1、Designation: D 2084 07Standard Test Method forRubber PropertyVulcanization Using Oscillating Disk CureMeter1This standard is issued under the fixed designation D 2084; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 the use of the
3、oscillating diskcure meter for determining selected vulcanization characteris-tics of vulcanizable rubber compounds.1.2 ISO 3417 is very similar to this test method. It has minortechnical differences that are not considered to be significant.1.3 The values stated in SI units are to be regarded as th
4、estandard. The values given in parentheses are for informationonly.1.4 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 ap
5、plica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1349 Practice for RubberStandard Temperatures forTestingD 3185 Test Methods for RubberEvaluation of SBR(Styrene-Butadiene Rubber) Including Mixtures With OilD 3186 Test Methods for RubberEvaluation of SB
6、R(Styrene-Butadiene Rubber) Mixed With Carbon Black orCarbon Black and OilD 3187 Test Methods for RubberEvaluation of NBR(Acrylonitrile-Butadiene Rubber)D 3190 Test Method for RubberEvaluation of Chloro-prene Rubber (CR)D 4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber
7、and Carbon Black ManufacturingIndustries2.2 ISO Standard:ISO 3417 RubberMeasurement of Vulcanization Charac-teristics With the Oscillating Disk Rheometer33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 The following measurements may be taken from thetorque versus time curve (s
8、ee Fig. 1).3.1.2 cure rate indexmeasure of rate of vulcanizationbased on the difference between optimum vulcanization andincipient scorch time.3.1.3 peak cure ratemeasure of rate of vulcanizationexpressed as the maximum slope of the torque versus timecurve.3.1.4 maximum, plateau, or highest torqueme
9、asure ofstiffness or shear modulus of the fully vulcanized test specimenat the vulcanization temperature.3.1.5 minimum torquemeasure of the stiffness of theunvulcanized test specimen taken at the lowest point of thecurve.3.1.6 time to incipient cure (scorch time)measure of thetime at which vulcaniza
10、tion begins.3.1.7 time to a percentage of full curemeasure of curebased on the time to develop some percentage of the highesttorque or difference in torque from the minimum.3.1.8 torquefor an oscillating shear cure meter, the valuemeasured by a torque transducer at the peak strain amplitude ofthe os
11、cillating cycle.3.1.9 optimum cure timemeasure of the time required toreach a percentage of full cure that corresponds to a desiredlevel of a property of the cured compound.3.1.9.1 DiscussionThe time to reach 90 % cure corre-sponds to a maximum in tensile strength for some rubbercompounds. This does
12、 not apply in all cases.4. Summary of Test Method4.1 A test specimen of vulcanizable rubber compound isinserted into the cure meter test cavity and after a closureaction is contained in a sealed cavity under positive pressure.The cavity is maintained at some elevated vulcanization1This test method i
13、s under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.12 on Processability Tests.Current edition approved July 1, 2007. Published July 2007. Originally approvedin 1971. Last previous edition approved in 2006 as D 2084 06.2For referenced ASTM sta
14、ndards, 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.3Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New
15、York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.temperature. The rubber totally surrounds a biconical disk afterthe dies are closed (see Fig. 2). The disk is oscillated througha small rotational amplitude (1 or 3) and
16、this action exerts ashear strain on the test specimen.The force required to oscillateor rotate the disk to maximum amplitude is continuouslyrecorded as a function of time, with the force being propor-tional to the shear modulus (stiffness) of the test specimen atthe test temperature. This stiffness
17、initially decreases as itwarms up; then it increases due to vulcanization. The test iscompleted when the recorded torque either rises to an equilib-rium or maximum value, or when a predetermined time haselapsed. The time required to obtain a cure curve is a functionof the characteristics of the rubb
18、er compound and of the testtemperature (see Fig. 1 for typical cure curves).4.2 Several configurations of the oscillating disk cure meterare currently in use. Fig. 3 illustrates example shifts of the curecurves associated with the configuration differences included inthis standard. Results between t
19、ests using rapid and slowtemperature recovery, or between heated and unheated diskscannot be compared without taking the heating differences intoaccount. The differences between test curves will vary with theLeft Curve: Cure to Equilibrium Torque.Middle Curve: Cure to a Maximum Torque with Reversion
