The pre-coating film of the pre-coated laminating machine is limited by the technology, production equipment, and raw materials, and the pre-coated type (mostly hot-melt adhesive) produced by domestic equipment still has quality defects. Since the production process is a process similar to that of the coating film, the colloid is dissolved in an organic solvent, and the rubber is roll coated on the substrate film by a concave anilox roll, so that the solvent volatilization is insufficient, and the odor is generated during operation. After the film is coated, the solvent evaporates and the surface is easy to foam.
At the same time, since the hot melt adhesive is blended by several kinds of polymer materials, the temperature control is not good, which will cause degradation and cross-linking of the high molecular polymer in the hot melt adhesive, and the surface of the film is poor. Some pre-coated film colloids easily adhere to the outer surface of the substrate, resulting in poor winding. Since the adhesive layer is thin and the surface is not activated, defects such as insufficient adhesion to the printed matter are likely to occur. Since the hot melt adhesive is composed of several kinds of materials, the transparency after coating is significantly worse than that of the low temperature pure resin type precoat film.

In recent years, the post-press processing at home and abroad has gradually developed into a refined, which has caused manufacturers to pay attention to the glazing technology in the subsequent processing of printing. There are several types of glazing, such as solvent-based, water-based, UV and EB curing. Among them, water-based glazing and UV glazing are mainly used in domestic and foreign markets.
It can be seen that solvent-type glazing will be eliminated due to large pollution, EB curing glazing is still in its infancy, and water-based glazing and UV glazing development momentum is strong, and will become the leading product in the market in the next few years.

The glazing process classification method of the glazing machine: according to the glazing coating, it can be divided into oxidative polymerization type coating glazing, solvent volatilization type coating glazing, photocuring type coating glazing and heat curing type coating glazing; Whole surface light, partial glazing, extinction and artistic glazing;
The equipment used for glazing can be divided into: glazing on a separate glazing machine, glazing with a printing unit and a printing machine; according to the glazing coating method, it can be divided into: smear coating, printing and coating. Light and special glazing machine are coated with glazing; according to the input mode of printing, it can be divided into manual paper feeding and automatic paper feeding.

For printing and carton enterprises, choosing a glazing machine with excellent structure, stable performance, convenient operation, high production efficiency, wide applicability and good energy saving is of great significance for scientific and rational organization of production. The glazing machine is an important equipment for surface finishing processing of packaging products such as carton boxes. It plays an important role in improving the surface properties of printed products and improving the wear resistance, stain resistance and water resistance of printed products. Therefore, correctly understanding and understanding the structure and characteristics of glazing equipment, mastering the procurement control essentials of glazing machines is an important part of improving production efficiency and product quality.

The glazing machine is an important equipment for the surface finishing processing of packaging products such as cartons. It plays an important role in improving the surface properties of printed products and improving the wear resistance, stain resistance and water resistance of printed products. For printing and carton enterprises, it is of great significance to select a machine with excellent structure, stable performance, convenient operation, high production efficiency, wide applicability, and good energy conservation. . Therefore, correctly understanding and understanding the structure and characteristics of glazing equipment, mastering the procurement control essentials of glazing machines is an important part of improving production efficiency and product quality.
Using a glazing machine, after some products are calendered, the surface is prone to cracking (thick paper is more obvious).
1. The temperature in the calendering is too high, so that the water content of the printed matter is reduced, and the paper fiber becomes brittle;
2. The pressure in the calendering is large, which makes the printability and flexibility of the print deteriorate.
3. The selection of post-processing conditions is not suitable;
4. Poor suitability after glazing coating.
The solutions for the above are:
1. Reduce the calender drying temperature and take effective measures to change the water content of the printed matter;
2. Reduce the calendering pressure;
3. Adjust the post-processing conditions to match the suitability of the printed matter (after calendering).
After the calender is calendered, the blank part of the printed matter is light-colored, and the cause of discoloration of the light-colored part is:
1. The ink is poorly dried, and the ink layer has poor solvent resistance;
2. The coating solvent has a certain dissolution effect on the ink layer;
3. The coating layer is not completely dried and the solvent residue is high.
The solution is as follows:
1. The printed matter is dried and then glazed;
2. Reduce the amount of solvent in the glazing coating (solvent that dissolves the ink), allowing the solvent to be changed or changing the coating;
3. Increase the drying temperature and reduce the residual solvent content inside the coating.