1、Designation: D 6515 00 (Reapproved 2004)Standard Test Method forRubber Shaft Seals Determination of Recovery FromBending1This standard is issued under the fixed designation D 6515; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e year 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.1. Scope1.1 This test method covers a procedure to determine therecovery response of rubber after particular bending de
3、forma-tion, subsequent to aging in selected media at a specifiedtemperature, and for a specified time period, thus providing ameasure of the relative performance potential of compoundsused in the manufacture of shaft seals.1.2 The values stated in SI units are to be regarded as thestandard. The valu
4、es given in parentheses are for informationonly.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 this standard to establish appro-priate safety and health practices and determine the applica-bility of reg
5、ulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTensionD 471 Test Method for Rubber PropertyEffect of LiquidsD 1349 Practice for RubberStandard Temperatures forTestingD 3183 Practice for RubberPreparati
6、on of Pieces for TestPurposes from ProductsD 4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3. Summary of Test Method3.1 The ends of rectangular specimens of candidate shaftseal compounds are clipped together and the specimens ex
7、-posed under specified conditions of time and temperature in afluid environment that best simulates anticipated operatingconditions. Upon completion of the exposure, the clamps areremoved and the specimen are allowed to recover frombending. After a specified period of time, the distance betweenends
8、of the specimens is measured and the amount of recoverycalculated.4. Significance and Use4.1 Among the factors affecting shaft seal life are the abilityto retain elasticity and compensate for shaft eccentricity, abilityto recover from bending, and resistance to wear and theswelling effects of contac
9、t fluids. In-service testing of candi-date materials is time consuming and therefore costly. Mea-surement of recovery from bending after exposure in fluids atelevated temperatures provides a means of quickly assessingthe materials potential and acceptability for use. Comparativerecovery data may the
10、n be screened and optimum performingcompounds selected for further improvement or seal fabrica-tion. It has been found that good to excellent correlation existsbetween a materials ability to recover from bending andsealing effectiveness.4.2 This method is designed to measure the recovery ofdifferent
11、 rubber compounds after aging in any liquid medium,including hydraulic oils and water. This method can also beused to test rubber compounds after aging in air. Test liquidsshould be chosen based on the intended end use.5. Apparatus5.1 Glass Test Tubes, 300 by 38 mm (12 by 112 in.)5.2 Specimen Hanger
12、s.5.3 Binder Clips.5.4 Aluminum Block Heater.5.5 Aluminum Plate, 300 by 400 by 2.3 mm (12 by 16 by0.09 in.) with surface roughness, Ra = 0.40.5 m (16 to 20in).5.6 Tweezers.5.7 Oven.5.8 Ruler, graduated in 0.5 mm (0.02 in.).6. Test Temperatures6.1 Unless otherwise specified, the standard temperature
13、fortesting shall be 23 6 2C (73.4 6 3.6F). Specimens shall beconditioned for at least 3 h when the test temperature is 23C(73.4F). If the material is affected by moisture, maintain the1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subco
14、mmittee D11.36 on Seals.Current edition approved Dec. 1, 2004. Published December 2004. Originallyapproved in 2000. Last previous edition approved in 2000 as D 6515 - 00.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annu
15、al Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.relative humidity at 50 6 5 % and condition the specimens forat least 24 h p
16、rior to testing. When testing at any othertemperature is required, use one of the temperatures listed inPractice D 1349.7. Test Specimen7.1 Test specimens shall be cut from test sheets with athickness of 2.0 6 0.2 mm (0.080 6 0.05 in.) of eachcompound to be evaluated, prepared according to the proce
17、-dure detailed in Practice 3183. Test sheets shall be vulcanizedaccording to the same conditions of time and temperature aswould be used for molding the sheets for testing physicalproperties in tension (see Test Method D 412).7.2 After the test sheets have been conditioned for at least16 h at 23C (7
18、3.4F), prepare three 100 6 0.5 by 10 6 0.05by 2.0 6 0.2 mm (3.937 6 0.02 by 0.393 6 0.002 by 0.080 60.008 in.) specimens for each material to be evaluated. Speci-mens shall be cut parallel to the mill grain direction.8. Procedure8.1 Mark each of three specimens of one compound type 56 0.5 mm (0.2 6
19、0.02 in.) from each end. Bring the ends of aspecimen together and place a piece of aluminum foil 10 by 15mm (0.395 by 0.590 in.) between them to prevent sticking.Insert the specimen in a binder clip to a depth of 5 mm (0.2 in.)in the lowest position so that the edge of it is even with the endof the
20、clip. This will avoid deforming the specimen whencutting. (see Figs. 1-3).8.2 Place each group of three specimens on the hangershown in Fig. 4 and insert the assembly in a 300 x 38-mm testtube, as in Fig. 5. Do not allow specimens to make contact.8.3 Add 225 6 5 cm of test fluid to each test tube, i
21、nsert acork stopper, and attach an identifying label.8.4 Place the test tubes in an oven block set at the desiredtest temperature, and age for the specified time as detailed inTest Method D 471, for suggested durations of 168, 336, and504 h. Verify the oil temperature periodically during exposure.8.
