Preferential wetting phenomenon in bicomponent polymer melt flow

Southern, John H.; Ballman, R. L.

doi:10.1002/app.1979.070240307

Cited by 16 publications

(13 citation statements)

References 9 publications

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“…Figure 2 shows the relationship between the difference in the viscosity between the two phases and the TRDP configuration. [17][18][19][20] In fluid mechanics, viscous dissipation is manifested by the transformation of kinetic energy into thermal energy through fluidic viscosity. The viscous dissipation (E) per unit length in a two-phase flow of solvents a and b is expressed as follows.…”

Section: Resultsmentioning

confidence: 99%

Consideration of Inner and Outer Phase Configuration in Tube Radial Distribution Phenomenon Based on Viscous Dissipation in a Microfluidic Flow Using Various Types of Mixed Solvent Solutions

et al. 2016

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When mixed solvent solutions, such as ternary water-hydrophilic/hydrophobic organic solvents, water-surfactant, and water-ionic liquid, are delivered into a microspace under laminar flow conditions, the solvent molecules radially distribute in the microspace, generating inner and outer phases. This specific fluidic behavior is termed "tube radial distribution phenomenon", and has been used in separation technologies such as chromatography and extraction. The factors influencing the configuration of the inner and outer phases in "tube radial distribution phenomenon" using the abovementioned mixed solvent solutions were considered from the viewpoint of viscous dissipation in fluidic flows. When the difference in the viscosity between the two phases was large (approximately >0.73 mPa·s), the phase with the higher viscosity formed as an inner phase regardless of the volume ratio. The distribution pattern of the solvents was supported by the viscous dissipation principle. Contrarily, when the difference was small (approximately <0.49 mPa·s), the phase with the larger volume formed as the inner phase. The distribution pattern of the solvents did not always correspond to the viscous dissipation principle. The current findings are expected to be useful in analytical science including microflow analysis research.

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Section: Resultsmentioning

confidence: 99%

Consideration of Inner and Outer Phase Configuration in Tube Radial Distribution Phenomenon Based on Viscous Dissipation in a Microfluidic Flow Using Various Types of Mixed Solvent Solutions

et al. 2016

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“…At a given melt temperature, viscosity ratio reversal can be obtained when the two components have viscosities such that crossovers occur in the plots of melt viscosity vs shear rate [1,2,4]. Experimental observations [1,2,5] have shown that interface curvature reversal occurred at approximately the shear rate where the viscosity crossover of the two melts also occurred.…”

Section: Effect Of Shearing Level Carreau-type Fluidsmentioning

confidence: 97%

“…However, it has been experimentally established that the viscosity difference between the two melts predominates over the elasticity ratio in determining the interface shape and the direction of encapsulation [1,5,4,8]. Based on this fact, this work focuses on the effect of the viscous properties on the interface deformation phenomena.…”

Section: Introductionmentioning

confidence: 97%

Three-dimensional studies on bicomponent extrusion

1990

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The present work is concerned with the mathematical modelling and numerical simulation of three-dimensional (3-D) bicomponent extrusion. The objective is to provide an understanding of the flow phenomena involved and to investigate their impact on the free surface shape and interface configuration of the extruded article. A finite element algorithm for the 3-D numerical simulation of bicomponent stratified free surface flows is described. The presence of multiple free surfaces (layer interface and external free surfaces) requires special free surface update schemes. The pressure and viscous stress discontinuity due to viscosity mismatch at the interface between the two stratified components is handled with both a double node ( u -v -w -P 1 -P 2 -h l -h 2) formulation and a penalty function ( u -v -w -P -h 1-h2) formulation.The experimentally observed tendency of the less viscous layer to encapsulate the more viscous layer in stratified bicomponent flows of side-by-side configuration is established with the aid of a fully 3-D analysis in agreement with experimental evidence. The direction and degree of encapsulation depend directly on the viscosity ratio of the two melts. For shear thinning melts exhibiting a viscosity crossover point, it is demonstrated that interface curvature reversal may occur if the shearing level is such that the crossover point is exceeded. Extrudate bending and distortion of the bicomponent system because of the viscosity mismatch is shown. For flows in a sheath-core configuration it is shown that the viscosity ratio may have a severe effect on the swelling ratio of the bicomponent system.Modelling of the die section showed that the boundary condition imposed at the fluid/fluid/wall contact point is critical to the accuracy of the overall solution.

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“…(12) and (13) with the momentum balance and energy balance equations, i.e., eqs. ( 6 ) and (7), numerical simulation of bicomponent spinning was carried out. In these equations, the mutual interaction between two components arising from a radial normal stress difference was neglected.…”

Section: Upper-convected Maxwell Modelmentioning

confidence: 99%

High-speed melt spinning of bicomponent fibers: Mechanism of fiber structure development in poly(ethylene terephthalate)/polypropylene system

Kikutani

Radhakrishnan

Arikawa

et al. 1996

J. Appl. Polym. Sci.

106

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SYNOPSISHigh-speed bicomponent spinning of poly(ethy1ene terephthalate) (PET) (core) and polypropylene (PP) (sheath) was carried out and the structure development in the individual components, PET and PP, was investigated. The orientation and crystallinity development in the P E T component was enhanced as compared to that of the single-component spinning while the PP component remained in a low orientation state and had a pseudo-hexagonal crystal structure even at high take-up speeds. T o clarify the mutual interaction between the two components in bicomponent spinning, a semiquantitative numerical simulation was performed. The simulation results obtained using the Newtonian fluid model showed that the solidification stress in the P E T component was enhanced while that of the PP component was decreased in comparison with the corresponding single-component spinning. This is due to the difference in the temperature dependence of their elongational viscosity. Simulation with an upper-convected Maxwell model as the constitutive equation suggested that significant stress relaxation of the PP component can occur in the spinline if the PET component solidifies earlier than does PP. Based on the structural characterization results and the simulation results, it was concluded that the difference in the activation energy of the elongational viscosity and solidification temperature between the two polymers are the main factors influencing the mutual interaction in the bicomponent spinning process.

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Preferential wetting phenomenon in bicomponent polymer melt flow

Cited by 16 publications

References 9 publications

Consideration of Inner and Outer Phase Configuration in Tube Radial Distribution Phenomenon Based on Viscous Dissipation in a Microfluidic Flow Using Various Types of Mixed Solvent Solutions

Consideration of Inner and Outer Phase Configuration in Tube Radial Distribution Phenomenon Based on Viscous Dissipation in a Microfluidic Flow Using Various Types of Mixed Solvent Solutions

Three-dimensional studies on bicomponent extrusion

High-speed melt spinning of bicomponent fibers: Mechanism of fiber structure development in poly(ethylene terephthalate)/polypropylene system

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