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Item The development of feedstock for 3D printing and 3D knitting of continuous carbon fibre composite filaments : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Mechatronics at Massey University, Albany, New Zealand(Massey University, 2019) Kvalsvig, Andrew D.The main purpose of this research was the development of a composite filament comprising of a thermoset resin and long/continuous carbon fibre reinforcement for the use with additive manufacturing applications. Currently, there are composite materials available that consist of fibre reinforcement but none that utilise long/continuous fibre reinforcement with a thermoset resin in a controlled manner. A series of prototypes were developed to determine the production processes required to produce the composite filament. Specimens were produced from these prototypes were subjected to cross-sectional analysis to analyse the quality of composite filament being produced. The results from this research is a production method that consistently produces the composite filament with the desired material properties. The secondary purpose of this research was to analyse a commercially available 3D printer, the Mark One, that can produce composite parts using long/continuous fibre reinforcement and a thermoplastic matrix. An analysis into the capabilities and limitations of the Mark One was conducted prior to analysing specimens produced by the Mark One. An analysis of the tensile properties of parts produced by the Mark One was conducted using fibreglass and carbon fibre long/continuous fibre reinforcement. Tensile specimens made in accordance with the standard ASTM D638 for Type I specimens were produced and tensile tested. The Taguchi method was used to analyse the effect and contribution that three parameters had on the tensile properties of specimens. Complications with specimens fracturing incorrectly lead to a redesign of the tensile specimens to ensure the specimens would fracture correctly. Several design iterations were tested until a final design was chosen. This final design was used for both fibreglass and carbon fibre specimens. The results from the tensile specimens showed the effect that changing certain parameters had on the tensile properties and the contribution that each parameter had on the tensile properties produced using the Mark One. These results were confirmed by producing tensile specimens using the optimal combination of parameters and provided insight into the capabilities of the Mark One.Item 3D printing materials for large-scale insulation and support matrices : thesis by publications presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering, Massey University, Albany, New Zealand(Massey University, 2019) Harris, MuhammadAdditive manufacturing (AM) techniques have promising applications in daily life due to their superiority over conventional manufacturing techniques in terms of complexity and ease of use. However, current applications of polymer-based 3D printing (3DP) are limited to small scale only due to the high cost of materials, print times, and physical sizes of the available machines. In addition, the applications of 3DP are yet to be explored for insulation of different large-scale mechanical structures. For example, milk vats are large structures with complex assemblies (like pipes, joints, couplings, valves, ladders, vessel doors) that requires insulation to store the milk at a low temperature of 6 °C as per the NZCP1 regulations in New Zealand. Generally, milk vats lack any kind of proper insulation around them and require additional cooling systems to keep the milk at a prescribed temperature. Any variations in the temperature can lead to deterioration in the quality of milk. Therefore, there exists a research gap that can not only help to solve an industrial issue but also can be a first step towards real large-scale 3DP applications that can potentially lead to many others in future. For example, pipe insulation, food storage tanks, chemical storage tanks, water treatment. This research explores new and inexpensive materials for large-scale 3DP. For this purpose, the current state of the 3DP materials is analyzed and based upon this analysis two distinct approaches are devised: 1) in-process approach to improve the mechanical properties of the existing materials like polylactic acid (PLA), and 2) modification of inexpensive materials (like materials used in injection, rotational, and blow moulding) to make them printable. In the first approach, by controlling the process parameters, mechanical properties are studied. While in the second approach, blends of high density polyethylene (HDPE) and polypropylene (PP) with different thermoplastics (acrylonitrile butadiene styrene, ABS and polylactic acid, PLA) are investigated to achieve printability. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) are used to analyze the proposed materials. The overall objective of this research is to devise low-cost materials comparable to the conventional processes that are capable of providing good mechanical properties (tensile, compressive and flexural) along with high resistance to thermal, moisture, and soil degradation. The results present significant enhancement, up to 30%, in tensile strength of PLA through in-process heat treatment. However, the softness induced during printing above 70 °C directs to the second approach of developing the novel blends of HDPE and PP. In this regard, the research develops three novel blend materials: 1) PLA/HDPE, 2) ABS/HDPE, and 3) ABS/PP. These materials are compatibilized by a common compatibilizer, polyethylene graft maleic anhydride (PE-g-MAH). PLA/HDPE/PE-g-MAH provides highest tensile strength among all existing FDM blends (73.0 MPa) with superior resistance to thermal, moisture and soil degradation. ABS/HDPE and ABS/PP provide one of the highest mechanical properties (tensile, compressive, and flexural) in ABS based FDM blends with superior thermal resistance to six days aging. ii The chemical characterization of aforementioned novel FDM blends shows partial miscibility with sufficient signs of chemical grafting. The significant intermolecular interactions are noted in FTIR that shows the grafting through compatibilizer (PE-g-MAH). The DSC analysis shows visible enhancement in different thermal parameters like glass transition, melt crystallization and degradation along with signs of partial miscibility. Furthermore, TGA analysis confirms the partial miscibility along with the enhanced onset of degradation temperature. The increase in onset temperatures of each of the three blends proves the thermal stability to high temperatures. Hence, each of the developed blends is capable of resisting any material deterioration during routine cleaning operation at 70 °C of milk vats. This research has resulted in 5 journal publication (four published and one submitted), two conference proceedings and a number of posters presented at local conferences. This research is the part of food industry and enabling technologies (FIET) research program funded by the ministry of business, innovation and employment (MBIE), New Zealand in collaboration with Massey University, Auckland.
