1、Designation: D531 15Standard Test Method forRubber PropertyPusey and Jones Indentation1This standard is issued under the fixed designation D531; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in
2、 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 U.S. Department of Defense.1. Scope1.1 This test method covers the determination of the inden-tat
3、ion of rubber or rubber-like materials by means of the Puseyand Jones type of plastometer. This apparatus is used tomeasure the depth of indentation of an indentor, under fixedforce into the surface of a specimen.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard d
4、oes 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 regulatory limitations prior to use.2. Referenced Documents2.1 ASTM St
5、andards:2D1349 Practice for RubberStandard Conditions for Test-ingD1415 Test Method for Rubber PropertyInternationalHardnessD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesNOTE 1The specific dated edition of the practice that pre
6、vails in thisdocument is referenced in the Section 9.3. Significance and Use3.1 The Pusey and Jones indentation value is the depth ofindentation, expressed in hundredths of a millimetre, of a ball3.175 mm (0.1250 in.) in diameter under an expressed force of9.8 N (2.2 lbf). This value may be used to
7、compare theindentation resistance of rubber and rubber-like materials.3.2 The indentation value obtained should not be confusedwith hardness as measured by Test Method D1415, since in thelatter test the rubber immediately adjacent to the indentor isprecompressed.4. Apparatus4.1 Plastometer, an instr
8、ument consisting of an indentor, amass for applying the stated force on the indentor, a microm-eter for indicating the depth of the indentation, a specimenholder and support.4.1.1 Indentor, for indenting the specimen, consisting of avertical steel shaft attached, at the upper end to a depthindicator
9、 gage, and terminating in a steel sphere having adiameter of 3.175 6 0.015 mm (0.1250 6 0.0005 in.) ofpolished, noncorrosive hard metal treated to resist wear.4.1.2 Mass, the mass shall be 1000 6 0.01 g.4.1.3 Depth Indicator Gage, a micrometer attached to theplastometer, either an electronic digital
10、 gage or analog dialgage, capable of displaying indentor movement (indentation)in increments of at least 0.01 mm (0.0004 in.) and having travelof 0 (zero) to no less than 3 mm (0.12 in).4.1.4 Support, a support frame, or fixture, for theplastometer, shall be configured so that the specimen holderand
11、 hence, the specimen, are perpendicular to the indentorsupport shaft and that the mass may be independently raised orlowered vertically, permitting the indentor to rest on thesurface of the specimen and the mass to be subsequentlyapplied.4.1.5 Specimen Holder, for the standard, or reference speci-me
12、n described in 5.1, shall consist of a clamping fixture of twometal plates secured by two threaded bolts. The uppermostplate shall have a hole and a slot, as depicted in Fig. 1, to allowfor the unencumbered introduction of the indentor to thespecimen.4.1.5.1 The purpose of the specimen holder is to
13、support thespecimen in a manner that reduces, or eliminates, relativepositioning or movement that may adversely affect test deter-minations.4.1.5.2 In routine testing, a specimen holder, a support, orboth, of other, but similar, configurations may be employed toaccommodate specimens other than those
14、 described in 5.1,refer to 5.1.1.1This test method is under the jurisdiction of ASTM Commitee D11 on Rubberand is the direct responsibility of Subcommittee D11.10 on Physical Testing.Current edition approved Aug. 1, 2015. Published January 2016. Originallyapproved in 1939. Last previous edition appr
15、oved in 2010 as D531 00 (2010).DOI: 10.1520/D0531-15.2For 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.Copyrigh
16、t ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Test Specimens5.1 The standard, or reference, test specimen shall be auniform molded rectangular block a minimum of 13 mm (0.51in.) in thickness, 30 mm (1.18 in.) in width, and 75 mm (2.95in.
