Investigating Material Degradation Through the Recycling of PLA in Additively Manufactured Parts

The field of additive manufacturing (AM) has been expanding rapidly with the decreasing cost of desktop-scale material extrusion AM systems. As the cost of AM systems decreases, more users are investing in the technology, including universities, which have turned to AM as an option for providing wide-scale access to prototyping technology. However, this type of wide-access printing generates significant waste due to cast-off support material as well as failed prints from inexperienced users. This paper investigates the feasibility of recycling this cast-off material through the relationship between the mechanical properties of recycled PLA and the number of lifecycles it has experienced on a desktop material extrusion machine. A three-stage pelletizing, extrusion, and printing process is used to investigate recycling of PLA material from cast-off build material. Additionally, the research investigates how adding virgin pellets to pellets of the recycled material in various ratios can affect tensile properties.