Comparative Life Cycle Assessments of Conventional Products and 3D-Printed Wood-Plastic Composite Alternatives

Abstract: As additive manufacturing gains market potential as a mainstream process in various sectors of industry, there is a growing need for addressing environmental aspects of this technology and the materials associated with it. In this master thesis, comparative life cycle assessments (LCAs) from cradle to grave between the conventional products and 3D-printed alternatives made of wood-plastic composite (WPC) were conducted based on the ISO 14044:2006 standard. Environmental impacts of each product were quantified for 10 impact categories. The goal of the LCAs was to determine whether the use of the 3D-printed WPC products may suggest a sustainable alternative to the conventional ones. This master thesis presents three case studies in which comparative LCAs were carried out. The first two case studies are about storage compartments for trucks from Scania, and the third one is about ceiling boards from Veidekke. The results showed that,  in  all  case  studies,  the  3D-printed  WPC alternatives  would  have smaller environmental   impacts   compared   with   the   conventional   products. The   most significant difference was observed in the first two case studies because of the light- weighting effect. The alternatives showed 51%, 68% and 13% lower global warming potential  (GWP)  than  the conventional  products  in  each  case study,  respectively. However, the results of the cradle-to-gate LCAs suggested that the 3D-printed WPC alternative might cause greater environmental impact than the conventional products regarding some impact categories. Therefore, in the LCA context, the 3D-printed WPC alternatives would be much more beneficial to the environment compared with the conventional products, but theenvironmental benefits might be insignificant from the manufacturer’s perspective.