Browsing Polymers Research Group Technical Report Series by Title
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Reflections on Inflections
(20151111)In plastics processing, the single most important rheological property is the steady shear viscosity curve: the logarithm of the steady shear viscosity versus the logarithm of the shear rate. This curve governs the volumetric ... 
Review of Nonlinear Oscillatory Shear Flow Notations and Presentations: Polymeric Liquids
(201812)We review notations for, along with ways of presenting, the shear stress responses to largeamplitude oscillatory shear flow (LAOS). We find that the Fourier loss and storage viscosities to be the simplest primal notations ... 
Series Expansion for Shear Stress in LargeAmplitude Oscillatory Shear Flow From Oldroyd 8Constant Framework
(201806)When polymeric liquids undergo largeamplitude oscillatory shear flow (LAOS), the shear stress responds as a Fourier series, the higher harmonics of which are caused by the fluid nonlinearity, and the first harmonic of ... 
Simple Accurate Expressions for Shear Stress in LargeAmplitude Oscillatory Shear Flow
(201705)Analytical solutions for shear stress in largeamplitude oscillatory shear flow (LAOS), for continuum or molecular models, often take the form of the first few terms of a power series in the shear rate amplitude. For ... 
Slip Heating in Die Drool
(20140514)When molten plastic is extruded from a die, it can collect on the open die face. Called die drool, this phenomenon costs plastics manufacturers by requiring shutdown for die cleaning. This has been attributed to cohesive ... 
Slip Heating in Die Drool with Viscous Dissipation
(20141006)Plastics can buildup on the die lip during extrusion. This phenomenon is called die drool and can be costly for plastics producers, requiring periodic shutdowns for die cleaning. Die drool has been attributed to the ... 
Startup Steady Shear Flow from the Oldroyd 8Constant Framework
(201901)One good way to explore fluid microstructure, experimentally, is to suddenly subject the fluid to a large steady shearing deformation, and to then observe the evolving stress response. If the steady shear rate is high ... 
Temperature Rise in a Verging Annular Die
(20151207)Plastic pipes, tubes or catheters are extruded by pressure‑driven flows through annular dies. Whereas die lands are straight, the section connecting the die land to the extruder either converges or diverges, converging ... 
Transport Phenomena in Eccentric Cylindrical Coordinates
(201609)Studies in transport phenomena have been limited to a select few coordinate systems. Specifically, Cartesian, cylindrical, spherical, Dijksman toroidal, and bipolar cylindrical coordinates have been the primary focus of ... 
Wall Slip Heating
(20150105)When molten plastic is extruded, the upper limiting throughput is often dictated by fine irregular distortions of the extrudate surface. Called sharkskin melt fracture, plastics engineers spike plastics formulations with ... 
πάντα ῥεῖ (Everything Flows): Motto for Rheology
(20140523)This historical study deepens the rheologist’s understanding of the motto of The Society of Rheology, of its history, and of its many typographies. The motto “πάντα ῥεῖ” is not verbatim something written or said by the ...