1、Designation: D1790 08D1790 14Standard Test Method forBrittleness Temperature of Plastic Sheeting by Impact1This standard is issued under the fixed designation D1790; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method covers the determin
3、ation of that temperature at which plastic sheeting 1.00 mm (0.040 in.) or less inthickness exhibits a brittle failure under specified impact conditions.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.NOTE 1This test meth
4、od was developed jointly with the Society of the Plastics Industry, primarily for use with plasticized vinyl sheetings. Itsapplicability to other plastic sheetings must be verified by the user.1.3 This standard does not purport to address the safety concerns, if any, associated with its use. It is t
5、he responsibility of theuser of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitationsprior to use.NOTE 2This test method and ISO 8570 address the same subject matter, but differ in technical content.2. Referenced Documents2.1 AST
6、M Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD5947 Test Methods for Physical Dimensions of Solid Plastics SpecimensD6988 Guide for Determination of Thickness of Plastic Film Test SpecimensE691 Practice for Conducting an Interlaboratory Study to
7、 Determine the Precision of a Test Method2.2 ISO Standard:ISO 8570 PlasticsFilm and SheetingDetermination of Cold-Crack Temperature33. Terminology3.1 Definitions:3.1.1 brittleness temperature, Tbthat temperature, derived statistically, where 80 % of the specimens would probably pass95 % of the time
8、when a stated minimum number are tested by this test method. The 80 %-passing value is determined by plottingthe data on probability graph paper, as described in 9.1.3.1.2 GeneralDefinitions of terms applying to this test method appear in Terminology D883.4. Significance and Use4.1 Data obtained by
9、this test method have been used to predict the behavior of plastic sheeting at low temperatures only if theconditions of deformation are similar to those specified in this test method. This test method is useful for specification testing andfor comparative purposes, but does not necessarily determin
10、e the lowest use temperature for a particular plastic.4.2 It has been demonstrated that on calendered sheeting the brittleness temperature is sensitive to the direction of fold. It hasalso been demonstrated that the brittleness temperature is sensitive to the direction of sampling. Therefore, it is
11、imperative that theprocedure for taking specimens and folding be followed explicitly.1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.30 on Thermal Properties.Current edition approved Oct. 1, 2008Oct. 1, 2014. Publish
12、ed October 2008October 2014. Originally approved in 1960. Last previous edition approved in 20022008 asD1790 - 02.D1790 - 08. DOI: 10.1520/D1790-08.10.1520/D1790-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Boo
13、k of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.This document is not an ASTM standard and is intended only to provi
14、de the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the s
15、tandard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Apparatus5.1 Cold Conditioning Chamber, at leas
16、t 450 by 450 by 450 mm (18 by 18 by 18 in.). Means (automatic or manual) shall beprovided for controlling the temperature of the chamber to within 62C of the desired value.5.2 Impact Tester shown in Fig. 1 shall be constructed of cold-rolled steel except for the bolts, screws, and rubber stopper. It
17、is recommended that all structural parts (that is, base, anvil, arm, arm supports, and shaft) be chromium plated to prevent corrosion.The arm, including the rubber stopper and bolt, shall weigh 3.09 kg 6 28 g (6 lb 13 6 1 oz).5.3 Die, 50.8 6 0.4 mm by 146.1 6 0.4 mm (2 6 164 in. by 534 6 164 in.) to
18、 cut the test specimens from the sample.5.4 Stapler, desk-type, with a stop mounted on the base exactly 12.7 mm (12 in.) back of the center of the groover that turnsthe staple.5.5 Index Card Stock, 50 by 127 mm (2 by 5 in.).5.6 Thickness GaugeAdead-weight dial or digital micrometer as described in D
19、5947 or D6988 as appropriate for the materialor specimen geometry being tested.6. Test Specimens6.1 The test specimens shall be cut with the die. The length of the test specimen shall be parallel to the transverse direction ofthe sheeting.6.2 The test specimens shall be selected so that the thicknes
20、s is uniform to within 10% of the thickness over the length of thespecimen in the case of specimens 0.25 mm (0.010 in.) or less in thickness and to within 5 % in the case of specimens greater than0.25 mm (0.010 in.) in thickness but do not exceed 1.00 mm (0.040 in.) in thickness.6.3 The 50-mm (2-in.
