D-RPA 3000
System Description

The testing instrument consists of the
D-RPA 3000 rheometer, a PC with screen, keyboard and mouse as well as a printer.

The test chamber is equipped with a pneumatic closing device, with a closing force of 11.6 kN equipped. The opening of the test chamber is at any time possible. Between measurements, the test chamber can be manually closed in standby mode.

To protect the user a safety shield is lowered before the test chamber is closed. Between tests the test chamber can manually be closed in a standby mode. A delay time for opening the safety shield can freely be configured in the software. Furthermore there is the possibility of the attachment of a suction for produced waste gas to the back of the instrument.

The temperature of the two test chamber halves are independently measured by means of PT 100 RTDs and heating is controlled via software.

The rubber mixture sample is tested under torsion generated by rotational vibration of the lower test chamber. The lower test chamber generates sinusoidal rotational vibrations with fixed-angle amplitude. The oscillation amplitude can be varied up to 180°. The torque is measured via a strain gauge torque transducer with very high resolution.

Due to the rugged construction of the D-RPA 3000, it can be used for quality control purposes not only in the laboratory, but also directly in the production area.

The data acquisition and the control of the testing instrument is made by the PC by means of the included 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 the test results from the viscous and elastic portions of the mixture.

Because of the very high measuring precision of the D-RPA 3000 smallest variations of the ingredients can be detected in the test result data, which simplifies quality control and the development of new rubber compounds.

Due to this there a lots of important advantages for the user:

• Lower costs per test
• Faster batch release - with only one test all essential physically characteristics can be determined. (Quality control data, cure characteristics and properties can be determined with only one test of one test sample)
• Significantly reduction of scrap and rework
• Efficiency increase of the production process
• Faster and significantly simplified development cycles
• Intuitive, simple operation of the MonControl Analyses Software
• No separate sample preparation necessary

Cooling system:

Pneumatic cooling system (Standard) Both chambers are cooled separately by a PID-controlled forced air cooling system. Also the cooling system can be freely programmed in the test definition to also run the cooling process during test sequences to conduct any friction heat from the sample.

MCool 10 Integrated cartridge cooling system that separates the provided air streams into cold (-45°C) and hot (+110°C) fraction. The cold fraction of the air is then used for the separate cooling of both test chambers down to +8°C. Only a forced air supply with at least 4 Bars is required - there are no additional chillers or cooling liquids required. (Performance of the cooling systems depends on supplied air). This technology is worldwide patented by MonTech.

MCool -40 Liquid cooling system with external chiller system. Both dies are separately chilled and cooled by an external cooling unit that is connected with the instrument. The cooling system works as an adition to the pneumatic cooling system - only if lower temperatures are required the chiller will be started. The total heating system of the dies remains unchanged so that instruments equipped with this devices are absolutely comparable with any other Moving Die Rheometer. This technology is worldwide patented by MonTech.

Test chamber system

The two test chamber halves form a closed, biconical system. That means the test chamber is formed by two conical test dies. This ensures a constant shear rate which is independent of the die radius in the sample.

The test chamber is equipped with a pneumatic closing system, which moves the upper test chamber half to the lower test chamber half to completely close the test chamber and keep the test sample during the test or cure under pressure. The default closing force is 11,6 kN at 4,5 bar air pressure.

During the test the lower die performs a sinusoidal movement with a variable amplitude and a fi xed frequency. This movement is generated by a high precision torque motor system with integrated ceramic bearing and precision-path-recording which is mounted directly at the shaft of the lower die. This motor is regulated by a corresponding high-resolution motor controller - this controller is freely programmable by the MonControl Analyses Software. Because of an integrated overload protection the drive will be switched of and the current test will be stopped if the maximum permitted torque is exceeded.

The measurement of the reaction torque is made by a DMS torque transducer with a very high resolution which is directly mounted above the upper test die. With this transducer it is also possible to measure the current pressure in the test chamber (optional).

The temperature control of both electrically heated test dies is made by the MonControl Analyses Software with a separate control system for each test die.

The temperature control and temperature measurement is performed by PT 100 resistance thermometers. For the heating of both test dies a heating film is used - one film for each test die. The heating film has a spiral shape with different distances between the windings. Therefore a heat concentration is prevented and a uniform temperature is ensured.

Automation options:

5 samples linear This system features an automated sample loading and unloading with a linear queue of 5 test samples. This is ideally suitable for online testing purposes.

10 samples linear This system features an automated sample loading and unloading with a linear queue of 10 test samples. This is ideally suitable for online testing purposes as well as a laboratory usage.

