Injection Molding of Degradable Interference Screws into Polymeric Mold
Nowadays the need for faster development cycle can be found all over in the industry. Rapid prototyping has become a common tool in product development, but available materials in these technologies can not always substitute the materials needed for product. Rapid tooling makes it possible to produce a small series of a product with the same technology and materials as that of the final product. In our work we have used the Polyjet technology (Objet Geometries Ltd.) to produce mold for the injection molding of biodegradable interference screws. Our goal was to produce enough quantity of interference screws for biomechanical measurements, with a technology that is more cost efficient than selective laser sintering (SLS). Two types of mold materials were tested. The first mold was prepared from Fullcure720, an acrylic based, UV curing resin on an Object ALARIS machine. The second mold was prepared with resin casting from AH-12/T-58 (100:40) epoxy resin filled with 25 m% Al2O3 powder. For injection molding Natureworks 3051D polylactide (PLA) was used. After injection molding the weight and the geometry of the screws were measured. The results showed that the molds can withstand 5-10 injection cycles, and the screws manufactured meet the requirements for biomechanical tests on porcine knees.
P. J. Szabó and T. Berecz
Á. Oroszlany et al., "Injection Molding of Degradable Interference Screws into Polymeric Mold", Materials Science Forum, Vol. 659, pp. 73-77, 2010