1、Designation: D6515 00 (Reapproved 2016)Standard Test Method forRubber Shaft Seals Determination of Recovery FromBending1This standard is issued under the fixed designation D6515; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year 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.1. Scope1.1 This test method covers a procedure to determine therecovery response of rubber after particular bendingdeform
3、ation, subsequent to aging in selected media at aspecified temperature, and for a specified time period, thusproviding a measure of the relative performance potential ofcompounds used in the manufacture of shaft seals.1.2 The values stated in SI units are to be regarded as thestandard. The values gi
4、ven 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 regulato
5、ry limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D412 Test Methods for Vulcanized Rubber and Thermoplas-tic ElastomersTensionD471 Test Method for Rubber PropertyEffect of LiquidsD1349 Practice for RubberStandard Conditions for Test-ingD3183 Practice for RubberPreparation of Pie
6、ces for TestPurposes from ProductsD4483 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-posed und
7、er 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 of the spe
8、cimens 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 contact fluids.
9、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 then be scree
10、ned 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 rubber co
11、mpounds 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 Hangers.5.3 Bind
12、er 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.).1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the d
13、irect responsibility of Subcommittee D11.37 on Coated Fabrics, RubberThreads and Seals.Current edition approved July 1, 2016. Published August 2016. Originallyapproved in 2000. Last previous edition approved in 2010 as D6515 00 (2010).DOI: 10.1520/D6515-00R16.2For referenced ASTM standards, visit th
14、e 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. U
15、nited States16. Test Temperatures6.1 Unless otherwise specified, the standard temperature 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 therelative humidity at 50 6
16、5 % and condition the specimens forat least 24 h prior to testing. When testing at any othertemperature is required, use one of the temperatures listed inPractice D1349.7. 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
17、 to be evaluated, prepared according to the proce-dure detailed in Practice D3183.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 D412).7.2 After the test sheets
18、have been conditioned for at least16 h at 23C (73.4F), 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
19、specimens of one compound type 56 0.5 mm (0.2 6 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
20、 that the edge of it is even with the endof the 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 38-mm testtube, as in Fig. 5. Do not allow specimens to make contact.8.3 Add
21、 225 6 5 cm of test fluid to each test tube, insert 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 D471, for suggested durations of 168, 336, and504 h. Verify the oi
22、l temperature periodically during exposure.8.5 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 p
23、arallel to thesurface of the plate. DO NOT touch 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.
24、5 mm (0.04 to 0.06 in.) from clamp edges and 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 containi
25、ngthe specimens in a preheated oven at 100 6 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
26、, measure thedistance between inside edgesAand B, as shown in Figs. 6 andFIG. 1 Placement Binder Clips with Rubber Specimen on the Aluminum PlateD6515 00 (2016)27, using a ruler graduated in 0.5 mm (0.02 in.). Do not touch ormove specimens during measurement. To maximize measure-ment accuracy, take
27、all readings using the central portion of theruler, rather than the en or zero point. Both hands can then beused to stabilize the ruler.8.5.7 Record the values taken as L1(see Fig. 8).8.5.8 When all measurements have been completed, removethe specimens from the aluminum plate with the tweezers,holdi
28、ng them at the maximum point of bending. Place 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 (1)
29、AOR 5 2 (2)P 5 L1/L2x 100 (3)where:RFB = recovery from bending,AOR = angle of recovery,L1= distance between specimen ends after relaxation for30 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 tes
30、tedfor each material being evaluated.10. 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 conditioni
31、ng oven, aluminum plate,and test, if other than specified, and10.1.6 Date of vulcanization and preparation of thespecimens, if known.11. Precision and Bias11.1 Precision and bias has been determined in accordancewith Practice D4483. Refer to this practice for terminology andother statistical calcula
32、tion details. Results are contained in theappendix.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 Re
33、coveryD6515 00 (2016)3the six participating 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, A mm 240 3
34、.0in. 9.45 0.12Bm 01.in. 3.54 0.04Cmm75in. 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 SpecimensD6515 00 (2016)4FIG. 6 Measurement of the Distance Between the Inside Edges After Aluminum Plate was Taken fr
35、om the Oven and Cooled for 30 minFIG. 7 Measurement of the Recovery after RelaxationFIG. 8 Clamping of SpecimensD6515 00 (2016)5APPENDIXX1. RECOMMENDED PRECISION SECTION FOR RECOVERY FROM BENDINGX1.1 Precision and Bias3X1.1.1 This precision and bias section has been prepared inaccordance with Practi
36、ce D4483. Please refer to this practicefor 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
37、 (ITP) as described below. The preci-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 Prog
38、ram 1Two interlaboratory test pro-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,
39、 and 504 h (7, 14, 21days). Cured 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 D4483, callsfor precision (repeatability) evaluation to be conducte
40、d on thebasis of replicate test 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 repeatab
41、ility isdesignated as a limited 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 la
42、boratory for3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D11-1092.FIG. 9 Measurement of Flattened SamplesTABLE X1.1 Special Type 1 Precision for: Recovery fromBending (Repeatability Calculated from Variation Among ThreeTest
43、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 0.028 0.079 8.88FKM 0.823 0.024 0.067 8.20 0.034 0.09
44、4 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 variation, SeePrecision section for explanation.BSr = S
45、pecial 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 = 2.83 x SR; measurement units.(R) = Relative repro
46、ducibility; percent of mean value.D6515 00 (2016)6each rubber and thus the final precision for all three rubbers isbased on six laboratories.X1.1.3.2 RepeatabilityThe special Program 1repeatability, r, of this test method has been established as thevalue tabulated in Table X1.1 for each material and
47、 immersiontime. Two single specimen test values, obtained under normaltest method procedures, that differ by more than this tabulatedr (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 thi
48、s test method has been established as 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 methodprocedures, that differ by more than the tabulated R must beconsidered to h
49、ave come from different or non-identical samplepopulations.X1.1.3.4 The relative special repeatability andreproducibility, (r) and (R), are also given in Table X1.1; theseprecision parameters have the same applicability statements asthose given 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 150 C. Cured sheets froma common supply were sent to each participating labo
