Degree Name

BS in Materials Engineering


Materials Engineering Department


Trevor Harding


Chopped carbon fibers are used as reinforcements in thermoplastics, but the viscous shear forces that arise in melt-processing reduces the fiber length well below its critical length resulting in only moderate strength and stiffness gains compared to the neat resin. This research project aimed to experimentally determine the effect of the melt–flow portion of a single-screw- extrusion process on carbon fiber length attrition in isolation from the immediately preceding screw–plastication step that is responsible for most of the heat needed for melting. Carbon fibers with an initial length of 2 mm were stirred into 5,000 centipoise and 10,000 centipoise silicone oils at a fiber volume fraction of 10\%. Each suspension was passed through a single–screw–extruder under the same conditions and the resultant fiber length distributions were compared for absolute and relative amounts of length attrition. Silicone oil suspensions of fibers were shown to be a viable method of determining the effect of the melt–phase of the extrusion process.... [RESULTS REDACTED]

Available for download on Monday, June 07, 2021

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