JPS5812843B2 - Manufacturing method for laminated plastic products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a laminated plastic product, which enables accurate molding of the shape of the product and securely adheres a plurality of upper and lower plastic members.

In more detail, when drawing and forming with two molds, air is evacuated from one mold to accurately form the surface shape, then air is evacuated from the other mold, and compressed air is drawn from the one mold. The present invention relates to a method for producing a laminated plastic product in which a plurality of plastic members are tightly pressed together by supplying the plastic members to ensure adhesion of the plastic members.

FIG. 6 shows a conventional method for manufacturing plastic products, and shows a method for manufacturing instrument panels and the like used in automobiles.

A ventilation hole 2 is formed inside the mold 1 to penetrate to the surface of the mold 1, and a plastic core material 3 having a hole 3a communicating with the ventilation hole 2 is mounted on the mold 1. has been done.

Adhesive is applied to the surface of the core material 3, and two sheet-shaped plastic members 4 and 5, which have been stacked one above the other in advance and are closely attached, are attached to the core material 3 via this adhesive. ing.

Air is removed from the ventilation holes 2 using a vacuum pump to remove the air that has intervened between the intermediate member 4 and the core material 3, thereby causing the atmospheric pressure acting on the outer surface of the upper member 5 to The two members 4 and 5 are tightly pressed against the core material 3 and bonded to the core material 3 with the adhesive.

At the same time, the two members 4 and 5 are molded into a shape corresponding to the shape of the mold 1, and a product is obtained.

However, when a product is molded in this way, the following problems occur.

Even if air is removed from the ventilation holes 2 with a vacuum pump and pressure is applied to the two members 4 and 5 to the core material 3, this pressure is generated by atmospheric pressure, so the pressure will not exceed atmospheric pressure. It is not possible to press the two members 4 and 5 against the core material 3 with pressure, and there is a limit to the pressing force.

For this reason, there is a concern about the adhesion force between the two members 4 and 5 to the core material 3, and the reliability regarding adhesion is poor.

Also, the two members 4 and 5 are bonded to the core material 3 and the mold 1 by atmospheric pressure.
Even if pressed, each corner 5a... of the upper member 5 inevitably becomes a curved shape, and it is not possible to make the corner sharp according to the set value, and each corner 5a... is formed into the required sharp shape. I can't.

When the product is used as an instrument panel, it is an interior material for an automobile, so particularly good appearance is required, and each corner 5a... must be reliably molded into a specific shape. .

In view of the problems of the conventional manufacturing method for laminated plastic products as described above, the inventors of the present invention have made the present invention as a result of intensive research to solve the problems.

The object of the present invention is to use a pair of molds that can be separated and combined, draw a laminated sheet on a core material attached to the molds by combining the pair of molds, and then draw air from one mold. The laminated sheet is brought into close contact with the mold, thereby molding the surface shape of the product in accordance with the shape of the mold, and then air is removed from the other mold and applied to the core material facing the mold. The core material and the laminated sheet are brought into close contact with each other through the formed holes, and at the same time, compressed air is supplied from one of the molds to press the laminated sheet against the core material, and the adhesive is used to bond and integrate these members. To provide a method for manufacturing laminated plastic products that makes it possible to produce laminated plastic products.

Therefore, the object of the present invention is to use two molds, and to evacuate air from one mold so that the laminated sheet is brought into close contact with the mold, and to maintain the shape of the mold as it is on the surface of the product. Even products that require sharp corners can be reliably molded into the corner shape according to the set value, and air is removed from the other mold to ensure close contact between the core material and the laminated sheet. By supplying compressed air from one mold to further pressurize them, it was possible to increase the pressurizing force as much as possible and ensure that the parts were integrated with each other using adhesive. A method for manufacturing laminated plastic products is provided.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

First, an outline of the apparatus used in the present invention will be described.

Reference numeral 10 in FIG. 1 is a roll wrapped with a laminated sheet 13 made of two sheet-like plastic members 11 and 12 that have been closely bonded and integrated in advance.
Laminated sheets 13 are sequentially supplied starting from 0.

This laminated sheet 13 is thermoplastic, and the upper sheet 11
is about 0. The lower seat 12 is made of 8 mm thick PVC (polyvinyl chloride) leather, and the lower seat 12 is approximately 4 mm thick PP (polypropylene) foam.

