JPS5947967B2 - Molding equipment that creates unevenness on thermoplastic resin sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a thermoplastic resin sheet with a reproduced painting, a building material woodgrain pattern, or other decorative printed design, and is molded to give a three-dimensional effect of an uneven shape to a desired part in accordance with the printed design. It is related to the device.

Conventional molding equipment for forming three-dimensional uneven patterns such as embossing on the surface of thermoplastic synthetic resin sheets and molded products includes: 1) mold (or silicone resin mold) pressing equipment using high-frequency dielectric heating;

2) Mold (or silicone mold) press equipment (lithography, roll press, etc.) using heater heating.

For example, the device described in Japanese Patent Publication No. 40-27014. 3
) One female injection heating device using an injection molding machine.

4) Heat vacuum forming method.

For example, the device described in Publication No. 43-17823. 5
) Other devices described in Japanese Patent Application Laid-Open No. 49-45164.

However, for example, when molding a large area or a product that requires high precision, the mechanical precision and processing precision of the equipment must be strict in order to ensure surface precision with any of the above devices. b. Equipment costs are extremely high, power consumption is high, and costs are high.Also, in terms of quality, temperature distribution during processing tends to be uneven, which reduces molding accuracy. This is especially true when trying to form precise uneven shapes that are faithful to the original painting, such as in the production of three-dimensional reproductions of paintings.
In these products, molding unevenness due to the non-uniformity of the temperature distribution becomes noticeable and becomes a cause of a decrease in yield and a decrease in commercial value.

The present invention is a new molding device that eliminates these drawbacks, and uses heated hydraulic pressure to form a desired matrix into a thermoplastic resin sheet with the above-mentioned printed pattern in an extremely simple and economical manner. The present invention aims to provide a molding device that accurately reproduces uneven shapes.

The present invention will be explained below based on the drawings. As shown in FIG. In addition to silicone resin molds, glass ceramics, and wooden molds,
Using natural materials, etc., first make a mold with the opposite shape of the desired uneven shape,
That is, a negative mold is formed, and a thermoplastic resin sheet 2 is provided with a printing ink layer 3 comprising a desired printed pattern such as a reproduced painting, a map, a natural wood grain pattern, etc. on the negative uneven surface of the mother mold 1. is placed 5 so that the printing ink layer 3 is in contact with the negative uneven surface and the position of the uneven surface matches the position of the printed pattern on the printing ink layer 3, and then the surrounding area is A pressure box 5 with a pressure seal 4 is placed on the part, and while the pressure seal 4 presses the periphery of the thermoplastic resin sheet 2, the periphery of the matrix 1 and the pressure box 5 are temporarily secured using a fixture 6. After the pressurized chamber is formed by sealing the inside surrounded by the pressurizing box 5 and the thermoplastic resin sheet 2, the heated liquid T is poured from the heated liquid tank 14 into the pressurized chamber. pump 1
The thermoplastic resin sheet 2 is introduced through the valve 10 opened at 2 and pressurized to soften it, and is press-molded onto the uneven surface of the mother die 1 as shown in FIG. This invention relates to a molding device for forming irregularities on a thermoplastic resin sheet, which is characterized by faithfully reproducing the irregularities of a matrix on both sides of a thin sheet and on one side of a thick sheet. When taking out the thermoplastic resin sheet molded by the above-described molding apparatus according to the present invention from the sealed pressurized chamber, it is necessary to first send the heated liquid to the outside and cool the inside of the room. After opening the compressor 8 and rapidly introducing compressed air from the compressor 13 through the pipe 16, the fixture 6 can be removed and taken out.

In addition, when manufacturing the mother mold 1, it is possible to use the conventionally used molten metal spraying method or silicone rubber injection method as a reproduction method of the original mold, but it is also possible to use a glass, ceramic mold, wooden mold, etc. In this case, it can be obtained by hair carving, mechanical processing, chemical processing, etc., and it is also possible to use natural materials such as natural stone or wood as they are.

In the molding conditions using a heated liquid, which is the mainstay of the present invention, the first liquid that can be used is water, as well as non-flammable or flame-retardant oil, which does not carbonize even at high temperatures and has extremely low evaporation components. For example, silicone oil, high-temperature hydraulic oil, etc. are used, and the heating temperature and pressurizing conditions for these heated liquids are as follows: In the case of water, the temperature is around 100°C and the pressure is 70 to 80 kg/Cd). Approximately 30 seconds is recommended. In the case of oil, the optimum conditions are a temperature of 120 to 140°C, a pressure of 30 to 50 kg/Cd, and a pressurizing time of 15 to 20 seconds.

