T/GDEIA 7-2019 Biaxially oriented polyester film for iron coating

Scope

Scope: This standard applies to bidirectionally stretched polyester films used for laminating tinplate, chrome-plated iron, galvanized iron, and other metal materials. Other film materials may also be used for reference. Main technical content: Project requirements (the products are divided into transparent films and non-transparent films, and the technical requirements apply to transparent films in the former case and to non-transparent films in the latter case). Tensile strength, MPa: longitudinal a ≥ 100, transverse b ≥ 120; elongation at break, %: longitudinal a ≥ 60, transverse b ≥ 60; heat shrinkage rate, %: longitudinal a ≤ 8.0, transverse b ≤ 8.0; friction coefficient: static ≤ 0.65, dynamic ≤ 0.55; roughness, μmRa: ≤ 0.3, ≤ 3.0; haze, % ≤ 8.0, ≥ 80; light transmittance, % ≥ 80, ≤ 40; glossiness, % ≥ 120, ≥ 60; wetting tension c (mN/m): ≥ 48, ≥ 48; oxygen permeability coefficient d (23℃, 0% relative humidity): [cm3?cm/(cm2·s·Pa)] ≤ 2.25×10-15, ≤ 2.25×10-15; water vapor permeability coefficient d (38℃, 90% relative humidity): [g?0.1mm/(m2·24h)] ≤ 6.6, ≤ 6.6. Note: a: longitudinal direction is the same as the extrusion direction, i.e., the machine direction. b: transverse direction is perpendicular to the extrusion direction. c: the wetting tension test only applies to corona films. d: the oxygen permeability and water vapor permeability tests apply to barrier polyester films. For films directly in contact with food, they shall comply with GB 4806.7 National Food Safety Standard - Plastic Materials and Products for Food Contact. The antimony limit shall comply with the provisions of GB 4806.1.

Development Information

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