ASTM_D_1822M_-_93_scan.pdf

ASTM D3822M 93 0759530 0534795 b 3 Designation:METRIC D 1822M-93 AMERICAN SOCIETY FOR TESTING AND MATERIALS 191 6 Race St.Philadelphia,Pa 191 03 Reprinted from the Annual Book of ASTM Standards.Copyright ASTM If not listed in the current combined inde%will appear in the next ediiion.Standard Test Method for Tensile-Impact Energy to Break Plastics and Electrical Materials Metric This standard is issued under the fixed designation D 1822M,the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A supersCnpt epsilon e)indicates an editorial change since the last revision or reapproval.1.Scope 1.1 This test method covers the determination of the energy required to rupture standard tension-impact speci-mens of plastic or electrical insulating materials.Materials that can be tested by this test method are those too flexible or too thin to be tested in accordance with Test Methods D 256,as well as more rigid materials.NOTE 1-This test method is the metric counterpart of Test Method 1.2 This standard does not purport to address all o f the safety problems,if any,associated with its use.It is the responsibility o f the user o f this standard to establish appro-priate safety and health practices and determine the applica-bility o f regulatory limitations prior to use.2.Referenced Documents 2.1 ASTM Standards:D 256 Test Methods for Impact Resistance of Plastics and D 6 18 Practice for Conditioning Plastics and Electrical D 638 Test Method for Tensile Properties of Plastics2 D 883 Terminology Relating to Plastics2 D 1822 Test Method for Tensile-Impact Energy to Break D 1898 Practice for Sampling of Plastics2 D 4000 Classification System for Specifjmg Plastic D 4066 Specification for Nylon Injection and Extrusion E 23 Test Methods for Notched Bar Impact Testing of D 1822.Electrical Insulating Materials2 Insulating Materials for Testing2 Plastics and Electrical Insulating Materials2 Materials3 Materials3 Metallic Materials4 3.Terminology method appear in Terminology D 883.4.Summary of Test Method 4.1 The energy utilized in this test method is delivered by a single swing of a calibrated pendulum of a standardized 3.1 Denitions-Definitions of terms applying to this test 1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.10 on Mechanical Current edition approved oct.IS,1993.Published December 1993.Onginally properties.published as D 1822M-83.Last previous edition D 1822M-89.Annual Book ofASTM Standards,Vol 08.01.3 Annual Book of ASTM Standards,Vol 08.02.Annual Book ofASTM Standards,Vol 03.01.tension-impact machine.The energy to fracture by shock in tension is determined by the kinetic energy extracted from the pendulum of an impact machine in the process of breaking the specimen.One end of the specimen is mounted in the pendulum.The other end of the specimen is gripped by a crosshead that travels with the pendulum until the instant of impact and instant of maximum pendulum kinetic energy,when the crosshead is arrested.5.Significance and Use 5.1 Tensile-impact energy is the energy required to break a standard tension-impact specimen in tension by a single swing of a standard calibrated pendulum under a set of standard conditions(Note 2).In order to compensate for the minor differences in cross-sectional area of the specimens as they will occur in the preparation of the specimens,the energy to break can be normalized to units of kilojoules per square metre of minimum cross-sectional area.An alterna-tive approach to normalizing the impact energy that com-pensates for these minor differences and still retains the test unit as joules is shown in Section 11.For a perfectly elastic material the impact energy might be reported per unit volume of material undergoing deformation.However,since much of the energy to break the plastic materials for which this test method is written is dissipated in drawing of only a portion of the test region,such normalization on a volume basis is not feasible.The test method permits two specimen geometries so that the effect of elongation or rate of extension,or both,upon the result can be observed.With the Type S(short)specimen the extension is comparatively low,while with the Type L(long)specimen the extension is comparatively high.In general,the Type S specimen(with its greater occurrence of brittle fracture)gives greater reproduc-ibility,but less differentiation among materials.Results obtained with different capacity machines may not be comparable.NOTE 2-Friction losses are largely eliminated by careful design and proper operation of the testing machine.Attention is drawn to Test Methods E23 for a general discussion of impact equipment and procedures.5.2 The scatter of data may be due to different failure mechanisms within a group of specimens.Some materials may exhibit a