1、Designation:D208407 Designation: D2084 11Standard 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 revisio
2、n, 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 Department of Defense.1. Scope1.1 This test method cover
3、s 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 units are to
4、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 practices a
5、nd determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1349 Practice for RubberStandard Temperatures for TestingD3185 Test Methods for RubberEvaluation of SBR (Styrene-Butadiene Rubber) Including Mixtures With OilD3186 Test Methods for Rubber
6、Evaluation 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 Standards
7、 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 torque vers
8、us 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, plateau,
9、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)measure of the
10、time at which vulcanization begins.3.1.7 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 minimum.3.1.8 torquefor an oscillating shear cure meter, the value measured by a torque transducer at the peak
11、strain amplitude of theoscillating cycle.1This test method is under the jurisdiction of ASTM Committee D11 on Rubber and is the direct responsibility of Subcommittee D11.12 on Processability Tests.Current edition approved July 1, 2007. Published July 2007. Originally approved in 1971. Last previous
12、edition approved in 2006 as D208406. DOI: 10.1520/D2084-07.Current edition approved Dec. 15, 2011. Published April 2012. Originally approved in 1971. Last previous edition approved in 2007 as D2084 07. DOI:10.1520/D2084-11.2For referencedASTM standards, visit theASTM website, www.astm.org, or contac
13、tASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Available from American National Standards Institute, 25 W. 43rd St., 4th Floor, New York, NY 10036.1This document is not an ASTM standard
14、 and is intended only to provide the user of an ASTM standard an indication 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 on
15、ly the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.9 optimum cure timemeasure of the time required to reach a percentage of full cur
16、e that corresponds to a desired levelof a property of the cured compound.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 in all cases.4. Summary of Test Method4.1 A test specimen of vulcanizable rubber compound
17、is inserted into the cure meter test cavity and after a closure action 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 oscilla
18、ted through a small rotationalamplitude (1 or 3) and this action exerts a shear strain on the test specimen. The force required to oscillate or rotate the disk tomaximum amplitude is continuously recorded as a function of time, with the force being proportional to the shear modulus(stiffness) of the
19、 test specimen at the test temperature. This stiffness initially decreases as it warms up; then it increases due tovulcanization. The test is completed when the recorded torque either rises to an equilibrium or maximum value, or when apredetermined time has elapsed.The time required to obtain a cure
20、 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 configurations of the oscillating disk cure meter are currently in use. Fig. 3 illustrates example shifts of the curecurves associated with the configuration
21、 differences included in this standard. Results between tests using rapid and slowtemperature recovery, or between heated and unheated disks cannot be compared without taking the heating differences intoaccount. The differences between test curves will vary with the compound being tested. Configurat
22、ions included in this test methodare listed in this section.Left 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 1124.2.1 Diaphragm dies, unheated r
23、otor, temperature recovery within 4.5 min.4.2.2 Solid dies, unheated 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 me
24、ters developed before rapid temperature recovery and heated rotors 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 vulca
25、nization characteristics of (vulcanizable) rubber compounds.5.2 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 (v
26、ulcanizable)rubber compounds.6. Apparatus6.1 Cure meter, consists 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 p
27、latens, dies, and a biconical disk.6.2.1 PlatensTwo platens made 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 sha
28、ll be fabricated from tool steel having a minimum RockwellHardness 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 an
29、d spaced at 20intervals. Each die shall have a well or hole drilled 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 suitabl
30、e low-friction seal shall be provided in this hole to prevent 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 s
31、lightly in volume during vulcanization.To provide thermal conduction 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 U
32、pper DieUpper die formed from one piece of steel, as described in Fig. 6.6.2.3 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).6.2.3
33、.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 direc
34、tly 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 appr
35、oximately 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 diamete
36、rshown 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.FIG. 3 Example Cure Curves from ODR ConfigurationsD2084 1136.2.3.4 A rotary drive system shall be pro
37、vided for oscillatory rotation of the disk. The amplitude 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 contrib
38、ute to slippage. Typically, torque values over 40 dNm 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 sensit
39、ivity may be possible using 63 arc of oscillation.6.2.4 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 (
40、50 psi) for a 203-mm (8-in.) diameter air cylinder. Provisionsare 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 5 PSpD24D (1)D2084-11_1where:F = closure force
41、on die,P = source air pressure, andD = diameter of piston in pneumatic cylinder.To 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:D2084-11_2where:Pc= pressure on sample in upper die cavity, andd = d
42、iameter of upper die cavity (55.9 mm (2.2 in.).D2084-11_36.3 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 heated, a temperature controller sh
43、all 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, producingFIG. 4 Lower DieD2084 114a signal that is directly proportional to the torq
44、ue 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 of1sorless and be c
45、apable of recording the torque withFIG. 5 Diaphragm Type Upper DieFIG. 6 Solid Type Upper DieD2084 115accuracy 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 4Dire
46、ct proportionality between torque and stiffness cannot be 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 necess
47、ary.7. Sampling7.1 The sample shall be taken from a vulcanizable rubber compound as required by the mixing method or other samplinginstructions.TABLE 1 Die DimensionsCodeDimension,mmTolerance,mmA 55.88 60.13B 10.64 60.25C 7.94 60.13D 18.26 60.13E 1.57 60.13F0.860.1G 4.76 60.13H 24.07 60.06I 12.70 60
48、.40J 2.38 60.40K 54.61 60.05L 41.91 60.03M 5.35 60.01N 1.65 60.03O 4.57 60.13P 15.38 60.03Q 5.08 60.05R 41.91 60.03FIG. 7 Biconical DiskD2084 1167.2 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 sig
49、nificantly affect 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 minimizetemperature and heat history variations prior to testing.8. Test Specimen8.1 A nearly circular test specimen taken from a sample shall be equivalent to have a volume of 9.5 6 1.5 cm3(0.55(0.58 60.09 in.3) (for example, approxim
