Effects of printing parameters on layer adhesion behaviours in fused deposition modelling

• Main Author: Sito, Jowyn
• Other Authors: Zhou Kun
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/77486
• Institution: Nanyang Technological University

3D printing has witnessed tremendous interest and developments in Fused Deposition Modelling (FDM) technology. The popular choices of printing material for FDM are acrylonitrile butadiene styrene (ABS) and poly (lactic acid) (PLA). Polyether-ether-ketone (PEEK) has been increasingly popular, as it exhibits high mechanical strength, flexibility, toughness, self-extinguishing properties, chemical and radiation resistance although its high melting point may not be compatible with some 3D printers. The objective of this project is to study the effects of various printing parameters such as bed temperature, layer height and raster angle on layer adhesion behaviours in FDM. Statistical analysis based on Design of Experiments (DOE) was used to assist the experimental testing and study of the influences of varying layer thickness of 100, 200, 250, 300 and 400 µm at different print bed temperatures of 80 ℃, 90 ℃ and 100 ℃. This was achieved by redeveloping and modifying an existing FDM machine to 3D print ABS and PEEK specimen coupons, which closely adheres to the ASTM standards. The mechanical behaviours of the various 3D printed ABS and PEEK samples were then evaluated under tensile load. It was observed that ABS specimens with bed temperature of 100 ℃ and raster angle of 45° acquire the most optimal tensile strength of 33.50 MPa at layer height of 200 μm while the toughness of 260.26 J/m3 was optimally obtained at layer height of 300 µm. As for PEEK, more in-depth experiences will be shared by the author, including the problems faced and how he overcame them. The research revealed that 3D printed parts printed from PEEK exhibit higher tensile strength than those printed with ABS. This concludes that PEEK generally exhibits much better mechanical properties than ABS. The substantial findings from the experiments also showcase that the various printing parameters indeed have a significant influence on the layer adhesion behaviours of the specimens.