Short basalt fibre reinforced recycled polypropylene filaments for 3D printing

Additive Manufacturing (3D Printing, and specifically Material Extrusion) is a rapid and convenient manufacturing method using raw material in filament form and is a potential candidate process for the use of recycled plastics and fibres gathered from industrial waste and domestic recycling. In this research, off-cuts of basalt fibre and recycled mushroom trays made of Polypropylene (PP) have been collected, recycled and com-bined in an extruder to make short fibre reinforced filaments as material extrusion feedstock filament material. A Noztek Touch Dual PID filament maker was utilized to make reinforced PP with 0%, 2%, 5%, and 8% basalt fibre weight fractions. The extruding parameters including motor speed, heating temperatures, cooling fan status, extrusion tension have been optimized to produce a filament made from these waste materials with the desired surface quality, void content, and profile. Microscopic assessment has been carried out to verify the fibre dispersion and above mentioned quality measures in the upcycled filaments. Differential scanning calorimetry has been done to measure the melting and crystallization temperatures of collected polypropylene and recycled filaments, and the tensile strength and elastic modulus of the reinforced recycled polypropylene have been measured in presence of different percentages of short basalt fibres with 4.5 mm length. The produced filaments with 5% wt. of basalt are a good candidate for use as feedstock in manufacturing using 3D printing.