1、Designation: D2084 11D2084 11 (Reapproved 2016)Standard Test Method forRubber PropertyVulcanization Using Oscillating Disk CureMeter1This standard is issued under the fixed designation D2084; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test m
3、ethod covers the use of the oscillating disk cure meter for determining selected vulcanization characteristics ofvulcanizable rubber compounds.1.2 ISO 3417 is very similar to this test method. It has minor technical differences that are not considered to be significant.1.3 The values stated in SI un
4、its are to be regarded as the standard. The values given in parentheses are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health
5、practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1349 Practice for RubberStandard Conditions for TestingD3185 Test Methods for RubberEvaluation of SBR (Styrene-Butadiene Rubber) Including Mixtures With OilD3186 Test Methods f
6、or RubberEvaluation of SBR (Styrene-Butadiene Rubber) Mixed With Carbon Black or Carbon Blackand OilD3187 Test Methods for RubberEvaluation of NBR (Acrylonitrile-Butadiene Rubber)D3190 Test Method for RubberEvaluation of Chloroprene Rubber (CR)D4483 Practice for Evaluating Precision for Test Method
7、Standards in the Rubber and Carbon Black Manufacturing Industries2.2 ISO Standard:ISO 3417 RubberMeasurement of Vulcanization Characteristics With the Oscillating Disk Rheometer33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 The following measurements may be taken from the to
8、rque versus time curve (see Fig. 1).3.1.2 cure rate indexmeasure of rate of vulcanization based on the difference between optimum vulcanization and incipientscorch time.3.1.3 peak cure ratemeasure of rate of vulcanization expressed as the maximum slope of the torque versus time curve.3.1.4 maximum,
9、plateau, or highest torquemeasure of stiffness or shear modulus of the fully vulcanized test specimen at thevulcanization temperature.3.1.5 minimum torquemeasure of the stiffness of the unvulcanized test specimen taken at the lowest point of the curve.3.1.6 time to incipient cure (scorch time)measur
10、e of the time at which vulcanization begins.1 This test method is under the jurisdiction of ASTM Committee D11 on Rubber and Rubber-like Materials and is the direct responsibility of Subcommittee D11.12 onProcessability Tests.Current edition approved Dec. 15, 2011Nov. 1, 2016. Published April 2012De
11、cember 2016. Originally approved in 1971. Last previous edition approved in 20072011 asD2084 07.D2084 11. DOI: 10.1520/D2084-11.10.1520/D2084-11R16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standar
12、dsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American National Standards Institute, 25 W. 43rd St., 4th Floor, New York, NY 10036.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indicatio
13、n of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be consid
14、ered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.7 time to a percentage of full curemeasure of cure based on the time to develop some percentage of the highest torqueor difference in torque from the minim
15、um.3.1.8 torquefor an oscillating shear cure meter, the value measured by a torque transducer at the peak strain amplitude of theoscillating cycle.3.1.9 optimum cure timemeasure of the time required to reach a percentage of full cure that corresponds to a desired level ofa property of the cured comp
16、ound.3.1.9.1 DiscussionThe time to reach 90 % cure corresponds to a maximum in tensile strength for some rubber compounds. This does not apply inall cases.4. Summary of Test Method4.1 A test specimen of vulcanizable rubber compound is inserted into the cure meter test cavity and after a closure acti
17、on iscontained in a sealed cavity under positive pressure. The cavity is maintained at some elevated vulcanization temperature. Therubber totally surrounds a biconical disk after the dies are closed (see Fig. 2). The disk is oscillated through a small rotationalamplitude (1 or 3) and this action exe
18、rts a shear strain on the test specimen. The force required to oscillate or rotate the disk toLeft Curve: Cure to Equilibrium Torque.Middle Curve: Cure to a Maximum Torque with Reversion.Right Curve: Cure to No Equilibrium in Maximum Torque.FIG. 1 Types of Cure CurveFIG. 2 Cure Meter AssemblyD2084 1