A hot air stove 15 for performing primary heating is installed near the roller 14 that guides the laminated sheet 13, and hot air from a heater or the like is sent by a fan or the like.

Close to this hot air stove 15, a male mold 16 and a female mold 17 are installed.
As shown in the figure, they are installed facing each other in the vertical direction, and are brought together and separated by a driving means such as a cylinder.

A core material 18 is attached to the male mold 16, and this core material 18 is made of ABS, which has particularly excellent heat resistance, strength resistance, and shock absorption properties.
Molded from resin.

The reason why the core material 18 is molded from ABS resin and the lower sheet 12 is molded from PP foam is that the products manufactured according to the present invention are interior materials for automobiles such as instrument panels and safety panels. This is because the impact on the human body in the event of an accident was taken into consideration since the vehicle is used as a vehicle.

In addition to performing secondary heating, a lower heater plate 19.20 is installed between the male mold 16 and the female mold 17, and a lower heater plate 19.20 is installed between the male mold 16 and the female mold 17.
Side plates 21 and 22 are hung from the lower surface of the cylinder 9, and one side plate 21 is rotatably displaced by a cylinder 23.

An adhesive is applied to the surface of the core material 18, and this adhesive is made of a heat-melting type that increases adhesive strength when heated, such as a chloroprene-based, urethane-based, dendritic polyester-based, or nitrile rubber-based adhesive. has been done.

As shown in FIG. 4, passages 16a, . . . , 17a are formed inside the male mold 16 and the female mold 17, respectively, and these passages penetrate to the joining surface of the molds.

In particular, the ventilation passages 16a of the male mold 16 communicate with the holes 18a formed in the core material 18, as shown in FIG. When covered with the mold 16, it is made to coincide with the ventilation passage 16a...

24 shown in FIG. 4 is a vacuum pump, and this pump 2
4 is solenoid valve 25. 26, one valve 25 communicates with the air passage 16a of the male mold 16, and the other valve 26 communicates with the air passage 17a of the female mold 17.

27 is an air compressor, which is connected only to the air passage 17a of the female mold 17 via a solenoid valve 28.

Next, the manufacturing method of the present invention will be described.

The laminated sheet 13 is transferred from the roll 10 shown in FIG.
5, and this sheet 13 is heated.

This heating temperature is preferably in the vicinity where a drawdown phenomenon does not occur, and the heating is performed at a uniform temperature.

This first heating step is performed in consideration of the case where the center of the laminated sheet 13 cannot be sufficiently heated in the next second heating step.

Next, the laminated sheet 13 is positioned between the male mold 16 and the female mold 17 and fixed with clamps 29, 29, and the upper heater plate 2
At 0, it is rapidly heated to the appropriate temperature for forming and bonding in a short time.

After the laminated sheet 13 is heated to an appropriate temperature, the upper heater plate 20 is moved back using a timer or the like, and the heater plate 20 is placed in the mold 16,
Separate from 17.

The lower heater plate 19 has the core member 18 fitted into the male die 16.
is heated to raise the temperature of the adhesive applied to the surface of this 18 to a temperature suitable for bonding.

The side plate 21 was rotated by the operation of the cylinder 23 to face the right side of the core material 18, and was applied to the entire surface of the core material 18 by heating both sides of the core material 18 together with the other side plate 22. Increase the temperature of the adhesive.

The laminated sheet 13 is intermittently conveyed to the molds 16 and 17 by a feed mechanism such as a caterpillar.

After the secondary heating is completed, the lower heater plate 19 is also moved back, leaving approximately the thickness of the laminated sheet 13 and core material 18, and the male mold 16 and female mold 17 are separated as shown in FIGS. 3 and 4. are combined, and thereby the laminated sheet 13 is drawn.

After that, the vacuum pump 24 is operated to evacuate the air interposed between the female mold 17 and the upper surface of the laminated sheet 13 from the ventilation passages 17a through the valve 26, and the laminated sheet 13 is removed by this vacuum action. is in close contact with the inner surface of the female mold 17.

As a result, the laminated sheet 13 is heated and becomes a plastic state, so the shape of the female die 17 remains as it is on the laminated sheet 13.
For example, even when forming sharp corners 11a on the surface of the sheet 13 as shown in FIG. 5, sharp corners can be reliably formed on the sheet 13.

