A comparative analysis of additive manufacturing filaments developed from recycled high-density polyethylene and recycled polypropylene: Extrusion process optimization

Abstract

Plastic solid waste continue to present opportunities. The use of recycled plastic material in additive manufacturing, also known as 3D printing, is expected to make the process more sustainable and help to address the global problem of plastic waste. However, there are still limitations to using recycled plastics as filament material such as getting the right quality of filaments that are well characterized. There is growing interest among researchers on the development of filaments from recycled plastics towards the realization of a circular economy in the additive manufacturing technology. In this paper, we present outcomes about filaments fabricated from recycled high density polyethylene and recycled polypropylene using the extrusion method. The extrusion process parameters considered in the fabrication of the filaments included extrusion temperature, screw speed and fan cooling. These parameters were analyzed and optimized using the Taguchi design of experiments technique. The response variable was the filament diameter which was desired to be 2.85 ± 0.05 mm with a circular cross section. The fabricated filaments were characterized and compared to establish their sustainability for fused filament fabrication. The results from this study are very significant in the development of printable filaments that meet the standards for 3D printing. Keywords — Additive Manufacturing (AM), High Density Polyethylene (HDPE), Polypropylene (PP), Fused Filament Fabrication (FFF), Taguchi Design of Experiments, ANOVA