21、) ends of each specimen shall be so collected that a gradual, closed loop is formed at room temperatures.The collected ends of the specimen and one end of the 50 by 127-mm (2 by 5-in.) card shall be matched exactly with the bodyof the loop lying on the card. Two staples shall be crimped through the
22、matched ends of the specimen and card. These staples shallbe 13-mm (12 in.) from, and parallel to, the 50-mm (2-in.) end of the stack.6.4 Since it has been demonstrated that this test is sensitive to the direction of fold on calendered sheeting, it is necessary tostipulate that all specimens be fold
23、ed in the same direction. It is recommended that, for materials with no grain, the specimen befolded so that the surface last in contact with the roll shall be inside the loop following the inherent shape of the specimen; grainedmaterials are to be tested with the grained surface on the inside of th
24、e loop.7. Conditioning7.1 ConditioningCondition the test specimens at 23 6 2C (73.4 6 3.6F) and 50 6 5 %10 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A of Practice D618, for those tests where conditioning is required. In casesof disagreement, the tolerances
25、shall be 61C (61.8F) and 62 %65 % relative humidity.Metric Equivalentsin.mm183.2146.471611.11212.7125.4212643764121141230514356FIG. 1 Brittleness Temperature Impact Testing MachineD1790 1427.2 Test ConditionsConduct tests in the standard laboratory environment of 23 6 2C (73.4 6 3.6F) and 50 6 5 %10
26、 %relative humidity, unless otherwise specified in the test methods or in this test method. In cases of disagreements, the tolerancesshall be 61C (61.8F) and 62 %65 % relative humidity.8. Procedure8.1 Measure the thickness of the specimen at several points along its length to an accuracy of 0.0025 m
27、m (0.0001 in.) or betterfor specimens 0.25 mm (0.010 in.) or less in thickness and to an accuracy of 1 % or better for specimens greater than 0.25 mm(0.010 in) in thickness but do not exceed 1.00 mm (0.040 in.) in thickness.NOTE 3Refer to D6988 for specimens 0.25 mm (0.010 in.) or less in thickness.
28、NOTE 4Refer to D5947 for specimens greater than 0.25 mm (0.010 in.) in thickness.8.2 Place the impact tester, with its base horizontal, in the cold conditioning chamber at the desired testing temperature, for aconditioning period of 1 h. Expose the specimens to the test temperature for 15 6 5 min.8.
29、3 Place each of ten mounted test specimens individually on the anvil with the crimped ends of the staples on the back of thecard fitted into the groove in the anvil. Handle the card, not the sample. Locate the bent loop of the sheeting on the anvil with theloop centered on the anvil and facing away
30、from the pivotal end of the impact arm.8.4 Allow the impact arm to fall free from a position within 5 perpendicular to the base onto the bent loop. Repeat until eachof the ten conditioned specimens has been tested.8.5 Remove the specimens and examine for failure. Partial fracture shall be construed
31、as failure as well as complete divisioninto two or more pieces.8.6 Adjust the temperature of the cold conditioning chamber and condition a second group in order to have a minimum of fourresults, two above and two below the 50 % point. Condition the groups of ten specimens for 15 6 5 min at a suitabl
32、etemperature,the selected temperatures, as indicated by the results of testing the first group of ten specimens. testing. Repeat thetesting procedure and examination.8.7 When using the standard graphic method to determine the 80 %-passing temperature, it is necessary to repeat this procedureof testi
33、ng ten specimens at a series of temperatures differing by uniform increments of 5C. When using the probability graph paperin 9.1, it is not necessary to obtain the lowest no-failure temperatures, at which no failure is obtained, or the highest failuretemperature.8.7 When testing for conformance to a
34、 specification, it shall be satisfactory to accept materials on the basis of testing a minimumof ten test specimens at the specified temperature. Not more than 20 % of the specified number of test specimens shall fail at thespecified temperature.9. Calculation9.1 Graphic MethodPlot the data on proba
