An image of the CAD model of injection mold used to create polycaprolactone sticks for 3D printing. | Credit: Krzysztof Formas/University of Bielsko-Biala

Osteochondral defects, which develop after acute traumatic injury, often must be repaired through a surgical transplant procedure. In the past, surgeons had to use bone taken from other bodily locations or wait for a matching donor, but advancements in 3D printing have opened doors for creating patient specific implants from biomedical polymers that are created layer by layer through FDM printing.

While the innovation has helped overcome important roadblocks for osteochondral patients, 3D printing with polymers used in biomedical applications is expensive. Researchers from the University of Bielsko-Biala in Poland have developed a cost-saving method for 3D printing the implants by using injection-molded polycaprolactone (PCL) sticks. They noted that, due to the small size of implants for cartilage or bone replacement, the filament spools are often only partially used. Thus, they used injection molding to develop small sticks that can be joined together based on the needed amount to avoid waste and that can be used in a commercially available 3D printer. In addition, the sticks allow for combining differently modified sticks for personalized implants.

To create more efficiency in the injection molding process, the researchers turned to simulation. They performed simulation and analyses of the injection process parameters and found it demonstrated the potential of using simulation as a tool to develop PCL parts for future implants and to optimize the injection molding process.

The team is continuing to use simulation to investigate the effects of different additives in the process as well as using different simulation software to repeat the process.

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