Potential of recycled PLA in 3D printing : a review

The growing demand for sustainable materials as substitutes for conventional materials has led to the need for sustainable manufacturing practices that can effectively balance the use of limited resources and reduce environmental impact while maintaining economic viability and promoting human welfare. Therefore, the use of recycled polylactic acid (rPLA) in 3D printing could be a promising solution for reducing the cost and environmental impact of the use of virgin PLA in 3D printing. However, the low strength of recycled PLA-printed components remains a challenge. In addition, the use of PLA in 3D printing may pose environmental, cost, and social issues. Therefore, it is necessary to understand the mechanical properties and sustainability potential of recycled PLA. Hence, this study aimed to provide an overview of the potential use of recycled PLA in 3D printing. To achieve this goal, this study followed a systematic review approach and analysed published academic research papers to discuss the degradation of thermal and mechanical properties, challenges and opportunities of PLA recycling, and sustainability aspects of additively manufactured PLA products. Studies have shown that recycled PLA can be an alternative to virgin PLA if its properties can be appropriately modified and controlled. Researchers have used different methods to upgrade the properties of recycled PLA, such as using virgin and recycled waste blends, altering the printing process parameters, and utilising additives. In addition, the sustainability implications of using recycled PLA for 3D printing have not been adequately discussed. The findings indicate that the majority of research has concentrated on evaluating the environmental aspect, while paying scant attention to economic and social dimensions. Further research is required to understand the environmental, economic, and social impacts of recycled PLA on 3D printing. The findings of this study will assist practitioners and academics in thinking about using recycled materials and adapting them to obtain desired qualities.