Simply Wood : Design of All-Wood Furniture Joints

Abstract: The need for sustainability, increasingly requires developing products according to a cradle to cradle approach. For furniture, wood, being potentially renewable, is a suitable material in this regard. However, most wooden furniture today utilizes steels and synthetic polymers in the joints, which can partially be recycled, but are far from being circular materials. All-wood joints have been used in traditional furniture and construction, but they are not adapted to modern manufacturing techniques and do not fulfill the need for easy assembly.  The aim of this thesis is to explore existing solutions for all-wood joints, as well as relevant manufacturing techniques to create an approach for the development of new joints by practitioners. The research questions are: What are the principles used in existing technical solutions and how can they be used to develop new all-wood furniture joints? What are the most important manufacturing techniques for wood today and how can they be considered in the early-stage development? The general approach in this thesis is to abstract the researched existing technical solutions and manufacturing techniques, ideate on this abstract level, and then detail the concepts on a more concrete level.  As results, fourteen different principles and six different patterns of transformation were extracted from existing solutions and documented in an accessible form. Similarly, seven manufacturing techniques were collected and documented. These were then used in an ideation workshop with practitioners from IKEA, which resulted in six abstract concepts. One of the concepts was further developed into a pre-design and tested with a simulations according to strength and stability requirements from applicable standards.  The testing of the pre-design proved its practicality and a team at IKEA is continuing the development of the concept and planning to manufacture a prototype. This is a good indicator for the usefulness of the approach. Even though it worked well, further exploration of the "toolbox" is recommended, as well as the use of different ideation methods. The full environmental benefits of furniture with all-wood joints are not clear, because only resource depletion was considered and the potential effect is small compared to other industries. Despite this, the thesis shows the potential in circular furniture and encourages IKEA and other furniture companies to delve into the topic of circular furniture more deeply.