PVC film pressing technology is very important in furniture industry, especially in door panel and cabinet production. Medium and high density substrates are processed into various linear shapes and then absorbed into various subglossy, high gloss, color and texture PVC films, which make the products colorful and dazzling, and create a great choice space for consumers. However, products manufactured using this technology. Its quality varies greatly. The reasons for these differences are not only the factors of PVC film itself, but also the control of processing parameters. Following is an example of a positive and negative pressure vacuum suction machine imported from Germany, using the two-component plastic suction machine imported from Germany to explain the whole process.

1. Working Principle of Positive and Negative Pressure Vacuum Plastic Absorber

Using the plasticity of PVC film, the PVC film was heated and pressurized by adjusting and controlling the film pressing time, temperature and air pressure in the equipment chamber, and the PVC film was coated on the workpiece surface.

Working process:

(1) Place the workpiece on the workbench;

(2) The worktable enters directly below the heating plate;

(3) The heating plate is closed with the worktable;

(4) The air between the heating plate and the silica gel film is extracted, and the silica gel film is adsorbed on the heating plate and heated.

(5) After reaching the set time, compressed air is injected between the heating plate and the silica gel film. The silica gel film contacts closely with the PVC absorbing film. The workpiece and the PVC absorbing film are heated. At the same time, the PVC absorbing film is softened, and the temperature of the edge of the plate reaches the activation temperature of the adhesive.

(6) The air between the worktable and the PVC film is rapidly pumped out to form a vacuum, then compressed air is injected between the PVC film and the heating plate, and the PVC film is coated on the plate under the set pressure and temperature.

PVC Membrane Pressing Process

2 Operational Procedures

2.1 Requirements for the Use of Suction Plastics

Absorbing plastic is a two-component glue, the activation temperature is about 60 degrees. Storage ambient temperature should be between 5 and 30 degrees, and flocculation will occur below 5 degrees Celsius. Rubber drums should not be placed directly on the ground, but on wooden brackets, especially in winter. The validity period of absorbent plastic is 6 months from the date of leaving the factory without dismantling the original packaging.

The ratio of curing agent is 20:1. When the main agent is mixed with the curing agent, the main agent should be kept in stirring state. The curing agent should be added slowly and stirred for at least 3 minutes. The glue quantity of each preparation should be guaranteed to be used up within 4 hours. The rubber drum should be tightly covered after mixing.

2.2 Spraying process requirements:

2.2.1 The spraying sequence is end face-front line-front + line-end face, the plane part of which can be sprayed once, and the end face and plane line need to be sprayed twice.

2.2.2 After mixing the main agent with curing agent, the active time is 4-6 hours. The sprayed workpiece should be processed within 4 hours to obtain the best bonding effect. Otherwise, the activation temperature needs to be increased because of the crosslinking reaction. Although the bonding effect is good in appearance, the heat resistance has been significantly reduced. If sprayed twice, the surface of the PVC film will show a rubber mark.

2.2.3 After spraying, the surface becomes white and dry, and the drying time is 30-50 minutes (depending on the temperature, humidity and spraying quality of the environment).

2.2.4 The common fan is 1.5-2.0 meters away from the workpiece, aiming at the workpiece to blow away the humid air, so as to avoid the PVC bubbling due to the high humidity of the workpiece.

2.2.5 In winter, in order to increase the temperature of the workpiece, the workpiece can be heated to 20-25 C in a small thermal insulation room (the temperature is forbidden to exceed 35 C, otherwise the workpiece will be deformed). Spraying glue should be carried out on the water curtain machine at no less than 16 C.

2.2.6 Gum spray operators should wear masks to protect their health.

2.3 Application of Silica Gel Film in Plastic Absorber

According to the characteristics of workpiece alignment (such as arc value, edge angle, width and depth of alignment, etc.), different thickness of silicone film is selected.

The sag of silica gel film will increase because it is often heated and stretched. It should be installed in time according to the sag degree of silica gel film to reduce the sag.

In order to prolong the service life of the silicone film and prevent the quality problems of the workpiece, the use direction of the silicone film should be regularly changed, such as changing the front end to the back end, changing the left end to the right end.

If there are holes or short cracks in the corner of the silica gel film, it can be repaired by silica gel and film repairing machine. When repairing, the top is compacted with a flat weight. After 24 hours of drying, the repairing area can be used normally with 24065507

2.4 Setting of Technological Parameters

2.4.1 Membrane pressing workpiece spacing: narrow workpiece with width less than 10 cm, workpiece spacing not less than 8 cm; workpiece with width greater than 10 cm, workpiece spacing not less than 6 cm; workpiece and worktable frame spacing not less than 8 cm. The horizontal and vertical spacing should be in a straight line to reduce the resistance of air flow.

2.4.2 Workpiece Cushion Plate: The width and length of the cushion plate should be 6-10 mm shorter than the width and length of the workpiece. The edges around the upper surface of the cushion plate should be rounded or chamfered by 3 mm-5 mm radius or 3*45 C angle, so as to ensure that the air between the PVC film and the workpiece is thoroughly pumped out and the effect of firmly gluing the PVC film to the edge of the workpiece is achieved. The thickness of the cushion plate should be about 3/4 of the workpiece thickness, which is one of the important measures to ensure that PVC is not whitened.

2.4.3 Setting temperature: According to the difference of PVC film, the setting temperature should be between 130 and 160 C, the temperature of ordinary PVC film (relative to high-light PVC film) should be higher, and that of high-light PVC film should be lower (to avoid losing light due to high temperature).