基于螺杆挤出PLA颗粒料3D打印工艺  

3D printing technology of PLA granular material based on screw extrusion

作　　者：刘彪强 钱波 梁雨心 胡珍涛 LIU Biaoqiang;QIAN Bo;LIANG Yuxin;HU Zhentao(School of Mechanical and Automotive Engineering,Shanghai University of Engineering Science,Shanghai 201600,China;Key laboratory of Intelligent Manufacturing technology of large complex thin-wall components of machinery industry aviation,Shanghai 201600,China)

机构地区：[1]上海工程技术大学机械与汽车工程学院,上海201600 [2]机械工业航空大型复杂薄壁构件智能制造技术重点试验室,上海201600

出　　处：《工程塑料应用》2024年第4期75-82,共8页Engineering Plastics Application

基　　金：国家重点研发计划项目(2018YFB1105300)。

摘　　要：针对现有的熔融沉积成型(FDM)打印技术出丝不稳、打印速度较低以及打印材料受限等问题,通过不断优化打印参数(料筒温度、螺杆转速、挤出倍率以及打印速度),比较不同填充方式下打印件的力学性能,最终确定了针对聚乳酸(PLA)颗粒料的成型参数。基于这些成型参数,利用自制的螺杆挤出颗粒料3D打印设备展开工艺研究。结果表明,料筒温度在170℃,喷嘴温度在205℃以及挤出倍率为0.65时PLA颗粒料能够在出丝稳定性的同时保证孔隙率最小;对不同喷嘴直径稳定出丝时的螺杆转速进行数值模拟得出二者的拟合公式,以便在选用不同喷嘴直径时能够快速确定螺杆转速;蜂窝填充表现出更加优异的弯曲性能,其值为22.49 MPa,相比于网格填充的19.37 MPa提升了16.10%;网格填充表现出更佳的拉伸性能,其值为24.75 MPa相比于蜂窝填充的22.36 MPa提升了10.69%;并且随着层厚的增大打印件的表面粗糙度渐升高,从层厚0.6 mm的160.51μm提升到层厚1.0 mm的220.38μm,表面粗糙度升高了37.30%。Aiming at the problems of unstable filament,low printing speed and limited printing materials in the existing fused deposition modeling(FDM)printing technology,the printing parameters(barrel temperature,screw speed,extrusion ratio and printing speed)were continuously optimized.The mechanical properties of the printed parts under different filling methods were compared,and the forming parameters for polylactic acid(PLA)granular materials were finally determined.Based on these forming parameters,the process research was carried out by using the self-made 3D printing equipment for screw extrusion of granular materials.The results show that the stability of spinning and the minimum porosity can be ensured when the barrel temperature is 170℃,the nozzle temperature is 205℃and the extrusion ratio is 0.65 for PLA granular materials.The screw speed with different nozzle diameters is numerically simulated to obtain the fitting formula of the two,so that the screw speed can be quickly determined when different nozzle diameters are selected.Honeycomb filling shows more excellent bending properties,the value of which is 22.49 MPa,which is 16.10%higher than that of grid filling,and the value of which is 24.75 MPa,which is 10.69%higher than that of honeycomb filling.And with the increase of layer thickness,the surface quality of printed parts gradually decrease,the surface roughness from 160.51μm with h=0.6 mm to 220.38μm with h=1.0 mm,which is 37.30%.

关 键 词：3D打印 螺杆挤出 表面粗糙度 填充方式 数值模拟 

分 类 号：TB302[一般工业技术—材料科学与工程]