1、Designation:D78814Standard Classification System forPoly(Methyl Methacrylate)(PMMA)Molding and ExtrusionCompounds1This standard is issued under the fixed designation D788;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of la
2、st 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.1.Scope*1.1 The purpose of this classification syst
3、em is to provide amethod of adequately identifying PMMA materials using asystem consistent with that of Classification System D4000.Itfurther provides a means for specifying these materials by theuse of a simple line callout designation.1.2 This classification system covers poly(methyl methacry-late
4、)molding and extrusion compounds.These compounds arepolymers based on methyl methacrylate,and at least 70%ofthe polymer shall be polymerized from methyl methacrylate.1.3 The properties in this classification system are thoserequired to identify the compositions covered.Other require-ments necessary
5、to identify particular characteristics importantto specific applications shall be described by using the suffixesas given in Section 5.1.4 Acrylic molding and extrusion compounds are usedfrequently in applications where extreme clarity and the abilityto retain that clarity and color under severe wea
6、thering andother environmental exposures are of primary significance.While the test specimen properties of this document extend tothe evaluation of nonvirgin materials,the user must takeprecautions to ensure that parts made from these materials meetthe desired end-use requirements.Accordingly,this s
7、pecifica-tion allows for the use of those acrylic plastic materials that canbe recycled,reconstituted,and reground provided the follow-ing:1.4.1 The requirements as stated in this specification aremet,1.4.2 The material has not been modified in any way to alterits conformance to food contact regulat
8、ions or similarrequirements,and1.4.3 The requirements of the particular end-use applicationare met.1.5 This classification system and subsequent line callout(specification)are not intended for the selection of materials,but only as a means to call out plastic materials to be used forthe manufacture
9、of parts.The selection of these materials is tobe made by personnel with expertise in the plastics field inwhich the environment,inherent properties of the materials,performance of the parts,part design,manufacturing process,and economics are considered.NOTE1This classification system is similar to
10、ISO 8257-1:1987 intitle only.The technical content is significantly different.1.6 The values stated in SI units are to be regarded asstandard.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to
11、 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power F
12、requenciesD150 Test Methods for AC Loss Characteristics and Permit-tivity(Dielectric Constant)of Solid Electrical InsulationD257 Test Methods for DC Resistance or Conductance ofInsulating MaterialsD618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1003 Test Meth
13、od for Haze and Luminous Transmittanceof Transparent PlasticsD1238 Test Method for Melt Flow Rates of Thermoplasticsby Extrusion PlastometerD1600 Terminology forAbbreviated Terms Relating to Plas-tics1This classification system is under the jurisdiction ofASTM Committee D20 onPlastics and is the dir
14、ect responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved Aug.1,2014.Published September 2014.Originallyapproved in 1944.Last previous edition approved in 2012 as D788 12.DOI:10.1520/D078814.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orconta
15、ct ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshoh
16、ocken,PA 19428-2959.United States1 D3641 Practice for Injection Molding Test Specimens ofThermoplastic Molding and Extrusion MaterialsD3892 Practice for Packaging/Packing of PlasticsD4000 Classification System for Specifying Plastic Materi-alsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 ISO Standards and Recommendations:3ISO179 PlasticsDeterminationofCharpyImpactPropertiesPart 1:Non-Instrumented Impact TestISO 294 PlasticsInjection Mouldin
