JPH0957843A - Laminating vacuum / pneumatic molding method - Google Patents

Abstract

(57) [Abstract] [Problem] A high-quality laminating vacuum that increases the degree of adhesion between the resin sheet and the surface of the base material sheet and has excellent surface transferability.
A pressure forming method is provided. SOLUTION: Among the molds which are vertically opposed to each other, a resin sheet for bonding is placed on the cavity surface of the lower mold, and then a plurality of vent holes for suction are arranged in the lower mold. Vacuum suction is performed, and then the base material sheet is superposed on the resin sheet, and then the upper die is lowered and the resin sheet and the base material sheet are sandwiched to clamp both dies. Pressurized air is jetted toward the material sheet and pressed along the cavity surface, and at the same time, the heat medium is circulated through the medium passage that heats and cools the die disposed inside the lower die, and the resin sheet Was heated above the softening point temperature, and then a refrigerant was circulated to cool the molded product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an appearance in which a base material sheet is superposed on a resin sheet placed on the cavity surface of a lower mold, and the resin sheet and the base material sheet have good adhesion. The present invention relates to a bonding vacuum / pneumatic molding method capable of obtaining an excellent and high-quality resin sheet bonded molded article.

[0002]

2. Description of the Related Art In FIG. 1, a pair of upper and lower molds 8 (a lower mold 8A and an upper mold 8B) are arranged in a molding apparatus main body (not shown) so that they can come into contact with and separate from each other. A cooling medium passage 8d for cooling the cavity surface of the lower mold 8A is provided inside the lower mold 8 and is connected to a cooling medium supply device (not shown).

Further, a plurality of vent holes 8b, which penetrates the lower mold 8A from the cavity surface of the lower mold 8A at right angles to the cavity surface and discharges air, are provided at appropriate intervals. Further, in the lower mold 8A, in order to positively suck the air discharged from the vent holes 8b, the lower mold 8A
A collecting duct 10A is provided so as to cover the outside of A, an exhaust pipe 11 is provided with a solenoid valve 12A and a suction fan 14, and a suction fan with the resin sheet S placed on the lower die 8A. 14 to operate the resin sheet S
It was designed to be sucked so as to contact the cavity surface. On the other hand, in the upper die 8B, the collecting duct 10B is arranged so as to cover the back of the die 8B so that the pressurized air can be ejected from the ejection holes 8c in the direction of the base material sheet M, and is connected to this. Supply pipe 11A and solenoid valve 12B
The pressurized fan 14B supplies the pressurized air in the longitudinal direction of the base material sheet M via the.

[0004]

However, while using such a conventional pair of vertically contacting and separating molds, the cavity surface of the mold becomes 80 ° C. in the cooling medium passage 8d of the lower mold 8A. When attempting to form a vacuum pressure-molded product by laminating with a cooling medium flowing,
The resin sheet S is torn during molding, wrinkles are generated on the surface of the molded product to impair the formation of a smooth flat surface, or air is present between the resin sheet S and the base material sheet M to form the molded product. The resin sheet S and the base material sheet M remain as bubbles on the surface.
There was a problem that and did not adhere to the entire surface. In addition, the surface properties of the conventional resin sheet of the vacuum-pressure-bonded laminated product are poor, and there is a drawback that the product value is low due to lack of gloss.

The present invention has been made in view of the above problems, and relates to a high-quality bonding vacuum / pressure air forming method which increases the adhesion between the resin sheet and the base material sheet surface and is excellent in surface transferability. is there.

[0006]

In order to achieve the above object, in the present invention, a resin sheet for bonding is placed on a cavity surface of a lower mold among a pair of molds arranged vertically. After that, vacuum suction is performed from a plurality of suction vent holes provided in the lower mold, and subsequently, the base material sheet is superposed on the resin sheet, and then the upper mold is lowered to lower the resin sheet and the mother sheet. Both molds are clamped with a material sheet sandwiched between them, and pressurized air is jetted from the upper mold toward the base material sheet to press along the cavity surface and at the same time, it is placed inside the lower mold. A heat medium was circulated in a medium passage for heating / cooling the mold to heat it to a temperature equal to or higher than the softening point temperature of the resin sheet, and then a refrigerant was circulated and cooled to take out the molded product.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, an ABS resin sheet having a decorative pattern such as a wood grain pattern is placed on the cavity surface of a lower mold and preheated to 150 to 200 ° C. The base material sheets are superposed and clamped. Then, after heating the lower mold to 130 ° C., which is the softening temperature of the resin, with a heating medium, switching to a cooling medium and cooling to 80 ° C. and taking out the molded product, the adhesion between the base material sheet and the resin sheet is improved. It is possible to easily obtain a bonded molded product which is further improved and has good surface properties and high commercial value.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings.

