Improvement of Surface Roughness and Hydrophobicity in PETG Parts Manufactured via Fused Deposition Modeling (FDM): An Application in 3D Printed Self–Cleaning Parts

Abstract

The fused deposition modeling (FDM) technique is used today by companies engaged in the fabrication of traffic signs for the manufacture of light-emitting diode LED spotlights. In this sector, the surface properties of the elements used (surface finish, hydrophobic features) are decisive because surfaces that retain little dirt and favor self–cleaning behavior are needed. A design of experiments (L27) with five factors and three levels has been carried out. The factors studied were: Layer height (LH), print temperature (T), print speed (PS), print acceleration (PA), and flow rate (F). Polyethylene terephthalate glycol (PETG) specimens of 25.0 × 25.0 × 2.4 mm have been printed and, in each of them, the surface roughness (Ra,0, Ra,90), sliding angle (SA0, SA90), and contact angle (CA0, CA90) in both perpendicular directions have been measured. Taguchi and ANOVA analysis shows that the most influential variables in this case are printing acceleration for Ra, 0 (p–value = 0.052) and for SA0 (p–value = 0.051) and flow rate for Ra, 90 (p–value = 0.001) and for SA90 (p–value = 0.012). Although the ANOVA results for the contact angle are not significant, specimen 8 (PA = 1500 mm/s2 and flow rate F = 110%) and specimen 10 (PA =1500 mm/s2 and F = 100%) have reached contact angle values above or near the limit value for hydrophobia, respectively.

FDM-Based 3D Printing of Polymer and Associated Composite: A Review on Mechanical Properties, Defects and Treatments

“…Because of the line effect that has occurred during the filament deposition, the finished surface of these parts tends to be rough. As per Figure 16 d, it is clearly visible that due to the layer arrangement process, the staircase effect is prominent in curved structures [ 207 , 209 , 211 ]. This is noted as one of the drawbacks in FDM printed parts when compared with the surface finish of parts created by milling or moulding [ 189 ].…”

Discrete-Event Simulation Thermal Model for Extrusion-Based Additive Manufacturing of PLA and ABS

“…Several polymers have been successfully used in the extrusion-based additive manufacturing process. Initially amorphous polymers were preferred for additive manufacturing including acrylonitrile butadiene styrene (ABS) [13][14][15][16], polyethylene terephthalate glycol (PETG) [8,17], and polycarbonate (PC) [18][19][20]. The thermal and rheological properties of semi-crystalline polymers caused difficulties in filament production and showed higher shrinkage and warping during the 3D printing process [21,22].…”

Use of 3D Printing in Model Manufacturing for Minor Surgery Training of General Practitioners in Primary Care

“…This company has developed its own slicing software for its 3D printers called FlashPrint [29]. In this software, it is necessary to indicate which material is going to be used, and which values for printing parameters are going to be selected [8]: extrusion temperature, layer height, print speed, among others. The values used in the present work are shown in Table 2.…”

“…However, the most commonly used technique today is the fused deposition modeling (FDM) technique [4][5][6][7]. This technique has several advantages [8]: machines and filaments have low costs; it is easy to find information on the internet about this technique; the learning curve is short; and there is a large catalog of filaments available on the market, with multiple qualities and applications [9]. This paper focuses on the use of 3D printing in primary care centers.…”