Polytetrafluoroethylene (PTFE) die can greatly inhibit the occurrence of melt fracture or surface distortion of mPE extrudate, the surface appearance of mPE extrudate gets greatly improved, and the critical shear rate increases nearly 3 times.

• 不同口模材质对mPE挤出口模压力、挤出流量和挤出物表面质量有着显著的影响。 与普通铸铁口模相比；经聚四氟乙烯(PTFE)口模挤出mPE熔体的口模压力降低近60%25；挤出流量增加1.；5倍；表观粘度降低65%25；挤出物表面光滑；基本无缺陷；出现熔体破裂的临界剪切速率提高了近3倍。