1、Designation: D4495 12An 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 oforigin
2、al 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 test method covers the determination of the energyrequired
3、to crack or 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 shapes
4、and the wide 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 an
5、d footnotes(excluding 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.NOTE 1There is no known ISO equivalent to this standard.1.6 This standard does not purport to address all of thesafet
6、y 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.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Pl
7、astics for TestingD883 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
8、brittle failure readilyvisible by the naked eye, including a sharp crack, split, orshatter in any part of the profile as a result of the impact of thefalling weight. Failure does not include ductile tears (where thesurfaces at the tip of the crack have a greater than 0 angle), orductile breaks (hing
9、ed breaks where the cracked part remainsjoined to the unbroken part throughout the length of thecracked part or section), (Fig. 1).3.2.2 mean failure heightthe height from which thefalling weight will cause 50 % of the specimens to fail.3.2.3 mean failure energyenergy required to produce50 % failure
10、s. The product of the weight and mean failureheight.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 stan
11、dard fallingweight will cause 50 % of the specimens 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
12、 assembling, installation, or inservice.5.2 Results 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.1This test method is under the
13、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: 10.1520/D4495-12.2For
14、 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.1*A Summary of Changes section appears at the end of this standar
15、d.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Apparatus6.1 GeneralOne type of impact tester is illustrated in Fig.2.6.2 Falling Weight, shall be cylindrical and 212 in. indiameter, with a flat-bottom surface that strikes the te
16、stspecimen.NOTE 2It is suggested that the striking portion of the weight 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 (a
17、pproximately12 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 must not “chatter”
18、down the tube.NOTE 3No particular material for the drop tube is specified. However,a cold-drawn seamless steel tubing with an inside diameter of 258 to 234in. (67 to 70 mm) has been found to be satisfactory. It may also benecessary to provide a protective barrier around the specimen, particularlyfor
19、 larger sizes of profile, to protect the operator from flying brokenpieces.NOTE 4The dropped weight may not fall freely if the clearancebetween the weight and tube is too large or too small, or if it is restrainedby a partial vacuum above the weight, such as can be caused by the holdand release devi
20、ce.6.3.2 Means shall be provided to hold the weight to bedropped at steps of 2 in. (50 mm) for a distance of 2 to 10 ft(600 mm to 3 m) above the flat-plate holder, to release theweight in a reproducible manner, and to allow the weight to fallfreely.6.4 Specimen HolderThe flat plate shall be used as
21、aspecimen holder.FIG. 1 Types of BreaksD4495 1226.4.1 The rigid steel flat-plate holder shall consist of a plateapproximately 8 by 12 by 1 in. (200 by 300 by 25 mm). Thespecimen holder shall be fastened to a concrete slab (floor).Means shall be provided to center the specimens under the droptube.7.
22、Test Specimens7.1 The profile shall be not less than 6 in. (150 mm) inlength.7.2 When the approximate mean-failure height for a givensample is known, 20 specimens usually yield sufficientlyprecise results. If the mean failure height is not able to beapproximated, six or more specimens shall be used
23、to deter-mine the appropriate starting point of the test.NOTE 5As few as five specimens often yield sufficiently reliableestimates of the mean failure height. However, in such cases, the estimatedstandard deviation will be relatively large.38. Conditioning8.1 Unless otherwise specified, condition th
24、e test specimensat 73.4 6 3.6F (23 6 2C) and 50 6 10 % relative humidityfor not less than 24 h prior to test in accordance with ProcedureA of Methods D618. In cases of disagreement, the toleranceshall be 61.8F (61C) and 65 % relative humidity.8.2 Quality-Control TestsCondition the test specimens at7
25、3.4 6 3.6F (23 6 2C) for4hinair.9. Procedure9.1 Cut the profile into samples 6 in. (152 mm) long.9.2 Choose a specimen at random from the sample.9.3 After raising the weight, place the specimen on thespecimen holder between two pair of snug-fitting right-angle-slotted brackets in such a way that it
26、rests in the most stableposition and is centered under the weight. The brackets areused to prevent any lateral movement of the profile and anysliding out during impact.NOTE 6During the round robin, it was found that choice of the side ofthe profile impacted made no difference on impact resistance. E
