Abstract
Additive manufacturing (AM) for construction applications has grown rapidly over the past 10 years. AM, also referred to as 3D printing, in construction has primarily been done with concrete as a medium up to this point. AM has the ability to rapidly manufacture complex geometry not possible with conventional building techniques. Additionally, AM has the ability to use recycled materials and produces very little waste. Wood-based composites have yet to be used in AM for the construction industry because a method to produce high strength wood-based composites in AM has not been developed. This study details the development of an AM method for wood-sodium silicate composites (WSSC). A 3D printer was designed and constructed utilizing a screw extruder for wood-based composites capable of extruding wood-based composites and depositing them layer by layer onto the printer’s bed. The printer is designed to use a feedstock material of wood flour and a thermoset resin binder. The samples were printed at various wood to resin ratios and were cured at various temperatures. The WSSC’s adhesion to the print bed was assessed in addition to the interlayer adhesion of the printed WSSC during extrusion and after curing. A panel was successfully constructed with wood element size less than 40 mesh, at a 45:55 wood to sodium silicate weight ratio and cured for two days at 60°C. When stressed in bending, the bond between panel layers did not fail, rather failure occurred in the base material. The failures happening away from the boundary layers are consistent with other manufactured wood composites. Thus, AM can be a suitable manufacturing technique for wood-based composites based on the interlayer adhesion.