1、Designation: D4226 11An American National StandardStandard Test Methods forImpact Resistance of Rigid Poly(Vinyl Chloride) (PVC)Building Products1This standard is issued under the fixed designation D4226; the number immediately following the designation indicates the year oforiginal adoption or, in
2、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 These test methods cover the determination of theenergy required to crack or break
3、rigid poly(vinyl chloride)(PVC) plastic sheeting and profile flat sections used in buildingproducts, as well as extruded or molded test samples, underspecified conditions of impact from a freefalling standardweight striking an impactor with either of two configurations incontact with the specimen.1.
4、2 Two test procedures are included:1.2.1 Procedure A, used to determine minimum impactenergy required to cause failure (hole, crack, split, shatter, ortear).1.2.2 Procedure B, used to determine minimum impactenergy required to cause brittle failure.1.3 The values stated in inch-pound units are to be
5、 regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.NOTE 1There is no known ISO equivalent to this standard.1.4 The text of this standard references notes and footnoteswhich provide explan
6、atory material. These notes and footnotes(excluding, those in tables in figures) shall not be considered asrequirements of this standard.1.5 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 e
7、stablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating
8、 to PlasticsD3679 Specification for Rigid Poly(Vinyl Chloride) (PVC)SidingD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE178 Practice for Dealing With Outlying Observations3. Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology D883, unless otherwise indic
9、ated.3.2 Definitions of Terms Specific to This Standard:3.2.1 failure (of test specimen, as related to impactresistance)signified by the presence of a punched hole,crack, split, shatter, or tear that was created in the target area bythe impact of the falling weight (see Fig. 1).3.2.2 ductile failure
10、 (ductile break, as related to impactresistance)a tear or split having an angle greater than 0 atthe tip and extending through the entire thickness of thespecimen such that light is directly visible through the tear orsplit (see Fig. 1).3.2.3 brittle failure (brittle break, as related to impactresis
11、tance)a punched hole, split, or shatter where a piece ofthe specimen separates from the main part of the specimen ora crack that has a 0 angle at the tip as viewed by the naked eye(see Fig. 1).3.2.4 mean failure height (Procedure A)the height fromwhich the falling weight will cause 50 % of the speci
12、mens tofail.3.2.5 mean failure energy (mean impact resistance), ( Pro-cedure A)energy required to produce 50 % failures; theproduct of the weight and mean failure height.3.2.6 normalized mean failure energy (normalized meanimpact resistance)the mean failure energy per unit (average)specimen thicknes
13、s (Procedure A).3.2.7 mean brittle failure heightthe height from which thefalling weight will cause 50 % brittle failures in specimens(Procedure B).3.2.8 mean brittle failure energy (mean energy of ductile-to-brittle transition), (Procedure B)energy required to pro-duce 50 % brittle failures; the pr
14、oduct of the weight and meanbrittle failure height.1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.24 on PlasticBuilding Products.Current edition approved Sept. 1, 2011. Published September 2011. Originallyapproved
15、 in 1983. Last previous edition approved in 2010 as D4226 - 10. DOI:10.1520/D4226-11.2For 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
16、page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.9 normalized mean brittle failure energy (normalizedmean energy of ductile-to-brittle trans
17、ition), (Procedure B)the mean brittle failure energy per unit (average) specimenthickness.3.2.10 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 building product profile is cut apart, if necessary, toobtain
18、a flat specimen at least 0.75 in. (19 mm) wide.4.2 Procedure A establishes the height from which a stan-dard falling 8-lb (3.6-kg) weight will cause 50 % of thespecimens to fail.4.3 Procedure B establishes the height from which a stan-dard falling 8-lb (3.6-kg) weight will cause 50 % of thespecimens
19、 to fail in a brittle mode.4.4 Both procedures employ either of two configurations ofimpactor heads resting on the specimen. The specimen lays ona stand that has a 0.64-in. (16.3-mm) hole. The falling weightimpacts on the impactor head tending to drive it through thespecimen into the hole of the sta
20、nd.4.5 The technique used to find 50 % failure level in bothprocedures is commonly called the Bruceton Staircase Methodor Up-and-Down Method. Testing is concentrated near themean, reducing the number of specimens required to obtain areasonably precise estimate.5. Significance and Use5.1 The impact s
21、trength values obtained on the flat sectionsof a building product profile are relevant only to the flat sectionthat has been tested and these values do not necessarily indicatethe impact resistance of the whole product, which is affected bythe configuration of the profile (that is, corners, ribs, et
