With the advantages of lower cost and more convenient ways of carrying and taking, flexible packaging has developed rapidly in many fields and has gradually become the mainstream of the packaging industry. Dry composite film for flexible packaging is a common flexible packaging material, but sometimes there are some air bubbles in this composite packaging film, which affects the appearance. Today yltpackaging takes everyone into the factory to explore the truth. 1. Surface tension If the surface tension of the composite film is too small, the wettability of the adhesive on the surface will be poor, which will lead to insufficient glue application, and bubbles will be generated where there is little or no glue. Or the surface tension of the film is uneven, which will also lead to uneven glue application, and then generate air bubbles. In order to avoid this problem, yltpackaging Co., Ltd. selects films with moderate tension and uniformity for different materials. For example, the surface tension of polyethylene films is above 3.8×10~(-2)N/m, and carefully checks before production to ensure that the surface Only when the tension meets the requirements can production be carried out. 2. High residual solvent If the residual solvent is too high during the production process, the solvent will vaporize and form bubbles trapped in the film, which will also form bubbles. The solution of yltpackaging Co., Ltd. is as follows: 1. Control the drying temperature, keep the temperature at 60-80°C, and set ventilation settings in the drying tunnel to accelerate the evaporation of solvents. 2. Control the temperature and humidity of the production workshop. When the humidity in the air is high, the volatilization of solvents slows down. Therefore, yltpackaging controls the humidity of the workshop at 50%-60% to suppress solvent residues. 3. Production technology When laminating the laminating roller, if the angle between it and the film is too large, air may be brought in, causing air bubbles to be contained in the laminating film. The hardness of the film is high, and the air bubbles are more likely to enter when the thickness is large. In this case, it is necessary to adjust the angle between the composite roller and the film, try to enter the composite roller in the tangential direction, and ensure the flatness of the substrate to avoid loose edges or shaking.