JPH0342177B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for closely adhering a film or sheet such as a surface protection film or a transfer film to the surface of a product such as wood or synthetic resin having uneven undulations. Conventionally, as a method for bringing a film into close contact with these uneven surfaces, a method has been used in which the film is softened by heating and then molded and brought into close contact with the uneven surface of the product using gas or liquid.
Another method is to place the product, film, and a heater for heating and softening the film in a vacuum mold, and then bring the film and product into close contact in a vacuum to prevent air from being drawn in when the product surface and film come into close contact. is currently being carried out. A currently used type of device for this purpose is shown in FIG. A moldable sheet 3 is stretched between the upper mold 1 and the lower mold 2,
The mold is closed by a mold clamping cylinder 8, and the sheet 3 is heated by a heater 4 installed in the upper mold 1.

At this time, the molded product 5 is placed on the product stand 6, the push-up cylinder 7 is lowered, and the sheet 3 and the product 5 are not in contact with each other. The space is made into a vacuum, and when the sheet 3 is softened by the heating heater 4, the thrusting cylinder 7 is activated, and the sheet 3 and the product 5 are heated.
After the sheet 3 and the molded product are brought into contact with each other or pushed up further as necessary to stretch the sheet, air is introduced into the upper mold 1 to return it to atmospheric pressure, and pressurized gas is introduced as necessary to form the mold. A method is used in which the sheet and product are brought into close contact with each other.

The machine of this method required two cylinders 8 and 7 which required a large force, and was structurally complex.

In addition, in this device, when the product and the sheet are in close contact with each other, that is, pressurized gas is introduced into the inside of the upper mold 1, and the inside of the lower mold 2 is under reduced pressure, the force applied to the product mount 6 is applied to the lower mold. Since the pressure is reduced, the force is greater than the force for clamping the upper mold 1, and therefore, there is a problem in that a larger force is required from the mold clamping cylinder 8, and the device for producing sufficient mold clamping force becomes complicated. was.

The present invention relates to a device that can perform the same operations using a single mold clamping cylinder in order to improve these drawbacks of the device.

That is, the present invention provides a product table having a vacuum suction mechanism, and a product table that is attached to the outer periphery of the product table and can be moved up and down relative to the product table while maintaining sealing performance by means of a piston and cylinder or a spring mechanism. An outer mold, an upper mold which is located above the outer mold and can be sealed by sandwiching a moldable sheet together with the outer mold and has an air blowing mechanism and a heating device, and a product stand or upper mold that moves up and down. In this method, the molded product is first placed on the product table, a moldable sheet is placed on the outer mold, and the molded product is placed on the product table. By moving the outer mold or the upper mold and sandwiching the moldable sheet between the outer mold and the upper mold,
After the space between the upper mold and the formable sheet and the space between the product stand, the outer mold and the formable sheet are sealed, both spaces are vacuumed and the formable sheet is heated using a heating device. The molded product is heated and softened, moved relative to the outer mold, the molded product is brought into contact with or close to the moldable sheet, and a pressure of atmospheric pressure or higher is applied between the moldable sheet and the upper mold. This is a contact molding method characterized by introducing air to bring the moldable sheet into close contact with the molded product.

The present invention will be explained below with reference to FIGS. 2 to 13.

The lower mold on which the molded product 16 is placed can be slid against each other, and the outer mold 11 can be kept in a sealed state. The inner mold 10 has a structure in which the outer mold is in contact with and is sealed, and the inner mold 10 has a ventilation hole 19 between it and the molded product 16, so that when the inside of the inner mold is reduced in pressure, the surface of the molded product is also at the same pressure. shall be.

The outer mold 11 and the inner mold 10 are slid by a cylinder, a spring, or the like. When the molding sheet 15 is sandwiched between the outer mold 11 and the upper mold 13, the outer mold 1 is held down by a spring cylinder or the like 17 until the molded product 16 and the moldable sheet 15 do not come into contact with each other.
Slide 1.

The upper mold 13 or the lower mold 10 is opened and closed by a mold clamping cylinder 12. The cylinder 12 is the lower mold 1
3 on the movable plate 18 to open and close (Fig. 2),
Either method of opening and closing the upper mold (Fig. 3) is possible. A heating device 14 such as a heater for heating the sheet 15 is installed inside the upper mold 13 .

The operation of the machine is shown in Figures 4-7.

Open the upper mold 13 and lower molds 10 and 11 and mold the product 1.
6 onto the inner mold 10, and the cylinder or spring 17
This prevents the molded product 16 from coming into contact with the moldable sheet 15 when the outer mold 11 is moved and the moldable sheet 15 is stretched over the upper surface of the outer mold 11. (4th
Figure) Next, the mold clamping cylinder 12 is operated, and the upper mold 1
3 comes into contact with the outer mold 11, and the mold is closed to a width that allows the moldable sheet 15 and the molded product 16 to be sealed without contacting with each other and with the moldable sheet 15 sandwiched therebetween. (FIG. 5) Next, the pressure inside the upper mold 13, the outer mold 11, and the inner mold 10 is reduced to create a vacuum on both sides of the moldable sheet 15.

