JPH0315546A - Vacuum adhesion molding method - Google Patents

Abstract

PURPOSE:To enhance productivity and to improve appearance by spraying air to the circumference of the rear part of an object to be coated to bond the end part of a coating sheet material to the object to be coated from the surface part thereof to the rear part thereof. 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 to evacuate the upper and lower vacuum boxes 6, 7. 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 cover the object 1 to be coated with the coating sheet material 12 and, thereafter, a valve is opened to allow external air to flow in both boxes from both vent holes 8, 9 to release the vacuum in the upper and lower vacuum boxes 6, 7. Thereafter, air is sprayed to the circumference of the rear part of the object 1 to be coated from nozzles 3 to bring the end part of the coating sheet material 12 into pressure contact with the object 1 to be coated to bond the same to the rear part of the object 1 to be coated.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a vacuum bond forming method for adhering a covering sheet material to the outer surface of an adherend with good adhesion, and in particular, to a vacuum forming method for adhering a covering sheet material to the outer surface of an adherend. The present invention relates to a vacuum contact molding method that allows the adhesive to be applied from the front surface to the back surface of the body.

(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 a 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 coating 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 covering sheet material, a vacuum is applied to the adherend side and a high pressure is applied to the covering sheet material side. A method has been proposed for adhering the adhesive well to the outer surface of the adherend, and according to this method, it can be applied with good adhesion even to an adherend having a somewhat uneven surface.

(Problems to be Solved by the Invention) However, in the conventional vacuum adhesion method described above, although it is possible to adhere a sheet material to the surface of an adherend having some unevenness on the surface, It was not possible to attach the sheet material from the front surface to the back surface of the adherend. 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 molding method that can improve productivity and appearance without the need for processing.

(Means for Solving the Problems) The vacuum contact molding method of the present invention provides a method for forming a spreadable coating between an upper vacuum box and a lower vacuum box provided with a vertically variable adherend mounting section. In the pasting method, in which the sheet material is installed, the lower adherend mounting part is raised, and the covering sheet material is coated on the adherend, gas is blown around the back side of the adherend to remove the edge of the covering sheet material. The above object is achieved by attaching the part from the front surface to the back surface of the adherend.

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 apparatus includes a lower vacuum box 7 whose top surface is open, and an upper vacuum box 7 that is detachably attached to the upper surface of the lower vacuum box 7. Box 6. A nozzle 3 for blowing out air is provided protruding from the inner wall of the upper vacuum box 6.

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 bottomed body 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 intended to be maintained by this.

A frame 10 for holding the periphery of the covering sheet material 2 is provided at the upper end of the lower vacuum box 7. Also,
A vent 8 and a vent 9 are provided on the 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. The inside of the vacuum box 7 is configured to be able to be vacuum degassed or brought to normal pressure as appropriate. Note that a heater may be provided on the inner surface of the upper and/or lower vacuum boxes 6, 7 to heat and soften the covering sheet material 2.

Using the above-described forming apparatus, the covering can be shaped as follows.

First, the upper vacuum ponox 6 is released, and the adherend 1 is held above the halter 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. The inside of the vacuum box 7 is evacuated.

Next, by raising the lifting table 4 and positioning the covering body 1 above the covering sheet material 2, the adherend 1 is covered with the covering sheet material 2 (Fig. 2 (a), (b) ))
Next, by opening the valve, external air is allowed to flow in through both vents 8 and 9 to release the vacuum in the upper and lower vacuum boxes 6 and 7, and then the nozzle 3 is placed around the back surface of the adherend 1.
By blowing gas from the coating sheet material 2
The end portion of the tape is pressed against the adherend 1 side and attached to the back side of the adherend 1 (FIG. 2(C)).

Rather than spraying the gas on the entire adherend 1, it is better to spray the gas specifically on the part extending from the front surface (outer periphery) to the back surface of the adherend 1, as shown in FIG. 2(C). It is preferable to carry out the process toward the inner side of the end of the adherend 1 because it is efficient. The gas is usually air, but if the covering sheet material 2 used is easily decomposed by oxygen, an inert gas such as nitrogen or argon may be used.

The blowing pressure of the gas is determined by the relationship between the elongation of the covering sheet material 2 and the load, and is at least 1. 5Kg
/cm2 or more is preferable.

