JPS63214424A - In-mold decoration of molded form - Google Patents

Abstract

PURPOSE:To eliminate faulty in-mold decoration and faulty bonding of deforming and bonding an in-mold decoration sheet so as to coincide with the surface condition of a molded form, by a method wherein heated air is sent into an upper chamber in evacuated condition to adhere the in-mold decoration sheet closely on the surface of the molded form under a condition that the in-mold decoration sheet is softened and an adhesive agent is activated. CONSTITUTION:An in-mold decoration sheet A is fixed between an upper chamber 20 and a lower chamber 21 so that adhesive agent is located at the side of a molded form B, then, the in-mold decoration sheet A is heated by a heater 50 to soften the sheet A and activate the adhesive agent. Valves 24A, 24B are opened during heating to evacuate the upper chamber 20 and the lower chamber 21, then, the valve 24A is closed and the valve 26A is opened when the in-mold decoration sheet A is softened, in order to send heated air instantaneously into the upper chamber 20 from a heated air tank 40. The temperature and pressure of the heated air are set considering the kind of the in-mold decoration sheet, the kind as well as the quality of the molded form and the cooling which is caused when the air is sent into the chambers under evacuated condition. When the in-mold decoration sheet is adhered to the surface of the molded form, the valve 26A is closed and the valves 22A, 22B, 24A are opened to introduce outside air, reduce the temperature of the in-mold decoration sheet A and fix the sheet to the surface of the molded form b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for decorating a molded article having a three-dimensional surface that cannot be decorated by direct printing.

[Subject skill]

Regarding the painting method that involves laminating a painted sheet onto a molded product having a three-dimensional curved surface or transferring the design, for example, this painting method involves gluing a sheet coated with adhesive to the painted surface of the molded product. The sheet is fixed to the inner periphery of the chamber so as to divide the inside of the chamber into two with the agent side facing, and after heating the sheet with a heater to soften it and activate the adhesive, vacuum suction is applied to the molded product side of the sheet, and the sheet is placed on the opposite side. The side of the molded product was placed in a compressed air state B (including normal pressure), and the sheet was glued to the decorated surface of the molded product to decorate it.

As mentioned above, in order to press the sheet against the painted surface of the molded product using gas, outside air was sent into the chamber in order to create a higher pressure than on the molded product side. At this time, adiabatic expansion occurred in the outside air and the sheet was cooled, making it impossible to adhere the molded product along the painted surface to the smallest detail, and the adhesive effect was also poor.

[Problem to be solved]

The present invention provides a painting method in which a decorative sheet is adhered to a molded product whose three-dimensional surface is a decorative surface by only suction and air pressure, and the decorative sheet can be adhered along the decorative surface when painting on the decorative surface. The purpose is to provide.

[Means for solving problems]

The molded product is placed in a chamber, a painted sheet is placed on the painted side of the molded product to divide the inside of the chamber into two, and then heated air is sent to the upper side of the molded product to bring the painted sheet into close contact with the surface of the molded product. It was resolved by this.

Here, the illustrated sheet is a plastic film that easily deforms along the molded product, such as a polyvinyl chloride film, with a pattern applied to it, and a true melt adhesive.
Either a laminate type, in which the sheet itself is adhered to the molded product, or a transfer type, in which the sheet is adhered to the molded product and then peeled off to leave only the pattern, may be used.

Further, the heated air may be pressurized air or air under normal pressure, and the heating temperature may be any temperature that does not cool the softened decorated sheet due to adiabatic expansion when fed into the chamber.

[For production]

Since the painted sheet is adhered to the surface of the molded product, even if air higher than the pressure inside the chamber is sent above the chamber separated by the painted sheet, the painted sheet will not be cooled down. Glued along the surface condition. Furthermore, the adhesive does not solidify during adhesion.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a painting device used in the present invention with a heater 50 installed at the top.
, it has a pedestal 60 on which the molded product B is placed at the bottom, and consists of an upper chamber 20 and a lower chamber 21 which are divided into two so that the illustrated sheet A can be sandwiched in the center. The upper chamber 20 and the lower chamber 21 are provided with vibrators 23A and 23 having opening/closing pulps 22A and 22B, respectively.
B and is connected to the vacuum pump 30 through a vibrator 25A, 25B having valves 24A, 24B.

Furthermore, the heated air tank 40 is passed through the vibrator 27 having the pulp 26A from the vibrator 25A from the upper chamber 20.
is connected to. To decorate a three-dimensional molded product using the apparatus shown in Figure 1, first fix the decorative sheet A between the upper chamber 20 and the lower chamber 21 so that the adhesive side faces the molded product B side. Then, the illustrated sheet A is heated by the heater 50 to soften it and activate the adhesive.

During the heating, the valves 24A and 24B are opened to suck air from the space surrounded by the upper chamber 20 and the lower chamber 21 to maintain a reduced pressure state.

Then, when the illustrated sheet A is softened, the pulp 24A is closed, the pulp 26A is opened, and heated air is instantly sent into the upper chamber 20 from the heated air tank 40.

At this time, the temperature and pressure of the heated air are set in consideration of the type of painted sheet, the type and nature of the molded product, and cooling due to adiabatic expansion that occurs when air is sent into the chamber in a reduced pressure state.

After sending the heated air as described above and bringing the painted sheet into close contact with the surface of the molded product, close the valve 26A and close the valve 22A.
, 22B and 24A and open the upper chamber 20. Outside air is introduced into the lower chamber 21, the temperature of the painted sheet A is lowered, and it is fixed on the surface of the molded article B.

〔effect〕

As described above, in the present invention, when bringing the painted sheet into close contact with the surface of the molded product, heated air is sent when air is sent into the chamber above the depressurized state, so that the painted sheet adheres to the surface of the molded product in a softened state. Because the agent remains activated, it remains in close contact with the skin.
The painted sheet is deformed to fully match the surface condition of the molded product,
Moreover, since it is bonded with adhesive, there may be defects in the details of the painting.
and no adhesion failure occurs.

In addition, when air is sent, heated air is sent in consideration of cooling by adiabatic expansion, so even if air is sent instantaneously, no defects in painting or adhesion will occur.

Furthermore, since the temperature and pressure of the heated air can be adjusted, beautiful painting is possible even if the type of decorative sheet, type of molded product, or properties change.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of an apparatus used in the painting method of the present invention.

Claims (1)

[Claims] (1) In a painting method in which a decorative sheet is placed in close contact with the surface of a molded product, the molded product is placed in a chamber, and then the painted sheet is placed on the painting surface side of the molded product in a state that divides the interior of the chamber into two. It is fixed to the inner peripheral edge, and the entire chamber is vacuum-suctioned while softening the painted sheet. Next, heated air is sent from above the molded product while vacuum suction is applied to the molded product side partitioned by the painted sheet. , a painting method in which a painted sheet is brought into close contact with the surface of a molded product.