1、Designation: D 6204 07Standard Test Method forRubberMeasurement of Unvulcanized RheologicalProperties Using Rotorless Shear Rheometers1This standard is issued under the fixed designation D 6204; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. 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 the use of a rotorless oscillatingshear rheometer for the measurement
3、 of the flow properties ofraw rubber and unvulcanized rubber compounds. These flowproperties are related to factory processing.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address al
4、l 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 Standards:2D 1485 Practice for
5、Rubber from Natural SourcesSampling and Sample PreparationD 1646 Test Methods for RubberViscosity, Stress Relax-ation, and Pre-Vulcanization Characteristics (Mooney Vis-cometer)D 3896 Practice for Rubber From Synthetic SourcesSamplingD 5289 Test Method for Rubber PropertyVulcanizationUsing Rotorless
6、 Cure MetersD 6601 Test Method for Rubber PropertiesMeasurementof Cure and After-Cure Dynamic Properties Using aRotorless Shear Rheometer3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 complex shear modulus, G*, nthe ratio of peakamplitude shear stress to peak amplitude shear
7、strain; math-ematically, G*=(S*/Area)/Strain=(G2+ G”2)1/2.3.1.2 complex torque, S*, nthe peak amplitude torqueresponse measured by a reaction torque transducer for asinusoidally applied strain; mathematically, S* is computed byS*=(S2+ S”2)1/2.3.1.3 dynamic complex viscosity h*, nthe ratio of thecomp
8、lex shear modulus, G* to the oscillation frequency, v,inradians per second.3.1.4 elastic torque, S, nthe peak amplitude torque com-ponent that is in phase with a sinusoidally applied strain.3.1.5 loss angle, d, nthe phase angle by which thecomplex torque (S*) leads a sinusoidally applied strain.3.1.
9、6 loss factor, tan d, nthe ratio of loss modulus tostorage modulus, or the ratio of viscous torque to elastictorque; mathematically, tan d = G”/G = S”/S.3.1.7 loss shear modulus G”, nthe ratio of (viscous) peakamplitude shear stress to peak amplitude shear strain for thetorque component 90 out of ph
10、ase with a sinusoidally appliedstrain; mathematically, G” =(S”/Area)/Peak Strain.3.1.8 real dynamic viscosity, h, nthe ratio of the loss shearmodulus, G” to the oscillation frequency, v, in radians persecond.3.1.9 storage shear modulus, G, nthe ratio of (elastic)peak amplitude shear stress to peak a
11、mplitude shear strain forthe torque component in phase with a sinusoidally appliedstrain; mathematically, G=(S/Area)/Peak Strain.3.1.10 viscous torque, S”, nthe peak amplitude torquecomponent, which is 90 out of phase with a sinusoidallyapplied strain.4. Summary of Test Method4.1 A rubber test speci
12、men is contained in a die cavity thatis closed and maintained at an elevated temperature. The cavityis formed by two dies, one of which is oscillated through arotary amplitude. This action produces a sinusoidal torsionalstrain in the test specimen, resulting in a sinusoidal torque,which measures a v
13、iscoelastic quality of the test specimen. Thetest specimen can be either a raw natural or synthetic rubber oran uncured rubber compound.4.2 These viscoelastic measurements can be made based on(1) a frequency sweep, in which the frequency is programmedto change in steps under constant strain amplitud
14、e and tem-perature conditions, (2) a strain sweep, in which the strain1This 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 approved July 1, 2007. Published July 2007. Originally appr
15、ovedin 1997. Last previous edition approved in 2005 as D 6204 05.2For 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 webs
16、ite.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.amplitude is programmed to change in steps under constantfrequency and temperature conditions, or (3) a temperaturesweep, in which the temperature is programmed to eitherincrease or
17、 decrease under constant strain amplitude andfrequency conditions. A timed test may also be performed inwhich a sinusoidal strain is applied for a given time periodunder constant strain amplitude, frequency, and temperatureconditions.4.2.1 For a frequency sweep test, the instrument is typicallyprogr
