【国外标准】 Standard Practice for Injection Molding Test Specimens of Thermoplastic Molding and Extrusion Materials

5.1 It is well known that plastic test specimens molded under different conditions can have significantly different properties. This practice is designed to minimize those differences by establishing operating protocols without being unnecessarily restrictive.5.2 Always refer to the ASTM material specification or ISO designation for the material for recommended molding conditions. If not available, consult the material supplier.5.3 This practice requires the use of adequate quantities of plastic material to find desirable operating conditions and to make the desired test specimens.1.1 This practice covers the general principles to be followed when injection molding test specimens of thermoplastic molding and extrusion materials. This practice is used to obtain uniformity in methods of describing the various steps of the injection molding process and to set up uniform methods of reporting these conditions. The exact conditions required to prepare suitable specimens will vary for each plastic material. Any requirements or recommendations in the material specification that differ from this standard take precedence over those in this standard. Always consult the referenced material document for specimen preparation. If no referenced document exists, then consult the material supplier for specimen preparation guidance and note such in the test report.1.2 The methodology presented assumes the use of reciprocating screw injection molding machines.1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.4 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 practice is equivalent to the following parts of ISO 294: Plastics—Injection Moulding of Test Specimens of Thermoplastic Materials; 294-1: Part 1—General Principles and Multipurpose Test Specimens (ISO Type A Mould) and Bars (ISO Type B Mould); ISO 294-2: Part 2—Small Tensile Bars (ISO Type C Mould); ISO 294-3: Part 3—Plates (ISO Type D Moulds).1.5 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.