There are many factors affecting the quality of the film, in addition to paper, ink layer, film, adhesive and so on In addition to the objective factors, it is also affected by subjective factors such as temperature, pressure, speed, and glue amount. If these factors are not handled well, various laminating quality problems will occur. There are snowflakes on the product 1.The amount of glue is too small: the amount of glue is too small, and snow spots will appear on the entire surface of the print. The amount of glue can be appropriately increased. 2.Inappropriate pressure: too much pressure on the pressure wheel will squeeze out the adhesive on the edge of the print, resulting in snowflake spots on the edge of the print; Snowflake spots can also appear if it is not compacted. The pressure can be adjusted appropriately. 3.Print powder spraying too much: print powder spraying too much, the compound appears loose pine flower white fog, encounter this situation, should be appropriate to increase the amount of glue, or in the coating before sweeping the print powder. 4.Pressure wheel pressure is too small: there are bubbles on the surface of the entire printing product because the pressure of the pressure wheel is too small, and the pressure of the pressure wheel can be appropriately increased. The coated product has wrinkles The main reasons for the wrinkling of the coated product are the imbalance of the film transmission spoke, the inconsistency of the tightness at both ends of the film or the wavy edge, the thickness of the rubber layer, or the uneven electric wheel and the rubber spoke at both ends, the pressure is inconsistent, and the linear speed is different. Measures can be taken to adjust the transfer wheel to the equilibrium state, increase the film, adjust the amount of glue and increase the temperature of the drying channel, adjust the position and process parameters of the electric heating wheel and rubber wheel, etc.

As a kind of widely used adhesive, coated adhesive has a variety of processes. Here are some of the common processes used: 1. Hot melt coating: hot melt coating is to place a layer of film on the surface of the print, and then through hot pressing the film and the print together.In this process, the laminating glue is heated to turn it into a liquid, which then forms a uniform coating between the print and the film. This method can make the surface of the printed matter smooth and bright, and has waterproof, wear-resistant, oil-proof and other properties. 2.Water-based coating: Water-based coating is an environmentally friendly coating process. It is achieved by coating a layer of water-based laminating glue, and then covering the film over the laminating glue. Because the water-based coating adhesive does not contain organic solvents, it has little pollution to the environment during use. 3.UV coating: UV coating is a coating process using ultraviolet curing technology. In this process, a layer of coated adhesive is first applied, and then ultraviolet light is used on its surface to cure the adhesive quickly. This method has the advantages of fast speed, stable quality, etc., and can also make the printed surface more durable and textured. In short, the use of coated adhesive process is mainly selected according to different application scenarios and use needs. In practical applications, we should combine materials, equipment and production process and other factors to choose the most suitable for their own film coating process to achieve the best results.

1. The effect of membrane material There are dust adsorption, particle impurities, poor plasticization and other crystal points in the film. The moisture absorption on the film surface of the material and the precipitation of additives in the material will cause composite bubbles. The thickness of the film should be as uniform as possible, if the distribution is uneven, it is easy to cause the imbalance of the compound pressure, and there will be a gap where the pressure is small, thus forming bubbles. The way to avoid these effects is to do a good job of raw material inspection and maximize the online corona at the same time of production. 2.The impact of adhesives A large amount of air was mixed in the preparation of the glue solution due to agitation and circulation, which was not discharged in time during static defoaming and was locked in the composite film to form bubbles. The correct approach is: The adhesive is prepared in strict accordance with the instructions, the main agent is added first, and then the ethyl acetate is added and stirred evenly, and then the curing agent is added while stirring, so that the curing agent is full of activity and evenly dispersed, which is conducive to affinity with the printing substrate and reduce bubbles. In addition, the prepared adhesive should be fully static and degassing, and then poured into the rubber tray for use. Moreover, when pouring glue, it is necessary to fall slowly along the edge of the glue tray, and the glue liquid in the glue tray cannot be violently stirred, so as to avoid the formation of bubbles in the composite film due to the mixture of air. The viscosity of the adhesive has an important influence on the fluidity, wettability and uniformity of the adhesive. In the dry composite, the viscosity value of the adhesive should be controlled within the appropriate range, if the viscosity of the adhesive is too high, the dispersion and leveling may be poor, affecting the wettability of the surface of the composite substrate, and failures such as coating leakage and bubbles may occur during the coating process. When the two-component two-liquid reaction adhesive is used, it is necessary to dilute the adhesive by adding diluent in order to ensure uniform coating and conducive to infiltration. Diluents include toluene, ethyl acetate, methyl ethyl ketone, etc. Toluene is being phased out because it is not conducive to environmental protection and is easy to cause bubbles. Methyl ethyl ketone is used less because of its high price and not very good affinity with adhesives. At present, the most used diluent is ethyl acetate. Diluent can not contain water, alcohol, amine, etc. If the water content is more than 0.2%, because the volatilization rate of water is much lower than that of ethyl acetate, the volatilization rate of solvent will be greatly reduced, and the spreading and hardening of adhesive will be affected. After the composite of BOPP film and CPP film, the composite product will pro...

According to the different raw materials and equipment, the coating process can be divided into two kinds of coating process and pre-coating process. That is to say, the film used in the coating process is now coated, and the adhesive used is generally solvent-based and emulsion type, prepared according to need. However, the film used in the pre-coating process is pre-coated, and the adhesive used is generally hot melt and solvent volatile. According to the film process of paper printed matter, the film process can be divided into three categories: dry film process. Wet laminating and precoating pressing. Dry laminating method is the most commonly used laminating method in China, which is to coat a layer of adhesive on the plastic film, and then evaporate and dry the solvent in the adhesive through the drying tunnel of the laminating machine, and then bond with the paper printed matter to form a laminating product under hot pressing. Wet film is coated on the surface of the plastic film with a layer of adhesive, in the case of the adhesive is not dry, through the press roller adhesive and paper printed matter bonding, forming a film product. Since the emergence of water-based laminating machine, the process of water-based laminating machine has been popularized and applied, which is closely related to the characteristics of the wet laminating machine, such as simple operation, less adhesive amount, no organic solvent damage to the environment, high strength, high grade and easy recovery. At present, the coating process is more and more favored by domestic packaging manufacturers, and has been widely used in gift boxes, handbags and other packaging. Coating glue manufacturers said that the pre-coating coating method is the coating film manufacturers directly purchase the plastic film coated in advance, and when the film needs to be coated, the film and paper prints are hot pressed on the coating equipment to complete the coating process. The pre-coating process began in the 1990s. The pre-coated film is obtained by applying hot melt adhesive or low temperature resin to the film substrate quantitatively and uniformly with special equipment according to design. According to the coating adhesive manufacturer, the pre-coating coating method eliminates the need for adhesives, preparation, coating and drying, and the entire coating process can be completed in just a few seconds, without polluting the environment, no fire hazards, and no need to clean the coating equipment. At present, the technology has been applied to the field of medicine and food packaging. Sinograce Chemical produces water-based dry laminating adhesive, color box carton, paper product laminating adhesive, which is suitable for all kinds of high-end printed matter, low, medium and high speed laminating machine.