DEVELOPMENT OF A FIBER ORIENTATION MEASUREMENT METHODOLOGY FOR INJECTION MOLDED THERMALLY-ENHANCED POLYMERS Timothy Hall Department of Mechanical Engineering University of Maryland College Park, MD 20742, USA Email: timrhall@umd.edu Arumugham Vaishnavi Subramoniam Department of Mechanical Engineering University of Maryland College Park, MD 20742, USA Email: avsubram@gmail.com Hugh A. Bruck Department of Mechanical Engineering & Multiscale Measurements Laboratory University of Maryland College Park, MD 20742, USA Email: bruck@umd.edu Satyandra K. Gupta Department of Mechanical Engineering & Institute for Systems Research University of Maryland College Park, MD 20742, USA Email: skgupta@umd.edu ABSTRACT Thermally-enhanced polymer composites are a promising alternative to exotic metals in seawater heat exchanger appli- cations due to the low cost and corrosion resistance of base polymers and heat transfer rates competitive with corrosion- resistant metals such as titanium or stainless steel. While the properties of thermally-enhanced polymer composites are well- suited for heat exchanger applications, fiber orientation has a strong influence on the structural and thermal performance of the manufactured components. In this study, a method of cre- ating samples, sectioning and polishing them for imaging, mi- croscope sampling for the identification of fibers, image process- ing to characterize fiber orientation, and finally comparison to predictions from computer-aided engineering (CAE) software is demonstrated for collecting experimental information on fiber orientation of molded parts. Understanding fiber orientation in injection-molded polymer heat exchangers is important for en- suring ideal heat transfer and structural performance and this study presents an experimental methodology for determining the influence of injection molding process parameters on fiber orien- tation in thermally-enhanced polymer composite geometries. 1 INTRODUCTION The utilization of polymers in heat exchangers is attractive due to their relatively low cost and weight, lower fabrication energy and lifecycle energy use than equivalent metal heat ex- changers [1], and corrosion and fouling resistance [2]. The in- troduction of new thermally-enhanced polymer composites and manufacturing processes has led to renewed interest in polymer heat exchangers and emerging applications previously supported only by heat exchangers made of exotic metallic alloys. Indus- trial applications which utilize seawater as a cooling medium for heat exchangers traditionally require exotic alloys to sur- vive the corrosive environment, leading to dramatically increased costs and processing requirements. Polymer composites utiliz- ing thermally-enhanced fillers, such as pitch-based carbon fiber, have led to orders of magnitude improvement in overall thermal conductivity, making them competitive with corrosion-resistant metals such as titanium and copper-nickel alloys. [3] In thermally-enhanced and other fiber-filled composites, fiber orientation can play an important role in determining the material properties of created parts. Thermally-enhanced fibers exhibit thermal and structural properties that are order of magni- tudes higher along the length of the fiber compared to transverse to the length of the fiber. Therefore fiber alignment can lead 1 Copyright c  2012 by ASME Proceedings of the ASME 2012 International Manufacturing Science and Engineering Conference MSEC2012 June 4-8, 2012, Notre Dame, Indiana, USA MSEC2012-7291 Downloaded From: http://proceedings.asmedigitalcollection.asme.org/pdfaccess.ashx?url=/data/conferences/asmep/75447/ on 07/03/2017 Terms of Use: http://www.asme.org/abo