Study on the optimization of extrusion processing for polymeric porous materials consists of the UHMWPE and LDPE

Abstract

The polymeric porous materials which consist of ultra high molecular weight polyethylene (UHMWPE) and low density polyethylene (LDPE) powder were prepared for the application to the air purification systems. Generally, polymeric porous materials were manufactured by moulding sintering process but this process has some problems in uniformity of pores and productivity etc. To improve those problems, extrusion sintering process was introduced in this study. The optimization of compositions and processing regimes were studied by the measurement of porosity and strength of samples, temperature distribution and pressure of the extruder cylinder, The porosity of samples was decreased with increasing the temperature of pumping zone in extruder, When the temperature of pumping zone was passed the 92 degrees C, the strength of sample was abruptly decreased. As the temperature of die head and melt index of LDPE were increased, the strength of samples was increased, but the porosity was decreased. Consequently, the strength and porosity of polymeric porous materials were closely related to the temperature distribution of pumping zone and die head of extruder. The extrusion processing was optimized when the temperature of pumping zone and die head were set to 125 similar to 130 degrees C and 130 degrees C respectively.