PE composite fresh-keeping packaging film for food modified atmosphere packaging as well as preparation and uses thereof

The invention discloses a PE composite preservative packaging membrane for modified atmosphere packaging of foods and a preparation method, which aims at providing a packaging membrane capable of adjusting the gas compositions in the pack so as to further extend the shelf life of the fresh foods. The packaging membrane is prepared through the following raw materials according to a certain weight percentage: 75 per cent to 98 per cent of polymer substrates, 1.5 per cent to 20 per cent of molecular sieves and 0.5 per cent to 5 per cent of plasticizers. By utilizing the molecular sieves as active inorganic particles, the PE composite preservative packaging membrane of the invention ensures that the membrane has favorable permeability, moisture permeability and porosity and is capable of spontaneously adjusting the gas compositions in the pack so as to suppress the respiration of the fresh foods and extend the freshness period of the fresh foods. The invention also discloses a preparation method for PE composite preservative packaging membrane and the packaging membrane prepared through the method has the advantages of uniform membrane, adjustable thickness, tear resistance, impact resistance, high heat sealing strength, simple processing technique, and convenient realization of industrialized production, etc.