22、5 When the specified aging period is completed:8.5.1 Remove the specimens, leaving them still in theclamps for 15 6 1 s to allow dripping of excess oil.8.5.2 Place the specimens on their edge, as shown in Fig. 1,on the aluminum plate, with edge surfaces parallel to thesurface of the plate. DO NOT to
23、uch the rubber surface. Nomore than nine specimens (three compounds) shall be placedon an aluminum plate, as shown in Fig. 6.8.5.3 In sequence, cut each group of three specimens fromthe clamps with a razor blade, preferably at a distance of about1.0 to 1.5 mm (0.04 to 0.06 in.) from clamp edges and
24、allowthem to relax for 15 6 1 min. If the aluminum foil sticks to thespecimen, do not attempt to remove it, thus preventing speci-men distortion.8.5.4 After the 15 6 1-min relaxation period at roomtemperature is complete, place the aluminum plate containingthe specimens in a preheated oven at 100 6
25、1C (212 6 2F)for 30 6 1 min to allow further relaxation.8.5.5 Upon completion of the 30 6 1-min relaxation periodin the oven, remove the aluminum plate and allow thespecimens and plate to cool to ambient temperature.8.5.6 Leaving each specimen on its side, measure thedistance between inside edgesAan
26、d B, as shown in Figs. 6 and7, using a ruler graduated in 0.5 mm (0.02 in.). Do not touch ormove specimens during measurement. To maximize measure-ment accuracy, take all readings using the central portion of theruler, rather than the en or zero point. Both hands can then beused to stabilize the rul
27、er.8.5.7 Record the values taken as L1(see Fig. 8).FIG. 1 Placement Binder Clips with Rubber Specimen on the Aluminum PlateD 6515 00 (2004)28.5.8 When all measurements have been completed, removethe specimens from the aluminum plate with the tweezers,holding them at the maximum point of bending. Pla
28、ce thespecimens on a cleaned dry surface, flatten them, and measuretheir length with the ruler, as is shown in Fig. 9.8.5.9 Record the values taken as L2.9. Calculation9.1 Calculate the recovery from bending for each specimenas follows:RFB 5 L1/L25 sin a (1)AOR 5 2 a (2)P 5 L1/L2x 100 (3)where:RFB =
29、 recovery from bending,AOR = angle of recovery,L1= distance between specimen ends after relaxationfor 30 min at 100C (212F),L2= length of the flattened specimen, andP (%) = percent recovery from bending.9.2 Report results as the mean of the three specimens testedfor each material being evaluated.10.
30、 Report10.1 Report the following information:10.1.1 Results calculated in accordance with Section 9,10.1.2 Type or description of the specimen,10.1.3 Date of test,10.1.4 Temperature and humidity of test room, if not asspecified,10.1.5 Temperature of conditioning oven, aluminum plate,and test, if oth
31、er than specified, and10.1.6 Date of vulcanization and preparation of the speci-mens, if known.11. Precision and Bias11.1 Precision and bias has been determined in accordancewith Practice D 4483. Refer to this practice for terminologyand other statistical calculation details. Results are contained i
32、nthe appendix.11.2 A Type I interlaboratory test program was conductedusing three different vulcanized rubber compounds (materials).Test slabs were prepared in one laboratory and distributed toFIG. 2 After Cutting the SpecimenFIG. 3 Measurement of the Angle of RecoveryD 6515 00 (2004)3the six partic
33、ipating laboratories. All test liquids were pur-chased from approved sources. Refer to Appendix X1 foradditional details and precision and bias results.12. Keywords12.1 recovery from bending; rubber; shaft sealsDrawing labels Units Dimensions Tolerance, 6A mm 240 3.0in. 9.45 0.12Bm 01.in. 3.54 0.04C
34、mm75in. 2.95 0.04Dm 1.in. 2.95 0.04E mm 1.6 0.1in. 0.062 0.004Fm 251.0in. 0.98 0.04Gmm1in. 0.39 0.04FIG. 4 Hanger for SpecimensFIG. 5 Immersion of SpecimensD 6515 00 (2004)4FIG. 6 Measurement of the Distance Between the Inside Edges After Aluminum Plate was Taken from the Oven and Cooled for 30 minF
35、IG. 7 Measurement of the Recovery after RelaxationFIG. 8 Clamping of SpecimensD 6515 00 (2004)5APPENDIXX1. RECOMMENDED PRECISION SECTION FOR RECOVERY FROM BENDINGX1.1 Precision and Bias3X1.1.1 This precision and bias section has been prepared inaccordance with Practice D 4483. Please refer to this p
36、racticefor terminology and other statistical calculation details.X1.1.2 The precision results in this precision and biassection give an estimate of the precision of this test methodwith the materials (rubbers, etc.) used in the particular inter-laboratory test program (ITP) as described below. The p
