The invention relates to a
composite film for flour packaging and a manufacturing method thereof. The
composite film comprises three
layers (figure. I), namely a PET (polythylene terephthalate) litho-coated thin film, a PE (
polyethylene) thin film and a
polyurethane adhesive layer arranged between the PET litho-coated thin film and the PET thin film, wherein the PET litho-coated thin film comprises three
layers (figure. II), namely a PET coated thin film, a printed layer on the coated thin film and a
polyurethane adhesive layer arranged between the PET coated thin film and the printed layer; the PET coated thin film comprises three
layers (figure. III), namely a PET base material, a modified crylic acid
coating layer on the surface of the base material and a
polyurethane adhesive layer arranged between the PET base material and the modified crylic acid
coating layer; the modified crylic acid
coating layer is obtained by coating the surface of the PET base material with crylic acid
emulsion through a coating technology; the modified crylic acid
emulsion is prepared from the following raw materials in percentage by weight: 5-10 percent of a
functional monomer, 8-12 percent of an adhesive
monomer, 6-8 percent of a cohesion
monomer, 0.02-0.08 percent of
chondroitin sulfate, 0.2-0.5 percent of an emulsifier, 0.05-0.2 percent of a defoaming agent, 0.05-0.1 percent of an initiator, 0.02-0.1 percent of
electrolyte, 1-3 percent of
ammonia water and 67-75 percent of deionized water. The
composite film disclosed by the invention can well achieve the effect of electrostatic dust (
powder) absorption during flour packaging and is high in thermal sealing performance.