17、) in length. The upper and lower surfaces, those oppositesurfaces with the largest area, shall be parallel to within 60.5mm (60.20 in).5.1.1 The standard, or reference, test specimen shall be usedwhen the plastometer is employed for the purpose of determin-ing a standard, or reference, either within
18、 or betweenlaboratories, that is, in other than routine testing.5.2 In routine testing, specimens may be used with aconfiguration other than those of the standard, or reference, testspecimen described in 5.1.6. Procedure6.1 Measurement of Indentation of Standard, or ReferenceSpecimens:6.1.1 When mea
19、suring the indentation on a standard, orreference specimen as described in 5.1, secure it in thespecimen holder (refer to Fig. 1 and Section 4.1.5) with thebolts tightened sufficiently to hold it firmly without measurablecompression.6.1.2 Place the specimen holder on the support.6.1.3 Mount the plas
20、tometer over the specimen so that theindentor shaft is perpendicular to the support and hence thespecimen holder, to within 60.05 mm (60.002 in).6.1.4 The plastometer and support shall be placed upon aflat surface in a manner that prevents unsteadiness or move-ment other than described in 6.3.6.1.5
21、Lower the indentor shaft until the indentor is at themoment of contact with the specimen.6.1.5.1 Adjust the depth indicator gage to record indenta-tions up to 3 mm (0.12 in).6.1.5.2 Adjust the depth indicator gage so the displayindicates zero.6.1.6 Lower the mass onto the indentor, in a fashion that
22、eliminates shock, until the mass rests fully on the indentor.6.1.7 The amount of indentation displayed on the depthindicator gage 60 s (61 s) after the application of a total forceof 9.8 N, shall be recorded.6.1.8 Make no less than 3 such determinations on thespecimen at least 13 mm (0.51 in) apart
23、and from any edge.6.1.9 The median of the determinations, expressed as awhole number indicating hundredths of millimetres, shall bereported as the Pusey and Jones Indentation Value, refer to8.1.1.6.2 Measurement of Indentation of Specimens for RoutineTests (Nonstandard Specimens):6.2.1 When making d
24、eterminations on specimens other thanthose described in 5.1, specimen holders, supports or othersuitable fixturing, similar to those previously described, may beemployed and the procedure in 6.1 may be followed, other-wise:6.2.2 Mount the plastometer over, or directly upon, thespecimen, so that the
25、indentor shaft is vertical and perpendicu-lar to the specimen surface and both are level, as determined bymeans of a spirit level or similar device.6.2.3 Position curved (convex or concave) or irregularlyshaped specimens, so that the center line of the indentor shaftis perpendicular to the tangent o
26、f the specimen at the point ofcontact of the indentor and that determinations shall be made inaccordance with 6.2.8.6.2.4 The plastometer and specimen, or any fixturesemployed, shall be secure and situated in a manner thatprevents unsteadiness or movement other than described in 6.3.6.2.5 Lower the
27、indentor shaft until the indentor is at themoment of contact with the specimen.mm in.A, min 80 3.15B, min 30 1.2D 17 to 18 0.67 to 0.70E 11 to 12 0.43 to 0.47F 60 2.36FIG. 1 Holder for Test SpecimensD531 1526.2.5.1 Adjust the depth indicator gage to record indenta-tions up to 3 mm (0.12 in).6.2.5.2
28、Adjust the depth indicator gage so the displayindicates zero.6.2.6 Lower the mass onto the indentor, in a fashion thateliminates shock, until the mass rests fully on the indentor.6.2.7 The amount of indentation displayed on the depthindicator gage 60 s (61 s) after the application of a total forceof
29、 9.8 N, shall be recorded.6.2.8 Make no less than 3 such determinations on thespecimen at least 13 mm (0.51 in) apart and from any edge.6.2.9 The median of the determinations, expressed as awhole number indicating hundredths of millimetres, shall bereported as the Pusey and Jones Indentation Value,
30、refer to8.1.1.6.2.10 When tests are performed on specimens other thanthose described in 5.1 and without the specimen holder andsupport the results shall be compared only to those obtained onsimilarly configured specimens under similar conditions.6.3 VibratorA small vibrator that is activated prior t
