1. Products are divided into low-temperature shrinkage types and non-low-temperature shrinkage types according to heat shrinkage temperature. 2. Products are divided into high barrier, ordinary barrier and non-barrier according to barrier properties. 3. Based on the actual use of multi-layer co-extruded heat shrinkable films and bags for packaging, the main technical contents involved in the standard include: (1) Appearance; (2) Specifications; (3) Physical and mechanical properties; including: ① Mechanics and optics Performance; ② Barrier performance; ③ Bag sealing performance; ④ Food contact safety; ⑤ Solvent residual amount. 4. Test method: sample condition adjustment and test standard environment, appearance, specifications, physical and mechanical properties, food contact safety, and solvent residue. 5. Inspection rules for batch grouping, inspection classification, sampling, and judgment regulations.