The torque rheometer is mainly used in rubber and plastic polymer materials. It is a multifunctional rheological test system that can be used for formula selection, quality control, rheological tests and processing performance tests. The test principle is to test the change of torque of the material under high temperature shear. The torque is related to the viscosity of the melt. The resistance encountered during sample mixing is proportional to the viscosity of the sample melt. This resistance is measured by the reaction torque acting on the rotor or screw.
The torque rheometer is a instrument that measures the viscous and elastic deformation behavior of polymer materials produced by the flow under the action of temperature and stress. Its relationship with various factors is the most basic process parameter in the molding of polymer materials. It plays an important guiding role in the use of raw materials, the selection of additives, the determination of processing parameters, and the design of molding equipment and molds.
The synthesis and production of molecular materials are mature technologies, and many brands have been developed. However, due to the actual needs of the market, further research and development of functional and specialized products is needed. In the process of researching new formulas, developing new products, and optimizing processing technology, it is necessary to conduct mixing tests, rheological tests, and processing tests on raw materials and formula materials with additives. These tests are inseparable from the torque rheometer. The torque rheometer has advanced technology, reasonable design, and powerful functions. It has the advantages of being fast, convenient, accurate, and reliable, and the experimental data covers a wealth of content. Therefore, it is necessary for researchers and users to fully understand and master its composition, principles, and functions.
The composition of the torque rheometer
The torque rheometer is an internationally common rheological test instrument, which is divided into three parts in terms of composition, namely the host control system, the measurement drive system, and the auxiliary machine accessories. The host control system is used for equipment calibration, test parameter setting, data collection, display and processing, and sends parameter control signals to the auxiliary machines; the measurement drive system is used to measure temperature, excitation, speed and torque signals, transmit information to the host at any time, and provide power and motor drive for the auxiliary machines; the auxiliary machine part includes mixer, single screw extruder, twin screw extruder, film blowing machine, calendering extruder, cable coating device and granulator, etc.; the accessories part includes rotor, screw, die head, funnel, feeder, sensor and electronic balance, etc. According to different test requirements, the host, auxiliary machine and accessories can be organically combined to complete the test.
Working principle of torque rheometer
The torque rheometer is equipped with screws with different parameters, which rotate in a cylinder with a certain temperature. The other end of the cylinder is equipped with a feeding hopper. When the raw material is sent to 2/3 of the barrel, it is gradually plasticized and homogenized when it enters the remaining part of the barrel. When all the particles are completely dissolved, the capillary tube can be used to extrude the mold to become a masterbatch or be injected into the mold for forming. At the same time, the equipment The measurement of the relationship between the apparent viscosity of the material and the shear speed and shear stress was also completed.
The moment rheometer support software set consists of the apparent viscosity test software plastic and the apparent viscosity test data processing software WinNian. The plastic software can collect test data and control parameters through the serial port of the PC, as well as establish a human-computer information interaction interface. This interface has relatively complete functions and can complete 6-channel temperature measurement and control, including speed setting, measurement and control, torque and excitation measurement, etc. The curve window can display the curve of each of the above data versus time in real time. These data can be processed by WinNian. When changing the screw speed of the extruder, the pressure difference P value inside and outside the die and the extrusion flow Q value can be changed. The test data can be saved in the form of a file. The file is opened in the software WinNian, and the representative data is filtered out and the gh and gt curves of double logarithmic coordinates are automatically output.
