Laminating equipment and application skills (1)

Precoat laminating machine has broad application prospects and popularity value, and is the development direction of laminating machine. However, due to the limitations of some conditions such as pre-coated plastic coating, few are currently used in China.

Film coating equipment

That is, the coating type laminating machine is a special device that combines the pressurized composite part with the printed matter after drying the plastic film coated with the adhesive. That is, Xu-type laminating machine has two kinds of automatic machines and semi-automatic machines. Each type of machine has its own unique structure and coating technology, but its basic structure and working principle are the same. It mainly consists of five parts: unwinding, glue coating, drying, compounding, winding, and mechanical transmission. , automatic tension control, automatic adjustment of unwinding and other auxiliary devices.

1. Unwind part. The unwinding of plastic film requires the film to maintain a constant tension all the time. Too much tension, easy to produce longitudinal shrinkage, and vice versa, easy to produce horizontal wrinkles, are not conducive to the coating of the adhesive and the composite with the print. In order to maintain proper tension, the unwinding section is generally provided with a tension control device. Commonly, there are mechanical friction disc clutches, short alternating current motors, and magnetic powder clutches.

2. Apply on the coating section. After the film is unwound, it goes through the coating roller and enters the gluing section. The coating forms are: drum reversal type, concave type, no-squeegee direct gluing, and scraper direct gluing.

(1) Roller reverse coating. Indirect coating is the most used type of each model. The rubber roller brings out the glue from the storage tank, and the rubber roller and the squeegee blade can scrape the excess glue back to the storage tank. The film counter-pressure roller presses the film to be coated on the surface of the rubberized roller and maintains a certain contact area. Under the pressure and adhesion force, the glue is continuously applied to the surface of the film. The amount of glue can be changed by adjusting the distance between the squeegee roller and the squeegee roller, the squeegee roller and the sizing sheet.

(2) Concave coating. It consists of a metal-coated roller with a textured surface and a set of film-dividing rollers. The gluing roller is directly immersed in the glue solution, and the glue is taken out from the glue storage tank as the roller rotates, and excess glue on the roller surface is scraped off by the scraper. Under the action of the lamination roller, the glue in the groove of the roller is driven by the directional movement of the film to be coated and evenly applied to the surface of the film. The amount of coating can be controlled by adjusting the grid pattern of the surface of the coating roller, the characteristic value of the adhesive, the pressure value of the laminating roller, and the like.

The advantage of concave gluing is that it can control the amount of gluing more accurately and coat evenly; however, the anilox roller is difficult to process and easy to be damaged, and it needs to be cleaned frequently. In addition, it requires higher adhesiveness when coating.

(3) Squeegee roller extrusion coating. The gluing roller is directly immersed in the glue solution. When the glue is applied, the rubberizing roller brings out the glue liquid and squeezing by the sizing roller, and the squeezing force between the film roll and the glue roller completes the sizing.

When squeezing, the thickness of the adhesive layer is determined by the pressure, the adhesive performance index, and the coating speed. The amount of glue applied is achieved by adjusting the squeezing force between the squeegee roller and the squeegee roller, the squeegee roller and the lamination roller. Therefore, there are high requirements on the surface accuracy, cylindricity and radial runout tolerances of the rollers.

(4) Direct squeegee with scraper. The gluing roller is directly immersed in the glue liquid, and is continuously rotated to drive the glue liquid from the glue tank. After the scraper blade removes the excess glue liquid, it is in contact with the film surface to complete the glue coating.


There are direct squeegee blade force, and the design requires that the squeegee must scrape the glue on the surface of the squeegee roller, that is, the straightness of the edge of the squeegee is required, and the surface precision of the squeegee roller is very high. The rubber scraper is usually made of a stainless steel belt with high flatness, smoothness and elasticity.