1、Designation: D 575 91 (Reapproved 2007)Standard Test Methods forRubber Properties in Compression1This standard is issued under the fixed designation D 575; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、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 These test methods cover two test procedures for de
3、ter-mining the compression-deflection characteristics of rubbercompounds other than those usually classified as hard rubberand sponge rubber.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
4、 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 regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 3183
5、 Practice for RubberPreparation of Product Piecesfor Test Purposes from ProductsD 3767 Practice for RubberMeasurement of DimensionsD 4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesE4 Practices for Force Verification of Testing Ma
6、chines3. Summary of Test Methods3.1 These tests constitute one kind of compression stiffnessmeasurement. Deflection is the change in thickness of thespecimen upon application of a compressive force. The twodifferent procedures are as follows:3.1.1 Test Method ACompression Test of SpecifiedDeflection
7、A compression test in which the force required tocause a specified deflection is determined.3.1.2 Test Method BCompression Test at SpecifiedForceA compression test in which the specified mass orcompressive force is placed on the specimen and the resultingdeflection is measured and recorded.4. Signif
8、icance and Use4.1 These test methods are useful in comparing stiffness ofrubber materials in compression. They can be used by rubbertechnologists to aid in development of materials for compres-sive applications.5. Apparatus5.1 Compression Testing MachineA compression testingmachine conforming to the
9、 requirements of Practices E4, andhaving a rate of head travel of 12 6 3 mm/m (0.5 6 0.1in./min), may be used for either type of test. Any other typemachine that will meet these requirements may be used. Forexample, a platform scale equipped with a yoke over theplatform and a hand-operated screw to
10、apply the force willserve if it will conform to the requirements prescribed foraccuracy and rate of travel. Compression tests at specifiedforces may be performed on any machine that applies minorand major forces gently, without impact, or by placing speci-fied masses gently on the specimen. The mach
11、ine shall beequipped to permit measurement of the deflection caused bythe increase from minor force to major force.5.2 Deflection GageThe deflection shall be read on a gageof dial type graduated in hundredths of millimetres (or thou-sands of an inch).5.3 MicrometerThe thickness of the specimen shall
12、 bemeasured in accordance with Test Method A of PracticeD 3767.6. Test Specimens6.1 The test may be performed either on rubber products oron standard test specimens, as specified.1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcom
13、mittee D11.10 on PhysicalTesting.Current edition approved May 1, 2007. Published July 2007. Originally approvedin 1940. Last previous edition approved in 2001 as D 575 91 (2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org.
14、For Annual 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.NOTE 1Comparable results are obtained only when tests are made onspe
15、cimens of exactly the same size and shape, tested to the samepercentage deflection, or tested under the same force.6.2 Standard test specimens shall be 28.6 6 0.1 mm (1.1296 0.005 in.) in diameter (650 mm2(1.000 in.2) in area) and 12.56 0.5 mm (0.49 6 0.02 in.) in thickness, from which allmolded sur
16、face layers have been removed.7. Preparation of Specimens7.1 The standard test specimens may be prepared as fol-lows: A slab approximately 13 mm (0.51 in.) in thickness maybe cut from a product or may be molded from the samecompound used in the preparation of the product and ground onboth sides to o
17、btain smooth parallel surfaces and the standardthickness of 12.5 6 0.5 mm (0.49 6 0.02 in.). The grindingshall be carried out as prescribed in Section 5 of PracticeD 3183 and shall be done without overheating the rubber. Thespecimens may then be cut from the slabs by means of asuitable rotating holl
18、ow cutting tool similar to that illustrated inFig. 1. In cutting the specimen, the die shall be suitably rotatedin a drill press or similar device and lubricated with soapywater so that a smooth-cut surface having square edges isobtained. The cutting pressure shall be kept sufficiently low toavoid “
19、cupping of the cut surface.NOTE 2The cutting tool is larger in diameter than the specimen toallow for cutting pressure.7.2 When rubber products are subjected to these tests, thesurfaces that will contact the platens of the testing machineshall be cleaned of any dust, bloom, grease, or other foreignm
