Extrusion and characterization of eggshell-based composite filaments for sustainable development in additive manufacturing

Abstract

Additive manufacturing (AM) is an extending manufacturing method which has many advantages such as minimalistic material wastage, less fabrication time and so on, over other manufacturing technologies such as subtractive, moulding, casting, etc. Strength enhancement of additively fabricated structures is an active area of study and much research was evolved in terms of developing innovative feedstock for AM. Polymers and their composites gain great attention in the research community. Even though many composites available commercially were observed with enhanced properties, most of them are not sustainable and recyclable in nature. Eggshell is a naturally available calcium carbonate, which gets wasted in a huge amount. Such eggshells were synthesized and transformed into nanosized for inclusion of filler in polylactic acid (PLA) matrix. PLA is a bio-degradable polymer with numerous applications and is one of the popular feedstocks for fused deposition modelling. This study explains the proper procedure to extrude commercial-grade eggshell-based composite filaments and qualities of such composites would be elaborately discussed with the help of single fibre tensile test, scanning electron microscopy and X-ray diffraction. Totally five filaments such as PLA, 5, 10, 15 and 20 wt % of eggshell in composites were extruded by following proper sonication and suitable filament extrusion process. 15 wt % composite seems to be the best among all filaments and possesses better characteristics than all other filaments.