22、c).5.2 Constant weight and variable height, employed in thesetest methods, allow the velocity of impact to vary and,therefore, by Procedure B, can determine the energy ofFIG. 1 Types of Failures of the SpecimenD4226 112ductile-to-brittle transition, which cannot be determined if avariable weight is
23、dropped from a constant height.5.3 These test procedures have been found to be usefulelements in rigid poly(vinyl chloride) (PVC) building productcharacterization. Compound qualification, finished productquality control, environmental and weatherability research anddevelopment studies, and fabricati
24、on tolerance prediction con-stitute useful applications.5.4 Choice of the specific impactor head configuration usedis related to a variety of product attributes, such as specimenthickness and product toughness as well as abstract factors,such as the anticipated mode of failure in a specific applicat
25、ion.The geometric uniqueness of the impactor head configurationsprevents any comparison or correlation of testing results onsamples tested with differing impactor head configurations. Ingeneral, the conical impactor, C.125, is useful to ensure failureof thicker specimens where the H.25 impactor caus
26、ed nofailure.NOTE 2Equivalent surface conditions are more likely to occur whenspecimens are prepared by compression molding or extrusion than byinjection molding.5.5 When comparing different samples tested with the sameimpactor head configuration, impact resistance shall be permit-ted to be normaliz
27、ed for average specimen thickness over areasonably broad range (for example, 1 to 3 mm).3However,this should only be done when the surface conditions listed in6.1 are essentially equivalent.6. Interferences6.1 The results obtained are greatly influenced by thequality of the test specimens. Cracks us
28、ually start at the surfacein tension; the surface opposite the one that is struck by theimpactor head. The composition of this surface layer and thedegree of orientation introduced during the formation of thespecimen are very important variables. Flaws in this surfacewill also affect results. Becaus
29、e of these factors, sometimesadditional information about the sample is achieved by testingthe sample from a variety of locations in a product or testingfrom both sides of a flat section.7. Apparatus7.1 Testing Machine The apparatus shall be constructedessentially as shown in Fig. 2 and Fig. 3 and s
30、hall consist of thefollowing: suitable base to withstand the impact shock; steel-rod impact weight weighing 8 6 0.2 lb (3.6 6 0.1 kg);hardened steel impactors as specified in 7.1.1; a slotted guidetube 40 in. (1.0 m) in length in which the impact weights slide,having an internal diameter sufficient
31、so that friction does notreduce the weight velocity, and having graduations in inch-pound (newton-metre) increments, or multiples thereof. Abracket is used to hold the tube in a vertical position byattaching it to the base and also to hold the hand knob, whichis a pivot-arm alignment for the impacto
32、r, about 2 in. (50 mm)under the tube. The top edge of the opening in the specimen3O.R. Weaver, “Using Attributes to Measure a Continuous Variable in ImpactTesting Plastic Bottles,” Materials Research building products; failure energy;falling weight; impact testD4226 117SUMMARY OF CHANGESCommittee D2
33、0 has identified the location of selected changes to this standard since the last issue(D4226 10) that may impact the use of this standard. (September 1, 2011)(1) Deleted Test Method D374 and added D5947 in 2.1 and7.3.Committee D20 has identified the location of selected changes to this standard sin
34、ce the last issue(D4226 09) that may impact the use of this standard. (July 1, 2010)(1) Revised 3.2.1 and 3.2.3.(2) Added 3.2.2.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are
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36、evised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you
37、 may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United
38、States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also
39、 be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 1 Within-Laboratory and Between-Laboratory VariationsMaterials Average SrSRrREmboss A 92.292 2.206 4.880 6.178 13.665Emboss B 71.157 3.031 4.207 8.486 11.957Emboss C 56.956 3.452 5.704 9.666 15.970Emboss D 61.406 2.538 4.922 7.107 13.
40、782where:Sr= repeatability standard deviationthe standard deviation of test results obtained under repeatability conditionsSR= reproducibility standard deviationthe standard deviation of test results obtained under reproducibility conditionsr = repeatability limitthe value below which the absolute d
41、ifference between two individual test results obtained under repeatability conditions may be expectedto occur with a probability of approximately 0.95 (95 %).R = reproducibility limitthe value below which the absolute difference between two individual test results obtained under reproducibility conditions may beexpected to occur with a probability of approximately 0.95 (95 %).D4226 118
