1、Designation: D 1052 09Standard Test Method forMeasuring Rubber DeteriorationCut Growth Using RossFlexing Apparatus1This standard is issued under the fixed designation D 1052; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers a test fo
3、r measuring the cutgrowth in rubber vulcanizates subjected to repeated bendflexing.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated
4、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:2D 573 Test Method for RubberDeterioration in an AirOvenD 1349 Pr
5、actice for RubberStandard Temperatures forTestingD 3183 Practice for RubberPreparation of Pieces for TestPurposes from ProductsD 3767 Practice for RubberMeasurement of Dimensions3. Summary of Test Method3.1 A pierced strip test specimen is bent freely over a rod toa 90 angle and the cut length is me
6、asured at frequent intervals,to determine the cut growth rate. The cut is initiated by aspecial shaped piercing tool.4. Significance and Use4.1 The test gives an estimate of the ability of rubbervulcanizates to resist crack growth of a pierced specimen whensubjected to bend flexing.4.2 No exact corr
7、elation between these test results andservice is implied due to the varied nature of service condi-tions.5. Apparatus5.1 Ross Flexing MachineThe machine, as illustrated inFig. 1 and Fig. 2, allows one end of the test specimen to beclamped firmly to a holder arm while the pierced end is placedbetween
8、 two rollers that must permit a free bending movementof the test specimen during the test. During each cycle, thepierced area of the test specimen is bent freely over a 10-mm(0.4 in.) diameter rod through a 90 angle. The machine shalloperate at 1.7 6 0.08 Hz (100 6 5 cpm).5.2 Piercing Tool and Holde
9、r, as shown in Fig. 3.5.3 Measuring Instrument, having graduations, or a resolu-tion, capable of measuring the cut length and cut growth,asdescribed in 8.4 and 8.5, to the nearest 0.5 mm (0.02 in.).5.4 Thickness Gage, as described and specified in PracticeD 3767, Procedure A, to measure the thicknes
10、s of the testspecimen as described in 8.1.6. Test Specimens6.1 At least two, preferably three, test specimens of eachsample shall be tested simultaneously.6.1.1 The test specimens shall be 25 6 1 mm (0.98 6 0.04in.) in width, a minimum of 152 mm (5.98 in.) in length, and6.35 6 0.03 mm (0.25 6 0.01 i
11、n.) in thickness, and shall be cutfrom a vulcanized sheet 6.35 6 0.03 mm (0.25 6 0.01 in.) inthickness and of suitable dimensions or from finished articlesby cutting and buffing. If obtained from a manufactured article,the piece of rubber shall be free of surface roughness, fabriclayers, and the lik
12、e, in accordance with the procedure describedin Practice D 3183.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.15 on Degradation Tests.Current edition approved July 1, 2009. Published July 2009. Originally approvedin 19
13、49. Last previous edition approved in 2005 as D 1052 05.2For 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 page onthe ASTM website.1Copy
14、right ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.2 Unless otherwise specified, the test specimens shall beprepared so that the longitudinal dimension is parallel with thedirection of the milling grain.NOTE 1When specimens of high hardn
15、ess are being tested, a thick-ness other than standard may be used as agreed upon between the supplierand the consumer.6.2 Unless otherwise specified, the test specimens shall beaged for 24 h at 100C (212F) in accordance with Test MethodD 573 and then allowed to remain in the Standard LaboratoryAtmo
16、sphere in accordance with Practice D 1349, having arelative humidity of 50 6 5 % and a temperature of 23 6 2C(73 6 3.6F), for a period of 16 to 96 h.6.3 The test specimens shall be pierced by use of thepiercing tool.3The piercing tool shall be adjusted in the holderwith the cutting edge projecting 7
17、.0 6 0.3 mm (0.275 6 0.010in.) from the base of the holder so that it will pierce completelythrough the test specimens when tapped. Before piercing eachtest specimen, the piercing tool shall be lubricated with a soapsolution that will not react with the rubber. The cut made by thepiercing tool shall