19、1 (2016)2maximum amplitude is continuously recorded as a function of time, with the force being proportional to the shear modulus(stiffness) of the test specimen at the test temperature. This stiffness initially decreases as it warms up; then it increases due tovulcanization. The test is completed w
20、hen the recorded torque either rises to an equilibrium or maximum value, or when apredetermined time has elapsed.The time required to obtain a cure curve is a function of the characteristics of the rubber compoundand of the test temperature (see Fig. 1 for typical cure curves).4.2 Several configurat
21、ions of the oscillating disk cure meter are currently in use. Fig. 3 illustrates example shifts of the curecurves associated with the configuration differences included in this standard. Results between tests using rapid and slowtemperature recovery, or between heated and unheated disks cannot be co
22、mpared without taking the heating differences intoaccount. The differences between test curves will vary with the compound being tested. Configurations included in this test methodare listed in this section.4.2.1 Diaphragm dies, unheated rotor, temperature recovery within 4.5 min.4.2.2 Solid dies, u
23、nheated rotor, temperature recovery within 4.5 min.4.2.3 Solid dies, unheated rotor, temperature recovery in less than 2 min.4.2.4 Solid dies, heated rotor, temperature recovery in less than 2 min.NOTE 1Diaphragm dies are unique to cure meters developed before rapid temperature recovery and heated r
24、otors were introduced. Diaphragm diesin combination with rapid temperature recovery or heated rotors are not a normal configuration for Oscillating Disk Cure Meters.5. Significance and Use5.1 This test method is used to determine the vulcanization characteristics of (vulcanizable) rubber compounds.5
25、.2 This test method may be used for quality control in rubber manufacturing processes, for research and development testingof raw-rubber compounded in an evaluation formulation, and for evaluating various raw materials used in preparing (vulcanizable)rubber compounds.6. Apparatus6.1 Cure meter, cons
26、ists of the following major components: specimen chamber and closure mechanism, temperature controlsystem, rotor drive and torque measuring system (see Fig. 2 for a detailed drawing of cure meter assembly).6.2 Specimen ChamberConsists of platens, dies, and a biconical disk.6.2.1 PlatensTwo platens m
27、ade of aluminum alloy, each containing an electric heater, and each having in the center, a cavityto accommodate a die and from the side, a well for inserting a temperature sensor.6.2.2 DiesTwo which form a cavity when closed and which shall be fabricated from tool steel having a minimum RockwellHar
28、dness HRC 50. The geometry of the standard dies is shown in Figs. 4-6 with dimensions and tolerances (see Table 1). The topand bottom surfaces of the die cavity shall contain rectangular-shaped grooves arranged radially about the center and spaced at 20intervals. Each die shall have a well or hole d
29、rilled from the side to accommodate a temperature sensor inserted through the platen.The upper die may be either solid or diaphragm type. The lower dies shall have a hole in the center to allow for the insertion ofthe disk shaft. A suitable low-friction seal shall be provided in this hole to prevent
30、 material leaking from the cavity.6.2.2.1 Diaphragm Upper DieUpper die manufactured so that the grooved die face is allowed to flex when closed on aspecimen and then to maintain essentially constant pressure on the specimen as it shrinks slightly in volume during vulcanization.To provide thermal con
31、duction to the metal body of the diaphragm die, an aluminum or stainless steel insert is placed in thediaphragm space with a hole designed to accommodate the temperature sensor. Fig. 5 describes the diaphragm type upper die.6.2.2.2 Solid Upper DieUpper die formed from one piece of steel, as describe
32、d in Fig. 6.FIG. 3 Example Cure Curves from ODR ConfigurationsD2084 11 (2016)36.2.3 DiskThe biconical disk shall be fabricated from tool steel having a minimum Rockwell Hardness of HRC 50. The diskshall be fitted with a stem that fits into the torque shaft. The disk is shown in Fig. 7 (see Table 2).