27、ven then,the position was defined so that it is likely that all would hit the same side.9.4 Raise the weight in the tube to the approximate failureheight value for the specific sample and release it so that itdrops on the specimen. Height is determined as the distancebetween the top surface of the p
28、rofile under impact, and thebottom surface of the falling weight.9.5 Remove the specimen and examine it to determinewhether or not it has failed.9.6 If the first impact of the specimen results in failure,decrease the drop height one increment. If the first impact ofthe specimen does not cause failur
29、e, increase the drop heightone increment. Then test a second specimen.9.7 In this manner, select the impact height for eachsuccessive test from the results observed with the specimen justpreviously tested. Do not test the same target point on aspecimen more than once.9.8 Keep a running plot of the d
30、ata. See Appendix X1. Useone symbol, such as “X” to indicate a failure and a differentsymbol such as “O” to indicate a non-failure at each heightlevel.9.9 For any specimen that gives a break behavior thatappears to be an outlier, the conditions of that impact shall beexamined. The specimen is discar
31、ded only if a unique cause forthe anomaly can be found, such as an internal flaw visible inthe broken specimen. Note that break behavior varies widelywithin a set of specimens. Data from specimens that showatypical behavior shall not be discarded simply on the basis ofsuch behavior. Refer to Practic
32、e E178 for detailed informationon how outliers shall be handled.3Brownless, K. A., Hodges, J. L., Jr., and Rosenblatt, Murray, “The Up-and-Down Method With Small Samples”, American Statistical Association Journal,JSTNA, Vol 48, 1953, pp. 262277.FIG. 2 Testing ApparatusD4495 12310. Calculation10.1 Me
33、an Failure Height (Procedure A) Calculate themean failure height from the test data obtained as follows:h 5 ho1 dhA/ N 6 0.5!where:h = mean failure height, in. (cm),dh= increment of weight height, in. (cm),N = total number of failures or non-failures, whichever issmaller. For ease of notation, call
34、whichever are used“events”,ho= lowest height at which an event occurred, in. (cm),A =(i50kini,i = 0,1,2.k (counting index, starts at ho),ni= number of events which occurred at hi, andhi= ho+ idh.In calculating h, the negative sign is used when the eventsare failures. The positive sign is used when t
35、he events arenon-failures.10.2 Mean Failure Energy (Procedure A) Compute themean failure energy as follows:MFE 5 h 3 wwhere:MFE = mean failure energy, in./lb (J),h = mean failure height, in. (cm), andw = weight.10.3 Estimated Standard DeviationCalculate the esti-mated standard deviation from the tes
36、t data as follows:s 5 1.620 dFFNB 2 A2!N2 G1 0.029GB 5(i50ki2ni11. Report11.1 The report shall include the following:11.1.1 Complete identification of the sample tested, manu-facturers code, form, and previous history.11.1.2 Weight being used.11.1.3 Number of test specimens (target points) employedt
37、o determine the mean failure height.11.1.4 Mean failure energy.11.1.5 Estimated standard deviation.11.1.6 Any departures from the specified test procedures.12. Precision and Bias12.1 PrecisionAn interlaboratory study with five labora-tories was conducted in which various rigid poly(vinyl chlo-ride)
38、(PVC) extruded profiles were tested by means of a fallingweight.12.1.1 The average within-laboratory and between-laboratory coefficients of variation were as follows:Average VWithin Laboratory Between Laboratory13.6 23.5where:V = 100 SMFE average12.2 BiasNo statement of bias is provided because of t
39、helack of a referee method for impact behavior of plastics whichcan provide a “true” or reference value.13. Keywords13.1 impact resistance; profile toughness; PVC rigid profilesAPPENDIX(Nonmandatory Information)X1. SAMPLE CALCULATIONSHeight in. Outcome ofXFailure 0Non-Failure403836343230 XXXX28 XOXO
40、OXO26 O O O O24 O22 X O20 O OD4495 124Height in. NxNoiNiiNi2Ni30 4044166428 3433 976 0420 004 01102 110120 0 2Totals 8(Nx)12(No)8(N)25(A)91(B)ho5 22, N 5 Nx5 7 d 5 2 in.h 5 ho1 dSAN2 0.5Dh 5 22 1 2S2582 0.5Dh 5 27.2 in.S 5 1.620 dSNB2A2N21 0.029DS 5 1.6202!S7282625641 0.29DS 5 5.3 in.SUMMARY OF CHAN
41、GESCommittee D20 has identified the location of selected changes to this standard since the last issue(D4495 00(2005) that may impact the use of this standard. (May 1, 2012)(1) Removed permissive language from 1.2 and 5.2.(2) Conditioning tolerance in 8.1 brought into alignment withPractice D618. It
42、 was not possible to hold original humidityvalues over temperature range initially specified.(3) Incorporated mandatory height definition from Note 7 into9.4. Notes cannot contain mandatory information. DeletedNote 7.ASTM International takes no position respecting the validity of any patent rights a
43、sserted 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 rights, are entirely their own responsibility.This standard is subject to revision at any time
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45、ceive 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 ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM In
46、ternational, 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 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 be secured from the ASTM website (www.astm.org/COPYRIGHT/).D4495 125