Next, the air evacuation action by the female mold 17 is released, and after at least several seconds, air is removed from the male mold 16 by the valve 25.

Since the ventilation holes 16a of the male mold 16 communicate with the holes 18a of the core material 18 as described above, this air is removed from the core material 1.
A vacuum is created between the core material 18 and the lower sheet 12, so that the sheet 12 and the core material 18 are brought into close contact with each other.

Therefore, the laminated sheet 13 and the core material 18 are integrated with the adhesive having an appropriate temperature for bonding.

At the same time as the male die 16 is vented, the compressor 27 is operated to blow compressed air from the air passage 17a to the inner surface of the female die 17, and this air further pushes the lower sheet 12 into the core material 1.
Press 8.

As a result, the laminated sheet 13 and the core material are more strongly pressed and integrated.

When combining the male mold 16 and the female mold 17, these 16.1
Cutter 30 attached to 7.30 and cutter receiver 3
1 and 31 cut both ends of the laminated sheet 13, and cut the sheet 13 into an appropriate length.

After the air blow molding is completed and the laminated sheet 13 and the core material 18 are tightly integrated with adhesive, the male mold 16 and the female mold 17 are separated and taken out by an ejector (not shown).

After that, a trimming process is performed to obtain a product. In the above explanation, the case of molding an instrument panel or a safety panel has been described, but the products that can be manufactured by this method are not limited thereto, and any suitable plastic product can be manufactured.

As is clear from the above description, according to the present invention, when manufacturing a laminated plastic product by laminating a laminated sheet on a core material, drawing is performed using two molds, and air is removed from one mold. Since the laminated sheet is then vacuum-formed with the laminated sheet in close contact with the mold, the shape of the mold can be directly shaped into the surface shape of the product, and even sharp corners, which could not be achieved with conventional manufacturing methods, can be reliably formed. After that, air is removed from the other mold and vacuum forming is performed from the hole in the core material facing the mold, which makes it possible to press the laminated sheet onto this core material. Since compressed air is supplied from one of the molds, it is possible to reliably bring them into close contact with each other with a pressure greater than atmospheric pressure, and the core material and the laminated sheet can be firmly integrated with the adhesive. I can do it.

Further, according to the present invention, for example, if a hot-melt adhesive is used as the adhesive as described above, and the core material and the laminated sheet are heated, the adhesive may be bonded to the adhesive before drawing. Since the strength can be further improved, it is possible to bond the core material and the laminated sheet even more firmly when integrating the adhesive, and it exhibits various features such as being able to improve the strength of the product. Extremely practical.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIGS. 1 to 4 show the method according to the present invention in the order of steps. A side view of the secondary heating process, Figure 3 is a side view of drawing processing using two molds, Figure 4 is a side view of vacuum processing and blow processing, and Figure 5 is an enlarged view of one mold part in Figure 4. 6 are side sectional views showing the conventional method. In addition, in the drawing, 13 is a laminated sheet, 18 is a core material, 16, 1
7 is a mold, 18a is a hole, and 16a and 17a are ventilation passages for performing vacuum processing and blow processing.

Claims (1)

[Scope of Claims] 1. A piece of material pre-molded into a predetermined shape using ABS resin or the like is placed on one side of a pair of molds that can be separated and combined, and PVC leather, PP foam, etc. is placed between the pair of molds in advance. A laminated sheet obtained by stacking multiple sheets is set, and this laminated sheet is drawn by combining a pair of molds, air is removed from the mold facing the laminated sheet, and the laminated sheet is brought into close contact with this mold. The air existing between the core material and the laminated sheet is extracted from the hole formed in the core material by removing air from one of the molds, and compressed air is jetted out from the other of the molds to form the laminated sheet. A method for manufacturing a laminated plastics product, characterized in that the core material is pressed into close contact with the core material and these are fixed and integrated using an adhesive. 2. In claim 1, the adhesive is a heat-melting adhesive such as a urethane adhesive or a polyester adhesive, and the core material and the laminated sheet are coated with the adhesive. A method for manufacturing a laminated plastic product, characterized in that the above-mentioned drawing process is heated before the drawing process.