Recycle of printed circuit boards from waste electric and electronic equipment and their reusability as filler in 3D printed poly(lactic) acid composites

Abstract

Recycling raw materials (RMs) from waste electric and electronic equipment (WEEE) and reusing them in additive manufacturing applications, has tremendous benefits, including health risk reduction by landfill decongestion. Furthermore, final composite products are given enhanced properties, increasing their added-value commercialization. The non-conductive substrate of printed circuit boards, composed of glass fibre-reinforced epoxy resin was processed and tested as poly(lactic acid) (PLA) filament additive. Scanning electron microscopy confirmed carbon, oxygen, and silicon as the main elements of the composite. Differential scanning calorimetry of 5% and 10% composites showed that the addition of fillers did not result in a significant change of composite filaments’ thermal properties. 15% filler addition resulted in higher crystallinity and melting point. Rheological analysis showed that composite filaments’ viscosity increased compared to pure PLA (300–400 Pas compared to 100–200 Pas), maintaining their structural strength during printing. Mechanical performance analysis showed that Young’s modulus, flexural modulus, flexural strength, and elongation of the composites increased compared to pure PLA (up to 9.6%, 24.6%, and 28.2%, respectively), enhancing mechanical properties, structural integrity, and load-bearing capacity. The abundance and low cost of RM and the small number of processes, present the upscaling potential, increasing the profit margin in a swiftly growing market.