1、Designation: D 1790 08Standard Test Method forBrittleness Temperature of Plastic Sheeting by Impact1This standard is issued under the fixed designation D 1790; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. 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 thattemperature at which plastic sheeting 1.00 mm (0.040 in.) orless in thickness e
3、xhibits a brittle failure under specified impactconditions.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.NOTE 1This test method was developed jointly with the Society ofthe Plastics Industry, primarily for use with plasti
4、cized vinyl sheetings. Itsapplicability to other plastic sheetings must be verified by the user.1.3 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices
5、and determine the applicability of regulatorylimitations prior to use.NOTE 2This test method and ISO 8570 address the same subjectmatter, but differ in technical content.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to Plast
6、icsD 5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensD 6988 Guide for Determination of Thickness of PlasticFilm Test SpecimensE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Standard:ISO 8570 PlasticsFilm and SheetingDeterm
7、ination ofCold-Crack Temperature33. Terminology3.1 Definitions:3.1.1 brittleness temperature, Tbthat temperature, de-rived statistically, where 80 % of the specimens would prob-ably pass 95 % of the time when a stated minimum number aretested by this test method. The 80 %-passing value is deter-mine
8、d by plotting the data on probability graph paper, asdescribed in 9.1.3.1.2 GeneralDefinitions of terms applying to this testmethod appear in Terminology D 883.4. Significance and Use4.1 Data obtained by this test method have been used topredict the behavior of plastic sheeting at low temperatureson
9、ly if the conditions of deformation are similar to thosespecified in this test method. This test method is useful forspecification testing and for comparative purposes, but doesnot necessarily determine the lowest use temperature for aparticular plastic.4.2 It has been demonstrated that on calendere
10、d sheeting thebrittleness temperature is sensitive to the direction of fold. Ithas also been demonstrated that the brittleness temperature issensitive to the direction of sampling. Therefore, it is impera-tive that the procedure for taking specimens and folding befollowed explicitly.5. Apparatus5.1
11、Cold Conditioning Chamber, at least 450 by 450 by 450mm (18 by 18 by 18 in.). Means (automatic or manual) shall beprovided for controlling the temperature of the chamber towithin 62C of the desired value.5.2 Impact Tester shown in Fig. 1 shall be constructed ofcold-rolled steel except for the bolts,
12、 screws, and rubberstopper. It is recommended that all structural parts (that is,base, anvil, arm, arm supports, and shaft) be chromium platedto prevent corrosion. The arm, including the rubber stopper andbolt, shall weigh 3.09 kg 6 28g(6lb136 1 oz).5.3 Die, 50.8 6 0.4 mm by 146.1 6 0.4 mm (2 6164 i
13、n. by534 6164 in.) to cut the test specimens from the sample.5.4 Stapler, desk-type, with a stop mounted on the baseexactly 12.7 mm (12 in.) back of the center of the groover thatturns the staple.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsib
14、ility of Subcommittee D20.30 on Thermal Properties.Current edition approved Oct. 1, 2008. Published October 2008. Originallyapproved in 1960. Last previous edition approved in 2002 as D 1790 - 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
15、 serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1*A Summary of Changes section appears
16、 at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.5 Index Card Stock, 50 by 127 mm (2 by 5 in.).5.6 Thickness GaugeA dead-weight dial or digital mi-crometer as described in D 5947 or D 6988 as appropriate
17、forthe material or specimen geometry being tested.6. Test Specimens6.1 The test specimens shall be cut with the die. The lengthof the test specimen shall be parallel to the transverse directionof the sheeting.6.2 The test specimens shall be selected so that the thicknessis uniform to within 10% of t
18、he thickness over the length of thespecimen in the case of specimens 0.25 mm (0.010 in.) or lessin thickness and to within 5 % in the case of specimens greaterthan 0.25 mm (0.010 in.) in thickness but do not exceed 1.00mm (0.040 in.) in thickness.6.3 The 50-mm (2-in.) ends of each specimen shall be
