1、Designation: D 5289 07Standard Test Method forRubber PropertyVulcanization Using Rotorless CureMeters1This standard is issued under the fixed designation D 5289; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a method for the measurementof selected vulcanization characteristics of rubber compoundsusing unseale
3、d and sealed torsion shear cure meters. The twotypes of instruments may not give the same results.NOTE 1An alternative method for the measurement of vulcanizationcharacteristics is given in Test Method D 2084.1.2 The values stated in SI units are to be regarded as thestandard. The values given in pa
4、rentheses are for informationonly.1.3 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 applica-bility of regulatory limita
5、tions prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1349 Practice for RubberStandard Temperatures forTestingD 1556 Test Method for Density and Unit Weight of Soil inPlace by the Sand-Cone MethodD 2084 Test Method for Rubber PropertyVulcanizationUsing Oscillating Disk Cure MeterD 4483 Pra
6、ctice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 rotorless cure metera name for a class of curemeters that uses one of the two specimen shaping members ordies to sense
7、the torque or stress during strain application.Rotorless cure meters do not have a third member in the formof a rotor (see definitions of cure meter inTest Methods D 1556and D 2084).3.1.2 torquefor an oscillating shear cure meter, the valuemeasured by a torque transducer at the peak strain amplitude
8、 ofthe oscillating cycle.3.1.3 The following measurements may be taken from therecorded curve of torque as a function of time (see Fig. 1):3.1.3.1 maximum, plateau, or highest torquemeasure ofthe stiffness or shear modulus of the vulcanized test specimenat the vulcanization temperature, measured wit
9、hin a specifiedperiod of time.3.1.3.2 minimum torquemeasure of the stiffness of theunvulcanized test specimen at the specified vulcanizing tem-perature, taken at the lowest point in the vulcanization curve.3.1.3.3 time to a percentage of full curemeasure of curebased on the time to develop some perc
10、entage of the differencein torque from the minimum to the maximum.3.1.3.4 time to incipient cure (scorch time)measure of thetime at which a specified small increase in torque has occurred;it indicates the beginning of vulcanization.4. Summary of Test Method4.1 A rubber test piece is contained in a d
11、ie cavity whichmay be closed or almost closed and maintained at an elevatedtemperature. The cavity is formed by two dies, one of which isoscillated through a small rotary amplitude. This action pro-duces a sinusoidal alternating torsional strain in the test pieceand a sinusoidal shear torque which d
12、epends on the stiffness(shear modulus) of the rubber compound. The envelope curve,which is defined as the amplitude of the oscillating torque, iscontinuously recorded as a function of time.4.2 The stiffness of the rubber test piece increases asvulcanization proceeds. The test is completed when the r
13、e-corded torque rises to either an equilibrium or maximum value,or when a predetermined time has elapsed (see Fig. 1).Acurve1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.12 on Processability Tests.Current edition appro
14、ved May 1, 2007. Published June 2007. Originallyapproved in 1992. Last previous edition approved in 2006 as D 5289 06.2For 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 t
15、o 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.representing the torque at peak strain in one direction of theoscillation cycle is continuously recorded as a function of time.5
16、. Significance and Use5.1 This test method is used to determine the vulcanizationcharacteristics 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 for
17、mula-tion, and for evaluating various raw materials used in preparing(vulcanizable) rubber compounds.5.3 The test specimen in a rotorless cure meter approachesthe test temperature in a shorter time and there is a bettertemperature distribution in the test specimen due to theelimination of the unheat
18、ed rotor found in oscillating disk curemeters.5.4 Several manufacturers produce rotorless cure meterswith design differences that may result in different torqueresponses and curve times for each design. Correlations of testresults between cure meters of different designs should beestablished for eac
19、h compound tested, and for each set of testconditions.6. Apparatus6.1 Rotorless cure meters of two types can be used. In eachcase, an oscillation of small amplitude is applied to one die.6.1.1 Unsealed Torsion Strain Rotorless Cure MeterThistype of cure meter measures the torque produced by an angul
