【国外标准】 Standard Classification System and Basis for Specification for Polyoxymethylene Molding and Extrusion Materials (POM)

This classification covers polyoxymethylene materials suitable for molding and extrusion. This specification allows for the use of polyoxymethylene plastic materials that are recycled, reconstituted, recycled-regrind, recovered, or reprocessed, or combination thereof, provided that the requirements as stated in this specification are met. Test specimens shall be molded by injection molding and all test pieces shall be tested as molded and conditioned in the standard laboratory atmosphere. The mechanical properties of the unreinforced and reinforced, filled, or lubricated polyoxymethylene materials shall be determined and shall conform to the following requirements: flow rate; melting point; tensile strength; tensile modulus; Charpy impact resistance; and deflection temperature.1.1 This classification system covers polyoxymethylene materials suitable for molding and extrusion. This classification system allows for the use of polyoxymethylene plastic materials that are recycled, reconstituted, recycled-regrind, recovered, or reprocessed, or combination thereof, provided that the requirements as stated in this specification are met. It is the responsibility of the supplier and the buyer of recycled, reconstituted, recycled-regrind, recovered, or reprocessed polyoxymethylene plastic materials, or combination thereof, to ensure compliance. (See Guide D7209).1.2 The properties included in this standard are those required to identify the compositions covered. Other requirements necessary to identify particular characteristics important to specialized applications are to be specified by using suffixes as given in Section 5.1.3 This classification system and subsequent line callout (specification) are intended to provide a means of calling out plastic materials used in the fabrication of end items or parts. It is not intended for the selection of materials. Material selection can be made by those having expertise in the plastic field only after careful consideration of the design and the performance required of the part, the environment to which it will be exposed, the fabrication process to be employed, the costs involved, and the inherent properties of the material other than those covered by this standard.1.4 The values stated in SI units are to be regarded as the standard.1.5 The following precautionary caveat pertains only to the test method portion, Section 11, of this classification system. 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.NOTE 1: This classification system is similar to ISO 29988-1/-2, although the technical content is significantly different.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.