Improving 3-D printing of plastic parts

As the 3-D printing market not only expands but also becomes more affordable, it is finding applications in many different areas. But this versatility is limited by the strength and durability of the printed parts. Most of these objects are printed in layers, which inherently results in weak spots where the layers meet. Thus, 3-D printed objects are not as strong as those made with current methods in which plastics are injected into molds. To create stronger 3-D printed parts, Miko Cakmak, Bryan D. Vogt and colleagues wanted to explore whether the starting materials could be changed to self-reinforce the printed parts.

The researchers made a structured, core-shell polymer filament in which a polycarbonate core acts as a stiff skeleton to support and reinforce the 3-D printed shape. An olefin ionomer shell around the polycarbonate core improves and strengthens the connection between the printed layers. During testing, printed parts with the filaments could withstand impacts without cracking, unlike parts made without them. The new filaments bring 3-D printed parts closer to the strength of parts manufactured by current methods.