1、Designation:D497612a(Reapproved 2020)Standard Specification forPolyethylene Plastics Molding and Extrusion Materials1This standard is issued under the fixed designation D4976;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year o
2、f last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.INTRODUCTIONThis specification is not intended
3、for the selection of materials,but only as a means to call outplastic materials to be used for the manufacture of parts.The selection of these materials is to be madeby personnel with expertise in the plastics field where the environment,inherent properties of thematerials,performance of the parts,p
4、art design,manufacturing process,and economics areconsidered.This specification does not specify the source of the resin to be used for the fabricationof any given article.1.Scope*1.1 This specification provides for the identification ofpolyethylene plastics molding and extrusion materials in sucha
5、manner that the supplier and the user can agree on theacceptability of different commercial lots or shipments.Thetests involved in this specification are intended to provideinformation for identifying materials in accordance with thegroups,classes,and grades covered.It is not the function ofthis spe
6、cification to provide specific engineering data fordesign purposes.1.2 Other requirements necessary to identify particular char-acteristics important to specialized applications shall be agreedupon between the user and the supplier,by using the suffixesgiven in Section 1.3.1.3 Ethylene plastic mater
7、ials,being thermoplastic,arereprocessable and recyclable(see Note 1).This specificationallows for the use of those ethylene plastic materials,providedthat any specific requirements as governed by the producer andthe end user are met.NOTE1See Guide D7209 for information and definitions related torecy
8、cled plastics.1.4 The values stated in SI units are regarded as standard.1.5 The following precautionary caveat pertains to the testmethod portion only,Section 12,of this specification.Thisstandard does not purport to address all of the safety concerns,if any,associated with its use.It is the respon
9、sibility of the userof this standard to establish appropriate safety,health,andenvironmental practices and determine the applicability ofregulatory limitations prior to use.1.6 For information regarding plastic pipe materials seeSpecification D3350.For information regarding wire and cablematerials,s
10、ee Specification D1248.NOTE2There is no known ISO equivalent to this standard.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and
11、 Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D257 Test Methods for DC Resistance or Conductance ofInsulating MaterialsD568 Method of Test for Burning and/or Extent and Time ofBurning of Flexible Plastics i
12、n a Vertical Position(With-drawn 1991)3D618 Practice for Conditioning Plastics for TestingD635 Test Method for Rate of Burning and/or Extent andTime of Burning of Plastics in a Horizontal PositionD638 Test Method for Tensile Properties of PlasticsD790 Test Methods for Flexural Properties of Unreinfo
13、rcedand Reinforced Plastics and Electrical Insulating Materi-als1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved Dec.1,2020.Published December 2020.Originallyappro
14、ved in 1995.Last previous edition approved in 2012 as D4976-12a.DOI:10.1520/D4976-12AR20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary p
15、age onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international s
16、tandard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.D792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD883 Terminology Relating to PlasticsD1238 Test Method for Melt Flow Rates of Thermoplasticsby Extrusion Plast
