The laminating process is widely used in various types of packaging and decoration printed matter in China, and books, magazines, calendars, maps, etc. in various binding forms are a very popular surface processing technology for printed products. The film-coating process entered China in the 1980s. Due to its many advantages, it has swept the country in a very short period of time and has gradually become the darling of the surface decoration of books and periodicals.
          Nowadays, people's awareness of environmental protection is gradually increasing, relevant laws and regulations are constantly improving, and the pollution caused by the laminating process and the difficulty of reusing the coated products when they are discarded are in front of people. When the laminating machine is lifted, people tend to Think of "white pollution." Many in the industry have doubts about the function of the film and its continued application.
          It is certain that in the future development process, the film coating technology will accept more and more tests. How will the film develop? Is it completely eliminated or rationally developed? These problems will become unavoidable problems in the development of the laminating process.

The characteristics of the instant coating:
(1) It is prone to foaming and film detachment. In large-area solid printing or high humidity working environment, foaming and film removal are particularly serious.
(2) The surface of the product often produces bright spots or fog points with different gloss.
(3) The product is prone to curling. If the pressure is too high when the glue is applied or the temperature is too high during drying, the curling phenomenon is more serious.
(4) Chemical substances such as organic solvents will volatilize into the atmosphere when the laminator is coated, causing environmental pollution and even causing fire.

Why the instant coating method is still widely used in China. Although the comprehensive performance of the pre-coated film is better than the instant coating method, the current domestic coating industry is the most domestic enterprises. The instant coating process is still widely used. The main reasons can be summarized as follows.
First, the pre-coating film technology started relatively late in China.
Second, the pre-coating film for the production of laminating machine has high technical content, complicated process and large equipment investment. The general enterprise has no ability to invest in the pre-coating film production line.
Third, due to China's surplus labor resources and low labor costs, material costs account for a large proportion of the total cost of the laminating process. The cost of the pre-coating type is higher than that of the coating type, which will inevitably affect its application.
Fourth, most of the equipment produced by domestic laminating equipment manufacturers are instant coating laminating equipment.
Fifth, although the Chinese government emphasizes the environmental protection of the industry, the laws and regulations specifically for the laminating industry have yet to be improved.

Due to limitations in technology, production equipment, and raw materials, pre-coated films (mostly hot melt adhesives) produced by domestic equipment still have 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, in the process of using the laminating machine, the temperature control is not good, which will cause degradation and cross-linking of the high molecular polymer in the hot melt adhesive, so that 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.

The pre-coating film refers to a process in which a plastic film is sized and re-rolled before being combined with a paper printed product. It is firstly applied to the film by the pre-coated film processing factory according to the size of the specification. The glue is applied to the film for re-rolling, and then combined with the printed matter.
The laminating machine laminating film, that is, the laminating film, is a processing technique in which a plastic film is coated with a binder and the paper printed matter is heated and pressurized to bond it together to form a paper-plastic composite product. The film-coated printed matter has a thin and transparent plastic film on the surface, and the surface is smoother and brighter, thereby improving the gloss and fastness of the printed matter. The color of the graphic is more vivid, three-dimensional, and waterproof. Anti-fouling, abrasion resistance, folding resistance, chemical corrosion resistance, etc.