Composite heat-sealing film and preparation method thereof

The invention relates to the technical field of heat-sealing films, and particularly discloses a composite heat-sealing film and a preparation method thereof.The composite heat-sealing film is composed of a base body layer and a heat-sealing layer; the matrix layer comprises modified PET, aminated basalt powder, an antistatic agent and other raw materials; the heat sealing layer comprises PETG (polyethylene terephthalate glycol), PCL (polycaprolactone), cellulose acetate, a tackifier, an antioxidant and other raw materials; the preparation method of the composite heat-sealing film comprises the following steps: S1, mixing modified PET, aminated basalt powder and an antistatic agent, and performing melt extrusion to obtain a material A; s2, treating a mixture of PETG and PCL by adopting plasma, then adding cellulose acetate, a tackifier and an antioxidant, mixing, and carrying out melt extrusion to obtain a material B; s3, the material A and the material B are subjected to a co-extrusion process, and the compo