Research On Influence Of Process On The Bonding Quality Of Three-dimensional Printing Polymer Parts

Three-dimensional printing technology has developed rapidly in nearly two decades, because of reducing development costs and effectively shortening product design cycles. Fused deposition modeling technology is a kind of three-dimensional printing technology with many features including low manufacturing cost, light weight, environmental use, etc. However, FDM part is also limited by the defects of relatively low intensity in parts, and there is a natural relationship between part strengh and the filaments bonding quality during processing..This paper highlights transverse bonding quality between filaments of FDM part.The purpose of this paper is to improve the bonding quality of FDM parts. Bonding strength are selected to be the evaluation objectives. The factors influence the filaments bonding such as process parameters including the layer height, the temperature of extrusion head, the heatbed temperature, printing speed during the processing, the extrusion head process and adding adhesive during processing are investigated primarily in the paper. This paper analyzes the basic mechanism of the bonding quality from the perspective of porosity.This study firstly proposes the essence of process parameters affecting the transverse tensile strength under different conditions is that the internal pores of the FDM part cause differences in intensity. Accordingly, the quantitative model of the tensile strength and porosity is established, and the model shows that the relationship between tensile strength and porosity is linear negative correlation. Therefore, an effective way to improve the transverse tensile strength of the FDM part is to reduce the pores during processing in the scope of model application. On this basis, this paper proposes two methods of improvement of the cooling effect of the extrusion head and adding adhesive during processing to reduce the pores, and the methods are confirmed by the experiment. Experimental results show that optimizing the process parameters, effective way to improve the cooling effect of the extrusion head and adding adhesive reasonably during processing are the effective ways to reduce the porosity and improve bonding quality of FDM part. The work presented in this paper provide effective methods and lay a firm theoretical foundation of improving the tensile strength of FDM part and providing the possibility to promote the development of FDM technology.