Impact of process parameters on mechanical properties of 3D printed polycaprolactone (PCL) parts

Abstract

Rapid prototyping is an innovative and powerful technology used for direct layer-by-layer fabrication of parts from a 3D computer model. Fused Deposition Modeling (FDM) is the most common and simplest technique in 3D printing technology. Fused Deposition Modeling technology has attracted many researchers, especially those interested in its biomedical applications in custom-made implants, tissue and cell printing and the dental industry. Polycaprolactone (PCL) is both biocompatible and biodegradable and generally used in fabrication of scaffolds in tissue engineering using FDM technology. Although there are reports on impact of different process parameters on parts performance of Polylactic Acid (PLA) using FDM technology there is no study about the effect of process parameters on 3D printed PCL parts. Therefore, in this thesis, we report the effects of 3D-printing parameters such as nozzle temperature and flow rate on a polycaprolactone tensile specimen fabricated by fused deposition modeling. Printrbot Simple metal heated bed 3D printer was used to optimized with polycaprolactone. Seven nozzle temperatures (115°C, 125°C,135°C,145°C, 155°C, 165°C and 175°C) and with optimized nozzle temperature remain constant six different flow rates (100% [2.2 mm3/s , 105% [2.31 mm3/s], 115% [2.53 mm3/s], 125% [2.75 mm3/s 135% [2.97 mm3/s ] and 145% [3.19 mm3/s ]) were tested to determine optimal parameters. Also with optimal printing condition remaining constant various process parameters such as infill density, layer height, and shell perimeters were investigated to find the optimal process parameters. The result suggested nozzle temperature of 165°C and flow rate of 135% results in a defect free PCL 3D printed test specimen and infill density of 90%, layer height of 0.1 mm and shell perimeter of 2 produce the strongest test specimen. Therefore, these data can assist designers to better understand the behavior of 3D-printed PCL material.