Additive Timber Manufacturing: A Novel, Wood-Based Filament and Its Additive Robotic Fabrication Techniques for Large-Scale, Material-Efficient Construction.

Julian Ochs,Jannis Heise,Stefan Böhm,Zuardin Akbar,Philipp Eversmann

doi:10.1089/3dp.2020.0356

Julian Ochs, Jannis Heise + Show 3 more

Open Access

https://doi.org/10.1089/3dp.2020.0356

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Abstract

Additive manufacturing (AM), as resource-efficient fabrication processes, could also be used in the dimensions of the construction industry, as a variety of experimental projects using concrete and steel demonstrate. In timber construction, currently few additive technologies have been developed having the potential to be used in large scale. Currently known AM processes use wood in pulverized form, losing its inherent structural and mechanical properties. This research proposes a new material that maintains a complete wood structure with continuous and strong fibers, and that can be fabricated from fast-growing locally harvested plants. We describe the material technology to create a solid and continuous filament made of willow twigs and investigate binding and robotic AM methods for flat, curved, lamination, and hollow layering geometric typologies. The resulting willow filament and composite material are characterized for structural capacity and fabrication constraints. We discuss our technology in comparison with veneer-based lamination, existing wood filament printing, and fiber-based AM in terms of fabrication, material capacity, and sustainability. We conclude by showing possible applications in the construction industry and future research possibilities.

Highlights

There is a great demand for new construction, which has increased the volume of orders in the construction industry by 1.5-times over the last 10 years in Germany.[1]
The goal of the filament joint was to have a connection that is at least as strong as the material itself. It is essential for the printing process, and for the later use phase of the manufactured structure, that the elastic properties of the joint area are similar to the rest of the wood filament
Several additive manufacturing (AM) technologies based on plastics, metals, and concrete are currently making the leap from prototype to series production at the scale needed for the construction industry

Summary

Introduction

There is a great demand for new construction, which has increased the volume of orders in the construction industry by 1.5-times over the last 10 years in Germany.[1]. With the current building techniques and available resources, this is hardly feasible and, above all, in relation to the CO2 balance, especially for concrete construction. Due to the positive ecological balance, and already established digital workflows, this has led to a rapid increase of timber construction. Little attention is paid to resource-saving construction methods, and enormous masses of cross-laminated timber and stacked timber are used.[3] Here, additive manufacturing (AM) processes could be very promising and resource-efficient construction processes, as a variety of pilot projects using concrete and steel demonstrate.[4,5] The following sections give an overview on veneer-based lamination, and wood filament- and fiber-based AM technologies, which form a background for this research

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