20、.Right Curve: Cure to No Equilibrium in Maximum Torque.FIG. 1 Types of Cure CurveFIG. 2 Cure Meter AssemblyFIG. 3 Example Cure Curves from ODR ConfigurationsD2084072compound being tested. Configurations included in this testmethod are listed in this section.4.2.1 Diaphragm dies, unheated rotor, temp
21、erature recoverywithin 4.5 min.4.2.2 Solid dies, unheated rotor, temperature recoverywithin 4.5 min.4.2.3 Solid dies, unheated rotor, temperature recovery inless than 2 min.4.2.4 Solid dies, heated rotor, temperature recovery in lessthan 2 min.NOTE 1Diaphragm dies are unique to cure meters developed
22、 beforerapid temperature recovery and heated rotors were introduced. Diaphragmdies in combination with rapid temperature recovery or heated rotors arenot a normal configuration for Oscillating Disk Cure Meters.5. Significance and Use5.1 This test method is used to determine the vulcanizationcharacte
23、ristics of (vulcanizable) rubber compounds.5.2 This test method may be used for quality control inrubber manufacturing processes, for research and developmenttesting of raw-rubber compounded in an evaluation formula-tion, and for evaluating various raw materials used in preparing(vulcanizable) rubbe
24、r compounds.6. Apparatus6.1 Cure meter, consists of the following major compo-nents: specimen chamber and closure mechanism, temperaturecontrol system, rotor drive and torque measuring system (seeFig. 2 for a detailed drawing of cure meter assembly).6.2 Specimen ChamberConsists of platens, dies, and
25、 abiconical disk.6.2.1 PlatensTwo platens made of aluminum alloy, eachcontaining an electric heater, and each having in the center, acavity to accommodate a die and from the side, a well forinserting a temperature sensor.6.2.2 DiesTwo which form a cavity when closed andwhich shall be fabricated from
26、 tool steel having a minimumRockwell Hardness HRC 50. The geometry of the standarddies is shown in Figs. 4-6 with dimensions and tolerances (seeTable 1). The top and bottom surfaces of the die cavity shallcontain rectangular-shaped grooves arranged radially about thecenter and spaced at 20 intervals
27、. Each die shall have a wellor hole drilled from the side to accommodate a temperaturesensor inserted through the platen. The upper die may be eithersolid or diaphragm type. The lower dies shall have a hole in thecenter to allow for the insertion of the disk shaft. A suitablelow-friction seal shall
28、be provided in this hole to preventmaterial leaking from the cavity.6.2.2.1 Diaphragm Upper DieUpper die manufactured sothat the grooved die face is allowed to flex when closed on aspecimen and then to maintain essentially constant pressure onthe specimen as it shrinks slightly in volume during vulc
29、ani-zation. To provide thermal conduction to the metal body of thediaphragm die, an aluminum or stainless steel insert is placedin the diaphragm space with a hole designed to accommodatethe temperature sensor. Fig. 5 describes the diaphragm typeupper die.6.2.2.2 Solid Upper DieUpper die formed from
30、one pieceof steel, as described in Fig. 6.6.2.3 DiskThe biconical disk shall be fabricated from toolsteel having a minimum Rockwell Hardness of HRC 50. Thedisk shall be fitted with a stem that fits into the torque shaft.The disk is shown in Fig. 7 (see Table 2).6.2.3.1 Heated DiskSome manufacturers
31、of oscillatingdisk cure meters offer a heated rotor as an option. If the disk isheated, both torque values and cure times may be significantlyaltered. The heated disk is a modification of the biconical diskshown in Fig. 7. This modification has provisions for directlycontrolling the disk temperature
32、, as shown in Fig. 8. In thisexample, an electrical heater and temperature sensor arelocated in a metal tube, which is inserted in the disk through avertical well in the disk shaft. The well is typically 0.325 cm(0.128 in.) in diameter and extends to within approximately0.25 cm (0.100 in.) of the di
33、sk apex. The insertion tube istypically 0.0125 cm (0.005 in.) less than the well diameter toallow for easy tube removal for cleaning.6.2.3.2 Disk wear will affect test results.Adisk worn to suchan extent that the disk diameter is less than the minimumdiameter shown in this procedure shall not be use
34、d.6.2.3.3 The standard frequency of the rotary oscillation ofthe disk shall be constant at 1.67 Hz (100 cpm) 61 %. Otherfrequencies may be used, if required.6.2.3.4 A rotary drive system shall be provided for oscilla-tory rotation of the disk. The amplitude of oscillation of theunloaded disk shall b
