JPH0315545A - Vacuum adhesion molding method - Google Patents

Abstract

PURPOSE:To improve the appearance of an object to be coated, to enhance handling properties and to also enhance productivity and product value, in raising the pressures in upper and lower space parts, by turning a coating sheet material to the rear part of the object to be coated by the pressure difference between both space parts. CONSTITUTION:At first, an upper vacuum box 6 is opened and an object 1 to be coated is held to the upper part of a holder 5. Next, a coating sheet material 2 is placed on a frame part 10 and the upper surface of a lower vacuum box 7 is covered with the upper vacuum box 6 and internal air is sucked from both vent holes 8, 9 to bring upper and lower space parts 12, 13 to a vacuum state. Subsequently, a lift table 4 is raised to position the object 1 to be coated on the upper side of the coating sheet material 2 to be coated with the coating sheet material 2 and, thereafter, a valve is opened to raise atmospheric pressure. Herein, by releasing the pressures in the upper and lower space parts 13, 12 in such a state that the pressure P1 in the lower space part 12 is lower than the pressure P2 in the upper space part 13, the end part of the coating sheet material 2 can be allowed to get in from the surface part of the object 1 to be coated to the rear part thereof without hindrance by the air flow pressure caused by the pressure difference between both space parts.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a vacuum adhesion forming method for adhering a coating sheet material to the outer surface of an adherend using vacuum, and in particular, to The present invention relates to a vacuum contact molding method that allows the end portion to be attached from the front surface to the back surface of an adherend.

(Prior art) An upper vacuum box equipped with a heating member inside and a lower vacuum box equipped with a vertically variable adherend mounting section are arranged vertically, and the space between the upper and lower vacuum boxes is arranged vertically. A method of coating an adherend with a covering sheet material by placing a spreadable covering sheet material, and raising the lower adherend mounting part by setting the upper and lower vacuum boxes in a vacuum state is as follows:
This method has been conventionally known as a vacuum forming method, and according to this method, a spreadable covering sheet material can be attached (packaged) to an adherend with good adhesion. In addition, the special public
Publication No. 8-13352 discloses that when coating an adherend with a coating sheet material, the coating sheet material is applied by applying vacuum suction to the adherend side and applying high pressure to the coating sheet material side. A method has been proposed for adhering it well to the external surface of the body, and according to this method, it can be applied with good adhesion even to an adherend having a somewhat uneven surface.

l-2 (Problem to be Solved by the Invention) However, with the conventional vacuum adhesion method described above, although it is possible to adhere a sheet material with good adhesion to the surface of an adherend having some irregularities on the surface, It was not possible to apply sheet material from the front surface to the back surface of the garment. In addition, in the method disclosed in the above publication, since the covering sheet material is coated with the adherend placed on a mounting table with a flat surface, the sheet material is placed on the back side of the adherend. It was not possible to cover it completely. Therefore, in all conventional methods, it is necessary to cut the end of the sheet material on the back side of the adherend and then treat the back side of the adherend with painting, etc., resulting in poor productivity and poor appearance. It was a loss.

The present invention has solved the above problem, and its purpose is to enable the end portion of the covering sheet material to be pasted from the front side to the back side of the adherend, so that the back side of the covering body can be attached later. It is an object of the present invention to provide a vacuum contact forming method that does not require processing, improves productivity, and improves appearance.

(Means for Solving the Problems) The vacuum contact molding method of the present invention includes disposing a covering sheet material in a vacuum box, partitioning the inside of the vacuum box into two spaces with the covering sheet material, and By arranging the adherend in one of the spaces so that the periphery of its back surface is exposed, and reducing the pressure in both spaces, at least one of the adherend or the covering sheet material is moved in a direction toward each other. The covering sheet material is applied to the adherend, and then the reduced pressure in both spaces is released while the pressure in the space where the adherend is disposed is lower than the pressure in the other space. The above object is thereby achieved.

The vacuum contact molding method of the present invention will be explained below with reference to the drawings.

FIG. 1 shows an example of an apparatus used in the molding method of the present invention, and this molding apparatus includes a lower vacuum box 7 whose top surface is open, and an upper vacuum box which is detachably attached to the upper surface of the lower vacuum box 7. A vacuum box 11 consisting of 6 is provided.

3-4 The lower vacuum box 7 is provided with an elevating table 4 that allows the adherend 1 to be raised and lowered, and a holder 5 for holding the adherend 1 is attached to the upper surface of the elevating table 4.

When the adherend 1 is placed on the upper part of the holder 5, the periphery of the back surface of the adherend 1 is exposed downward.

When a cylinder with a bottom is used as the adherend 1, the holder 5 is inserted into the adherend 1 from the lower opening of the adherend 1, and the upper end of the holder 5 is brought into contact with the bottom surface of the adherend 1. It is maintained by

A frame portion 10 for holding the periphery of the covering sheet material 2 is provided at the upper end of the lower vacuum box 7, and this frame portion 10
By placing the periphery of the covering sheet material 2 on the vacuum box 11, the vacuum box 11 is partitioned into upper and lower parts by the covering sheet material 2.
A lower space 12 and an upper space 13 are formed in which the adherend 1 is accommodated.

