Mechanical properties comparison between new and recycled polyethylene terephthalate glycol obtained from fused deposition modelling waste

Abstract

The recycling of materials and the efficient use of resources are nowadays fundamental in a circular economy perspective. This concept also applies to additive manufacturing (AM) where waste can be reused to produce new material. Using mostly thermoplastic polymers, fused deposition modeling (FDM) is an AM technique that allows to melt waste materials and, successively, using a suitable extruder, obtain new filament. In the process, polymers are subject to multiple re‐melting and polymer orientations by extrusion operations. The aim of this work is to evaluate the influence of the recycling process over polyethylene terephthalate glycol‐modified (PETG) mechanical properties by tensile testing of samples produced using pure and recycled material. Furthermore, filament itself has been tested to evaluate recycle process influence before FDM printing.

Fused deposition modelling: Current status, methodology, applications and future prospects

“…Moreover, the layer thickness affects irreversible thermal strain and mechanical properties [103]. Recycling of FDM waste, which is nowadays fundamental in a circular economy perspective, can also change the mechanical properties of the pristine material [104]. FDM feedstock exists in the form of filament with an average diameter of 1.78 mm, although diameters as large as 3 mm can still be found [105].…”

Materials Requirements in Fused Filament Fabrication: A Framework for the Design of Next‐Generation 3D Printable Thermoplastics and Composites

“…If the object is properly designed for FFF printing, the waste material originated from removable supports is limited and, in principle, defective parts from failed jobs can be recycled. [30][31][32] The assessment of particulate emission and volatile organic compounds (VOCs) is presently the subject of research, since additives may lead to the release of noxious substances in the temperature range typically required for printing by FFF. [33] However, for most feedstock materials, especially poly(lactic acid) (PLA) which is bio-based and low melting (thus requiring a relatively low printing temperature), a well-ventilated place may suffice to work safely, although the safe operating instructions are different for each material and should be carefully considered before printing.…”