FIG. 1 is a molding die apparatus for carrying out the bonding vacuum / pneumatic molding method of the present invention, and FIG. 2 is a graph for explaining the mold temperature change in the bonding vacuum / pneumatic molding method of the present invention. FIG. 3 is a process explanatory view showing a process procedure of the bonding vacuum / pneumatic molding method of the present invention.

In FIG. 1, a pair of upper and lower molds 8 (a lower mold 8A and an upper mold 8B) are arranged in a molding apparatus main body (not shown) so that they can come into contact with and separate from each other. Inside the lower die 8, a medium passage 8a for switching and flowing a heat medium or a refrigerant body to heat or cool the cavity surface of the lower die 8A is arranged, and a medium (heat medium or refrigerant body) switching supply device not shown. Connected with.

Further, a plurality of vent holes 8b, which penetrate the lower mold 8A from the cavity surface of the lower mold 8A at right angles to the cavity surface and discharge the air, are arranged at appropriate intervals. Further, in the lower mold 8A, in order to positively suck the air discharged from the vent holes 8b, the lower mold 8A
A collecting duct 10A is provided so as to cover the outside of A, and an exhaust pipe 11 is provided with a solenoid valve 12A and a suction fan 14. Alternatively, the lower mold 8A has a vent hole 8
Instead of b, a metal innumerable with fine air holes, that is, a porous metal may be used.

On the other hand, in the upper die 8B, for example, 5
Collecting duct 10 so that low-pressure pressurized air of about 6 kg / cm @ 2 can be jetted in the direction of base material sheet M from jet holes 8c.
B is arranged so as to cover the back of the mold 8B, and pressurized air is supplied in the longitudinal direction of the base material sheet M by the pressure fan 14B via the supply pipe 11A and the electromagnetic valve 12B connected to this. It

The thickness of the resin sheet S is not preferably too thick because it is necessary to manufacture a laminated product, and is usually 1 mm or less, but preferably 0.5 mm or less. If the resin sheet S is too thick, it is difficult to obtain a molded product that matches the cavity shape in the deep shape in which wrinkles easily occur. In addition, the cooling time after molding becomes long and the productivity is lowered. If it is too thin, the resin sheet S
May be damaged during molding. On the surface of the resin sheet S, fine through holes for discharging the air present between the base material sheet M and the resin sheet S at the time of pressure-bonding with the base material sheet M are provided, for example, in a lattice shape or a zigzag shape. A plurality of them are arranged and provided.

The diameter of the fine through holes is 0.1 mm to 1 mm.
It is preferable that the arrangement density is at least 0.1 mm to 0.3 mm and the arrangement density is at least 1 per 100 cm ² , but preferably 4 to 5 per 100 cm ^2.
It is desirable that the number is 00 or less. The reason is that if the diameter of the fine through holes is 0.1 mm or less, it is difficult to discharge the gas, and if it is 0.3 mm or more, the traces of holes are likely to remain after molding, and the lower limit of the array density (one per 100 cm ² ). The above is determined from the minimum required gas discharge area, and the upper limit of the array density (500 or less per 100 cm ² ) is derived even if the larger number is provided, the same gas discharge effect.

Since the "return" at the time of drilling the fine through holes remains as convex projections on the resin sheet S, the resin sheet S is set with the convex projections facing the lower mold 8A. As a result, the convex projections are pressed against the heated cavity surface of the lower mold 8A and softened and melted to close the fine through holes, so that traces of holes disappear and the appearance of the molded product is not impaired. However, when the elongated ribbon-shaped resin sheet S is locally attached to the surface of the base material sheet M, the fine through holes may be omitted (the intervening air deviates from the left and right ends of the ribbon-shaped resin sheet S). Therefore, it does not need a fine through hole).