20、aterial. Grinding is not required because tests on products areintended to be nondestructive.8. Test Conditions8.1 The temperature of the testing room shall be maintainedat 23 6 2C (73.4 6 3.6F). The specimens to be tested shallbe kept in this room for at least 3 h prior to the time of testing.Speci
21、mens that have compression properties affected by atmo-spheric moisture shall be conditioned in an atmosphere con-trolled to 50 6 6 % relative humidity for at least 24 h.Test Method ACompression Test at Specified Deflection9. Nature of Test9.1 In this test method the compressive forces are appliedan
22、d removed in three successive cycles. The first two cycles arefor the purpose of conditioning the specimen, and the readingsare taken during the third application of force.10. Procedure10.1 After measuring the thickness of the test specimen,place the specimen between the platens of the testing machi
23、ne.Place sheets of sandpaper3between the rubber surfaces and thetesting machine platens. The sandpaper resists lateral slippageof the rubber at the contact surfaces and should be slightlylarger than the specimen. Omit the sandpaper when the surfaceof the specimen is bonded to metal.10.2 Apply the fo
24、rce to produce a deflection rate of 12 6 3mm/min (0.5 6 0.1 in./min) until the specified deflection isreached, after which release the force immediately at the samerate. Repeat this loading cycle a second time. Apply the forcea third time until the specified deflection is again reached. Readand reco
25、rd the force required.10.3 If desired, the machine may be stopped at intervals of5 % deflection during the third application and the forcerecorded for each deflection so that a stress-strain curve may bedrawn.10.4 Deflection percentage shall be based on the thicknessof the specimen prior to the firs
26、t force application.10.5 Report the median of values taken from three speci-mens.Test Method BCompression Test at Specified Force11. Nature of Test11.1 This test is intended for rapid testing with a constantforce type of machine, although it can be performed on theother machines described in 5.1. Be
27、cause speed with reason-able accuracy is desired, a single force application cycle isused.12. Procedure12.1 Apply a specified minor mass or force for a period longenough to adjust the deflection gage, after which apply themajor force for 3 s. Read the deflection on the dial gage at theend of the 3-s
28、 period. The reading shall not include anydeflection caused by the minor force. Calculate the percentdeflection on the basis of the original thickness of the speci-men.12.2 Report the median of values taken from three speci-mens.13. Report13.1 Report the following information:13.1.1 Deflection expre
29、ssed as a percentage of the originalthickness of the specimen,13.1.2 Force in kilopascals or pounds-force per square inch,based on original cross section,13.1.3 Description of sample and type of test specimen,including dimensions,13.1.4 Description of test method and apparatus, and13.1.5 Date of tes
30、t.3400 Grit waterproof sandpaper has been found satisfactory.FIG. 1 Cutting ToolD 575 91 (2007)214. Precision and Bias414.1 This precision and bias section has been prepared inaccordance with Practice D 4483. Refer to Practice D 4483 forterminology and other statistical calculation details.14.2 The
31、precision results in this precision and bias sectiongive an estimate of the precision of this test method with thematerials (rubbers) used in the particular interlaboratory pro-gram as described in this section. The precision parametersshould not be used for acceptance/rejection testing of anygroup
32、of materials without documentation that they are appli-cable to those particular materials and the specific testingprotocols that are included in this test method.14.3 Two separate precision programs were conducted forthis test method, one in 1983 and a second in 1989.14.3.1 AType 1 (interlaboratory
33、) precision was evaluated inboth programs. Both repeatability and reproducibility are shortterm; a period of a few days separates replicate test results. Atest result is the value, as specified by this test method,obtained on a single determination(s) or measurement(s) of theproperty or parameter in
34、 question. The third deflection cycle isused for the measurement. For the 1983 program, threedifferent materials were used; these were tested in threelaboratories on two different days.14.4 For the 1989 program seven materials were tested innine laboratories on two separate days.14.4.1 The results o
