【国外标准】 Standard Specification for Polyethylene Films Made from Medium-Density Polyethylene for General Use and Packaging Applications

This specification covers unpigmented, unsupported, sheet or tubular, medium-density polyethylene films intended for general uses and packaging applications. The film shall be made from homopolymer polyethylene, copolymer polyethylene commonly referred to as low-pressure polyethylene, or blends of homopolymers and copolymers that include ethylene/vinyl-acetate copolymers. The specimens shall be conditioned before testing in the standard laboratory temperature. Tests shall be conducted to determine the physical properties of the specimens which shall conform to the following physical requirements: secant modulus or stiffness; kinetic coefficient of friction; optical properties such as clarity, gloss, and haze; surface treatment level or wetting tension; impact resistance; tensile strength and elongation at break; heat sealability; and odor level.1.1 This specification covers unpigmented, unsupported, sheet or tubular, medium-density polyethylene films (hereafter referred to as film or films) from resins having densities in the range from 926.0 to 938.0 kg/m3 (0.926 to 0.938 g/cm3), inclusive, as measured on molded plaques.1.2 This specification is applicable to homopolymer polyethylene but is not restricted to it.1.3 This specification is also applicable to films made from copolymer polyethylene commonly referred to in industry as low-pressure polyethylene.1.4 This specification is also applicable to films made from blends of homopolymers and copolymers, including ethylene/vinyl-acetate copolymers.1.5 This specification allows for the use of recycled polyethylene film or resin as feedstock, in whole or in part, as long as all the requirements of this specification are met and as long as any specific requirements as governed by the producer and end user are also met (see Note 1).NOTE 1: Guide D7209 contains terminology and definitions relating to recycled plastics.1.6 Special care must be exercised if this specification is applied to colored or pigmented films. This specification does not address specific problems associated with coloring, such as, quantity and quality of pigment dispersion, optical properties, and increase in density. These and other areas must be taken into account by mutual agreement between the supplier and the purchaser.1.7 The thickness of the films covered by this specification range from 25 to 100 μm (0.001 to 0.004 in.), inclusive. The maximum width of the sheet or lay-flat is 3.05 m (120 in.).1.8 This specification does not cover oriented heat-shrinkable films.1.9 This specification defines the levels of various physical properties from which specifications for specific films are to be described. The levels of physical properties required by a film for a given application are selected from Section 6 and the corresponding tables. However, Sections 7.2 – 7.5 relating to tolerances shall apply without change to all film falling within the scope indicated by the title and 1.1 – 1.4.1.10 This specification covers dimensional tolerances, classification, intrinsic quality requirements, and test methods. The dimensional tolerances include thickness, width, and length or yield. Classification defines types, classes, surfaces, and finishes. The intrinsic quality requirements include density, workmanship, impact strength, tensile strength, heat sealability, and odor, as well as the classification properties for stiffness, coefficient of friction, optical properties, and surface treatment. A sampling method is included.1.11 The values stated in SI units are to be regarded as standard. The values in parentheses are given for information only.1.12 The following precautionary caveat pertains only to the test methods portion, Section 10, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.NOTE 2: There is no known ISO equivalent to this standard.