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dc.contributor.advisorWhiteside, Benjamin R.
dc.contributor.advisorSweeney, John
dc.contributor.authorBabenko, Maksims*
dc.date.accessioned2018-01-30T16:15:02Z
dc.date.available2018-01-30T16:15:02Z
dc.date.issued2015
dc.identifier.urihttp://hdl.handle.net/10454/14745
dc.description.abstractThis thesis investigates the cooling behaviour of polymers during the microinjection moulding process. The work included bespoke experimental mould design and manufacturing, material characterisation, infra-red temperature measurements, cooling analysis and cooling prediction using commercial simulation software. To measure surface temperature of the polymers, compounding of polypropylene and polystyrene with carbon black masterbatch was performed to make materials opaque for the IR camera. The effects of addition of carbon black masterbatch were analysed using differential scanning calorimetry and Fourier transform infrared spectroscopy. Sapphire windows formed part of the mould wall and allowed thermal measurements using an IR camera. They were laser machined on their inside surfaces to generate a range of finishes and structures. Their topographies were analysed using laser confocal microscope. The surface energy of sapphire windows was measured and compared to typical mould steel, employing a contact angle measurement technique and calculated using Owens-Wendt theory. A heating chamber was designed and manufactured to study spreading of polymer melts on sapphire and steel substrates. A design of experiments approach was taken to investigate the influence of surface finish and the main processing parameters on polymer cooling during microinjection moulding. Cooling curves were obtained over an area of 1.92 by 1.92 mm of the sapphire window. These experiments were conducted on the Battenfeld Microsystem 50 microinjection moulding machine. A simulation study of polymer cooling during the microinjection moulding process was performed using Moldflow software. Particular interest was paid to the effect of the values of the interfacial heat transfer coefficient (HTC) on the simulated cooling predictions. Predicted temperature curves were compared to experimentally obtained temperature distributions, to obtain HTC values valid for the material and processing parameters.en_US
dc.language.isoenen_US
dc.rights<a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>.en_US
dc.subjectHeat transfer coefficient; Thermal contact resistance; Thermal contact conductance; Surface roughness; Interface; Microinjection moulding; Polymer; Infrared; Simulationen_US
dc.titleA Study of Heat Transfer at the Cavity-Polymer Interface in Microinjection Moulding. The effects of processing conditions, cavity surface roughness and polymer physical properties on the heat transfer coefficienten_US
dc.type.qualificationleveldoctoralen_US
dc.publisher.institutionUniversity of Bradfordeng
dc.publisher.departmentSchool of Engineering and Informaticsen_US
dc.typeThesiseng
dc.type.qualificationnamePhDen_US
dc.date.awarded2015
refterms.dateFOA2018-07-29T03:49:32Z


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