33、6.2.3.1 Heated DiskSome manufacturers of oscillating disk cure meters offer a heated rotor as an option. If the disk is heated,both torque values and cure times may be significantly altered. The heated disk is a modification of the biconical disk shown inFig. 7. This modification has provisions for
34、directly controlling the disk temperature, as shown in Fig. 8. In this example, anelectrical heater and temperature sensor are located in a metal tube, which is inserted in the disk through a vertical well in the diskshaft. The well is typically 0.325 cm (0.128 in.) in diameter and extends to within
35、 approximately 0.25 cm (0.100 in.) of the diskapex. The insertion tube is typically 0.0125 cm (0.005 in.) less than the well diameter to allow for easy tube removal for cleaning.6.2.3.2 Disk wear will affect test results.Adisk worn to such an extent that the disk diameter is less than the minimum di
36、ametershown in this procedure shall not be used.6.2.3.3 The standard frequency of the rotary oscillation of the 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 oscillatory rotation of the disk. The amplit
37、ude of oscillation of the unloadeddisk shall be constant at 61.00 with a tolerance of 60.03 about the center position, that is, a total amplitude of 2. Otheramplitudes may be used, if specified.NOTE 2Disk and die surface contamination may contribute to slippage. Typically, torque values over 40 dNm
38、may be subject to slipping, thusreducing torque values. Torque values approaching 100 dNm are also typically compromised by a significant torsion deformation of the disk shaft. Whereslipping or torsion deformation is not a concern, greater sensitivity may be possible using 63 arc of oscillation.6.2.
39、4 Die Closing MechanismA pneumatic cylinder or other device shall close the dies and hold them closed during the testwith a force of 11.0 6 0.5 kN (2500 6 100 lbf).NOTE 3One manufacturer recommends the source air pressure be adjusted to 345 kPa (50 psi) for a 203-mm (8-in.) diameter air cylinder. Pr
40、ovisionsare made for this adjustment to the instrument. This pressure acting on a 203-mm (8-in.) diameter air cylinder will produce a force of 11 kN (2500 lbf)on the die per the following equation:F 5PS piD24 D (1)where:F = closure force on die,P = source air pressure, andD = diameter of piston in p
41、neumatic cylinder.FIG. 4 Lower DieD2084 11 (2016)4To calculate maximum cavity pressure, the effect of this force acting on the surface area of the upper die may be calculated per the following equation:Pc 5 4Fpid 2 (2)where:Pc = pressure on sample in upper die cavity, andd = diameter of upper die ca
42、vity (55.9 mm (2.2 in.).SFor example , Pc 5 S 4!11!pi55.9!2D 5 4485 kPa 5 650 psi D (3)6.3 Temperature Controlling SystemA temperature controller shall be provided for maintaining the dies within 60.5C(61F) of the specified test temperature.6.3.1 Heated Disk Temperature ControlWhen the disk is heate
43、d, a temperature controller shall be provided for maintainingthe disk temperature within 60.5C (61F) of the specified test temperature.6.4 Torque Measuring SystemThe torque measuring system shall consist of a device, such as a torque transducer, producinga signal that is directly proportional to the
44、 torque required to oscillate the disk. A recording system, as used in this test method,may consist of any suitable data collection device, including computers, printers, plotters, and chart recorders. The recordingsystem shall have a full-scale deflection response on the torque scale of 1 s or less
45、 and be capable of recording the torque withaccuracy of 60.5 % of the torque range. A minimum of four torque ranges shall be provided; 0 to 25, 0 to 50, 0 to 100, and 0 to200 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 be
46、expected under all test conditions, particularly in higher torque ranges, becauseelastic deformation of the disk shaft and driving device must be taken into account. However, for routine quality control test purposes corrections arenot necessary.7. Sampling7.1 The sample shall be taken from a vulcan
47、izable rubber compound as required by the mixing method or other samplinginstructions.FIG. 5 Diaphragm Type Upper DieD2084 11 (2016)57.2 The sample shall be in sheeted form, at room temperature, and as free of air as possible.7.3 The temperature of the sample and its heat history can significantly a
48、ffect test results. For referee testing and for testingunder controlled circumstances, the sample shall be conditioned at 23 6 1C (73 6 2F) for at least 1 h before testing.7.4 In production control testing, samples may be tested without the conditioning period, but care should be taken to minimizete
49、mperature and heat history variations prior to testing.8. Test Specimen8.1 A nearly circular test specimen taken from a sample shall have a volume of 9.5 6 1.5 cm3 (0.58 6 0.09 in.3) (for example,approximately 30 mm (1.2 in.) in diameter and 13.5 mm (0.53 in.) in thickness).8.2 The test specimen is considered to be of proper size when a small bead of compound is extruded uniformly around theperiphery of the die as it is closed (116 to 160 % of the test cavity volume). This is achieved when the test specimen volume isbetween
