Research On FDM 3D Printing Technology Based On Model Contour Feature

Fused deposition molding is a new technology of "additive manufacturing",which has been widely used in various fields due to its low cost,easy operation and green manufacturing.In order to enhance the quality and efficiency of printing,this paper analyzes the defects of the printed model.Furthermore,the filling algorithm and printing process is also optimized according to the slicing engine.Firstly,an adaptive filling algorithm based on contour features is proposed to overcome the drawbacks of existing filling algorithms,such as low molding efficiency and single filling mode.By analyzing the contour characteristics of slice layers,the small region partition algorithm and mutation region construction algorithms of single slice layer are developed.Then,the small region expansion algorithm of multi-slice layer is further proposed.The algorithm of small region partition realizes the expansion of elongated area and the identification of small area and slender area.On the other hand,the algorithm of mutation region construction discriminates the singular vertex and expands mutation region.The small region expansion algorithm of multislice layer extends the small area in the vertical direction of the model.Secondly,to address low accuracy and poor surface quality of the existing printing process,the optimal schemes of printing process for contour region,non-normal filling region and normal filling region are proposed respectively.Furthermore,the extrusion process and external contour printing process are optimized by analyzing the feature of contour section and considering the extruded printed material.Then,the molding quality of non-normal filling region is improved through setting the non-normal filling region boundary by the virtual offset contour and changing the regional scanning type and scanning direction.After that,the movement of spray-head becomes smoother and the edge defect is reduced in normal filling region by combining the continuous control of spray-head motion and multiple oblique scanning.Experiments are carried out to validate the developed algorithms.The results show that the variable filling algorithm saves the model printing time and reduces the loss of printed material.The strength of non-normal filling region and the surface quality of model are also improved.Furthermore,the new printing process boosts the molding precision and reduces the warpage of models.