20、arstrain of constant amplitude in a cavity that is not completelyclosed (see Fig. 2(a).6.1.2 Sealed Torsion Strain Rotorless Cure MeterThistype of cure meter measures the torque produced by an angularstrain of constant amplitude in a cavity that is completelyclosed and sealed (see Fig. 3(a).6.2 Die
21、CavityThe die cavity is formed by two dies. In themeasuring position, the two dies are fixed a specified distanceapart so that the cavity is almost closed (see Fig. 2(b), orclosed and sealed (see Fig. 3(a).6.2.1 The dimensions for typical torsional shear curemetersinclude biconical-shaped dies havin
22、g a diameter of 40 6 2mm(1.57 6 0.08 in.), and an angle of separation ranging from 7 to18, depending on the manufacturers design. In the center ofthe dies, a separation equal to 0.5 mm (0.02 in.) plus the diegap should be maintained (see Fig. 2(b) or Fig. 3(b). Manu-facturers guidelines should be fo
23、llowed to determine if thedies have been excessively worn and should be replaced.6.2.2 Die GapThe gap between the edges of the dies inthe closed position shall be between 0.05 and 0.20 mm (0.002to 0.008 in.), preferably 0.1 mm (0.004 in.) for unsealedcavities. For sealed cavities, no gap should exis
24、t at the edges ofthe dies.6.2.3 Die Closing MechanismA pneumatic cylinder orother device shall close the dies and hold them closed duringthe test with a force of not less than 8.0 kN (1820 lbf).6.3 Die Oscillating SystemThe die oscillating systemconsists of a rigid eccentric drive, which imparts a t
25、orsionaloscillating movement to one of the dies, in the plane of thecavity.6.3.1 The amplitude of the oscillation should be 60.1 to63.0, preferably 60.5 of arc for torsional shear cure meters.6.3.2 The frequency of oscillation should be between 0.5and 2 Hz, preferably 1.7 6 0.1 Hz.6.4 Torque Measuri
26、ng SystemA torque measuring systemshall measure the resultant torque.6.4.1 The torque measuring device shall be rigidly coupledto one of the dies and any deformation shall be negligibly smalland shall generate a signal which is proportional to the torque.The total error resulting from zero point err
27、or, sensitivity error,linearity, and reproducibility errors shall not exceed 1 % of themeasuring range selected.NOTE 2The elastic deformation of the oscillating and measuringsystem should not be more than 1 % of the oscillating amplitude;otherwise, the curemeter curves must be corrected.6.4.2 The to
28、rque recorder device shall be used to record thesignal from the torque measuring device. It shall record thetorque at maximum oscillation continuously as a function oftime (see Fig. 1) and shall have a response time for full-scaledeflection on the torque scale of1sorless. The torque shall berecorded
29、 with an accuracy of 60.5 % of the range. Torquerecording devices may include analog chart recorders, printers,plotters, or computers.6.5 Torque calibration equipment is required to measure theangular strain amplitude and to calibrate the torque measuringdevice. Examples of calibration equipment are
30、 shown in Fig. 4and Fig. 5. The amplitude of oscillation of the device shall bechecked with no test specimen in it.Adisplacement transducershall be used to measure the amplitude and torque measure-ments shall be checked against standard masses using a deviceas shown in Fig. 4. An alternate technique
31、 shall use a torquestandard.6.5.1 For calibrating torsion shear curemeters, either adisplacement transducer and wire-mass calibration or a torquestandard shall be used.6.5.1.1 A displacement transducer for checking angulardisplacement shall be coupled by a knife-edge bearing incontact with a rod fix
32、ed to one of the dies (see Fig. 4). Theforce measuring system shall be checked by loading a wire,attached to the die or block by a pulley, with masses corre-sponding to the full-scale force being measured. The torqueshall be calculated in this case from the product of the appliedforce and the radius
33、 of the die block where the wire is attached.6.5.1.2 Torque standard calibration checks the torque mea-surement at the selected angular displacement by clamping areference steel torsion rod to the oscillating die and the torquemeasuring die of the torsion shear cure meter (see Fig. 5). TheFIG. 1 Typ
34、es of Vulcanization CurvesD5289072FIG. 2 (a) and (b)Typical Unsealed Torsion Shear Rotorless CuremeterD5289073reference values for angular displacement and correspondingtorque have been established by the manufacturer for eachtorque standard.6.6 Temperature Controlling SystemThe method of tem-peratu
