聚丙烯3D打印剪切螺杆设计及仿真分析

Design and Simulation Analysis of a Polypropylene 3D Printed Shear Screw

为了改善物料熔融均化的程度,提升物料的混合性能,设计了1种3D打印机喷头。基于单螺杆挤出原理,提出在螺杆计量段适当添加剪切元件,并根据螺杆的工作特点,选取了螺杆加工的材料。以聚丙烯为流体研究对象,运用有限元法,结合POLYFLOW软件对聚丙烯的挤出过程进行仿真模拟分析。结果表明:带有剪切元件的螺杆相较于普通螺杆提供的压力场提高约0.399%,剪切速率相较于普通螺杆提高约94%。通过添加剪切元件可以提高螺杆的建压能力,促进物料的平稳挤出,有效改善物料熔融均化的程度,还可以提高物料在打印过程中的利用率。

A 3D printer nozzle has been designed in order to improve the degree of homogenisation of the material melt and to enhance the mixing performance of the material.Based on the principle of single-screw extrusion,it is proposed to add shear elements to the metering section of the screw appropriately,and the materials processed by the screw are selected according to the working characteristics of the screw.Taking polypropylene as the fluid research object,the finite element method is applied,combined with POLYFLOW software to simulate and analyse the extrusion process of polypropylene.The results show that the pressure field provided by the screw with shear elements is increased by approximately 0.399%,and the shear rate is increased by approximately 94%compared to a normal screw.By adding shear element,the pressure building ability of the screw can be improved,the smooth extrusion of the material can be promoted,the degree of melting and homogenization of the material can be effectively improved,and the utilization rate of the material in the printing process can be improved.