37、reci-sion parameters should not be used for acceptance or rejectiontesting of any group of materials without documentation thatthe parameters are applicable to the particular group ofmaterials and the specific testing protocols of the test method.X1.1.3 Precision Program 1Two interlaboratory test pr
38、o-grams (ITP) were conducted in the development of this test.Program 1 was conducted in 1998 on three materials orcompounds, using three rubbers; VMQ, FKM, and HNBR.Seven laboratories participated in the ITP conducting tests forthree period of oil immersion; 168, 336, and 504 h (7, 14, 21days). Cure
39、d sheets from a common supply were sent and threetest specimens prepared and tested in each laboratory for eachrubber (compound) and each immersion period.X1.1.3.1 The D11 precision standard, Practice D 4483, callsfor precision (repeatability) evaluation to be conducted on thebasis of replicate test
40、 results on two (or more) separate days.However Program 1 was not conducted on a Day 1 versus Day2 basis, and the repeatability as given in precision Table X1.1was evaluated from the variation among the three test speci-mens for each immersion period. Thus the repeatability isdesignated as a limited
41、 or special repeatability (it does notinclude a day-to-day variation) and a test result is a singlemeasurement of recovery from bending rather than the mean ofthree as specified in the test method. Outlier analysis of thedatabase disclosed that there was one outlier laboratory foreach rubber and thu
42、s the final precision for all three rubbers isbased on six laboratories.3Supporting data for the precision evaluation of this test method are availablefrom ASTM Headquarters. Request RR:D11-1092.FIG. 9 Measurement of Flattened SamplesTABLE X1.1 Special Type 1 Precision for: Recovery fromBending (Rep
43、eatability Calculated from Variation Among ThreeTest Specimens)A, BAgingPeriod,h Material MeanWithin Labs Between LabsSr r (r) SR R (R)168 VMQ 0.920 0.006 0.017 1.85 0.013 0.036 3.88FKM 0.872 0.007 0.020 2.30 0.019 0.052 6.01HNBR 0.804 0.037 0.103 12.8 0.067 0.187 23.3336 VMQ 0.888 0.009 0.024 2.74
44、0.028 0.079 8.88FKM 0.823 0.024 0.067 8.20 0.034 0.094 11.4HNBR 0.706 0.033 0.092 13.0 0.082 0.228 32.3504 VMQ 0.867 0.012 0.035 3.99 0.048 0.135 15.5FKM 0.772 0.039 0.108 14.1 0.040 0.112 14.6HNBR 0.683 0.046 0.130 19.0 0.099 0.278 40.7AWithin-lab results do not contain a day-to-day component of va
45、riation, SeePrecision section for explanation.BSr = Special within-lab standard deviation, measurement units.r = Special repeatability = 2.83 x Sr; measurement units.(r) = Special relative repeatability; percent of mean value.SR = Between-Lab standard deviation, measurement units.R = Reproducibility
46、 = 2.83 x SR; measurement units.(R) = Relative reproducibility; percent of mean value.D 6515 00 (2004)6X1.1.3.2 RepeatabilityThe special Program 1 repeatabil-ity, r, of this test method has been established as the valuetabulated in Table X1.1 for each material and immersion time.Two single specimen
47、test values, obtained under normal testmethod procedures, that differ by more than this tabulated r(for any given level) must be considered as derived fromdifferent or non-identical sample populations.X1.1.3.3 ReproducibilityThe Program 1 reproducibility,R, of this test method has been established a
48、s the valuetabulated in Table X1.1 for each material and immersion time.Two single test results (the mean of three specimens) obtainedin two different laboratories, under normal test method proce-dures, that differ by more than the tabulated R must beconsidered to have come from different or non-ide
49、ntical samplepopulations.X1.1.3.4 The relative special repeatability and reproducibil-ity, (r) and (R), are also given in Table X1.1; these precisionparameters have the same applicability statements as thosegiven in X1.1.3.2 and X1.1.3.3.X1.1.4 Precision Program 2The second ITP was con-ducted in 1999 using one material (or compound) based onFKM. Six laboratories participated in the ITP conducting testsfor an immersion period of 168 h at 150C. Cured sheets froma common supply were sent to each participating laboratoryand two sets of three test specimens
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