Further, as a pressurizing means, a gear pump may be used in the case of oil, but a plunger pump must be used in the case of water. Furthermore, in order to remove air present in the gap between the thermoplastic resin sheet and the matrix surface, which may be an obstacle during molding, an appropriate air vent may be provided around the matrix surface. Example 1 In the production of three-dimensional reproduction paintings, a desired original image is printed by gravure or offset printing on a silicone rubber master mold 1 which has been previously molded from the original image to a thickness of 0.4~
0.25? The hard vinyl chloride sheets 2 are stacked so that the printed surface and the mold surface of the matrix 1 are in contact and the pattern matches the mold surface, and then placed on the back side of the original print sheet, that is, around the non-printing surface of the original. A pressure box 5 with a pressure-resistant seal 4 provided on the periphery is placed thereon, and the processing box 5 and the matrix 1 are placed in such a way as to create a sealed pressure chamber surrounded by the pressure box 5 and the original print sheet 2. After fixing with the fixture 6 around the pressurizing chamber, hot water of around 100° C. is sent from the heated liquid tank to fill it,
Plunger pump pressure is 70k9/Ct! After the molding is completed by applying pressure for 110 seconds, hot water is discharged by sending compressed air into the pressurizing chamber.

That is, the valves 8 and 11 are closed and the heat source 19 is opened by opening the valves 9 and 10.
After heating the hot water in the heated liquid tank 14 using the plunger pump 12 and filling it into the pressurizing chamber through the introduction pipe 15, the valve 9 was closed and the pressure in the pressurizing chamber was 70 k9.
/Cd, close the valve 10 and apply pressure for 10 seconds,
Next, at the same time as the pulp 11 is opened, the valve 8 is opened to send compressed air from the compressor 13 through the air pipe 16 to the pressurizing chamber, and heat water through the discharge pipe 18 to the liquid tank 14.
When the hot water and air have been completely replaced, the valve 8
, close 11.

The compressed air that enters the pressurizing chamber undergoes adiabatic expansion and its own temperature drops rapidly, so it softens and has the effect of significantly cooling the uneven surface of the hard pinyl chloride sheet. Therefore, residual moisture in the pressurized chamber is evaporated and easily discharged outside the pressurized chamber. After that, the valve 9 is opened and compressed air is discharged from the exhaust pipe IT to return the inside of the pressurized chamber to normal pressure, and then the fixture 6 is released and removed. The resulting hard vinyl chloride sheet, which has unevenness that is faithful to the original image, is taken out after cooling, and when the recesses on the non-printing side are filled with vinyl resin to make it flat, and that side is pasted onto a canvas, the unevenness will be created on the surface. A three-dimensional reproduction of the painting is obtained. As mentioned above, the molding device of the present invention for forming irregularities on a thermoplastic resin sheet is different from the conventional molding devices described above in that it uses a heated liquid and directly molds the thermoplastic resin sheet, which is the workpiece. Since it is press-molded onto the sheet surface, it is possible to apply extremely uniform temperature and pressure to the entire surface of the workpiece, and the highly flexible hydraulic effect faithfully reproduces even the minute unevenness of the mother mold. Of course, it is possible to obtain uniform, high-precision products with high quality, and it is also possible to mold extremely large and wide-area products that are difficult to mold using other conventional methods, even if the surface accuracy is somewhat rough. Since the pressure is increased, the equipment itself is simple and light, and therefore the equipment cost is low, and power consumption is also low, so it has the feature that it can be implemented extremely economically.Furthermore, the heating and pressurizing equipment according to the present invention The range of application is wide, and it is a molding device that can process not only a single sheet but also multiple laminated sheets. This molding device is useful for molding various other three-dimensional decorative sheets.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a molding apparatus for forming irregularities on a thermoplastic resin sheet according to the present invention, and is a cross-sectional view showing the equipment used and the state of use. b is a sectional view showing the molding process of the thermoplastic resin sheet and the shape after molding; a shows the finished molded shape when the sheet is thin, and b shows the finished molded shape when the sheet is thick. In the figure, 1 is a matrix made of an object with an uneven surface, 2 is a thermoplastic resin sheet, 3 is a printing ink layer, and 4 is a pressure-resistant seal (
O-ring), 5 is a pressure box, 6 is a fixture, 7 is a heated liquid,
8, 9, 10, 11 are valves, 12 is a pump (plunger pump or gear pump flyer, 13 is a compressor, 14 is a heated liquid tank, 15 is an inlet pipe, 16 is an air supply pipe, 17 is an exhaust pipe, and 18 is a discharge pipe) , 19 is a heating source.

Claims (1)

[Claims] 1. A pressurized box that has an inlet and an outlet for the heated liquid and compressed air that are introduced from the outside, and that is provided with a pressure-resistant seal on the contact surface with the opposing mother mold surface inside the periphery; A matrix made of an object having a desired uneven surface provided opposite to the inside of the pressurizing box, and a fixture for removably fixing the matrix and the pressurizing box in a peripheral area. The thermoplastic resin sheet is characterized in that the sheet to be processed is sandwiched between a pressure-resistant seal and the surface of the matrix, and the sheet to be processed is pressed onto the surface of the matrix from the pressure box side using heated liquid. A molding device that creates unevenness.