1、Designation:D542021Standard Test Method forImpact Resistance of Flat,Rigid Plastic Specimen by Meansof a Striker Impacted by a Falling Weight(Gardner Impact)1This standard is issued under the fixed designation D5420;the number immediately following the designation indicates the year oforiginal adopt
2、ion 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 test method covers the determination of the relativeranking of materials a
3、ccording to the energy required to crackor break flat,rigid plastic specimens under various specifiedconditions of impact of a striker impacted by a falling weight.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This sta
4、ndard 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 establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1There is no
5、 known ISO equivalent to this standard.1.4 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 T
6、rade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsD2794 Test Method for Resistance of Organic Coating
7、s tothe Effects of Rapid Deformation(Impact)D3763 Test Method for High Speed Puncture Properties ofPlastics Using Load and Displacement SensorsD4066 Classification System for Nylon Injection and Extru-sion Materials(PA)D4226 Test Methods for Impact Resistance of Rigid Poly-(Vinyl Chloride)(PVC)Build
8、ing ProductsD5628 Test Method for Impact Resistance of Flat,RigidPlastic Specimens by Means of a Falling Dart(Tup orFalling Mass)D5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE171 Practice for Conditioning and Testing Flexible BarrierPackagingE456 Terminology Relating to Quali
9、ty and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2935 Practice for Conducting Equivalence Tests for Com-paring Testing Processes3.Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nologies D883 and D1600,unless otherwi
10、se specified.Forterms relating to precision and bias and associated issues,theterms used in this standard are defined in accordance withTerminology E456.3.2 Definitions of Terms Specific to This Standard:3.2.1 failure(of test specimen)the presence of any crackor split created by the impact of the fa
11、lling weight that can beseen by the naked eye under normal laboratory lightingconditions.3.2.1.1 DiscussionFailure shall include the following:(1)complete shattering of the plaque;(2)any crack radiatingout toward the edges of the plaque on either surface of theplaque;(3)any radial crack within or ju
12、st outside the impactarea of the striker;(4)any hole in the plaque,whether due tobrittle or ductile puncture,where unobstructed light or watercould pass through;(5)any brittle splitting of the bottomsurface of the plaque;and(6)any glassy-type chip dislodgedfrom or loosened from the plaque.3.2.1.2 Di
13、scussionRefer to the appropriate material speci-fication for guidance on the interpretation of failure differencesbetween material types.3.2.1.3 DiscussionCracks usually start at the surface op-posite the one that is struck.For example,in some casesincipient cracking in glass-reinforced polymers is
14、difficult todifferentiate from the reinforcing fibers.In such cases,apply a1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved Jan.15,2021.Published February 2021.Origin
15、allyapproved in 1993.Last previous edition approved in 2016 as D5420-16.DOI:10.1520/D5420-21.2For 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 Summa
16、ry 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 Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(
