An Investigation Of Rheology Behavior Of LLDPE Under Vibration And Shear Complex Stress Field In Extrusion Molding

The final properties of polymer materials are not only related with the chemical constitution and structure ,but also depend on the formation and change of morphosis in preparation process mostly. The investigation of the effect of the external field on the polymer system has already become a hot point in polymer processing engineering, high polymer physics and high polymer chemistry, etc. The shear-thinning treatment by combining rotational shear and vibration can bring lots of benefits the operator expects: lowering the viscosity without reducing the molecular weight and mechanical properties ,the pressure and temperature can be drastically reduced in the process of injection or extrusion, the throughput can be increased without the appearance of shark skin on the exited extrudate.When processing products in this field , the microscopic structures and properties of products improved.This work designed a set of mechanical vibration and shear complex stress field device to treat the polymeric melt. The frequency and amplitude in vibration field and the shear rotational speed in shear field are adjustable. The rheology behavior of LLDPE was researched under various conditions. We got the optimal value of technological conditions by comparing methods, and we also compared the effect of different mandrels and temperatures on the apparent viscosity of LLDPE. And we had further studies on the dynamic rheological behavior of LLDPE using dynamic...