设计了螺杆、机筒、螺旋叶片等结构,建立了螺杆式塑化三维(3D)打印系统,利用Polyflow软件对压力场、速度场、剪切速率进行了数值模拟分析,并对粒状物料3D打印出丝性能进行了研究.结果表明,螺旋叶片结构通过施加轴向力实现了强制喂料;在整个螺杆挤出段上,熔融物料沿挤出方向随螺杆转速的提高压力逐步增加,梯形螺棱设计有利于熔体流动;材料熔融需要通过剪切作用与加热装置热量传递协同作用以降低熔体黏度;螺杆转速从0.1 r/s向1 r/s的变化过程中,丝材直径呈小幅度增加.%A screw-plasticizing 3D printing system was fabricated by designing the structures of a screw,barrel and spiral blade in this work.The pressure,velocity and shear rate were simulated by Polyflow software,and the extrusion performance of this device was investigated.The results indicated that the forced feeding could be realized by an axial force through spiral blade,and the pressure of the melt was improved with increasing rotation speed of the screw along the extrusion direction.The designed ladder-shaped threads favored the flow of the melt.The materials were molten by a synergic effect of shear and heat transfer within the heating appliance.The diameter of the extrudate increased slightly when the rotation speed increased from 0.1 r/s to 1 r/s.
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