ASTM D4976 – Standard Specification for Polyethylene Plastics Molding and Extrusion Materials
This specification provides the standard requirements for polyethylene plastic molding and extrusion materials. The tests involved in this specification are intended to provide information for identifying materials in accordance with the groups, classes, and grades covered. Polyethylene plastic materials are classified into two groups in accordance with the molecular structure which may be branched or linear. Test specimens shall be compression molded, conditioned in a standard or controlled laboratory atmosphere, and tested to determine the materials’ physical and electrical properties. The specimens shall comply with the following requirements: flow rate; density; tensile stress at yield; nominal strain at break; secant flexural modulus; environmental stress-crack resistance; slow crack growth resistance; thermal stress crack resistance; permittivity; dissipation factor; volume resistivity; water immersion stability; flammability; and weatherability.
1.1 This specification provides for the identification of polyethylene plastics molding and extrusion materials in such a manner that the supplier and the user can agree on the acceptability of different commercial lots or shipments. The tests involved in this specification are intended to provide information for identifying materials in accordance with the groups, classes, and grades covered. It is not the function of this specification to provide specific engineering data for design purposes.
1.2 Other requirements necessary to identify particular characteristics important to specialized applications shall be agreed upon between the user and the supplier, by using the suffixes given in Section 1.3.
1.3 Ethylene plastic materials, being thermoplastic, are reprocessable and recyclable (see Note 1). This specification allows for the use of those ethylene plastic materials, provided that any specific requirements as governed by the producer and the end user are met.
NOTE 1: See Guide D7209 for information and definitions related to recycled plastics.
1.4 The values stated in SI units are regarded as standard.
1.5 The following precautionary caveat pertains to the test method portion only, Section 12, 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 For information regarding plastic pipe materials see Specification D3350. For information regarding wire and cable materials, see Specification D1248.
NOTE 2: There is no known ISO equivalent to this standard.