Vent holes 8 and 9 are provided in the inner walls of the upper vacuum box 6 and the lower vacuum box 7, and a vacuum deaerator is connected to each vent 8 and 9 via a valve, and the upper space 13 and the lower space are 12 is configured so that the inside can be vacuum degassed or brought to normal pressure as appropriate. Note that the inner surfaces of the upper and/or lower vacuum boxes 6 and 7 are covered with a coating sheet material 2.
A heater may be provided to heat and soften the material.

The covering body can be formed using the above-mentioned cutting device in the following manner.

First, the upper vacuum box 6 is released, and the adherend 1 is held on the upper part of the holder 5 provided on the lifting table 4. next,
The covering sheet material 2 is placed on the frame 10, the upper vacuum box 6 is placed over the upper surface of the lower vacuum box 7, and the air inside is sucked through both the vents 8 and 9, thereby removing the upper space 13 and the lower part. The inside of the space 12 is brought into a reduced pressure state. The degree of vacuum here is preferably 50 Torr or less, more preferably 10 Torr or less.

Next, by raising the lifting platform 4 and positioning the adherend 1 above the covering sheet material 2, the adherend 1 is covered with the covering sheet material 2 (Fig. 2 (a), b))
Then, by opening the valve, external air is allowed to flow in through both the vents 8 and 9, thereby increasing the air pressure in the upper space 13 and the lower space 12. Here, the atmospheric pressure P in the lower space 12 is the upper space 1
Both spaces l3, l2 in a state lower than the atmospheric pressure P2 in
In particular, it is preferable to rapidly change the internal pressure from the above-mentioned degree of vacuum to normal pressure. The lower space 12 in which the adherend 1 is accommodated in this way
By releasing the pressure in the upper and lower spaces 13 and 12 while the pressure inside the upper space 13 is lower than the air pressure P2 in the upper space 13, as shown in FIG. The end portion 2a of the sheet material 2 can be inserted from the front surface (side surface) to the back surface of the adherend 1 without any trouble by the wind pressure caused by the pressure difference. The ratio P2/P of the air pressure in the upper space 13 to the lower space 12 may be as long as it allows the covering sheet material 2 to enter the back side of the adherend 1, for example, 1.1 to 1. It is preferable to set it to about 2.0. Next, after bringing the atmospheric pressure in the upper space 13 and the lower space 12 to normal pressure, the upper vacuum box 6 is opened and the covering is taken out.

The covering sheet material 2 used in the present invention is usually made of a material whose sheet has a spreadability of about 5% or more at room temperature or in a heated state, and the sheet material is spreadable under the pressure of a gas such as air. Any material or sheet structure that can be used can be used as long as it is deformable.For example, the following may be mentioned, and in order to improve adhesion, adhesive may be used on the adherend 1 side. A sexual layer may be provided.

■Thermoplastic resins and their foams: polyolefins such as polyethylene and polypropylene, vinyl chloride resins such as polyvinyl chloride and polypinylidene chloride, copolymers of ethylene-vinyl alcohol, ethylene-vinyl acetate, ethylene-vinyl acetate carbon monoxide, etc. Coalescing, polystyrene, fluororesins such as polyvinyl fluoride and polyvinylidene fluoride, acrylic resins, urethane resins, etc.

■Elastomers: acrylic rubber, chloroprene rubber (natural rubber), butadiene rubber, etc.

■ Thermosetting resin: uncured or semi-cured material consisting of acrylic polyol and blocked isocyanate, or -8 uncured or semi-cured material containing acrylic resin and reactive monomer.

■Photocurable resin, etc.

■Animal leather, etc.

According to the above method, the back side of the adherend 1 held by the holder 5 is exposed downward and a gap is formed between the back side and the top surface of the lifting platform 4, so the covering sheet The end portion 2a of the material 2 can be inserted into the adherend 1 from the front surface (side surface) to the back surface without any trouble by wind pressure, and can be attached to the back surface of the adherend 1.

In addition, in the above, both the upper vacuum box 6 and the lower vacuum box 7 are evacuated, but a vacuum contact molding method in which only the lower vacuum box 7 on the adherend 1 side is evacuated and sheet adhesion is performed, The lower vacuum box 7 is opened to the atmosphere and the upper vacuum box 6 is pressurized to adhere the sheet using a compressed air forming method, or a molding method that combines the above-mentioned vacuum contact molding and pressure forming is adopted. Good too. In addition, by locally heating a part of the sheet material 2, the sheet material 2 can be made to stretch easily and can be applied to the back surface of the adherend 1 more effectively and in a shorter time. In this case, hot air may simply be blown, but a heating device such as a sheet heating element may be installed outside the back surface of the adherend 1.