24 & 48 samples trays This system features an automated sample loading and unloading with a direct tray to chamber handling system. A rotary table with a stock of 24 samples is attached at the right side to the instrument. The samples are picked from this tray and directly placed into the test chamber. This system is especially suitable for an operator-less operation over long testing times.

10 X 24 & 10 x 48 samples tray This system features an automated sample loading and unloading with a direct tray to chamber handling system as well as a separate tray handling mechanism. Up to 10 rotary tables with a stock of 24 or 48 samples each can therefore be stored in the instrument an automatically processed. Trays are automatically moved into loading and unloading positions where the samples are picked from the trays and directly placed into the test chamber. This system is especially suitable for a long-time operator-less operation over long testing times, nights or whole shifts.

Advanced technology options:

Axial force measurment device. Features a combined torque / forced transducer to measures torques 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 realtime simulataneous measurements ot torque and normal force.

Cavity pressure controller system With this option, that cavity pressure can also be controlled either to a pre-programmed or to an online calcluated pressure level. Therefore the closing force as well as the die gap are designes 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.

High Speed data acquisition system The high speed DAQ option offer unique result stream resulotion as well as an ultimate level of precision for torque as well as the motor position signal. Therefore both channels are sampled and processed simultanously with a resolution of 24Bit at a data rate of 180KHz. All data streams are provided on the PC an calculated online in a Realtime kernel. Also it is possibe to save the raw data streams to the PCs memory. This makes the system especially suaitble for FT-Rheology purposes.

Moving Die Rheometer Volume Punch

For the exact production of test samples for the D-RPA 3000, the R-VS 3000 sample cutter for rheometers 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.

D-RPA 3000
Software

The 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 D-RPA 3000 in combination with the MonControl Analyses Software offers a huge variety of test parameters, which makes it possible to determine the sample properties in a very wide range.

The following test parameters are freely definable:

• Temperature
• Oscillation frequency
• Oscillation amplitude
• Time
• Sampling rate
• Number of measuring cycles
• Pressure (optional)
• Die gap (optional)

The following test programs are available with the D-RPA 3000:

• Amplitude Sweep: The deflection angle (Amplitude) is changed during test at a predefined frequency and temperature.
  
  
• Frequency Sweep: The frequency of the oscillation is changed during test at a predefined amplitude and temperature.
  
  
• Temperature Sweep: The temperature of the test chamber is changed during test at a predefined amplitude and frequency.
  
  
• Shear rate Sweep: Changing of the shear rate during the examination. The shear rate sweep represents a sequence of different retardation cycles.
  
  
• Relaxation: Relaxation 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.
  
  
• Retardation: Examination of the fatigue behavior of a material under a constant load. Besides the elastic deformation the material experiences a time-dependent reversible (viscoelastic) and an irreversible (plastic) deformation. At the transition to the plastic condition the tension remains constant in the material. The force-time graph describes an e-function. If the stress is too high it comes time-dependently to a break of the material.
  
  
• Hysteresis: The change of the viscosity under influence of one constant shear gradient, depending on the duration of the infl uence. With increasing duration of the infl uence by the shear force the hysteresis effect is increasingly irreversible.
  
  
• Tensile tests: A material identification value which indicates the lasting prolongation of the
  break related to the initial measuring length.
  
  
• many more test programs

D-RPA 3000
Specifications

International standards	ISO 6502 / ASTM D 5289 / ASTM D 6204 / ASTM D 6601 / DIN 53529
Test chamber	Biconical, closed system
Test chamber gap	0.45 mm nominal
Force measurement	Torque and force transducer attached to upper die
Closing system	Damped closed system, pneumatically with non-contact spring elevation system
Oscillation frequency	0.001 Hz - 100 Hz
Oscillation amplitude	0.0001° to 180° variable
Torque range	0.0001 to 235 dNm
Sample volume	approx. 4.5 cm³
Temperature control system	30 °C to 230 °C, precision +/- 0.03 °C both microprocessor controlled -40 °C low-temperature cooling system available
Temperature check system	Recordings of the temperature gradient on the screen, microprocessor monitored
Units of measure	Torque (dNm, lbf.in, kgf.cm) Shear modulus (Pa, dynes/cm², psi) Dynamic viscosity (Pa s) Temperature (°C, °F) Pressure (bar, kg per cm²) Time (min - min / min - sec) Frequency (Hz, cpm) Shear rate (1/s, rad/s)
Pneumatics	min 4,5 Bars
Sub tests	Amplitude Sweep, Frequency Sweep, Temperature Sweep, Shear rate Sweep, Relaxation, Retardation, Hystereses, Tension test
Electrical	Single phase 220 V - 230 V, 5 Amps
Weight	230 kg
Connection for dust / vapor extraction	100mm dia
Dimensions