Paste Extruder—Hardware Add-On for Desktop 3D Printers

This paper presents the design, development and testing of a paste/clay extrusion device intended to be used as a drop-in replacement for the conventional thermoplastic extruder of a desktop filament-based 3D printer. A plastic cylinder loaded with gel, paste or clay material is placed into the device. Feedstock is pressed through an extrusion nozzle by a piston driven by an electrically actuated drive-screw and nut mechanism. The device allows the build material to heat up to 80 °C. Forced air cooling is used to assist the cooling or hardening process of the freshly-printed material during fabrication. The feedstock container, nozzle, and material-loading process are all suitable for use in a sterile environment. The device is designed for seamless integration with existing 3D printing firmware and slicing software. After designing the device, a prototype was produced and installed on a 3D printer. Silicone and acrylic polymers, as well as dental gel, were used to fabricate 3D printed sample objects.