1、Designation:D449512An American National StandardStandard Test Method forImpact Resistance of Poly(Vinyl Chloride)(PVC)RigidProfiles by Means of a Falling Weight1This standard is issued under the fixed designation D4495;the number immediately following the designation indicates the year oforiginal ad
2、option 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 energyrequired to crack or
3、break rigid poly(vinyl chloride)(PVC)profile under specified conditions of impact by means of afalling weight.1.2 This test method is used either by itself or in conjunctionwith other methods for measuring PVC product toughness.1.3 Because of the wide variety of profile sizes and shapesand the wide
4、variety of manufacturing procedures and fieldabuse,this test method does not correlate universally with alltypes of abuse.Therefore,correlations must be established asneeded.1.4 The text of this standard references notes and footnoteswhich provide explanatory material.These notes and footnotes(exclu
5、ding those in tables and figures)shall not be consideredas requirements of this standard.1.5 The values stated in inch-pound units are to be regardedas the standard.NOTE1There is no known ISO equivalent to this standard.1.6 This standard does not purport to address all of thesafety concerns,if any,a
6、ssociated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883
7、Terminology Relating to PlasticsE178 Practice for Dealing With Outlying Observations3.Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology D883,unless otherwise indicated.3.2 Definitions of Terms Specific to This Standard:3.2.1 failure the presence of a brittle failure readily v
8、isibleby the naked eye,including a sharp crack,split,or shatter inany part of the profile as a result of the impact of the fallingweight.Failure does not include ductile tears(where thesurfaces at the tip of the crack have a greater than 0 angle),orductile breaks(hinged breaks where the cracked part
9、 remainsjoined to the unbroken part throughout the length of thecracked part or section),(Fig.1).3.2.2mean failure heightthe height from which thefalling weight will cause 50%of the specimens to fail.3.2.3 mean failure energyenergy required to produce50%failures.The product of the weight and mean fa
10、ilureheight.3.2.4 outlieran observation that appears to deviate mark-edly from other members of the sample in which it occurs.4.Summary of Test Method4.1 The profile is cut into lengths of at least 6 in.The testmethod establishes the height from which a standard fallingweight will cause 50%of the sp
11、ecimens to fail.5.Significance and Use5.1 The impact strength of PVC profiles relates to suitabilityfor service and to quality of processing.Impact tests are usedfor quality-control purposes and as an indication that productscan withstand handling during assembling,installation,or inservice.5.2 Resu
12、lts obtained by use of this test method are able to beused in two ways:5.2.1 As the basis for establishing impact-test requirementsin product standards,and5.2.2 To measure the effect of changes in materials orprocessing.6.Apparatus6.1 GeneralOne type of impact tester is illustrated in Fig.2.1This te
13、st method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.24 on Plastic BuildingProducts.Current edition approved May 1,2012.Published June 2012.Originallyapproved in 1985.Last previous edition approved in 2005 as D4495 00(2005).DOI:10.
14、1520/D4495-12.2For 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
15、this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2 Falling Weight,shall be cylindrical and 212in.indiameter,with a flat-bottom surface that strikes the testspecimen.NOTE2It is suggested that the striking portion of the weigh
16、t be madeof scratch-resistant steel to reduce damage to the striking surface.Badlyscarred surfaces may affect test results.6.2.1 The mass of the falling weight shall be 10 6 0.5 lb.6.3 Drop Tube,shall be of sufficient length(approximately12 ft(4 m)to provide for a fall of at least 10 ft(3 m)and shallbe mounted so that the lengthwise direction is vertical,asmeasured with a plumb bob or a spirit level at least 2 ft(600mm)in length.6.3.1 Care must be taken to ensure that the weight fallsfreely;it m