19、socollected that a gradual, closed loop is formed at roomtemperatures. The collected ends of the specimen and one endof the 50 by 127-mm (2 by 5-in.) card shall be matched exactlywith the body of the loop lying on the card. Two staples shallbe crimped through the matched ends of the specimen andcard
20、. These staples shall be 13-mm (12 in.) from, and parallelto, the 50-mm (2-in.) end of the stack.6.4 Since it has been demonstrated that this test is sensitiveto the direction of fold on calendered sheeting, it is necessaryto stipulate that all specimens be folded in the same direction.It is recomme
21、nded that, for materials with no grain, thespecimen be folded so that the surface last in contact with theroll shall be inside the loop following the inherent shape of thespecimen; grained materials are to be tested with the grainedsurface on the inside of the loop.7. Conditioning7.1 ConditioningCon
22、dition the test specimens at 23 62C (73.4 6 3.6F) and 50 6 5 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D 618, for those tests where conditioning is required.In cases of disagreement, the tolerances shall be 61C(61.8F) and 62 % relative humidity
23、.7.2 Test ConditionsConduct tests in the standard labora-tory environment of 23 6 2C (73.4 6 3.6F) and 50 6 5%relative humidity, unless otherwise specified in the test meth-ods or in this test method. In cases of disagreements, thetolerances shall be 61C (61.8F) and 62 % relative humid-ity.8. Proced
24、ure8.1 Measure the thickness of the specimen at several pointsalong its length to an accuracy of 0.0025 mm (0.0001 in.) orbetter for specimens 0.25 mm (0.010 in.) or less in thicknessand to an accuracy of 1 % or better for specimens greater than0.25 mm (0.010 in) in thickness but do not exceed 1.00
25、mm(0.040 in.) in thickness.NOTE 3Refer to D 6988 for specimens 0.25 mm (0.010 in.) or less inthickness.NOTE 4Refer to D 5947 for specimens greater than 0.25 mm (0.010in.) in thickness.8.2 Place the impact tester, with its base horizontal, in thecold conditioning chamber at the desired testing temper
26、ature,for a conditioning period of 1 h. Expose the specimens to thetest temperature for 15 6 5 min.8.3 Place each of ten mounted test specimens individuallyon the anvil with the crimped ends of the staples on the backof the card fitted into the groove in the anvil. Handle the card,not the sample. Lo
27、cate the bent loop of the sheeting on theanvil with the loop centered on the anvil and facing away fromthe pivotal end of the impact arm.8.4 Allow the impact arm to fall free from a position within5 perpendicular to the base onto the bent loop. Repeat untileach of the ten conditioned specimens has b
28、een tested.8.5 Remove the specimens and examine for failure. Partialfracture shall be construed as failure as well as completedivision into two or more pieces.Metric Equivalentsin.mm183.2146.471611.11212.7125.4212643764121141230514356FIG. 1 Brittleness Temperature Impact Testing MachineD17900828.6 A
29、djust the temperature of the cold conditioning chamberand condition a second group of ten specimens for 15 6 5 minat a suitable temperature, as indicated by the results of testingthe first group of ten specimens. Repeat the testing procedureand examination.8.7 When using the standard graphic method
30、to determinethe 80 %-passing temperature, it is necessary to repeat thisprocedure of testing ten specimens at a series of temperaturesdiffering by uniform increments of 5C. When using theprobability graph paper in 9.1, it is not necessary to obtain thelowest no-failure temperatures, at which no fail
31、ure is obtained,or the highest failure temperature.8.8 When testing for conformance to a specification, it shallbe satisfactory to accept materials on the basis of testing aminimum of ten test specimens at the specified temperature.Not more than 20 % of the specified number of test specimensshall fa
32、il at the specified temperature.9. Calculation9.1 Graphic MethodPlot the data on probability graphpaper with the temperature on the linear scale and the percent-age failure on the probability scale. Select the temperaturescale so that it represents a minimum of two divisions perdegree Celsius. Draw
33、a straight line through a minimum of fourpoints, two above and two below the 50 % point. The tempera-ture indicated at the intersection of the data line with the 20 %failure line shall be reported as Tb, the 80 % passing tempera-ture (20 % failure temperature).10. Report10.1 Report the following inf
