Effect of machine parameters on strength and hardness of FDM printed carbon fiber reinforced PETG thermoplastics

Abstract

Poly Ethylene Terephthalate Glycol (PETG), a thermoplastic polyester is widely used for the various consumable and commercial applications like manufacturing of bottles, containers, packaging materials for medical implants, etc. due to its excellent formability, durability and resistive to chemical changes. The low forming temperature makes PETG, a desirable material for fused deposition modelling (FDM). The properties of PETG further increase when it is reinforced with carbon fibre. The objective of this research is to analyze the mechanical strength of carbon fibre reinforced PETG thermoplastics and optimize the various machine parameters. To this end, nine set of each tensile and flexural specimen are fabricated as per ASTM standard. The factors selected for 3D printing of the specimen are print speed, infill density and layer height. The results of tensile, flexural and hardness tests are optimized using Taguchi L9 experimental approach. The major impacts of various factors on strength and ANOVA analysis are also performed to suggest the relationship between factors and responses statistically. The optimum tensile, flexural strength and hardness obtained in this research are 31.567 MPa, 35.045 MPa and 67.0011 BHN respectively. The most desirable machine parameters that have come out in this research are print speed 60 mm/sec, infill density 80% and layer height 200 μ. The optimized values for machine parameters may be useful in selecting the working ranges to 3D print PETG material for different applications.