1、Designation: D4226 10An 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 in inch-pound units are to be regard
5、ed as thestandard.NOTE 1There is no similar or equivalent ISO standard.1.4 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotes(excluding, those in tables in figures) shall not be considered asrequirements of this standard.1.5 This sta
6、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 and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary st
7、atements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D374 Test Methods for Thickness of Solid Electrical Insu-lationD618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD3679 Specification for Rigid Poly(Vinyl Chloride) (PVC)SidingE178 Practic
8、e for Dealing With Outlying Observations3. Terminology3.1 Definitions Definitions are in accordance with Termi-nology D883, unless otherwise indicated.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 pun
9、ched 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 (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 the
10、specimen such that light is directly visible through the tear orsplit (see Fig. 1).3.2.3 brittle failure (brittle break, as related to impactresistance)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
11、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 specimens 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
12、 failure height.3.2.6 normalized mean failure energy (normalized meanimpact resistance)the mean failure energy per unit (average)specimen thickness (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
13、mean brittle failure energy (mean energy of ductile-to-brittle transition), (Procedure B)energy required to pro-duce 50 % brittle failures; the product of the weight and meanbrittle failure height.1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct resp
14、onsibility of Subcommittee D20.24 on PlasticBuilding Products.Current edition approved July 1, 2010. Published July 2010. Originally approvedin 1983. Last previous edition approved in 2009 as D4226 - 09. DOI: 10.1520/D4226-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orco
15、ntact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary 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, We
16、st Conshohocken, PA 19428-2959, United States.3.2.9 normalized mean brittle failure energy (normalizedmean energy of ductile-to-brittle transition), (Procedure B)the mean brittle failure energy per unit (average) specimenthickness.3.2.10 outlieran observation that appears to deviate mark-edly from o
17、ther members of the sample in which it occurs.4. Summary of Test Method4.1 The building product profile is cut apart, if necessary, toobtain 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 th
18、especimens 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 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 h
19、as 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 stand.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 concen
20、trated near themean, reducing the number of specimens required to obtain areasonably precise estimate.5. Significance and Use5.1 The impact strength 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 nec
21、essarily indicatethe impact resistance of the whole product, which is affected bythe configuration of the profile (that is, corners, ribs, etc).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 th
22、e energy ofFIG. 1 Types of Failures of the SpecimenD4226 102ductile-to-brittle transition, which cannot be determined if avariable weight is dropped from a constant height.5.3 These test procedures have been found to be usefulelements in rigid poly(vinyl chloride) (PVC) building productcharacterizat
23、ion. Compound qualification, finished productquality control, environmental and weatherability research anddevelopment studies, and fabrication tolerance prediction con-stitute useful applications.5.4 Choice of the specific impactor head configuration usedis related to a variety of product attribute
24、s, such as specimenthickness and product toughness as well as abstract factors,such as the anticipated mode of failure in a specific application.The geometric uniqueness of the impactor head configurationsprevents any comparison or correlation of testing results onsamples tested with differing impac
25、tor head configurations. Ingeneral, the conical impactor, C.125, is useful to ensure failureof thicker specimens where the H.25 impactor caused nofailure.NOTE 2Equivalent surface conditions are more likely to occur whenspecimens are prepared by compression molding or extrusion than byinjection moldi
26、ng.5.5 When comparing different samples tested with the sameimpactor head configuration, impact resistance shall be permit-ted to be normalized 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 in
27、6.1 are essentially equivalent.6. Interferences6.1 The results obtained are greatly influenced by thequality of the test specimens. Cracks usually 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 o
28、rientation introduced during the formation of thespecimen are very important variables. Flaws in this surfacewill also affect results. Because of these factors, sometimesadditional information about the sample is achieved by testingthe sample from a variety of locations in a product or testingfrom b
29、oth sides of a flat section.7. Apparatus7.1 Testing Machine The apparatus shall be constructedessentially as shown in Fig. 2 and Fig. 3 and shall 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
30、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 so that friction does notreduce the weight velocity, and having graduations in inch-pound (newton-metre) increments, or multiples thereof. Abracket is used to
31、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 impactor, 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 ImpactTest
32、ing Plastic Bottles,” Materials Research building products; failure energy;falling weight; impact testD4226 107SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D4226 09) that may impact the use of this standard. (July 1, 2010)(1) R
33、evised 3.2.1 and 3.2.3.(2) Added 3.2.2.Committee D20 has identified the location of selected changes to this standard since the last issue(D4226 05) that may impact the use of this standard. (November 1, 2009)(1) Section 15 was revised to add a precision and biasstatement for the method used on viny
34、l siding.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 expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such ri
35、ghts, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additiona
36、l standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the AST
37、M 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 States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the abov
38、eaddress 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 be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 1 Within-Laboratory and Between-Laboratory Variations
39、Materials 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 13.782where:Sr= repeatability standard deviationthe standard deviation of test results obtained under repeatability condit
40、ionsSR= reproducibility standard deviationthe standard deviation of test results obtained under reproducibility conditionsr = repeatability limitthe value below which the absolute difference 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 108