35、bility graph paper with the temperature on the linear scale and the percentagefailure on the probability scale. Select the temperature scale so that it represents a minimum of two divisions per degree Celsius.Draw a straight line through a minimum of four points, two above and two below the 50 % poi
36、nt. The temperature indicated atthe intersection of the data line with the 20 % failure line shall be reported as Tb, the 80 % passing temperature (20 % failuretemperature).10. Report10.1 Report the following information:10.1.1 Complete identification of the material tested, including type, source,
37、manufacturers code designation, form, andprevious history,10.1.2 Eighty percent passing temperature, to the nearest degree Celsius,10.1.3 Thickness of test specimen,10.1.4 Direction of fold,10.1.5 Conditioning procedure, and10.1.6 Date of test.10.2 For routine acceptance testing, report the followin
38、g instead 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 in accordance with Practice E691, involving three materials testedby seven laboratories. For each
39、material, all of the samples were prepared at one source, but the individual specimens wereD1790 143prepared at the laboratories that tested them. The test result for each material was based on a minimum of four trials, performedunder varying conditions, involving ten specimens in each trial. Each l
40、aboratory obtained two test results for eachmaterial.(WarningThe following explanations of r and R (11.2 through 11.2.3) are only intended to present a meaningful wayof considering the approximate precision of this method. It is not appropriate to apply the data in Table 1 rigorously to acceptanceor
41、 rejection of material, as those data are specific to the round robin and are unlikely to be representative of other lots, conditions,materials, or laboratories. It is recommended that users of this test method should apply the principles outlined in Practice E691to generate data specific to their l
42、aboratory and materials, or between specific laboratories. The principles of 11.2 through 11.2.3would then be valid for such data.)NOTE 5Material Number 3 (SP-61737 Lot 30) was tested successfully by only three of the seven participating labs due to equipment limitations.11.2 Concept of r and RIf Sr
43、 and St have been calculated from a large enough body of data, and for test results that wereaverages from testing 40 specimens (four trials involving ten specimens in each trial):11.2.1 Repeatability Limit, r(Comparing two test results for the same material, obtained by the same operator using the
44、sameequipment on the same day.) The two test results shall be judged not equivalent if they differ by more than the “r” value for thatmaterial.11.2.2 Reproducibility Limit, R(Comparing two test results for the same material, obtained by two different operators usingdifferent equipment in different l
45、aboratories.) The two test results shall be judged not equivalent if they differ by more than the“R” value for that material.11.2.3 Any judgment in accordance with 11.2.1 or 11.2.2 would have an approximate 95 % probably of being correct.11.3 There are no recognized standards by which to estimate th
46、e bias of this test method.12. Keywords12.1 brittleness temperature; cold-crack temperature; impact; plastic sheetingSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D1790 - 02D1790 - 08) that may impact the use of this standard. (
47、October 1, 2008)2014)(1) Removed permissive language.Changed relative humidity requirement to 610 % from 65 % in 7.1 and 7.2.(2) Added referencesChanged 8.6 to D6988 andreflect using D5947 to Section 2.probability graph paper(3) Added reference to a thickness gauge in Section 5.Removed old 8.7: Refe
48、rence to standard graph method.(4) Revised Section 6.Renumbered 8.8 to 8.7(5) Added new Section 8.1 andRemoved “Graphic Method” title from 9.1Notes 3 and 4 to Section 8. Remaining notesrenumbered(6) Removed supplier info since the supplier that had been listed is no long manufacturing the fixture(7)
49、 Incorporated Note 4 into Section 11.1TABLE 1 Statistical Assessment of Brittleness TemperatureRound-Robin ResultsValues Expressed in CNumber Material Description Average Sr A SR B rC RD1 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 10.4A Sr = within-laboratory standard deviation.B SR = between-laboratory standard deviation.C r = within-laboratory repeatability limit = 2.8*Sr .D R = betw
