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Now showing items 1-10 of 13

#### Extruding Plastic Pipe From Eccentric Dies

(2015-05-25)

To solidify plastic pipe, the pipe is transported through a long cooling chamber. Inside this chamber, inside the pipe, the plastic remains molten, and this inner surface solidifies last. The flow due to the self-weight ...

#### Exact Analytical Solution for Large-Amplitude Oscillatory Shear Flow from Oldroyd 8-Constant Framework: Shear Stress

(2017-01)

The Oldroyd 8-constant model is a continuum framework containing, as special cases, many important constitutive equations for elastic liquids. When polymeric liquids undergo large-amplitude oscillatory shear flow, the shear ...

#### Exact Analytical Solution for Large-Amplitude Oscillatory Shear Flow

(2015-03-16)

When polymeric liquids undergo large-amplitude shearing oscillations, the shear stress responds as a Fourier series, the higher harmonics of which are caused by fluid nonlinearity. Previous work on large-amplitude oscillatory ...

#### Padé Approximants for Large-Amplitude Oscillatory Shear Flow

(2015-03-17)

Analytical solutions for either the shear stress or the normal stress differences in large-amplitude oscillatory shear flow, both for continuum or molecular models, often take the form of the first few terms of a power ...

#### Reflections on Inflections

(2015-11-11)

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 ...

#### Padé Approximant for Normal Stress Differences in Large-Amplitude Oscillatory Shear Flow

(2017-11)

Analytical solutions for the normal stress differences in large-amplitude oscillatory shear flow (LAOS), for continuum or molecular models, normally take the form of the first few terms of a series expansion in the shear ...

#### Nonlinear Core Deflection in Injection Molding

(2018-02)

Injection molding of thin slender parts is often complicated by core deflection. This deflection is caused by molten plastics race tracking through the slit between the core and the rigid cavity wall. The pressure of this ...

#### Power Series for Shear Stress of Polymeric Liquid in Large-Amplitude Oscillatory Shear Flow

(2018-04)

xact solutions for shear stress in a polymeric liquid subjected to large-amplitude oscillatory shear flow (LAOS) contain many Bessel functions. For the simplest of these, for instance, the corotational Maxwell fluid, in ...

#### Plastic Pipe Solidification: Exact Solutions in Cylindrical Coordinates

(2015-12)

For polymer melt solidification in plastic pipe extrusion, we perform an energy balance on the pipe extrudate in cylindrical coordinates to arrive at exact solutions for the temperature, and for the solidification rate. ...

#### Bubble Growth From First Principles

(2016-07-05)

We consider the simplest relevant problem in the foaming of molten plastics, the growth of a single bubble in a sea of highly viscous Newtonian fluid, and without interference from other bubbles. This simplest problem has ...