31、o themass being applied to the indentor and operates continuouslyduring a test to overcome any friction in the apparatus. Aninstrument that vibrates approximately 120 times per s, with anamplitude of vibration of the fixed platform of the testervarying from approximately 0.002 to 0.005 mm (0.0001 to
32、0.0002 in.), has been found satisfactory.6.4 Such a vibrator may consist of a simple-cored solenoidfastened to the top of a C-shaped piece of strap steel. The lowerpart of the solenoid core is a loose cylindrical piece of steelwith a shoulder at its lower end. When the current is off, theloose-cored
33、 section rests on a screw projecting from the bottomof the C-shaped support. When the current is on, the loose-cored section is attached to the solenoid but is restrained by aflat split ring of spring brass through which the cored sectionpasses, and which bears on the shoulder of the cored section.T
34、he cored section is caused to vibrate by the alternating forcesof attraction by the solenoid and repulsion by the flat ringacting as a spring. A small plate bearing a toggle switch forclosing the circuit to the solenoid is fastened to the top of theC-shaped piece of strap steel by means of the same
35、bolt thatholds the solenoid. The bottom of the C-shaped piece isfastened by screws to a portion of a brass nut that serves toclamp the vibrator to one upright post of the tester.7. Laboratory Atmosphere and Test SpecimenConditioning7.1 The tests shall be conducted in the standard laboratoryatmospher
36、e as defined in Practice D1349, Terminology: “stan-dard laboratory atmosphere.”7.2 Test specimen conditioning shall be in accordance withPractice D1349, Section 5 Conditioning of Materials forTesting.7.3 These conditions may be modified if agreed uponbetween laboratories or between supplier and user
37、 and are inaccord with the alternative procedures described in PracticeD1349.7.4 When tests are conducted, within a laboratory, forpurposes of research, development, or empirical study andreported beyond that laboratory, the conditions shall be re-ported in accordance with Practice D1349.8. Report8.
38、1 State that the test was made in accordance with thisdesignation and include the following information:8.1.1 The Pusey and Jones indentation number,8.1.2 Description of test specimen including dimensions,8.1.3 Date of vulcanization, if known,8.1.4 Duration and temperature of vulcanization, if known
39、,8.1.5 Temperature of test room, and8.1.6 Date of test.9. Precision and Bias39.1 These precision statements have been prepared in ac-cordance with Practice D4483. Refer to Practice D4483 forterminology and other testing and statistical concepts.9.2 The Pusey and Jones Indentation Plastometer is used
40、mainly in the rubber roll industry. In this program no inter-laboratory precision data were obtained due to the limited useof this test method. The precision program consisted of tests byone operator on three different (in-house) instruments on threedifferent days. Four materials were tested. A test
41、 result is themedian value of three separate (determinations) indentationmeasurements.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D11-1028.TABLE 1 Special Precision ResultsPusey and Jones IndentationMaterial Mean LevelWithin
42、 InstrumentABetween InstrumentAS(w) r(w)(r)(w) S(B) r(B)(r)(B)1 11.7(a) 0.265 0.750 6.4 0.374 1.06 9.12 20.9 0.296 0.838 4.0 0.309 0.875 4.23 38.1 0.379 1.073 2.8 0.668 1.89 5.04 63.0 0.192 0.543 0.86 1.67 4.73 7.5AS(w) = within instrument, standard deviation.r(w) = repeatability (within instrument)
43、 measurement units.(r)(w) = repeatability (within instrument), %.S(B) = between instrument, standard deviation.r(B) = repeatability (between instrument) measurement units.(r)(B) = repeatability (between instrument), %.(a) = Pusey and Jones indentation number.D531 1539.3 Table 1 gives the within and
44、among “instrument”precision. Repeatability refers to within instrument variation;reproducibility refers to among (between) instrument variation,with the same operator for both.9.4 BiasIn test method statistical terminology, bias is thedifference between an average test value and the reference ortrue
45、 test property value. Reference values do not exist for thistest method since the value or level of the test property isexclusively defined by the test method. Bias, therefore, cannotbe determined.10. Keywords10.1 hardness; indentation hardness; relative hardness; plas-tometerASTM International take
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