34、ormation:10.1.1 Complete identification of the material tested, includ-ing type, source, manufacturers code designation, form, andprevious history,10.1.2 Eighty percent passing temperature, to the nearestdegree Celsius,10.1.3 Thickness of test specimen,10.1.4 Direction of fold,10.1.5 Conditioning pr
35、ocedure, and10.1.6 Date of test.10.2 For routine acceptance testing, report the followinginstead of 10.1.1, and 10.1.2:10.2.1 Number of specimens tested,10.2.2 Temperature of test, and10.2.3 Number of failures.11. Precision and Bias11.1 Table 1 is based on a round robin conducted in 1991 inaccordanc
36、e with Practice E 691, involving three materialstested by seven laboratories. For each material, all of thesamples were prepared at one source, but the individualspecimens were prepared at the laboratories that tested them.The test result for each material was based on a minimum offour trials, perfo
37、rmed under varying conditions, involving tenspecimens in each trial. Each laboratory obtained two testresults for each material.(WarningThe following explana-tions of r and R (11.2 through 11.2.3) are only intended topresent a meaningful way of considering the approximateprecision of this method. It
38、 is not appropriate to apply the datain Table 1rigorously to acceptance or rejection of material, asthose data are specific to the round robin and are unlikely to berepresentative of other lots, conditions, materials, or laborato-ries. It is recommended that users of this test method shouldapply the
39、 principles outlined in Practice E 691 to generate dataspecific to their laboratory and materials, or between specificlaboratories. The principles of 11.2 through 11.2.3 would thenbe valid for such data.)NOTE 5Material Number 3 (SP-61737 Lot 30) was tested success-fully by only three of the seven pa
40、rticipating labs due to equipmentlimitations.11.2 Concept of r and RIf Srand Sthave been calculatedfrom a large enough body of data, and for test results that wereaverages from testing 40 specimens (four trials involving tenspecimens in each trial):11.2.1 Repeatability Limit, r(Comparing two test re
41、sultsfor the same material, obtained by the same operator using thesame equipment on the same day.) The two test results shall bejudged not equivalent if they differ by more than the “r” valuefor that material.11.2.2 Reproducibility Limit, R(Comparing two test re-sults for the same material, obtaine
42、d by two different operatorsusing different equipment in different laboratories.) The twotest results shall be judged not equivalent if they differ by morethan the “R” value for that material.11.2.3 Any judgment in accordance with 11.2.1 or 11.2.2would have an approximate 95 % probably of being corr
43、ect.11.3 There are no recognized standards by which to estimatethe bias of this test method.12. Keywords12.1 brittleness temperature; cold-crack temperature; im-pact; plastic sheetingTABLE 1 Statistical Assessment of Brittleness TemperatureRound-Robin ResultsValues Expressed in CNumber Material Desc
44、ription Average SrASRBrCRD1 HN-81414 Lot 3Squirrel Grey0.013 in.(0.33 mm)16.2 0.62 2.36 1.74 6.612 HC-41310 Lot 2Special Tan0.014 in.(0.36 mm)18.3 0.80 2.88 2.24 8.103 SP-61737 Lot 30Blue0.020 in.(0.51 mm)39.2 0.73 3.71 2.04 10.4ASr= within-laboratory standard deviation.BSR= between-laboratory stand
45、ard deviation.Cr = within-laboratory repeatability limit = 2.8*Sr.DR = between-laboratory reproducibility limit = 2.8*SR.D1790083SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D 1790 - 02) that may impact the use of this standard
46、. (October 1, 2008)(1) Removed permissive language.(2) Added references to D 6988 and D 5947 to Section 2.(3) Added reference to a thickness gauge in Section 5.(4) Revised Section 6.(5) Added new Section 8.1 and Notes 3 and 4 to Section 8.Remaining notes renumbered.(6) Removed supplier info since th
47、e supplier that had beenlisted is no long manufacturing the fixture(7) Incorporated Note 4 into Section 11.1ASTM 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 t
48、hat 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 by the responsible technical committee and must be reviewed every five years andif not revised, either reapp
49、roved 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 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 C