18、 be parallel to the width of the test specimen,at a right angle to and across the longitudinal center line of thespecimen at a 62 6 2 mm (2.44 6 0.05 in.) distance from theclamped end.7. Test Temperature7.1 Unless otherwise specified, the test temperature shall be23 6 2C (73 6 3.6F).8. Procedure8.1
19、Measure and record the median thickness of the testspecimen taken at three points across the width at the point ofthe cut in accordance with Procedure A of Practice D 3767.8.2 With the holder arm of the flexing machine in ahorizontal position, clamp side by side the test specimens ofthe same making
20、sure that the cuts are at the center point of thearc of the rod.8.3 Lower the adjustable top rollers until they just touch thetest specimen and lock in this position by means of the wingnuts, permitting free travel of the test specimens between therollers during the bending movement. The position of
21、 the testspecimen is shown in Fig. 2.NOTE 2It is recommended that the test specimens be distributedevenly on both sides of the apparatus if only a few are tested.8.4 Start the machine and record the number of cycles bythe use of a counter. Make frequent observations, recording the3The sole source of
22、 supply of the piercing tool and apparatus known to thecommittee at this time is CCSI, 221 Beaver St., Akron, OH 44304. If you are awareof alternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theres
23、ponsible technical committee,1which you may attend.FIG. 1 Ross Flexing MachineATest Specimen.BHolder arm.CHolder arm adjustment.DAdjustable top roller.EFixed lower roller.FSupporting fixed lower roller.GPierced section.H10 mm (0.375 in.) diameter rod over which specimen bends freely througha 90 angl
24、e.FIG. 2 Schematic Diagram of Ross Flexing MachineD1052092number of cycles and the increase in cut length measured to thenearest 0.5 mm for the purpose of determining the rate ofincrease in cut length. When observing cut growth, the holderarm shall be at an angle approximately 45 from the vertical.T
25、he test shall be continued until the cut length has increased500 %, that is, until the combined length of the cut and crackhas increased to a total of 15.0 mm (0.60 in.) or when 250kilocycles has been reached with slow cracking samples.8.5 In some cases the cut growth is not in a straight line asa c
26、ontinuation of the cut made by the piercing tool, and“star-shaped” cracking may develop. In this event, the cutgrowth shall be measured as the length of the longest continu-ous crack, regardless of its direction.8.6 When it is necessary to stop operation of the machinetemporarily, the holder arm sha
27、ll be in a horizontal position, sothat the test specimens remain horizontal while not beingflexed.9. Report9.1 The report shall include the following:9.1.1 Sample identification,9.1.2 Specimen medium thickness,9.1.3 Test temperature if other than 23 6 2C (73 6 3.6F),and9.1.4 The average number of cy
28、cles for each 100 % increasein cut growth above the initial pierce of 2.5 mm (0.10 in.) ofthe tested specimens, up to and including 500 %, wherepossible.10. Precision and Bias10.1 A precision and bias statement is not applicable, as thismethod employs qualitative ratings, providing only empiricalass
29、essments of the subjected materials.mm in.A6.46 0.01 0.2506 0.005B706 0.01 0.2756 0.005C36 0.01 0.1256 0.005D 127 6 0.06 5 6 0.025E626 0.03 2.4386 0.015F86 0.01 0.3136 0.005G356 0.02 1.3756 0.010H46 0.02 1.2506 0.010I226 0.02 0.8756 0.008J176 0.02 0.6886 0.008K16 0.02 0.5006 0.008L16 0.02 0.6256 0.0
30、08M56 0.01 0.1256 0.005N46 0.01 0.2506 0.005P106 0.01 0.3756 0.005Q116 0.01 0.4386 0.005R46 0.02 1.6256 0.010S 6 to 32 screwsT706 0.03 2.7506 0.015U2.56 0.01 0.106 0.005V26 0.02 1 6 0.010FIG. 3 Piercing Tool and HolderD105209311. Keywords11.1 crack growth; cut growth; cut length; growth rate; Rossfl
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32、ts, 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 additional
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34、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 aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D1052094
