The Design And Simulation For Four Plunger Extrusion Of UHMWPE

Ultra-high molecular weight polyethylene(UHMWPE), a new engineering plastic with excellent comprehensive performance, which used widely in many fields, but its processing properties not satisfactory. In the meantime of improving UHMWPE processing performance by modified, it will reduce some performance of UHMWPE in a certain extent. The existing molding machinery in molding pure UHMWPE products process exist many shortcomings, including material skid, unfavorable feeding, obstruction piston cylinder, melt rupture and low production efficiency.According to the existing defects in forming process UHMWPE, the article designs a kind of new molding institutions——Four plunger extrusion device. The equipment mainly consists of hydraulic drive system, charging parts, heating parts and buffer parts etc. The basic principle of the device is expected to join by four piston cylinder preheated and heating melting, then by hydraulic transmission system control four piston in turn will melt pushed to a collection device——Cushioning part, Finally through the mouth, thus realize die extrusion product continuous extrusion. This device to pure UHMWPE processing, in raising production efficiency and improving product surface quality has important theoretical significance.During the design process, in order to set the parameters of the piston cylinder preheating segment and heating section, this paper use the CFD numerical analysis software POLYFLOW to simulate heat conduction problem in the material melting process in extrusion, analyze temperature distribution and the influence of main process parameters makes on the temperature distribution. The simulation of the melt extrusion was conducted by means of POLYFLOW and the velocity field, pressure field and shear-rate was analyzed. Through multiple simulation analysis and comparison, to sure the geometry size of buffer segment and transition section theoretically.