Moving Die Rheometer
The MDR one Moving Die Rheometer (MDR) is a reliable, accurate, and easy-to-operate rotorless curemeter perfect for routine and standards-driven testing of rubber curing. The MDR one is configured for measuring curing profiles of rubber compounds under isothermal and non-isothermal test conditions at constant strain and frequency. The MDR one employs sealed biconical dies meeting all relevant ASTM, ISO, and DIN standards. The unique design includes an ultra-rigid test frame, direct drive motor, precision temperature control with optional cooling, available Autosampler, and intuitive Scarabaeus Control and Analysis software making it the ideal platform for QC or R&D environments.
Unmatched data precision, accuracy, and reproducibility
Robust, field proven torque transducer for high stability and reliable torque measurements
Extremely rigid test frame for accurate compliance free data
Available autosampler for simple unattended operation
Pneumatic locking cylinders for repeatable sample sealing
Powerful and intuitive Scarabaeus Software available in multiple languages & compatible with other manufacturers’ instruments
User calibration and user replaceable seals
TA Instruments is the world’s leading supplier of analytical instrumentation for the measurement of viscosity and viscoelastic properties. The new rubber testing instruments are uniquely designed to deliver the highest quality of torque, amplitude, frequency, temperature, and pressure measurement and control setting the NEW STANDARD for testing of rubber products at all stages of manufacturing.
Rigid Testing Platform
The MDR one is built with an ultra-stiff testing frame and crosshead which eliminate the effects of instrument compliance on test data. Instrument compliance, or instrument deformation, produces erroneously low values of measured properties such as modulus and torque, irregular strain and torque waveform signals, and other errors.
Large diameter steel rods and a thick crosshead brace in the H-shaped load frame of the MDR one provide unmatched rigidity to resist instrument deflection while the motor deforms the sample. This special design ensures that the commanded strain is achieved with each cycle of deformation, even for highly filled, fully cured rubbers. Additionally, a non-compliant system allows for truly sinusoidal strain profiles under all conditions. This can be verified by continuous Fourier Transform analysis of the deformation and measured torque signals which is available in the Scarabaeus Software. The superior design also guarantees smooth travel, proper alignment, and precise application of vertical load.
Direct Drive Motor
A powerful direct drive motor applies precise deformation in the MDR one. A high quality rheological or dynamic measurement relies on the precise application of deformation. In a direct drive system the start-up delays, compliance, and translational losses seen in clutch or belt driven configurations are eliminated. The superior motor design of the MDR one ensures that the most accurate and repeatable deformations are always applied to the sample.
The MDR one provides continuously variable strain and frequency ranges for flexible testing. This provides important material information such as:·
The linear viscoelastic response of highly filled rubbers at low strains
Behavior at extreme processing and use conditions characterized by high strains
Terminal material behavior exhibited at low frequencies
Response to high speed deformations measured at high frequencies
Advanced Data Processing
The complex deformations and stress-strain response common to rubber testing demand the most advanced data processing techniques. The MDR one from TA Instruments utilizes a state-of-the-art 20 bit encoder and advanced data sampling technique to perform calculations based on a Fast Fourier Transform (FFT) analysis using 90 data points for each cycle of oscillation.
The MDR one is compatible with either the Standard or Enhanced Subambient Cooling System. The Standard Cooling System uses ambient air to expedite temperature changes above ambient conditions and improve temperature stability near room temperature.
The Enhanced Subambient Cooling System is a mechanical device that employspressurized air to cool the test environment, allowing characterization of rubbers at temperature as low as 18 °C and greatly accelerating cooling time between nonisothermal experiments. The system has no moving parts, making it extremely reliable and easy to use.
Dies & Rotors
The MDR one employs the industry-standard sealed cavity biconical die design. The dies are constructed from durable, high stiffness, low thermal expansion stainless steel to minimize system compliance and prevent gap changes with temperature. The test fixtures are connected directly in line with the motor below for precision deformation control and the torque transducer above for accurate measurement.
Direct contact electric heaters mounted within the dies provide exceptional temperature control and stability under isothermal, step and temperature ramp conditions. This highly responsive system returns rapidly to the programmed test temperature upon the addition of a cold sample, providing the most representative values for scorch time and other cure characteristics. Extremely durable user-replaceable seals provide absolute sample containment at all temperatures and conditions.
High Pressure Pneumatic System
The MDR one employs a high pressure pneumatic system to seal the sample properly and reproducibly. The high capacity pneumatic system applies up to 8 bar nominal pressure to the during gap closure. Proper alignment and the use of mechanical bearings ensure efficient transfer of load from the system to the sample without load frame losses. Actual sealing pressure is measured directly and recorded. This high pressure automated sample containment removes operator dependence and tightly contains the test specimen. This sealing process is particularly important for materials that undergo positive or negative volumetric changes with curing and highly stiff materials such as carbon-filled fluoroelastomers.
The MDR one die surfaces feature an optimized arrangement of radial serrations to guarantee constant sample contact at even the highest strain values. Polyester or polyamide films may be used to facilitate sample release and avoid the need to clean dies between experiments.
Torque calibration is made simple with a certified torque calibration device. This feature allows the user to calibrate the instrument directly, increasing data confidence and operation time, and reducing the reliance of service engineers for calibration.