3D Printing with Core–Shell Filaments Containing High or Low Density Polyethylene Shells

Polyolefins dominate the market for commodity plastics due to their low cost and suitable properties, but polyolefins are rarely used in 3D printing due to issues with deformation of the printed structure during crystallization from the large volume change. Here, we demonstrate that filaments containing approximately 50% of either high density or low density polyethylene (HDPE/LDPE) as a shell with a polycarbonate (PC)/acrylonitrile-butadiene-styrene (ABS) blend core can be printed using standard fused filament fabrication methods with adequate to good dimensional accuracy, improved impact resistance, and enhanced elongation at break relative to samples printed with PC/ABS alone. The combination of lower crystallinity (28%) of LDPE in comparison to HDPE (62%) and lower crystallization temperature of LDPE (89 °C) than HDPE (117 °C) leads to improved dimensional accuracy of the printed part. However, the elastic modulus of the composite containing LDPE is only 48% of the part printed with only PC/ABS for fl...