Research On The Pressure Capillary Rheometer

Since the 1960's,with appearance of new polymer materials continuously, polymer materials are more and more widely used in industries such as chemistry, mechanical, light industry, national defense, automobile, food and medical, space, and so on. It is obviously important to research and test new polymer materials, the capillary rheometer is just an instrument that can test polymer material.The common rheometers are capillary rheometer, rotor rheometer, mixing torque rheometer and oscillator rheometer. The capillary rheometer has the similar flow form with that of the process of material machine-shaping,and can be used not only to measure material viscosity but also to research the extrude behavior and elasticity of polymer materials. Now capillary rheometer is widely used in research department and factory laboratory, and is an important instrument of science and application research in factory. In foreign countries there are several famous companies, but there is only the HRBHUST company in our country that produces the torque rheometer. The torque rheometer uses more material in testing, so it is not suitable for expensive materials. Based on this point, we work on the research of pressure capillary rheometer.When material is heated to certain temperature, the pressure capillary rheometer begins measuring materials. In measuring experiments, it controls motor's rotational speed in order to control piston speed. Under the function of high pressure, material will be extruded from the capillary, then the parameters will be gotten, therefore material flow-shape performance will be gotten. The instrument includes mechanical system and control system. Among them the mechanical system is used to finish motion change from power source to acting mechanism, then make the piston complete straight reciprocating motion in barrel and guarantee the pressure in barrel and flow from capillary .The control system is used to control, measure the pressure and temperature, then to realize online measurement and adjustment. At the same time, it records, displays and storages the corresponding data.In this thesis, according to present conditions at home and abroad, the pressure capillary rheometer is put forward. It has characteristics of simple operation,accurate measurement and vast measuring scope. If the instrument can be realized, it can not only fill up the blank of local related realm, but also reach the requirement of the same instrument abroad. So it has the broad application prospect.