Low temperature heat sealing film is one of the basic varieties of BOPP film, mainly used for printing, compound bag making or packaging. Divided into single-sided heat-sealing film and double-sided heat-sealing film. Single-sided heat-sealing film, after printing the pattern on the non-heat-sealing layer, compounded with PE, BOPP and aluminum foil to make food and tea packaging bags. Double-sided heat-sealing film is directly heat-sealed to package food, textiles, audio-visual products, poker, etc., which requires the film to have good heat-sealing properties. In addition, with the increase of packaging speed, BOPP heat sealing film is required to have high smoothness, low temperature instantaneous heat sealing performance and good heat sealing strength. In order to adapt to different types of packaging machines, the film should have a wide range of heat sealing temperatures (60℃-135℃)
At present, the initial heat-sealing temperature of BOPP heat-sealing film is above 100℃, and there are some BOPP heat-sealing films abroad, and the initial heat-sealing temperature is lower than 90℃. The initial heat sealing temperature is low, which is suitable for high-speed packaging. It should be said that this is the development trend of heat sealing materials.
In the production of BOPP heat-sealing film, the selection of surface materials is the key, including the type of heat-sealing material, production adaptability, heat-sealing temperature, thickness of heat-sealing layer, heat-sealing strength, etc. At the same time, appropriate additives should be selected to improve other properties of BOPP film. Properties such as smoothness, antistatic, stiffness, optical properties, etc.