18、ammed to increase the frequency with each subsequentstep change. For a strain sweep test, the instrument is usuallyprogrammed to increase the strain amplitude with each subse-quent step change. This is done to minimize the influence ofprior test conditions on subsequent test steps. For temperaturesw
19、eeps, the temperature may be programmed either to increaseor decrease with each subsequent step change, depending onthe effects to be studied. The results from increasing frequency,strain amplitude, or temperature may not be the same as resultsfrom decreasing these test parameters.4.3 Rheological pr
20、operties are measured for each set offrequency, strain, and temperature conditions. These propertiescan be measured as combinations of elastic torque S, viscoustorque S”, storage shear modulus G, loss shear modulus G”,tan d, complex dynamic viscosity h*, and real dynamicviscosity h.4.4 This standard
21、 is organized in three different parts (A, B,and C), which can be run in the following combinations:ABA, BA, B, CA, CB, CC4.5 These three parts are described below:4.5.1 Part A is a rapid three-point frequency sweep per-formed at a low strain of 7 % to relate to differences in averagemolecular weigh
22、t, molecular weight distribution, and longchain branching for raw elastomers and to relate to differencesin flowability, shear thinning, and die swell for mixed batches.4.5.2 Part B is a rapid two-point frequency sweep performedat a moderate strain of 100 % (or higher) to relate to geldifferences wi
23、th raw elastomers and to relate to differences inhigher shear rate viscosity and die swell for mixed batches. Thehigher applied strain is commonly needed to help break up gelstructure in some raw elastomers and break up filler aggregatenetworks for mixed batches.Although 100 % strain is the morecomm
24、on test condition, significantly higher test sensitivity ispossible by performing this frequency sweep at 200 % strain orhigher.4.5.3 Part C is a linear ramped temperature rise fromprocessing temperature (typically 100C) to cure temperature(usually 140, 160, or 180C) in a predetermined time period.T
25、his ramped temperature cure is performed to enhance statis-tical test sensitivity to real differences in scorch times provid-ing better scorch control than traditional isothermal cure tests(Test Method D 5289), and to provide a controlled transitionfrom Part A or Part B tests, or both, in this metho
26、d to a curetest.5. Significance and Use5.1 This test method is used to measure viscoelastic prop-erties of raw rubber as well as unvulcanized rubber com-pounds. These viscoelastic properties may relate to factoryprocessing behavior.5.2 This test method may be used for quality control inrubber manufa
27、cturing processes and for research and develop-ment testing of raw rubber and rubber compounds. This testmethod may also be used for evaluating compound differencesresulting from the use of different compounding materials.6. Apparatus6.1 Torsion Strain Rotorless Oscillating Rheometer With aSealed Ca
28、vityThis type of rheometer measures the elastictorque S and viscous torque S” produced by oscillatingangular strain of set amplitude and frequency in a completelyclosed and sealed test cavity.6.2 Sealed Die CavityThe sealed die cavity is formed bytwo conical surface dies. In the measuring position,
29、the twodies are fixed a specified distance apart so that the cavity isclosed and sealed (see Fig. 1).6.3 Die GapFor the sealed cavity, no gap shall exist at theedges of the dies. At the center of the dies, the die gap shall beset at 0.45 6 0.05 mm.6.4 Die Closing MechanismFor the sealed cavity, a pn
30、eu-matic cylinder or other device shall close the dies and holdthem closed during the test with a force not less than 11 kN(2500 lbf).6.5 Die Oscillating SystemThe die oscillating systemconsists of a direct drive motor that imparts a torsionaloscillating movement to the lower die in the cavity plane
31、.6.5.1 The oscillation amplitude can be varied, but a selec-tion of 60.5 arc (7.0 % shear strain) is preferred for frequencysweep tests. The oscillation frequency can be varied between0.03 and 30 Hz.6.6 Torque Measuring SystemThe torque measuring sys-tem shall measure the resultant shear torque.6.6.
