1、Designation: D 1052 05Standard 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 (e) 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 f
3、or measuring the cutgrowth in rubber vulcanizates subjected to repeated bendflexing.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of thi
4、s 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 Practice for RubberStandard Temperatures forTestingD 3183
5、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 measured at frequent intervals,to determine the cut growth
6、 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 correlation between these test results andservice is implied
7、 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 two rollers that must permit a free bending movementof
8、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 Holder, as shown in Fig. 3.5.3 Measuring Instrument, having g
9、raduations, 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 thickness of the testspecimen as described in 8.1.6. Test Specim
10、ens6.1 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 in.) in thickness, and shall be cutfrom a vulcanized shee
11、t 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 like, in accordance with the procedure describedin Practice
12、 D 3183.6.1.2 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 hardness are being tested, a thick-ness other than standard may be used as agreed upon between the supplier
13、and the consumer.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 May 1, 2005. Published May 2005. Originallyapproved in 1949. Last previous edition approved in 1999 as D 1
14、052 85 (1999)e1.2For 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.1Copyright ASTM International, 100 Barr Harbo
15、r Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 LaboratoryAtmosphere in accordance with Practice D 1349, having
16、 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. The piercing tool shall be adjusted in the holderwith the cutting edge projecting 7.0 6 0.3 mm (0.275 6 0.010in.) from the base of t
17、he 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 be parallel to the width of the test specimen,at
18、 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 Measure and record the median thickness of the te
19、stspecimen 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 sure that the cuts are at the center point of the
20、arc 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 the testspecimen is shown in Fig. 2.NOTE 2It is
21、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 thenumber of cycles and the increase in cut length measured to theneare
22、st 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.The test shall be continued until the cut length has increased500 %, that is, until the combined length of the cut and crackhas
23、 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 continuation of the cut made by the piercing tool, and“star-shaped” cracking may develop. In this event, the cutgrowth shall be
24、 measured as the length of the longest continu-ous crack, regardless of its direction.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 spe
25、cimen bends freely througha 90 angle.FIG. 2 Schematic Diagram of Ross Flexing MachineD10520528.6 When it is necessary to stop operation of the machinetemporarily, the holder arm shall be in a horizontal position, sothat the test specimens remain horizontal while not beingflexed.9. Report9.1 The repo
26、rt 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 cycles for each 100 % increasein cut growth above the initial pierce of 2.5 mm (0.10 in.) ofthe tested specimens, up to a
27、nd including 500 %, wherepossible.10. Precision and Bias10.1 A precision and bias statement is not applicable, as thismethod employs qualitative ratings, providing only empiricalassessments of the subjected materials.11. Keywords11.1 crack growth; cut growth; cut length; growth rate; Rossflex testmm
28、 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 0.008M56 0.01 0.1256 0.005N46 0.01 0.2506
29、 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 HolderD1052053ASTM International takes no position respecting the validity of any patent rights asserted in connection with an
30、y 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 by the responsible technical
31、 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 standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration a
32、t 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
33、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).D1052054
