Surface Roughness Reduction in A Fused Filament Fabrication (FFF) Process using Central Composite Design Method

Abstract

The objective of this study is to optimize the fabrication factors of a consumer-grade fused filament fabrication (FFF) system. The input factors were nozzle temperature, bed temperature, printing speed, and layer thickness. The optimization aims to minimize average surface roughness (Ra) indicating the surface quality of benchmarks. In this study, Ra was measured at two positions, the bottom and top surface of benchmarks. For the fabrication, the material used was the Polylactic acid (PLA) filament. A response surface method (RSM), central composite design (CCD), was utilized to carry out the optimization. The analysis of variance (ANOVA) was calculated to explore the significant factors, interactions, quadratic effect, and lack of fit, while the regression analysis was performed to determine the prediction equation of Ra. The model adequacy checking was conducted to check whether the residual assumption still held. The total number of thirty benchmarks was fabricated and measured using a surface roughness tester. For the bottom surface, the analysis results indicated that there was the main effect from only one factor, printing speed. However, for the top surface, the ANOVA signified an interaction between the printing speed and layer thickness. The optimal setting of these factors was also recommended, while the empirical models of Ra at both surface positions were also presented. Finally, an extra benchmark was fabricated to validate the empirical model.

Comparison of Additively Manufactured Polymer-Ceramic Parts Obtained via Different Technologies

“…K. Kandananond [37], L. Zheng et al [38], W. Li et al [39] FDM/FFF Development of filament production with the use of composite fibers and densely loaded ceramic particles (up to 60% volume) into thermoplastic binders. Obtained material is similar to the conventional FDM/FFF filament, and the printed ceramic parts underwent debinding and sintering to achieve proper densification.…”

Improving surface smoothness in FDM parts through ironing post-processing

“…Both methods have been used in the research. [38][39][40][41][42] In this investigation, the average surface roughness (Ra) of the top surface of the PLA-FDM samples was measured perpendicular to the ironing path using both methods. A Mitutoyo SURFTEST 301 (Mitutoyo Ltd., Kawasaki, Japan) as a contact method and Keyence VR-5000 (Keyence corp., Osaka, Japan) as a non-contact method were used for measuring the surface roughness.…”

The Effect of Layer Thickness and Orientation of the Workpiece on the Micro- and Macrogeometric Properties and the Machining Time of the Part during 3D Printing

“…In FDM 3D printing, the thermoplastic polymer filament is extruded while the extruder head moves along the "x-y" axes on a given cross-sectional layer of the model to be printed. Once a layer is created, the whole platform is lowered by the layer thickness in the "z" direction and the process is repeated until the whole model is created [13][14][15][16].…”