Heat sealing film is one of the basic varieties of BOPP film, mainly used for printing, composite bag making or wrapping packaging. Divided into single-sided heat sealing film and double-sided heat sealing film. Single sided heat sealed film, after printing patterns on non heat sealed layers, is combined with PE, BOPP, and aluminum foil to form bags for packaging of food, tea, beverages, and other items. Double sided heat sealing film is directly heat sealed to form packaging for food, textiles, audiovisual products, poker, etc. All of these require the film to have good heat sealing performance. In addition, with the increasing speed of packaging, BOPP heat sealing film is required to have high smoothness, low-temperature instantaneous heat sealing performance, and good heat sealing strength. To adapt to different types of packaging machines, the film is required to have a wide heat sealing temperature range (60-135 ℃).