Research and development of a material extrusion system and method to enhance production in fused filament fabrication

This thesis was submitted for the award of Master of Philosophy and was awarded by Brunel University LondonAn early phase of propagation can be observed in the use of additive manufacturing to fabricate parts for use in domestic and commercial applications. As additional industries begin to embrace additive manufacturing technology, adaptation and development of the technology is essential to allow the potential for an enhanced manufacturing approach to better control the process, fabrication time and enhancement of the interlayer bonding to permit for further adaptation of the technology in the industry. This study aims to investigate hardware and process parameter optimisations in Fused Filament Fabrication (FFF) to facilitate for a better manufacturing approach. An investigation was conducted to study the effects of process parameters on interlayer bonding with varying nozzle orifice sizes and nozzle optimisation. Additionally, the research was further evaluated and concluded with the tensile assessment of optimised fabricated sample prints. Furthermore development of two hardware extrusion approaches was also studied to further assist in the reduction in fabrication time, material throughput and adaptation in the industry. Analysis of the experimentation concluded that a combination of nozzle optimisation and the correct selection of the processing parameters reflected a distinguishable improvement in the enhancement of interlayer bonding amongst the fabricated specimens; A superior improvement was seen in the larger orifice sizes over smaller orifices. The developed hardware allowed for a better extrusion approach with the increase in throughput while reducing the fabrication time. On the aforementioned basis, an optimised manufacturing approach has been proposed as part of the study that outlines the foundation of a starting point to allow for an easier adaption of the technology in the field