At this time, the pressure inside the upper mold 13 and the inside of the outer mold 11 must always be the same pressure. This is because if there is a pressure difference, the sheet will be pulled to one side, and the sheet 15 will be pulled to one side by the heating device 14 such as a heater.
If heating becomes uneven, and in severe cases, sheet 1
5 is broken.

When the moldable sheet 15 is heated and softened by the heater 14, the molded product and the heated and softened sheet are brought into close proximity or in contact with each other by the mold clamping cylinder 12.

For this purpose, the force for sliding the outer mold by the cylinder or spring 17 is greater than the force necessary for sliding and the sealing force that can maintain airtightness with the moldable sheet 15 sandwiched between the upper mold 13 and the outer mold 11. and must be less than the mold clamping force of the mold clamping cylinder.

Next, the inside of the upper mold 13 is returned to atmospheric pressure, and if necessary, pressurized gas is introduced to mold the sheet 15 and bring it into close contact with the molded product 16 (FIG. 6).

Next, after returning the interiors of the upper mold 13 and the lower mold 10 to atmospheric pressure, the molds are opened and the molded product 16 with the moldable sheet 15 in close contact with it is taken out.

Conventionally, when performing this type of contact molding, it was necessary to use a special machine with a special mechanism, but if the mechanism of the present invention is used to create a mold device, it can be used with a press machine commonly available on the market. It can be installed on the device, the device can be simplified, and the cost advantage is also very large.

The following will explain based on examples.

Example 1 The apparatus schematically described in FIG. 2 was mounted on a press having a pressing force of 50 tons. Far-infrared ceramic heaters (8 100W) were used as heaters, and two cylinders were used to move the product stand 10 and the outer mold 11. In addition, the inner side of the mold is 400 x 400
The width was mm. Plastic injection molded products (ABS
(Fig. 8) and print the wood grain between the upper and outer molds.
An ABS sheet (300μ) (Figure 9) was molded in close contact with the plastic molded product with an adhesive layer interposed toward it.
The molding method is to sandwich a wood grain pattern sheet and
The outer mold is tightened, and at the same time the sheet is heated while reducing the pressure in the upper and lower space through the sheet, until the sheet temperature reaches approximately 120℃.
℃, after the degree of vacuum in the upper and lower spaces is 10 Torr or less, apply 2 kg/cm ² of compressed air from the upper chamber, place the heating sheet along the molded product, maintain the pressure for about 10 to 15 seconds, and then open the upper and lower chambers. was returned to atmospheric pressure, the mold was opened, and a molded product was obtained. The end film of the molded product was cut off with a cutter and the ends were finished to obtain a final molded product. The obtained sheet molded product closely adhered to the plastic molded product 20 as shown in FIG. 10, and the adhesion strength was also very strong.

Example 2 Using the contact molding apparatus described in Example 1 above, the ABS molded product shown in FIGS. 11 and 12 was left standing with the concave portion facing upward, equipped with a receiving jig, and the transfer foil whose structure is shown in FIG. 13 was placed. The product was sandwiched between upper and outer molds, and the same operations as in Example 1 were performed to perform close contact molding. After the product was taken out, the base film 26 was peeled off to obtain a product transferred onto a concave curved surface. These transfer-painted products had good physical properties and a good appearance.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional device, Figs. 2 to 7 are explanatory diagrams of an apparatus of the present invention, Fig. 8 is a sectional view of a plastic molded product, and Figs. 9 and 13 are an explanatory diagram of a molding sheet (transfer sheet). 10 is a sectional view of a close contact molded product, FIGS. 11 and 12 are a sectional view and front view of a plastic molded product, and FIG. 13 is a sectional view of a transfer sheet. 1, 13... Upper mold, 2, 11... Outer mold,
3,15... Seat, 4,14... Heater,
5,16... Molded product, 6,10... Product stand, 7,
8, 12... Piston and cylinder, 19...
Vent hole, 17... Piston and cylinder or spring, 20... Plastic molded product, 21...
...Top coat layer, 22, 29...Ink layer, 2
3, 26... Base film, 24, 30... Adhesive layer, 27... Mat layer, 28... Peeling layer, 25
...Picture layer.

Claims (1)

[Scope of Claims] 1. A product table having a vacuum suction mechanism, which is in contact with the outer periphery of the product table and can be moved up and down relative to the product table while maintaining sealing performance by means of a piston and cylinder or a spring mechanism. A possible outer mold, an upper mold that can be sealed by sandwiching a moldable sheet together with the outer mold, and has an air blowing mechanism and a heating device, and a product stand or upper mold. A contact molding device with a piston and cylinder for vertical movement. 2 Place the molded product on the product stand, place the moldable sheet on the outer mold, move the product stand and the outer mold or the upper mold, and place the molded product between the outer mold and the upper mold. By sandwiching the formable sheet, the space between the upper mold and the formable sheet and the space between the product stand, the outer mold, and the formable sheet are sealed, and then both spaces are vacuum-sucked. , the moldable sheet is heated and softened by a heating device, the product stage is moved relative to the outer mold, the molded product is brought into contact with or close to the moldable sheet, and the molded product is placed between the moldable sheet and the upper mold. A contact molding method characterized by introducing air at atmospheric pressure or higher pressure to bring a moldable sheet into close contact with a molded product.