MonTech MDR 3000
Moving Die Rheometer
Rotorless moving die rheometer for rubber compound testing with programmable oscillation from ±0.01— 5° (0.14—70% Strain)
The MDR 3000 rheometer is designed for measuring the viscoelastic properties of elastomeric and rubber compounds before, during and after cure according to ISO 6502, ASTM D5289 and DIN 53529.
The MDR 3000 is used to determine the Plasticity of vulcanization, the cure rate, and to examine the behavior of the rubber mixture at post-vulcanization. Further, it is possible to determine, the viscous and elastic fraction (S 'and S'') of the rubber mixture.
The determined measurements such as torque, viscous and elastic component for the upper and lower halves of the test chamber are displayed on the screen as a function of time. The acquired data gives exact information about the processability, the cure characteristics, the cure speed, and behavior of the compound after vulcanization.
The testing instrument consists of the rheometer, computer with MonControl analysis software, wide-screen monitor, keyboard, mouse, and printer.
Because of the very high measuring precision of the MDR 3000, small variations of ingredients can be detected in the test result data, which simplifies quality control and the development of new rubber compounds.
Due to its rugged construction, the MDR 3000 can be used for quality control purposes in the laboratory and directly in the production area.
- Lower costs per test
- Faster batch release - with only one test, all essential physical characteristics can be determined: (quality control data, cure characteristics and properties)
- Significant reduction of scrap and rework
- Efficiency increase of the production process
- Faster and significantly simplified development cycles
- Intuitive, simple operation of the MonControl Analysis Software
- No separate sample preparation necessary
Description of Operation
The test chamber is equipped with a pneumatic closing system which moves the upper test chamber half to the lower test chamber half. The two test chamber halves form a closed, bi-conical system. This ensures a constant shear rate which is independent of the die radius in the sample.
The default closing force is 11.6 kN at 4.5 bar air pressure. This completely closes the test chamber and keeps the test sample under pressure during the test / cure. The opening of the test chamber is possible at any time.
To protect the user a safety shield is lowered before the test chamber is closed. Between tests the chamber can manually be closed in a standby mode. A delay time for opening the safety shield can be configured in the software. Furthermore there is a port on the back of the rheometer for suction of waste gas produced during testing.
Temperature control of both electrically heated test dies is made by the MonControl Analysis Software with a separate control system for each test die. Temperature measurement is performed by PT 100 resistance thermometers. Both dies are heated by a heating film with spiral windings. This design ensures temperature uniformity throughout the dies. Both chambers are cooled separately by a PID-controlled forced air cooling system. The cooling system can be programmed in the test definition to cool the dies and compound during test sequences
The rubber mixture sample is tested under sinusoidal torsion generated by the lower test chamber during the test. The MDR 3000 can vary oscillation amplitude from ±0.01° to 5° with a frequency of 1.667 Hz. This movement is generated by a high precision torque motor system with integrated ceramic bearings and precision path recording. The motor is mounted directly to the shaft of the lower die. The motor is software controlled and regulated by a corresponding high-resolution motor controller with overload protection.
The reaction torque is measured by a high-resolution strain gauge transducer mounted above the upper test die.
Control and data acquisition is performed via the connected computer using MonControl analysis software. For the storage and analysis of the determined measurement data a modern SQL database structure is provided. Over 1,500 time and torque characteristics are available for the selection of test results from the viscous and elastic portions of the mixture.
For the best possible determination of all relevant test parameters the MDR 3000 is equipped with a large variety of test methods, test parameters as well as calculation and evaluation options.
The following measurands can be determined:
- Torque S’ and S’
- Complex torque S*
- Pressure (optional)
||Elastic modulus S‘
Viscous Modulus S‘‘
||Normal force measurement P (optional)
MonControl Analysis Software
MonControl Analysis Software enables the user to configure, combine and execute the respective tests. After inserting the test sample, the actual test sequence is executed fully automatic without any intervention of the operator. The MDR 3000 in combination with the MonControl Analysis Software offers a huge variety of test parameters, which makes it possible to determine a wide range of properties in rheometry.
The following test parameters are freely definable:
- Oscillation frequency
- Oscillation amplitude
- Sampling rate
- Number of measuring cycles
- Pressure (optional)
- Die gap (optional)
The following test programs are available with the MDR 3000:
- Temperature sweep
The temperature of the test chamber is changed during test at a predefined amplitude and frequency.
Describes the unstressing after a strain. Stable physical systems return to an outer perturbation over relaxation processes nearly into their ground state. The relaxation time is a time constant which is characteristic for the given relaxation process. If the quantity f(t) of the relaxations follows an exponential rule: f(t) = exp( - t / t) * f(t = 0) then t is the accompanying relaxation time.
- many more test programs
Features a combined torque / forced transducer to measure torque as well as the pressure within the test chamber. Before each test, the transducer and amplifier is balanced automatically. The system also includes a second channel amplifier system for real-time simultaneous measurements of torque and normal force.
With this option, that cavity pressure can also be controlled either to a pre-programmed or to an on-line calculated pressure level. Therefore the closing force as well as the die gap are designed as a variable, independent axis, so that the cavity pressure can be precisely controlled. This system is especially suitable for test sequences that include curing as well as a cool-down of the sample for a dynamical mechanical analyses. Therefore the system can be utilized to compensate material shrinkage as well as to avoid any slippage in the test chamber. This technology is worldwide patented by MonTech.
Pneumatic Cooling System
This system uses pressurized air to cool both chambers separately using a PID-controlled forced air cooling system. In MDR mode this system can be used to rapidly cool the rheometer from a higher to lower testing temperature. This significantly reduces non-productive time of the instrument, shortens stabilization time, and operator waiting time. Non-Isothermal and RPA operation modes can be programmed in the test definition to cool the sample during test sequences and follow precise cooling ramps or steps as well as conduct any friction heat from the sample during a test with high shear rates.
Rheometer volume punch
For the exact production of test samples for rheometers, the R-VS 3000 sample cutter is an available option. This volume punch is used for rapid and accurate preparation of test specimens. The usage of a volume cutter is recommended because this ensures reliable and reproducible test results.
||ISO 6502 / ASTM D 5289 / DIN 53529|
||Bi-conical, closed System|
||Programmable via Software, ±0.01— 5° (±0.14—70%)|
|Temperature control system
||30°C to 232°C, precision +/- 0.03°C both microprocessor controlled|
|Temperature check system
||Recordings of the temperature gradient on the screen, microprocessor monitored|
|Units of measure
||Torque (dNm, lbf•in, kgf•cm)|
Temperature (°C, °F)
Pressure (bar, kg per cm²)
Time (min - min / min - sec)
Shear rate (1/s, rad/s)
||min. 4.5 Bar|
||Single phase 220 V - 230 V, 5 Amps|
|Connection for dust / vapor extraction