Investigation on the effects of multijet fusion printing parameters on porosity of mechanical properties of printed polymer parts

• Main Author: Kumar, Timothy Theodore
• Other Authors: Du Hejun
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/168463
• Institution: Nanyang Technological University

The era of the fourth industrial revolution has acted as a catalyst for the development in additive manufacturing (AM) technology resulting in new, different and more creative ways of producing prototypes and changing the manufacturing industry. Hewlett-Packard (HP) have delved in the world of additive manufacturing by creating a Multijet Fusion (MJF) printer that fabricates nylon-based part. In previous studies, researches have altered the orientation of the intended printer specimen to various position in the printing space as well as differing the orientation at various angles to determine which of the positions results in enhanced mechanical properties. HP's multijet fusion comes with several adjustable printer setting such as lamp power, carriage speed and layer thickness that can be altered to give the sample the best mechanical properties. This report aims at determining which printing parameters should be varies and to what extent in order to reduce the porosity characteristics and to optimise the mechanical properties of printer parts. Testing like dynamic mechanical analysis, density test method and computed tomography will be conducted on the printed specimens to obtain the overall porosity characteristics and mechanical properties so that a relationship between these two factors can be defined. This report will identify how certain printing parameters alter the pore characteristics of the printed part which results in either higher porosity or undesirably shaped pores. This results in exhibiting the strengths and limitations of the printed specimen. From these results future users of the HP MJF printer will have better insight on alternating various printing parameters to attain a printed specimen with more desirable mechanical properties.