Pvdc-Polyolefin Coextruded Thermal-Formed High-Blocked Composite Packaging Material

A PVDC-Polyolefin co-extruded thermal-formed high-blocked composite packaging material, comprising:

• two parts, i.e. a top film and a bottom film;
• the top film, as a display side of a package, is a multilayer film that is transparent or on that is printed graphic and text information of a packaged object;
• and the bottom film, as a forming side of the package, is a multilayer film suitable for thermoforming, vacuum surface packaging or inflation packaging, and gets a second thermal sealing;
• wherein:
• A. top film
• a. the top film is a film with seven or more layers, having a basic structure as below:
• BOPP/PE-TIE-PVDC-TIE-PP-PE
• b. materials
• in the top film structure:
• i. PVDC is selected from one of the following three film-class materials:
• homopolymerized polyvinylidene chloride;
• copolymer of methyl acrylate and polyvinylidene chloride;
• and
• copolymer of chloroethylene and polyvinylidene chloride;
• ii. PE is polyethylene or modified PE with a density of 0.92±0.03 g/cm3 that is a mixture of polyethylene and at least one of the following four materials:
• metallocene polyethylene, with a density of 0.86±0.94 g/cm3;
• thermoplastic polyolefin elastomer, with a density of 0.86˜0.905 g/cm3;
• metal-ion polymer of sodium and zinc, with a density of 0.92˜0.94 g/cm3;
• and
• ethylene-vinyl acetate copolymer, with a density of 0.92±0.945 g/cm3;
• c. process
• multilayer cast or multilayer blowing film coextrusion is adopted for forming of the PE-TIE-PVDC-TIE-PP-PE, which is compounded with BOPP in a solventless dry way;
• B. bottom film
• a. the bottom film is a film with five or more layers, having a basic structure as below:
• PP-TIE-PVDC-TIE-PE
• b. materials
• in the bottom film structure:
• i. PP is polypropylene or modified PP with a density of 0.91±0.03 g/cm3 that is a mixture of polypropylene and at least one of the following four materials:
• metallocene polyethylene, with a density of 0.86±0.94 g/cm3;
• thermoplastic polyolefin elastomer, with a density of 0.86±0.905 g/cm3;
• ethylene-vinyl acetate copolymer, with a density of 0.92±0.945 g/cm3;
• and
• high-density polyethylene, with a density of 0.94±0.96 g/cm3;
• ii. PVDC is the same with that in the top film;
• iii. PE is the same with that in the top film;
• c. process
• multilayer cast or multilayer blowing film coextrusion is adopted for forming of the PP-TIE-PVDC-TIE-PE.