Significance and Use

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.

Always refer to the ASTM material specification or ISO designation for the material for recommended molding conditions. If not available, consult the material supplier.

This practice requires the use of adequate quantities of plastic material to find desirable operating conditions and to make the desired test specimens.

1. Scope

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 to be 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 which differ from this standard take precedence over those in this standard.

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 and health practices and determine the applicability of regulatory limitations prior to use.

Note 1This 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).

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D256 Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics

D570 Test Method for Water Absorption of Plastics

D638 Test Method for Tensile Properties of Plastics

D648 Test Method for Deflection Temperature of Plastics Under Flexural Load in the Edgewise Position

D790 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials

D883 Terminology Relating to Plastics

D955 Test Method of Measuring Shrinkage from Mold Dimensions of Thermoplastics

D957 Practice for Determining Surface Temperature of Molds for Plastics

ISO Standards

Keywords

injection-molding; mold design; test specimen preparation; thermoplastics; Acetal plastics; Injection molding/extrusion compounds; Molding/extrusion compounds/materials; PET (poly(ethylene terephthalate)); PMMA (poly(methyl methacrylate)); Polyalkylene terephthalates; Polyamide (PA); Polycarbonate (PC); Polypropylene (PP); Reciprocating screw injection molding machines; Thermoplastic elastomers (TPE); Thermoplastics; Acetal plastics; Injection molding/extrusion compounds; Molding/extrusion compounds/materials; PET (poly(ethylene terephthalate)); PMMA (poly(methyl methacrylate)); Polyalkylene terephthalates; Polyamide (PA); Polycarbonate (PC); Polypropylene (PP); Reciprocating screw injection molding machines; Thermoplastic elastomers (TPE); Thermoplastics

ICS Code

ICS Number Code 83.080.20 (Thermoplastic materials)

DOI: 10.1520/D3641-12

ASTM International is a member of CrossRef.

ASTM D3641