Optimization Of Forming Process For FDM Based On PLA Filament

The low cost of the fused deposition molding system is a major advantage compared with other rapid prototyping processes,Therefore,it has been popularized and widely used in the market.During the fused deposition molding,the process parameters have an important influence on the characteristics of the forming parts.This paper studies the main process parameters in the process of forming through theoretical analysis and lots of experiments,and they improve the dimension precision,forming time and elastic properties of the molded parts.The main work and achievements of this paper are as follows:(1)This paper introduces the factors which affect the accuracy of fused deposition molding parts systematically,and analyse the principle,forming process and postprocessing,Then put forward the corresponding improvement measures according to the influencing factors.This provides a method support for optimizing the process parameters of the molding process and improving the dimensional accuracy,forming time and elastic properties of the molded parts.(2)Taking the spinning process of forming parts as an object,studying the cross section model of extruded filament,and the width model is established;Considering the influence of material shrinkage on the macro dimension of the molded parts,the compensation model of the inner and outer contour of the molded parts is built;The step effect in forming process is studied,and the theoretical model of step error is established.(3)Taking the dimension precision of the forming parts as the research object,design standard parts and orthogonal experiments,the influence of the thickness of the layer,the width of the path and the number of contours on the dimensional accuracy is studied by using different orthogonal design methods,and the combination of process parameters with the minimum size error is obtained.The influence of the path width on the appearance of molded parts is studied through the experiment,the width of the path is obtained when the appearance of different size parts is optimized.(4)The influence of the process parameters on the elastic properties of the molded parts is studied by using PLA material,the elastic properties of the molded parts is reflected by a set of toy instruments,and the mapping relationship between the process parameters and the system evaluation indexes is established,then single factor test and response surface test are carried out to optimize the constraint conditions,the optimal scheme of model prediction is tested,This provides guidance for maximizing the elastic properties of molded parts.