After the mold is closed, the resin sheet to be bonded to the base material sheet M by the injection pressure injected from the injection holes 8c provided in the upper mold 8B to the back surface (the resin sheet S side is the front surface) of the base material sheet M. The air between S and S is completely eliminated, and in order to prevent defects such as generation of bubbles on the surface of the molded product due to the air remaining between the two, pressurizing air at a low pressure of, for example, about 5 to 6 kg / cm @ 2 is used. .

The heating temperature and the cooling temperature of the lower mold 8A are appropriately selected according to the kind of resin on the surface of the resin sheet S which is in contact with the mold. That is, the resin sheet S is usually manufactured by extrusion molding and has a poor surface property. In order to improve the surface property of the bonded vacuum-pressurized molded product of the present invention, in other words, the surface transfer property of the molded product is improved. In order to achieve this, the resin is heated to a temperature at which it softens or higher, and after surface transfer is sufficiently performed, it is cooled immediately. The base material sheet M
In order to improve the adhesiveness with the resin sheet S, it is necessary to heat the base material sheet M to a temperature at which the resin softens in advance. The softening temperature of the resin is equal to the glass transition temperature in the case of the amorphous resin, and 110 ° C to 13 in the case of the ABS resin.
It is 0 degreeC, and is 120 degreeC-140 degreeC about modified PPO resin.

On the other hand, in the case of a crystalline resin, the temperature between the crystallization temperature and the melting point is suitable, 130 ° C. to 160 ° C. for PP and 100 ° C. to 1 ° C. for PE.
The temperature is 30 ° C and 180 ° C to 230 ° C for nylon 6. On the other hand, the cooling temperature is set to about 80 ° C. to 100 ° C., and the temperature change of the mold temperature in one step is, for example, as shown in FIG. , And either may be used. Temperature curve A
Is called the "cool start" method in which the mold temperature is low when the parison P is injected and the mold is closed, and the temperature curve B is called the "hot start" method in which the mold temperature is high when the mold is closed. Various types of oil, water, and pressurized water (steam) can be used as the heat carrier and refrigerant.
Is preferably used, and it is desirable to use the same substance at different temperatures.

The operation of the laminating and molding method using the vacuum / compressed air molding apparatus configured as described above will be described.

FIG. 3 is a process explanatory view showing a procedure of a laminating and forming process using a vacuum / pressure forming device. As shown in FIG. 3, first, in the first step, a decorative pattern (for example, a wood grain pattern) is placed on one lower mold 8A while holding both molds 8A and 8B in the upper and lower mold open states. The resin sheet S made of ABS resin is placed so as to face the cavity surface. Next, the suction fan 14 is operated to perform vacuum suction of the internal air from the cavity surface of the lower mold 8A to help the resin sheet S fit to the cavity surface of the lower mold 8A. As described in the above-mentioned prior art, the resin sheet S does not have to completely fit the cavity surface of the mold, and if the approximate shape is along the cavity surface, the subsequent heating step (the third step). ), The cavity facing surface of the resin sheet S is completely melted to transfer the cavity surface, and the residual gas is discharged by suction from the vent hole 8b. Therefore, the resin sheet S fits the mold cavity surface exactly. It does not cause wrinkles or bubbles.

In the second step, the resin sheet S is placed on the lower die 8A.
After the base material sheet M made of ABS resin preheated to 150 to 200 ° C. is placed on the resin sheet S while being attached to the cavity surface of the above, the upper die 8B is lowered in the die closing direction.

In the third step, the lower die 8A is heated by passing the heat medium through the medium passage 8a, and the resin sheet S and the base material sheet M are heated.
And the mold cavity surface is transferred onto the surface of the resin sheet S. Then, after that, the cooling medium is passed through the medium passage 8a to cool the lower mold 8A. The heating / cooling of the lower mold 8A is performed by, for example, the temperature curve A shown in FIG.
According to any of B, the temperature is raised or lowered. That is, in the third step, the temperature of the cavity surface of the lower mold 8A is in the vicinity of the softening point of the resin sheet S, the surface of the resin sheet S is softened and melted, and the mold cavity surface is pressed by the mold cavity surface. When the pressurized air is transferred from the injection holes 8c of the upper die 8B toward the back surface side of the base material sheet M (the front surface side is the surface facing the resin sheet S), the resin sheet S And base material sheet M
And are pressure-bonded together and joined.

