ASTM_D_6338_-_17.pdf

Designation:D633817Standard Classification System forHighly Crosslinked Thermoplastic Vulcanizates(HCTPV)Based on ASTM Standard Test Methods1This standard is issued under the fixed designation D6338;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This classification system covers highly crosslinkedthermoplastic vulcanizates(HCTPV)for extrusion,moldingand other fabrication methods.Highly crosslinked thermoplas-tic vulcanizates(HCTPV)are thermoplastic elastomers(TPE)consisting of two or more polymer systems at least one ofwhich is rubbery and highly(95%)crosslinked and at leastone of which is thermoplastic,with each system having its ownphase.The thermoplastic phase will tend to be continuous andthe rubbery phase discontinuous.The high level of crosslinkingand ultrafine particle size(ca 1 m diameter)of the rubberyphase give rise to properties more closely approaching those ofconventional thermoset rubber,when compared to the samethermoplastic/rubbery polymer composition with a lower level(95%)of crosslinking.The HCTPV polymer compositionsmay contain fillers,reinforcing agents,plasticizers,resins,antidegradants,colorants and other beneficial constituents.Recycled HCTPV are not covered in this classification system.1.2 The properties included in this standard are thoserequired to identify the compositions covered.Other require-ments necessary to identify particular characteristics importantto specialized applications are to be specified by using suffixesas given in Section 5.1.3 This classification system and subsequent line callout(specification)are intended to provide a means of calling outplastic materials used in the fabrication of end items or parts.It is not intended for the selection of materials.Materialselection can be made by those having expertise in the plasticfield only after careful consideration of the design and theperformance required of the part,the environment to which itwill be exposed,the fabrication process to be employed,thecosts involved,and the inherent properties of the material otherthan those covered by this standard.1.4 As given in IEEE/ASTM SI-10,values in SI units are tobe regarded as standard.NOTE1There is no known ISO equivalent to this standard.1.5 This standard is based on testing completed in accor-dance with ASTM standard test methods.1.6 The following safety hazards caveat pertains only to thetest methods portion,Section 11,of this classification system.This standard does not purport to address all of the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety,health and environmental practices and determine the appli-cability of regulatory limitations prior to use.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 Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D395 Test Methods for Rubber PropertyCompression SetD412 Test Methods for Vulcanized Rubber and Thermoplas-tic ElastomersTensionD471 Test Method for Rubber PropertyEffect of LiquidsD573 Test Method for RubberDeterioration in an AirOvenD618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD883 Terminology Relating to PlasticsD1434 Test Method for Determining Gas Permeability Char-acteristics of Plastic Film and SheetingD1566 Terminology Relating to RubberD2240 Test Method for Rubber PropertyDurometer Hard-nessD3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD3892 Practice for Packaging/Packing of Plastics1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved Aug.1,2017.Published August 2017.Originallyapproved in 1998.Last previous edition approved in 2010 as D6338-10.DOI:10.1520/D6338-17.2For 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 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 Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International