polyethylene terephthalate (PET), nylon or mixed with them. In addition, the coating layer is preferably made of polypropylene (PP), the thickness is preferably formed to have about 50 ~ 200㎛ not to have a significant effect on the overall thickness of the interior material.

Next, the internal air of the upper mold 10 is discharged to vacuum the skin material 30, and at the same time, the substrate 40 in a liquid resin state on the upper surface of the substrate protective layer 50 formed on the lower mold 20. To supply. Here, the upper mold 10 has a plurality of vacuum holes (not shown) and the discharge port 12 is formed so that air can be discharged, by operating a vacuum pump (not shown) inside the upper mold 10 When the air is discharged, the skin 30 is vacuum-compressed on the lower surface of the upper mold 10. In addition, the lower die 20 has a built-in hot runner nozzle 22 for supplying the base material 40 of the liquid resin, the base material 40 of the liquid resin supplied from the hot runner nozzle 22 is a substrate protective layer ( 50) on the top surface. The base material 40 of the liquid resin is preferably formed by adding a blowing agent, a crosslinking agent, a crosslinking aid, an antioxidant, and the like to the olefin resin, and in particular, an ethylene propylene diene monomer (EPDM) is further added for electron beam crosslinking. It is more preferable to add. The ethylene propylene diene monomer (EPDM) is a synthetic rubber composed of Ethylene, Prorylene, and Non conjugated Diene to further improve rubber characteristics, and it has excellent flexibility as well as ozone resistance, cold resistance, heat resistance, and solvent resistance. After the base material 40 of the resin is subjected to electron beam crosslinking, foaming is performed by selecting the expansion ratio and thickness.

Next, the upper mold 10 is lowered and combined with the lower mold 20. Here, the liquid resin supplied to the lower mold 20 is molded in a mold shape to form the base 40, and is integrally formed with the skin material 30 which is not yet cooled without a separate adhesive. At this time, as described above, since the base protective layer 50 is formed on the upper surface of the lower die 20, the shape may be prevented from being difficult or damaged at a deep part by the pressure of the heat. Cooling is then performed to hold the integrally molded article fixed.

Next, when the upper mold 10 is raised and the molded product is released from the lower mold 20, the outer periphery is pierced to have an appropriate size. Here, the piercing process is generally the same as the piercing process used when forming a vehicle interior material, and a detailed description thereof will be omitted.

As described above, according to the manufacturing method of the vehicle interior material using the vacuum and low-pressure injection according to the present invention, the vacuum molding of the skin material and the low-pressure injection molding of the substrate is performed at the same time, a separate bonding process is not necessary, the manufacturing process is shortened In addition, it does not use a separate oil-based adhesive has an environmentally friendly effect.

In addition, by using the thermoplastic olefin-based skin material and the base material, heat resistance and moldability can be secured.

In addition, by forming the substrate protective layer on the lower mold, damage to the substrate due to low-pressure injection can be prevented as well as the failure rate can be reduced.

Claims (7)

Charging the skin material to the upper mold and preheating the skin material; Forming a substrate protective layer on the upper surface of the lower mold; Operating a vacuum pump to discharge the inner air of the upper mold to vacuum-form the skin material and simultaneously supplying the liquid resin substrate to the upper surface of the substrate protective layer through an inlet formed in the lower mold; Lowering the upper mold and combining with the lower mold to cool the mold to maintain the shape of the molded article including the skin material and the substrate; And Raising the upper mold and releasing the molded article from the lower mold and then piercing; The manufacturing method of the vehicle interior using a vacuum and low-pressure injection molding comprising a. The method of claim 1, The skin material is a polypropylene, polyethylene, thermoplastic vulcanizate and a high melt strength polypropylene comprising a method of manufacturing a vehicle interior using a vacuum and low-pressure injection molding, characterized in that it comprises. The method of claim 1, The substrate comprises an olefin resin, a foaming agent, a crosslinking agent, a crosslinking aid and an antioxidant, characterized in that the manufacturing method of the vehicle interior using vacuum and low pressure injection molding. The method of claim 3, The substrate is a method for manufacturing a vehicle interior material using vacuum and low pressure injection molding, characterized in that further comprises an ethylene propylene diene monomer for electron beam crosslinking. The method according to any one of claims 1 to 4, The substrate protective layer is a film made of any one of polyethylene, polypropylene, characterized in that the manufacturing method of the vehicle interior using a vacuum and low-pressure injection molding. The method according to any one of claims 1 to 4, The substrate protective layer is a manufacturing method of a vehicle interior using a vacuum and low-pressure injection molding, characterized in that the fiber woven with any one of polypropylene, polyethylene terephthalate and nylon. The method according to any one of claims 1 to 4, The substrate protective layer is made of polypropylene and the coating layer having a thickness of 50 ~ 200㎛ characterized in that the manufacturing method of the vehicle interior using a vacuum and low-pressure injection molding.

Images