Wood-based 3D printing

Abstract

With a building industry that is responsible for a large amount of our carbon emissions, a rising population, and the over-extraction of resources, architects and engineers have the responsibility to use environmentally friendly products. Lignin and cellulose are the most abundant biopolymers on earth and produce a lot of waste by ending up burnt or in landfills. Thus, a great field of research is currently explored with cellulose and lignin waste as an alternative to petrochemical-based products. Coming from the pulping and paper industry, lignin waste could be implemented through the use of an additive manufacturing process to reduce or avoid the necessity to cut trees. Also, 3D printing elements with lignin and cellulose as feedstocks have not yet been explored. Thus, this master thesis aims to promote wood waste as an ecological contributor to the building industry through the use of an additive manufacturing process. This research will be driven by 3D printing a window frame as there is a lack of replacing or enhancing existing window frames. Moreover, large-scale 3D printing companies are faced with the problem that the interface between window frames and 3D printed walls does not perfectly fit within each other. As current fabrication processes to produce building elements are based on flat regular machinery and 3D printing technology is based on curved stacking layers, a perfect connection could only be implemented by 3D printing a window frame. Thus, after understanding the explored limits and possibilities of 3D printing with a wholly bio-based material coming from its waste in regard to mechanical and printability properties, a window frame will be designed and printed as a proof of concept. The final results have shown the potential of 3D print elements in a cold extrusion process with lignin and cellulose in combination with water and methylcellulose. However, more research is necessary to improve the material and printability properties of the recipe to become a fully reliable and integrated facade component to replace existing building components or improve the connection between window frames and habitats.