超高相对分子质量聚乙烯管材新型连续挤出成型技术

New Continuous Extrusion Technology for Ultra-high Molecular Weight Polyethylene Pipes

超高相对分子质量聚乙烯(PE-UHMW)管材连续挤出成型法有压制-烧结、柱塞推压、单螺杆挤出、双螺杆挤出和柱塞冲压挤出等几种,其中柱塞冲压挤出成型法是新开发的一种PE-UHMW管材连续挤出成型技术,该技术的突出优点表现在:能加工任意相对分子质量的PE-UHMW树脂,加工能力强;能实现连续挤出,生产效率不低于单螺杆挤出法,而制品的表面质量、力学性能(如耐磨性)则优于单螺杆挤出法;完全正位移输送机理,温度控制简单可靠(控温段只有三个),因此加工过程中的降解程度较小,能很好地保持原料固有的优良性能;主机结构简单,能耗低 (约为螺杆挤出法的30％-50％),生产线造价便宜。另外,采用该技术还能挤出高质量的聚四氟乙烯(PTEE)和过氧化物交联聚乙烯(PEX-a)制品。

Punching plunger extrusion is a novel continuous extrusion molding technology, which provided higher processing capacity, better appearance and quality of the extrudate, compared with singlescrew extrusion. A special facility was designed for the processing of PE-UHMW, PTFE, and peroxidecrosslinked polyethylene（PEX-a）with low degradation and high property retaining because of its absolute positive displacement transportation mechanism and reliable temperature control. Owing to the simple structure of the machinery, a low energy consumption （30 %～50 % that of screw extruder） was achieved. Otherwise, the novel processing method is suitable for the pipes of polytetrafluoroethylene （PTFE） and PEX-a.