Extrusion Mechanism And Experimental Study Of Short Fiber Reinforced Rubber Composites Using Gear Pumps

With the increasing demand for polymer materials and the performance requirements having been continuously improved,new polymer materials have emerged.Short fiber reinforced rubber composites are included.Short fibers stretched along the direction of force by flowing,the performance of product can be improved.However,the materials have high Mooney viscosity,low plasticity,difficulty to process.They requires high performance requirements for extrusion equipment.This paper will design a gear pump auxiliary device.Utilizing the characteristics of forward delivery,it cooperate with extruder to eliminate problems by pressure fluctuations and other factors causing the performance of the extrusion moldingt to decline.The study of extrusion process will not only improve the extrusion efficiency of short fiber reinforced rubber composites,but also maintain its excellent characteristics.Extrusion mechanism of gear pump was studied.Gear pump auxiliary device of rubber extruder was designed.Using FEM software dynamically simulated the flow conditions in the gear pump to determine the rationality of the gear pump design.The effect of gear pump on the quality of short fiber reinforced rubber composite extrusion products was studied and optimal extrusion parameters were explored by experiments.The quality of tread rubber was certified from extruded composite materials under optimum process parameters by road test simulation.The main tasks are as follows:(1)Extrusion mechanism of gear pump was researched.Factors affecting the extrusion stability of composite materials,such as the instantaneous flow rate,leakage flow phenomenon,trapped rubber phenomenon and rotational speed limitation,was analyzed.(2)The gear pump auxiliary device's structure was designed and optimized.The main structural parameters are determined.(3)The finite element software was used to dynamically simulate about melt flow in the gear pump.The pressure field,velocity field,and outlet instantaneous speed were analyzed about the influence of the “trapped oil” phenomenon,the leakage condition and the pulsation flow during the flow of the rubber material.(4)The effect of increasing the gear pump device on the quality of rubber composite extrusion molding products was studied.The experimental results show that after the use of gear pump,the extrusion efficiency is increased by 10.95%,and the extrusion stability of the rubber composite material is also greatly improved.When the screw speed was 30r/min,the barrel temperature was 80°C and the gear pump speed was 25r/min,it have the best performance.(5)The tread rubber wear test equipment was used to test the tread rubber made of the rubber composites material extruded under the optimum process conditions of the screw extruder and the gear pump auxiliary extruder.It is further proved that the wear resistance of the composites material using the gear pump auxiliary extrusion device is superior to that of the screw extruder.