Design of an innovative new extrusion system for a printing machine for ceramics

摘要

Abstract The introduction of ceramic materials in the medical field is becoming a vital necessity because of its stable physicochemical characteristics, high biocompatibility, and good osteoconductivity. On the contrary, machining ceramic components is difficult, owing to their extreme hardness and brittleness. Additive manufacturing (AM) technologies are an appropriate alternative to obtain the complex shapes of implants, which can have porous structures. Thus, since the development of 3D printing, direct ink writing (DIW) is one of the most promising and inexpensive techniques for shaping free-form ceramic medical components such as prostheses or dental implants from liquids or pastes. However, the assurance of performance criteria of the extrusion system for simultaneous usage becomes the major challenge for most direct ink writing (DIW) platforms, for instance for printing large parts, for multi-material printing, to decrease printing time, and to increase efficiency in terms of motor usage and weight of the extruders. To address the current deficiencies, a new extrusion system is designed for a 3D printing machine for ceramics that is compatible with different low-cost, open-source 3D printers. The proposed extrusion model enables printing with a loader with different syringes simultaneously, without stopping the operational process while switching the syringe. It adopts three subsystems. The automatic syringe loading system, which is operational to manually receive several syringes of the same or different volumes, allows the syringe feeding system to be loaded and unloaded once the syringe is empty. The syringes are automatically transferred to the holding system using an arm. The holding system allows the fixing of the syringe in order to perform printing with ceramic material. Pugh concept analysis was used to select the optimum design shape. After that, the 3D CAD environment was used to combine the strength of Pugh’s method and the design space. This brings a new concept into the mechanical design field for 3D printers, which is in line with the technological trends prevalent in the industry.