Wetting phenomena during processing of high-viscosity shear-thinning fluid

Bhamidipati, Kanthi Latha; Didari, Sima; Bedell, Prince; Harris, Tequila A. L.

doi:10.1016/j.jnnfm.2011.03.009

Cited by 35 publications

(22 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Other process parameters such as the slot gap width ( W ) and the coating gap ( H ) can affect the quality of the film as cast, with irregularities being introduced into the film if the process is not properly controlled. Depending on the flow rate of the membrane solution there exists an upper and lower limit with respect to the substrate speed, for which irregularity‐free wet films are obtained . These limits encompass what is known as a casting window.…”

Section: Methodsmentioning

confidence: 99%

“…However, the availability of such membrane samples is essentially non-existent. In this study, we utilize a lab-scale polymer casting line to create membrane samples with ''real'' processcreated irregularities by casting the films under process-window conditions known to cause bubbles, pinholes, and other irregularities [39][40][41][42]. In this way, we enable the exploration of irregularities of naturally formed shape and size.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Effect of Membrane Casting Irregularities on Initial Fuel Cell Performance

et al. 2020

View full text Add to dashboard Cite

Membrane electrode assemblies (MEA) for polymer electrolyte membrane fuel cells (PEMFC) may possess as‐manufactured non‐uniformities in any of its constituent components. This work studies casting irregularities located within the PEM to understand their potential impact on MEA initial performance. Membrane material was cast on a lab‐scale polymer casting line operating either within or at the boundaries of the process window. The resulting membrane material was either pristine in the former case, or, in the latter case, contained air bubbles, cracks, and other irregularities, ranging in size from about 0.6 to 3 mm. Spatial polarization experiments were conducted using a 121‐channel segmented fuel cell system, and thermal imaging was performed subsequently to map hydrogen crossover to spatial performance. While total‐cell polarization data was minimally impacted by the irregularities, the spatial diagnostics showed local performance impacts that, in operation over time, could cause degradation in performance or earlier failure of the MEA. Such impacts could lead to these irregularities being classified as defects, i.e., manufacturing variations that should be identified and not included in a fuel cell stack. Classification of irregularities as defects will ultimately assist the industry by contributing to the development of threshold detection limits for in‐line quality control diagnostics.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Effect of Membrane Casting Irregularities on Initial Fuel Cell Performance

et al. 2020

View full text Add to dashboard Cite

show abstract

“… Casting window illustration for varying substrate speed and volumetric flow rate with defects typically seen at each boundary …”

Section: Methodsmentioning

confidence: 99%

Does casting method matter in filtration membranes? A comparison in performance between doctor blade and slot‐die extruded polymeric membranes

Chede

Griffiths

Escobar

et al. 2017

J of Applied Polymer Sci

View full text Add to dashboard Cite

Scaling up from a laboratory batch process to a continuous manufacturing process can result in unexpected changes in membrane morphology and performance. To understand how processing effects the structure and performance of cellulose acetate filtration membranes, membranes were produced using laboratory‐scale doctor blade and industrial/production‐scale slot die casting. Differences in morphology were seen because of the different casting method. However, filtration performance using bovine albumin serum and lipase showed no significant differences. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45563.

show abstract

“…Therefore, they were treated as two kinds of substrates in the experiments. The microstructure of Toray series carbon paper has been measured and studied extensively; thus, it is assumed to be consistent for different batches. Therefore, other properties related with microstructure including permeability, porosity, and average pore radius are assumed to be consistent for different batches.…”

Section: Experimental Validationmentioning

confidence: 99%

Analytical models for predicting penetration depth during slot die coating onto porous media

et al. 2014

Self Cite

View full text Add to dashboard Cite

A series of analytical models have been developed to predict the penetration depth during slot die coating on porous media. Analytical models for both Newtonian and non-Newtonian fluids were derived based on Lubrication Theory, Darcy's law, and a modified Blake-Kozeny equation. Using these models, the penetration depth can be quickly solved and the effects of material properties and processing conditions on penetration depth can be easily investigated. Experiments of coating Newtonian glycerin and non-Newtonian blackstrap molasses onto Toray series carbon paper were conducted to validate developed models. The overall relative error between the predicted and measured penetration depth was found to be typically lower than 20%, which demonstrates the relative accuracy of developed models. Furthermore, based on a parametric study, it was found that the effect of capillary pressure on penetration depth is less than 10% when the ratio of coating bead pressure and capillary pressure is larger than 10.

show abstract

Wetting phenomena during processing of high-viscosity shear-thinning fluid

Cited by 35 publications

References 35 publications

The Effect of Membrane Casting Irregularities on Initial Fuel Cell Performance

The Effect of Membrane Casting Irregularities on Initial Fuel Cell Performance

Does casting method matter in filtration membranes? A comparison in performance between doctor blade and slot‐die extruded polymeric membranes

Analytical models for predicting penetration depth during slot die coating onto porous media

Contact Info

Product

Resources

About