Mechanical behaviour of 3D printed Lightweight Nano-composites

Abstract

Background: The nanoclay (NC) and glass micro balloons (GMB) based reinforced polymer composites are explored extensively through traditional processing methods. NC shows substantial enhancement in mechanical properties. Polymer composites developed by reinforcing GMB fillers provide a substantial reduction in weight, which is essential in the marine, aerospace, and automotive field. In this study, an attempt is made by developing polymer nano composites by reinforcing NC and GMB particles. Objective: The paper deals with 3 dimensional printing (3DP) of lightweight nanocomposite foam (NF) developed by mixing nanoclay (NC) and glass micro balloons (GMB) in high-density polyethylene (HDPE). The NF blend is prepared by keeping NC at 5 weight %. Subsequently, GMBs are added by volume (20 - 60 %) to NC/HDPE blend to realize lightweight NFs. Methods: The lightweight feedstock filaments are developed by extruding the blends using a single screw extruder. The extruded NF filaments are used as an input in a 3D printer to print NFs. The density of extruded filaments and prints are measured. The printed NFs are subjected to tensile and flexural testing. Conclusion: With an increase in GMB loading the density of both filaments and prints decreases. Compared to neat HDPE, printed NFs show ~30 % weight reducing potential. The tensile, flexural modulus and strength increases with GMB loading. NFs exhibited superior mechanical performance as compared to HDPE and NC/HDPE. Further, the property map reveals that the 3D printed NFs show superior tensile, flexural modulus, and strength in comparison with injection and compression-molded foams.