Additive Manufacturing with Solid Wood
DC I/O 2020 proceeding by JULIAN OCHS, ZUARDIN AKBAR and PHILIPP EVERSMANN.
Contents
Abstract
Current commercially available additive manufacturing methods with wood filaments are based on extruding a thermoplastic which is mixed with grounded timber. Therefore, these filaments lose the inherent structural and mechanical properties of continuous fibers of timber, also having only a wood proportion of 40%. With a proportion of grounded wood, the thermoplastics’ mechanical strength can also decrease (cf. WIMMER, STEYRER, WOESS, KODDENBERG, MUNDIGLER, 2015). As thermoplastics still may take 100 to 1000 years to decompose in a non-controlled composing environment (cf. ROYTE 2006), renewable and a more biodegradable alternatives are needed.
We have developed an additive manufacturing method with the use of a wooden filament made of a fast-growing local plant: willow/ wicker twigs. This technique enables direct and laminated wooden-filament-extrusion without the use of thermoplastics. The material, used in this new method, keeps its natural tensile-strength, which is actually higher than beech wood, due to the unique material production and additive manufacturing technique. The willow filament is made through joining homogenized willow strips. In a continuous process, the resulting endless filament is then coated with a contact adhesive, dried. and fed into a specially designed extruder that combines up to five upright willow filaments to one single laminated square profile. The adhesive on each separate string is activated both through contact pressure and with the help of a PID (proportional–integral–derivative) controlled heat block.. Due to this technique, a fast layer-based printing method was achieved. The willow strings’ bending ability in layer direction allows design inputs with a minimum radius of 20mm. Apart from this restriction, a comparable printing experience to an FDM (Fused Deposition Modeling) based printing technique was achieved that is suitable for a large-scale application such as furniture or architectural building components.
Keywords
Additive Manufacturing, Wood, 3D-Printing, Column, Computational Design, Fiber
Topics
Architecture, Bio-Integrated Design, Computational and Parametric Geometry, Computer-Aided Design (CAD), Construction, Engineering, Manufacturing, Resources, Technology.