32、1 The torque measuring device shall be rigidly coupledto one of the dies, any deformation between the die and deviceshall be negligibly small, and the device shall generate a signalthat is proportional to the torque. The total error resulting fromzero point error, sensitivity error, linearity, and r
33、epeatabilityerrors shall not exceed 1 % of the selected measuring range.6.6.2 The torque recording device shall be used to record thesignal from the torque measuring device and shall have aresponse time for full scale deflection of the torque scale of 1s or less. The torque shall be recorded with an
34、 accuracy of60.5 % of the range. Torque recording devices may includeanalog chart recorders, printers, plotters, or computers.6.6.3 A reference torque device is required to calibrate thetorque measurement system. A torque standard shall be used tocalibrate the torque measuring system at the selected
35、 angulardisplacement by clamping a steel torsion rod to the oscillatingand the torque measuring dies of the torsion shear rheometer(see Fig. 2). The reference values for angular displacement andcorresponding torque shall be established by the manufacturerfor each torque standard.D62040726.7 Referenc
36、e Test TemperatureThe standard referencetest temperature shall be 100C (212F) or 125C (257F) forprocessability measurements. Tests may be carried out at othertemperatures when appropriate.6.8 Temperature Control SystemThis system shall permitthe set point temperature to be varied between 40C and 220
37、Cwith an accuracy of 60.3C or better.6.8.1 The dies shall heat to the set point temperature in 1.0min or less from closure of the test cavity. Once the initialheating-up time has been completed, die temperature shall notvary by more than 60.3C for the remainder of a test at a settemperature. When th
38、e set temperature is changed in a pro-grammed temperature sweep (step changes in temperature),rheological measurements shall not be recorded until the dietemperatures are within 60.3C of the new set temperature forat least 30 s. When the set temperature is set for a rampedincrease as described in Pa
39、rt C of this test method, thetemperature shall not overshoot by more than 3C withrecovery to within 60.3C within 1 min of control at theplateau temperature at the end of the temperature ramp.6.8.2 Temperature distribution within the test piece shall beas uniform as possible. Within the deformation z
40、one, a toler-ance of 61C of the average test piece temperature shall not beexceeded.6.8.3 Die temperature is determined by a temperature sensorused for control. The difference between the die temperatureand the average test piece temperature shall not be more thanFIG. 1 Typical Sealed Torsion Shear
41、Rotorless CuremeterD62040732C. Temperature measurement accuracy shall be 60.3C forthe die temperature sensor.7. Test Specimen7.1 A test specimen taken from a sample shall be between 5and6cm3for the sealed cavity oscillating rheometer. Thespecimen volume shall exceed the test cavity volume by asmall
42、amount, to be determined by preliminary tests. Typically,specimen volume should be 130 to 150 % of the test cavityvolume. Once a target weight for a desired volume has beenestablished, specimen weights shall be controlled to within60.5 g for best repeatability. The initial test specimen shapeshall f
43、it well within the perimeter of the test cavity.7.2 Raw Rubber SpecimensCondition the specimen ob-tained in accordance with Practice D 1485 or Practice D 3896until it has reached room temperature (23 6 3C (73 6 5F)throughout. A raw rubber test specimen should be tested asreceived, that is unmassed (
44、not milled). If the material cannotbe tested unmassed, then follow the sample preparation sectionof Test Methods D 1646.7.2.1 Raw rubber test specimens in a sealed cavity oscillat-ing rheometer must be pre-conditioned in the instrument beforerheological measurements are made to improve test precisio
45、n.A programmed pre-conditioning step shall consist of oscillat-ing the specimen at 0.5 Hz, 62.8 % strain, 100C (or 125C)for the time interval specified in Table 1.7.3 Compounded Rubber SpecimensTest specimens shallbe taken from a rubber compound as required by the mixingmethod or other sampling inst
46、ructions. Rubber compoundswith or without curatives may be tested.7.3.1 The rubber compound shall be in the form of a sheet,at room temperature, and as free of air as possible.7.3.2 Compounded rubber test specimens in a sealed cavityoscillating rheometer must be pre-conditioned in the instru-ment be
47、fore rheological measurements are made to improvetest precision. A programmed pre-conditioning step shall con-sist of oscillating the specimen at 0.5 Hz, 62.8 % strain, 100Cfor the time interval specified in Table 1.8. Procedure8.1 Part AMeasuring Rheological Properties At LowStrain:8.1.1 Select the
48、 frequency, strain, temperature, and time forthe conditioning step as listed in Table 1.8.1.2 Select the frequency steps and the strain and tempera-ture conditions for the frequency step as listed in Table 1.8.1.3 Program a test configuration that incorporates theseconditions and store on the instru
49、ment computer operatingsystem.8.1.4 Load the test configuration to run the test.8.1.5 Enter specimen identification.FIG. 2 Typical Torque Standard Calibration Devices for Torsion Shear CuremetersD62040748.1.6 Wait until both dies are at the initial test temperature.Open the test cavity and visually check both upper and lowerdies for cleanliness. Clean the dies if necessary. Place the testspecimen on the center of the lower die and close the dieswithin 20 s.8.2 Part BMeasuring Rheological Properties at HighStrain:
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