Three-dimensional printing of porous polyethylene structure using water-based binders

This study demonstrated a freeform fabrication of porous hydrophobic polyethylene parts by three-dimensional printing technique, using water-based binder. This involved initially making a green structure by printing a binder onto the mixture of polyethylene and water soluble adhesive powder bed. The green structure was thermal treated to melt polyethylene fraction to achieve a well-connected structure within the part. Adhesive components were then leached out in water, leaving only porous structure of polyethylene. Specimens with ratios of polyethylene to adhesive from 80:20 to 20:80 were fabricated and characterized. It was found that increasing polyethylene content increased density, modulus, and strength while decreased porosity. Preliminary in vitro toxicity test of porous parts using L929 cells showed that the cells that were in contact with samples were healthy. No inhibition zone was observed.