35、f the precision calculations for repeat-ability and reproducibility are given in Tables 1-4, in ascendingorder of material average or level, for each of the materialsevaluated. Table 1 and Table 2 are for the 1983 program (No.1), and Table 3 and Table 4 are for the 1989 program (No. 2).14.5 The prec
36、ision of this test method may be expressed inthe format of the following statements that use an “appropriatevalue” of r, R,(r), or (R), to be used in decisions about testresults. The appropriate value is that value of r or R associatedwith a mean level in the precision tables closest to the meanleve
37、l under consideration at any given time for any givenmaterial in routine testing operations.14.6 RepeatabilityThe repeatability, r, of this test methodhas been established as the appropriate value tabulated in theprecision tables. Two single test results, obtained under normaltest method procedures,
38、 that differ by more than this tabulatedr (for any given level) must be considered as derived fromdifferent or non-identical sample populations.14.7 ReproducibilityThe reproducibility, R, of this testmethod has been established as the appropriate value tabulatedin precision tables. Two single test r
39、esults obtained in twodifferent laboratories, under normal test method procedures,that differ by more than the tabulated R (for any given level)must be considered to have come from different or non-identical sample populations.14.8 Repeatability and reproducibility expressed as a per-centage of the
40、mean level, (r) and (R), have equivalentapplication statements as above for r and R. For the (r) and (R)4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D11-1058.TABLE 1 Program 1, 1983 Precision,AType 1 PrecisionMethod A (kPa)B
41、NOTESr = repeatability standard deviation, in measurement units,r = repeatability, in measurement units,(r) = repeatability, (relative) percent,SR = reproducibility standard deviation, in measurement units,R = reproducibility, in measurement units, and(R) = reproducibility (relative) percent.Materia
42、l(kPa)AverageLevelWithin Laboratories Between LaboratoriesSr r (r) SR R (R)No. 3 Cl-Butyl 1106 28.2 79.8 7.2 40.4 114 10.3No. 2 EPDM 1731 92.8 263 15.2 69.3 196 11.3No. 1 SBR 1746 41.5 117 6.7 77.3 219 12.5Pooled (average)values1528 60.9 172 11.3 64.3 182 11.9AThree laboratories participating.BkPa =
43、 psi 3 6.89.TABLE 2 Program 1, 1983 Precision,AType 1 PrecisionMethod B (% DEF)NOTESr = repeatability standard deviation, in measurement units,r = repeatability, in measurement units,(r)= repeatability, (relative) percent,SR = reproducibility standard deviation, in measurement units,R = reproducibil
44、ity, in measurement units, and(R) = reproducibility (relative) percent.MaterialAverageLevel,%Within Laboratories Between LaboratoriesSr r (r) SR R (R)No. 1 SBR 36.0 1.11 3.14 8.7 1.38 3.91 10.9No. 2 EPDM 37.1 1.16 3.28 8.9 2.57 7.27 19.7No. 3 Cl-Butyl 43.7 0.78 2.20 5.1 2.03 5.74 13.2Pooled (average
45、)values38.9 1.03 2.91 7.5 2.05 5.80 14.9AThree laboratories participating.TABLE 3 Program 2, 1989 Precision,AType 1 PrecisionMethod A (kPa)BNOTESr = repeatability standard deviation, in measurement units,r = repeatability, in measurement units,(r) = repeatability, (relative) percent,SR = reproducibi
46、lity standard deviation, in measurement units,R = reproducibility, in measurement units, and(R) = reproducibility (relative) percent.MaterialAverageLevel,kPaWithin Laboratories Between LaboratoriesSr r (r) SR R (R)NR/RSS 836 20.8 58.9 7.0 74.4 211 25.2CR 1012 14.8 41.9 4.1 72.7 206 20.3SBR 1528 18.5
47、 52.4 3.4 59.1 167 11.0IIR 1564 18.8 53.2 3.4 120 340 21.7IR 1694 40.4 114 6.8 79.2 224 13.2EPDM 2218 45.1 128 5.8 179 507 22.8SIR 20 2591 62.0 175 6.8 206 583 22.5Pooled (average)values1636 36.2 102 6.3 118.5 335 20.5ANine laboratories participating.BkPa = psi 3 6.89.D 575 91 (2007)3statements, the
48、 difference in the two single test results isexpressed as a percentage of the arithmetic mean of the two testresults.14.9 The user of this test method should give greateremphasis to Program 2 (1989) precision results. This 1989program was substantially more comprehensive and the resultsare more typi
49、cal of the current status of this test method.14.10 BiasIn test method terminology, bias is the differ-ence between an average test value and the reference (or true)test property value. Reference values do not exist for this testmethod since the value (of the test property) is exclusivelydefined by this test method. Bias, therefore, cannot be deter-mined.15. Keywords15.1 compression; compression deflection characteristics;compression test at specified deflection; compression test atspecified force; compression testing of rubber; compressiveforce; constant