Then, in the next step, the upper mold 8B is lifted to open the mold, and the molded product is taken out. The resin sheet S used in the molded product obtained by the bonding vacuum / pressure of the present invention is
A normal commercial product produced by extrusion molding may be used, but as described above, a decorative pattern or a decorative pattern is printed on one surface (the surface side of the molded product), for example, an ABS extruded sheet may be used. For example, various panel-shaped molded articles having high gloss and arbitrary colors and patterns can be obtained.

As its applications, daily commodities (chairs, TV stands, bookshelves, cabinets, system kitchens, blackboards, sheds, desk tops, piling tops, furniture doors, side panels, bathtubs, mirror stands, etc.) Dishwasher door, washing machine door, washing machine side plate, TV, speaker box, computer housing, etc. Automotive products (spoiler, glove box door, instrument panel, rear partial shelf, door trim, side garnish, console box, road floor, Humpers, fender trunk lids, motorcycle fenders, outer panels, etc.) Construction materials (doors, wall materials, partition boards, partitions, etc.) There are daily sundries.

[0025]

As is apparent from the above description, in the present invention, after the resin sheet for bonding is placed on the cavity surface of the lower mold, of the pair of molds arranged vertically. , Vacuum suction from a plurality of vent holes for suction arranged in the lower mold, and subsequently, the base material sheet is superposed on the resin sheet, and then the upper mold is lowered to lower the resin sheet and the base material. While sandwiching the sheet and clamping both dies, the upper die blasts pressurized air toward the base material sheet and presses it along the cavity surface, and at the same time, the dies placed inside the lower die The heat medium is circulated in the medium passage that heats and cools the mold to heat it above the softening point temperature of the resin sheet, and then the refrigerant is circulated and cooled to take out the molded product. Use resin sheets with decorative patterns and decorative patterns More design, it is possible to enjoy the diversity of design, to improve the commercial value. In addition, there are no wrinkles in the resin sheet and air bubbles between the resin sheet and the base material sheet, and since the fine through holes of the resin sheet can be crushed by heating the lower mold, the appearance becomes a completely smooth surface, and the quality is Greatly improved. Furthermore, only the coloring of the surface of the resin sheet is required, and painting after molding is unnecessary, and labor can be saved.

[Brief description of drawings]

FIG. 1 is a molding die apparatus for carrying out a bonded vacuum / pneumatic molding method according to the present invention.

FIG. 2 is a graph illustrating a mold temperature change in the bonding vacuum / compressed air molding method according to the present invention.

FIG. 3 is a process explanatory view showing a process procedure of a bonding vacuum / pneumatic molding method according to an embodiment of the present invention.

FIG. 4 is an overall vertical sectional view of a conventional blow molding machine.

[Explanation of symbols]

 1 Blow Molding Machine 2 Die Head 2a Resin Supply Port 3 Mandrel 3a Core 4 Injection Device 5 Valve 6 Paricon Cylinder 6a Paricon Rod 7 Annular Space Passage 8 Die 8A Lower Die 8B Upper Die 8a Medium Passage 8b Vent Hole 8c Injection Hole 10A, 10B Collecting duct 11A Supply pipe 11B Exhaust pipe 12A, 12B Solenoid valve 14A Suction fan 14B Pressurizing fan M Base material sheet S Resin sheet

Claims (1)

[Claims] 1. A pair of molds arranged vertically, a resin sheet for bonding is placed on a cavity surface of a lower mold, and then a plurality of suction molds arranged in the lower mold are arranged. Vacuum suction is performed from the vent hole, and subsequently, the base material sheet is superposed on the resin sheet, and then the upper die is lowered to clamp the resin sheet and the base material sheet to clamp the die and the upper die. Pressurized air is jetted from the mold toward the base material sheet and pressed along the cavity surface, and at the same time, the heat medium is circulated in the medium passage for heating and cooling the mold disposed inside the lower mold. A laminated vacuum / pneumatic molding method characterized in that a molded product is obtained by heating the resin sheet to a temperature not lower than the softening point of the resin sheet, then circulating a cooling medium to cool the molded product.