Additive Manufacturing for Design in a Circular Economy

This PhD project explored how the use of 3D printing can support design in a circular economy. 3D printing is an emerging technology and is viewed as a promising production process for the circular economy because of its unique additive and digital character. The aim of design in a circular economy is to preserve the value of products and materials through lifetime prolongation or high value reuse and recovery. Product integrity and material integrity are relevant for this, because they represent the quality of products and materials to remain whole and complete over time. In this research, we studied how 3D printing can support product integrity and material integrity in a circular economy. Research through design (RtD) was the main research method. In this method the design process is used to generate knowledge and we used a prototyping process to develop 3D printing in the new context of a circular economy. The main contributions of this research can be summarised as following: •We helped establish of a new research direction by exploring design approaches for product integrity and material integrity in a circular economy. •We developed a circular 3D print process flow for product integrity. This is demonstrated by showing that the digital and additive character of 3D printing can be harnessed to develop reversible connections that enable products to be disassembled and reassembled without loss of quality. We developed reversible joints and demonstrated these with a proof-of-concept of a lamp and vase. •We established a design approach for developing reprintable materials. This was demonstrated by producing reprintable materials from locally available bio-based resources, i.e. ground mussel shells with two different binders (sugar and alginate). We designed a lampshade and hairpin and 3D printed them using these materials. •We contributed to the domain of ‘research through design’ by using the prototyping process for knowledge generation; a less common use. The design goal in the prototyping process was used to obtain relevant information (from other disciplines) for developing technology in a new context. This resulted in an iterative process between experimental prototyping processes and scientific knowledge generation. We would like to conclude by nothing that, in spite of all the optimism about the way the use of 3D printing can accelerate the transition to a circular economy, there are currently few 3D print applications that actually support and enable the circular economy. Our exploration shows that to successfully print for product integrity and material integrity, both in-depth knowledge and understanding of the AM production technique is required.