Fused deposition modeling of polyethylene (PE): Printability assessment for low-density polyethylene and polystyrene blends

There is a global emphasis on recycling and reuse of plastic waste. Despite constituting over one-third of the world's annual plastic production, only 10 % of polyethylene is recycled. This study explores the use of fused deposition modeling (FDM) to enable the recycling of industrial waste of low-density polyethylene (LDPE) blended with expanded polystyrene (EPS). Two LDPE/EPS ratios (50/50 and 70/30) were investigated, and two types of styrene-ethylene-butylene-styrene (SEBS) rubber were incorporated as compatibilizers. The mechanical, rheological, thermal, and morphological properties of these blends were analyzed to assess their printability. Results indicate that the use of SEBS enhances the mechanical properties, thermal stability, and morphological uniformity of the blends. Particularly, malleated SEBS exhibited superior compatibilizing ability, fostering strong interactions at the LDPE/EPS interface. The best blend, based on printability assessments, was the 50/50 LDPE/EPS ratio with a 5 wt% malleated SEBS. Consequently, this blend was extruded into feedstock filaments, and it was successfully printed via FDM. The proposed blends are anticipated to perform effectively in various applications and serve as a foundation for future development of wear-resistant materials. The outcomes of this study present a novel approach for upcycling LDPE waste while promoting sustainable FDM practices.