Experimental Study on the Flexural Performance of Sustainable Composites Utilizing Processed Solar Panel Waste

The exponential rise in end-of-life photovoltaic (PV) waste necessitates innovative recycling pathways. This study pioneers the utilization of ground PV waste powder as a high-performance reinforcing filler in Digital Light Processing (DLP) 3D-printed resin composites. Three filler variations based on particle size SN 2 (coarse), SN 4 (medium), and SN 6 (fine) were incorporated into a photopolymer matrix and characterized using SEM-EDX, FTIR, and flexural testing. Results reveal a remarkable 73% increase in flexural strength, peaking at 33.11 MPa for the coarser SN 2 composite compared to 19.13 MPa for the neat resin. Morphological analysis (SEM) indicates that the angular Silicon-based particles in SN 2 effectively diverted crack propagation, transforming the fracture mechanism from brittle failure to a toughened, energy-absorbing mode. EDX analysis confirmed high Silicon purity in the reinforcing phase, while FTIR verified that the filler interaction remained purely physical, preserving the resin’s chemical stability. Interestingly, contrary to trends favoring ultra-fine fillers, the finest SN 6 fraction exhibited reduced performance due to particle agglomeration and impurity concentration (Rb/Nb) found in the dust. These findings demonstrate that upcycling PV waste into DLP materials offers a sustainable, low-cost solution that significantly enhances mechanical performance without requiring complex chemical modification.