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dc.contributor.authorGray, Robert Williamson IVen_US
dc.date.accessioned2014-03-14T21:52:58Z
dc.date.available2014-03-14T21:52:58Z
dc.date.issued1997-07-30en_US
dc.identifier.otheretd-7497-232759en_US
dc.identifier.urihttp://hdl.handle.net/10919/46512
dc.description.abstractThis work is concerned with preliminary studies on developing thermoplastic composite materials suitable for use in fused deposition modeling (FDM). Polypropylene (PP) strands reinforced with continuous thermotropic liquid crystalline polymer (TLCP) fibrils were generated in a novel dual extruder process. Strands were then re-extruded to form short fiber composite monofilaments that were used as feed stock in the FDM 1600 rapid prototyping system. Prototypes containing 40 wt% Vectra A were shown to have tensile properties twice those of parts built using acrylonitrile butadiene styrene copolymer (ABS), a commercially available material used in the FDM 1600 rapid prototyping system. It was also shown that the final mechanical properties of a composite prototype can be tailored to a specific application by adjusting the lay-down pattern, increasing the functionality of the prototype. In order to obtain the maximum tensile properties in these composite prototype, additional studies were performed to determine the effects of thermal and deformation histories on the mechanical properties of monofilaments that were re-extruded from long fiber TLCP reinforced strands. Strands were consolidated uniaxially at temperatures just above the melting point of the matrix in order to determine the effects of thermal history, and an approximate 20% reduction in tensile modulus relative to the modulus of the strands was observed. Monofilaments that could be used as feed stock in FDM were extruded from long fiber TLCP reinforced strands using a capillary rheometer in order to study the effects of capillary diameter, capillary L/D, and apparent shear rate on the tensile properties.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartetd.PDFen_US
dc.rightsI hereby grant to Virginia Tech or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University Libraries in all forms of media, now or hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation.en_US
dc.subjectPolymeren_US
dc.subjectCompositeen_US
dc.subjectTLCPen_US
dc.subjectPrototypeen_US
dc.subjectFDMen_US
dc.titleThe Effects of Processing Conditions on Thermoplastic Prototypes Reinforced with Thermotropic Liquid Crystalline Polymersen_US
dc.typeThesisen_US
dc.contributor.departmentChemical Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineChemical Engineeringen_US
dc.contributor.committeechairBaird, Donald G.en_US
dc.contributor.committeememberDavis, Richey M.en_US
dc.contributor.committeememberBohn, Jan Helgeen_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-7497-232759/en_US
dc.date.sdate1997-07-30en_US
dc.date.rdate1998-08-07
dc.date.adate1997-08-07en_US


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