A Design of Experiment Analysis Approach to Improve Part Quality in 3D Printing

Abstract

Fused Deposition Modelling (FDM) is used widely in additive manufacturing technology. The research community is becoming increasingly concerned about FDM products' surface quality and dimensional accuracy. The design of the experimental methodology is based on the analysis of variance (ANOVA) of fractional factorial design. This analysis was used to study the effect of layer thickness, extrusion temperature, speed of deposition, and fill density on dimensional accuracy and surface roughness of the model developed by FDM. Polylactic Acid (PLA) material has been selected as an article-forming material. The results showed that layer thickness has an influential factor in determining surface roughness. Fill density (X and Z dimensions), layer thickness (Y dimension), and speed of deposition (Z dimension) are significant factors affecting dimensional accuracy. The influence of curvature on surface roughness was presented and discussed; however, , the minimum optimization point was not attained, Therefore, further experiments were required to reach it. In terms of optimizing dimensional accuracy, it was observed that lower levels of every factor except for fill density led to greater accuracy in the dimensions along X, Y, and Z. Consequently, fill density was optimized to enhance dimensional accuracy.