芯棒几何结构对旋转挤出聚乙烯管结构和性能的影响

Geometric Structure Effects of Mandrel on Structure and Performance of Polyethylene Pipes Prepared via Rotation Extrusion

在自行研制的新型旋转挤出加工装置的基础上,设计了凹槽型和螺纹型芯棒,对比研究了芯棒几何结构对聚乙烯(PE)管结构与性能的影响。实验结果表明,凹槽型芯棒不利于串晶的形成,而螺纹型芯棒对串晶的产生有明显促进效果。因而,在旋转挤出和螺纹型芯棒耦合作用下,可形成大量偏离轴向排列的串晶结构,从而提高PE管的环向强度。相较于常规挤出PE管,制备的PE管环向强度为29.3 MPa,提高幅度达34%。

In this study, the groove-type and screw-type mandrels were designed, and the geometricstructure effects on the structure and properties of polyethylene （PE） pipes prepared via self-designedrotation extrusion equipment were studied. The experimental results show that the groove-type mandrel is notconducive to the formation of shish-kebab while the screw-type mandrel has the promoting effect. As a result,under the coupling effect of rotation extrusion and the screw-type mandrel, a large number of shish-kebabcrystals off the axial direction are generated in the PE pipe to improve the hoop strength greatly to 29. 3 MPawhich is increased by 34% compared to the convention-extruded PE pipe.