35、re control shall maintain the following process param-eters: heating up time, curing temperature, temperature distri-bution, and reference temperature, which are necessary forreproducible measurement of the vulcanization curve. Thetemperature control system shall permit the reference tempera-ture to
36、 be varied between 110C and 200C with an accuracyof 60.3C or better.6.6.1 Die shall heat up in 1.5 min or less from closure of thedie cavity.6.6.2 Once heating up time hs been completed, die tempera-ture shall not vary by more than 60.3C for the rest of the test.6.6.3 The temperature distribution wi
37、thin the test specimenshall be as uniform as possible. Within the deformation zone,a tolerance of 61C of the average test specimen temperatureshall not be exceeded.6.6.4 The reference temperature is determined by a tempera-ture sensor used for control. The difference between thereference temperature
38、 and the average test specimen tempera-ture shall not be more than 2C.6.6.5 Temperature measurement accuracy shall be60.3C for the reference temperature sensor.6.7 Reference Test TemperatureThe standard referencetest temperature shall be 160C (320F). Tests may be carriedout at other temperatures if
39、required. Temperatures should beselected in accordance with Practice D 1349.7. Sampling7.1 The sample shall be taken from a vulcanizable rubbercompound as required by the mixing method or other samplinginstructions.FIG. 3 Typical Sealed Torsion Shear Rotorless CuremeterFIG. 4 Displacement Transducer
40、 and Wire-Mass CalibrationEquipment for Torsion Shear CuremetersFIG. 5 Typical Torque Standard Calibration Device for TorsionShear CuremetersD52890747.2 The sample shall be homogeneous, at room temperature,and as free of trapped air as possible.8. Test Specimens8.1 The recommended test specimen volu
41、me is between 3and5cm3, depending on the model of instrument being used.The size of the test specimen should exceed the test chambervolume by a small amount, to be determined by preliminarytests. Typically, specimen volume should be 130 to 190 % ofthe test chamber volume. Once a target weight is est
42、ablished,the weight of specimens should be controlled to within 60.5 gfor best repeatability.8.2 The test specimen taken from the sample should becircular, with a diameter smaller than the test chamber of theinstrument to be used.9. Procedure9.1 Preparation for TestBring the temperature of bothdies
43、to the reference temperature with the cavity closed.Adjustthe zero of the force or torque measuring device, if necessary.9.2 Loading the Curemeter:9.2.1 Open the dies, unload the previous sample (if neces-sary), place the test piece in the cavity, and close the dieswithin 20 s.9.2.2 The test time sh
44、all be counted from the instant that thedies are closed. Oscillation of the movable die shall be startedat zero time or before.10. Report10.1 Report the following information:10.1.1 A full description of the sample, its origin andcompound details,10.1.2 Test method and test details,10.1.2.1 Referenc
45、e to this test method,10.1.2.2 Type and model curemeter used (sealed or un-sealed, manufacturer, die options, if any),10.1.2.3 Amplitude of the die oscillation, in degrees,10.1.2.4 Frequency of oscillation,10.1.2.5 Torque range selected, in deci Newton metres(dNm). (The equation for conversion from
46、dNm to lbfin. is1.13 (dNm) = 1.00 (lbfin.),10.1.2.6 Time scale of the recording device,10.1.2.7 Curing temperature in degrees Celsius, and10.1.2.8 Date of the test.10.2 Test results reported are normally chosen from thefollowing parameters (refer to Fig. 1 for guidance):10.2.1 MLMinimum torque, in d
47、Nm (lbfin.).10.2.2 Maximum TorqueAll in dNm (lbfin.).10.2.2.1 MHFMaximum torque where curve plateaus.10.2.2.2 MHRMaximum torque of reverting curve.10.2.2.3 MHHighest torque attained during a specifiedperiod of time when no plateau or maximum torque isobtained.10.2.3 tsxScorch time, in minutes (time
48、to an increase ofx units of torque from ML). The preferred scorch time for testsat an oscillation amplitude of 60.5 is tsl.10.2.4 Cure Time, in minutes.10.2.4.1 t8xequal to the time to x % of torque increase ort8x = minutes to ML + x (MH ML)/100 torque.NOTE 3This method of determining the cure times
49、 is considered thestandard method. The most commonly used values of x are 50 and 90. Acure time of t810 is sometimes used as a measure of scorch time.10.2.4.2 txequal to the time to x % of maximum torque, ortx = minutes to (xMH)/100 torque.NOTE 4This is an alternate method for cure time determination.10.2.5 Cure Rate Indexequal to 100/(cure time scorchtime).10.2.6 “t10 % Rise” is the time for the force or torque to riseto 110 % of the minimum value. This may be used to measurescorch in some cases.11. Precision and B