(Example) Next, the present invention will be explained based on examples.

Vacuum contact molding machine shown in Figure 1 (vertical 300 x horizontal 300 x
Height 800m+n: Lifting platform stroke length 200mm=
The distance between the seat and the surface of the platform during descent) was used.

The lifting platform of the above molding machine has a radius of 50 mm and a height of 90 mm.
Attach a cylindrical holder, and place a steel plate (with a radius of 120 mm, a height of 60 mm, and a thickness of 1 mm) on top of this holder.
An adherend consisting of a bottomed cylindrical body of SS-41) was placed with the opening facing downward. A gap of 30 mm was created between the lower surface of the adherend and the upper surface of the lifting platform.

Next, a soft vinyl chloride resin adhesive sheet (manufactured by Sanpo Jushi Kogyo, made by laminating 30 μm of acrylic adhesive on one side of a 60 μm thick soft vinyl chloride resin sheet) was placed on the frame of the molding machine, with the adhesive on the bottom side. After tightening the molding machine, the upper vacuum box of the molding machine was closed.

Next, the pressure inside the upper space and the lower space is reduced, and when the ultimate vacuum level reaches 8 Torr, the lifting platform is raised and a soft vinyl chloride resin adhesive sheet is applied to the adherend, and then the inside of the upper space and the lower space are With the internal pressure ratio set at 1.5 times, the upper and lower spaces were opened to normal pressure, and then the covering was taken out from the vacuum box.

Appearance was evaluated by visually observing the appearance of the back surface of the obtained covering, and the length of the sheet pasted inward from the lower end of the side surface of the adherend was measured. The results are shown in Table 1.

A cylindrical holder with a radius of 100 mm and a height of 100 mm was attached to the top surface of the lifting platform using the same vacuum contact forming machine as in Example 1, and a cylindrical holder with a radius of 150 mm and a thickness of 1 mm was placed on top of this holder.
A hemispherical adherend (bowl shape) made of a steel plate (SS-41) with a diameter of 1 mm was set with the convex portion facing upward. A gap of 30 mm was created between the periphery of the lower surface of the adherend and the upper surface of the lifting platform.

Next, acrylic polyol (manufactured by Nippon Shokubai Chemical Co., Ltd., Alotane 145, weight average molecular weight 339,000, Tg 40
0C, OH value 80) too parts by weight and Prosoxyisocyanate (manufactured by Nippon Polyurethane Industries, Coronate 1513)
, NGO=10. An uncured thermosetting resin sheet consisting of 47 parts by weight (2%) was set in the frame of the molding machine, and the upper vacuum box was closed. Next, the pressure inside the upper and lower spaces is reduced to reach an ultimate vacuum of 8 Torr, and the lifting platform is raised to cover the adherend with a resin sheet, and then the pressure inside the upper and lower spaces is reduced. The ratio is 1.
The upper and lower spaces were opened to normal pressure in the 5 times larger state, and then the covering was taken out from the vacuum box.

The obtained coating was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Salt drinking Example 1 A coating was obtained in the same manner as in Example 1, except that the upper and lower spaces were opened to normal pressure with almost no pressure difference between the upper and lower spaces.

-11 -12 The obtained coating was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Table 1 As shown in Table 1, the covering obtained in the comparative example had wrinkles at the end on the back side, and no sheet material was attached to the back side.

On the other hand, in the coated bodies obtained in Examples 1 and 2, the sheet material was attached even to the back side, and the appearance was good.

(Effects of the Invention) According to the present invention, when increasing the pressure in the upper and lower spaces, the pressure difference between the two spaces causes the covering sheet material to wrap around the back surface of the adherend. A sheet material will be pasted on the back side. Therefore, the back side of the adherend can be coated with a sheet material without particularly requiring complicated and expensive equipment, and wrinkles etc. may occur when covering the adherend with a paint sheet, adhesive sheet, etc. In addition to improving the appearance without causing any damage, it is also possible to improve the handling of the covering after processing (cutting) the sheet material at the edge, thereby increasing the productivity and product value of the covering.

4. 1 is a schematic explanatory diagram of a molding apparatus used in the present invention, and FIGS. 2(a) to 2(c) are explanatory diagrams of the molding method of the present invention.

1... Adherent, 2... Covering sheet material, 6...
Upper vacuum box, 7... Lower vacuum box, 11.
...Vacuum box, l2...Lower space, l3...
Upper space.

that's all

Claims (1)

[Claims] 1. Arrange a covering sheet material in a vacuum box, partition the inside of the vacuum box into two spaces with this covering sheet material, and expose the back side of the adherend in one space. The covering sheet material is applied to the adherend by moving at least one of the adherend and the covering sheet material in a direction toward each other with both spaces in a reduced pressure state, and then A vacuum contact molding method characterized in that a reduced pressure state in both spaces is released in a state where the pressure in the space in which the body is disposed is lower than the pressure in the other space.