35、e constant at 61.00 with a tolerance of60.03 about the center position, that is, a total amplitude of2. Other amplitudes may be used, if specified.NOTE 2Disk and die surface contamination may contribute to slip-page. Typically, torque values over 40 dNm may be subject to slipping,FIG. 4 Lower DieD20
36、84073thus reducing torque values. Torque values approaching 100 dNm are alsotypically compromised by a significant torsion deformation of the diskshaft. Where slipping or torsion deformation is not a concern, greatersensitivity may be possible using 63 arc of oscillation.6.2.4 Die Closing MechanismA
37、 pneumatic cylinder orother device shall close the dies and hold them closed duringthe test with a force of 11.0 6 0.5 kN (2500 6 100 lbf).NOTE 3One manufacturer recommends the source air pressure beadjusted to 345 kPa (50 psi) for a 203-mm (8-in.) diameter air cylinder.Provisions are made for this
38、adjustment to the instrument. This pressureacting on a 203-mm (8-in.) diameter air cylinder will produce a force of11 kN (2500 lbf) on the die per the following equation:F 5 PSpD24D (1)where:F = closure force on die,P = source air pressure, andD = diameter of piston in pneumatic cylinder.To calculat
39、e maximum cavity pressure, the effect of this force acting onthe surface area of the upper die may be calculated per the followingequation:Pc54Fpd2(2)where:Pc= pressure on sample in upper die cavity, andd = diameter of upper die cavity (55.9 mm (2.2 in.).For example, Pc5S4!11!p 55.9!2D5 4485 kPa 5 6
40、50 psi (3)6.3 Temperature Controlling SystemA temperature con-troller shall be provided for maintaining the dies within60.5C (61F) of the specified test temperature.6.3.1 Heated Disk Temperature ControlWhen the disk isheated, a temperature controller shall be provided for main-taining the disk tempe
41、rature within 60.5C (61F) of thespecified test temperature.6.4 Torque Measuring SystemThe torque measuring sys-tem shall consist of a device, such as a torque transducer,producing a signal that is directly proportional to the torquerequired to oscillate the disk. A recording system, as used inthis t
42、est method, may consist of any suitable data collectiondevice, including computers, printers, plotters, and chart re-corders. The recording system shall have a full-scale deflectionresponse on the torque scale of1sorless and be capable ofrecording the torque with accuracy of 60.5 % of the torquerang
43、e.Aminimum of four torque ranges shall be provided; 0 to25, 0 to 50, 0 to 100, and 0 to 200 dNm (or 0 to 25, 0 to 50,0 to 100, and 0 to 200 lbf in.)NOTE 4Direct proportionality between torque and stiffness cannot beexpected under all test conditions, particularly in higher torque ranges,because elas
44、tic deformation of the disk shaft and driving device must betaken into account. However, for routine quality control test purposescorrections are not necessary.7. Sampling7.1 The sample shall be taken from a vulcanizable rubbercompound as required by the mixing method or other samplinginstructions.7
45、.2 The sample shall be in sheeted form, at room tempera-ture, and as free of air as possible.7.3 The temperature of the sample and its heat history cansignificantly affect test results. For referee testing and fortesting under controlled circumstances, the sample shall beconditioned at 23 6 1C (73 6
46、 2F) for at least 1 h beforetesting.7.4 In production control testing, samples may be testedwithout the conditioning period, but care should be taken tominimize temperature and heat history variations prior totesting.8. Test Specimen8.1 A nearly circular test specimen taken from a sampleshall be equ
47、ivalent to a volume of 9 6 1.5 cm3(0.55 6 0.09in.3) or approximately 30 mm (1.2 in.) in diameter and 11.5mm (0.45 in.) in thickness.8.2 The test specimen is considered to be of proper sizewhen a small bead of compound is extruded uniformly aroundthe periphery of the die as it is closed. This is achi
48、eved whenthe test specimen volume is between 8 and 11 cm3(9 to 13 gof rubber compound with a specific gravity of 1.15 Mg/m3).FIG. 5 Diaphragm Type Upper DieD2084074Undersized test specimens can cause low cavity pressure andlow torque readings. Oversized test specimens cool the diesexcessively during
49、 the early part of the test period, affecting thevulcanization characteristics.9. Test Temperatures9.1 The standard test temperature shall be 160C (320F).9.2 The test temperature tolerance shall be 60.5C(61.0F).9.3 Tests may be carried out at other temperatures, ifrequired. They should be selected in accordance with PracticeD 1349.10. Calibration10.1 The cure meter shall be calibrated mechanically inaccordance with the manufacturers instructions.10.2 Provisions shall be made for electronic verification ofthe recording system an
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