3D printing of composite material through blending of PLA and PETG using fused deposition modelling

Multi-material additive-manufacturing (MMAM) in fused deposition modelling (FDM) became popular due to the emergence of various filaments with different properties being offered in the market. Composite printing of different materials allows engineers to design function parts with dedicated mechanical properties based on part geometry/functional requirements. This study investigated composite material using polylactic acid (PLA) as the shell material and polyethylene terephthalate glycol (PETG) as the infill material. PLA material exhibits a higher elastic modulus but lower ultimate tensile strength than PETG. Therefore, unique composite properties would be formulated through discrete blending on both base materials. The composite samples were printed with 60 % (triangular infill patterns) and 100 % infill density. Their ultimate tensile strength and elastic modulus were compared against their base materials, i.e. PLA and PETG materials. Experimental results demonstrate that under 100 % infill density, composite samples show improvement in the tensile modulus over its base material, i.e. +5.29 % (PLA) and +36.45 % (PETG). However, in the aspect of ultimate tensile, it is only showing improvement over PLA (+9.78 %) and deterioration for PETG (-4.83 %). Whereas, for 60 % infill density, the composite demonstrates significant improvements over its base material in the aspect of tensile modulus (+23.66 % PLA and +11.14 % PETG) and ultimate tensile strength (+4.34 % PLA and +50.51 % PETG). The result demonstrated that through a blending of two discrete materials, i.e. PLA and PETG, researchers could achieve composite material which has higher mechanical strength than its base materials.