The covering sheet material 2 used in the present invention is usually made of a material that has a spreadability of about 5% or more at room temperature or in a heated state, and the sheet material is spreadable and deformed by the pressure of a gas such as air. Any material or sheet configuration can be used as long as it is suitable for use.For example, the following may be mentioned, and an adhesive layer may be provided on the adherend side to improve adhesion. You can leave it there.

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

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

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

■Photocurable resin, etc.

■Animal leather, etc.

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

In the above, both the upper vacuum box 6 and the lower vacuum box 7 are evacuated, but a vacuum contact molding method is used in which only the lower vacuum box 7 on the adherend 1 side is evacuated to adhere the sheet. Or, lower vacuum box 7
It is also possible to adopt a pressure forming method in which the film is exposed to the atmosphere and the inside of the upper vacuum box 6 is pressurized to form a sheet, or a forming method that combines the vacuum contact molding and pressure forming described above.

In addition, the nozzle 3 is preferably located on the inner wall of the upper vacuum box 6 of the molding machine so as not to interfere with molding using the vacuum bonding method, etc., but it should be installed on the processing device (sheet cutting) before taking out the adherend 1. It's okay. In addition, as described above, by blowing gas to the end of the adherend 1 and locally heating that part, the sheet material 2 is made easy to stretch and extends downward from the back surface of the adherend 1. The covering sheet material 2 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 (vertical 300 x horizontal 300 x
Height: 800 mm: Elevating table stroke length: 200 mm = distance between the seat and the elevating table surface during descent). The inner wall of the upper vacuum box of this vacuum contact molding machine has a protruding nozzle with a width of 5 mm that sprays gas toward the lower surface of the adherend after the lifting platform has been raised. The distance between the nozzle and the end of the adherend after the lifting platform was raised was set to 10 mm.

A cylindrical holder with a radius of 50 mm and a height of 90 mm is attached to the lifting platform of the above-mentioned cutting machine, and a steel plate (S
An adherend consisting of a bottomed cylindrical body of S-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 facing downward. After setting the molding machine as follows, the upper vacuum box of the molding machine was tightened.

9 = 10 Next, the insides of the upper and lower vacuum boxes were evacuated, and when the ultimate vacuum level reached 8 Torr, the lifting platform was raised to cover the adherend with a soft vinyl chloride resin adhesive sheet, and then the upper and lower vacuum boxes were evacuated. The inside of the vacuum box was opened to normal pressure, and air at 2 Kg/cm2 and 70°C was blown from a nozzle around the lower surface of the adherend for 15 seconds to obtain a coated body.

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.

Round cone 1 Using the same vacuum contact molding machine as in Example 1, attach a cylindrical holder with a radius of 100 mm and a height of 100 mm to the top of the lifting platform, and place a cylindrical holder with a radius of 150 mm and a thickness of 1 on top of this holder.
An adherend bowl-shaped hemisphere made of n+m steel plate (SS-41) 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
°C, OH value 80) 100 parts by weight and blocked isocyanate (Coronet, manufactured by Nippon Polyurethane Industries) 151
3.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 inside of the upper and lower vacuum boxes is evacuated to reach a vacuum level of 8 Tor.
When the temperature reached r, the lifting platform was raised to cover the adherend with a resin sheet, and then the upper and lower vacuum boxes were opened to normal pressure, and 5 kg/cm2.50 was applied from the nozzle.
A coated body was obtained by blowing air at °C around the lower surface of the adherend for 10 seconds.

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

A coated body was obtained in the same manner as in Example 1, except that air was not blown around the back surface of the adherend.

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

11 12 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 of Examples 1 and 2, the sheet material was attached to the back surface i with * marks, and the appearance was also good.

(Effects of the Invention) According to the present invention, the back side of an adherend can be covered with a sheet material without particularly requiring complicated and expensive equipment, and the adherend can be coated with a coating sheet, adhesive sheet, etc. In addition to improving the appearance when covering, it also improves the handling of the covering after processing (cutting) the sheet material at the edge.
The productivity and product value of the coating can be increased.

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

1... Adherent, 2... Covering sheet material, 3...
Nozzle, 4... Lifting platform, 5... Holder or more

Claims (1)

[Claims] 1. A spreadable coating sheet material is installed between the upper vacuum box and the lower vacuum box with a vertically variable adherend placement part, and the lower adherend placement part is raised. In the pasting method of covering an adherend with a covering sheet material,
A vacuum adhesion molding method characterized by spraying gas around the back surface of the adherend and pasting the edge of the covering sheet material from the front surface to the back surface of the adherend.