Effect of FDM Process on Adhesive Strength of Polylactic Acid(PLA) Filament

Fused deposition modeling (FDM) is one of the most widely used technologies in rapid prototyping. On the principle of layered manufacturing, the melted polymer filament is extruded and formed. In order to achieve transition from nonfunctional prototypes to functional prototypes of FDMed models, using the RepRap Kossel delta 3D printer and 1.75mm diameter polylactic acid (PLA) filament, it was analyzed that the effects of the nozzle moving rate and slice thickness on adhesive strength based on the existing technology research by orthogonal test. The experiment results indicated that adhesive strength of filament increased both with the nozzle moving rate and with its slice thickness. The latter induced increase more significantly. Finally, comprehensive experiments had been performed to quantitatively study the adhesive strength variation with the filling rate, which provides data reference for setting proper filling rate. Reasonable filling rate setting can not only satisfy the strength requirement without debasement of printing quality, but also reduce filament consumption, improve the manufacturing efficiency and provide important instruction significance for actual printing.