3D printing optimization using recycled HDPE filaments made from used milk jugs

Abstract

3D Printing has gained popularity over the years for its improved affordability and great versatility. There is a wide variety of 3D printing technologies and a wide spectrum of materials that could be 3D printed, ranging from metallic to nonmetallic. Fused deposition modelling (FDM) has emerged as the most common technology used in desktop/home 3D printers and it is most typically used for printing thermoplastics such as acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). High density polyethylene (HDPE) is a thermoplastic widely used for packaging. The sheer availability of recycled HDPE (rHDPE) from used packaging encourages efforts to apply it in 3D printing, in particular FDM printing. However, rHDPE is a challenging filament material to work with, with critical problems such as part detachment from print bed and high warpage. The focus of this project would be to determine the optimal conditions that would mitigate, if not eliminate, the print bed adhesion problem associated to printing rHDPE filaments. This was done by carrying out a series of tests, one leading to the next. Finally, a comparison between human perception on part removability and shear strength of print bed adhesion was done to identify the necessary range of print bed adhesion and corresponding parameters.