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Flexible scraping of viscous fluids

Published online by Cambridge University Press:  09 January 2013

Jacopo Seiwert
Affiliation:
LadHyX, UMR 7646 du CNRS, École Polytechnique, 91128 Palaiseau CEDEX, France Physique et Mécanique des milieux hétérogènes, UMR 7636 du CNRS, ESPCI, 75005 Paris, France
David Quéré
Affiliation:
LadHyX, UMR 7646 du CNRS, École Polytechnique, 91128 Palaiseau CEDEX, France Physique et Mécanique des milieux hétérogènes, UMR 7636 du CNRS, ESPCI, 75005 Paris, France
Christophe Clanet*
Affiliation:
LadHyX, UMR 7646 du CNRS, École Polytechnique, 91128 Palaiseau CEDEX, France Physique et Mécanique des milieux hétérogènes, UMR 7636 du CNRS, ESPCI, 75005 Paris, France
*
Email address for correspondence: [email protected]

Abstract

We study the thickness ${h}_{d} $ of the liquid film left on a wet surface after scraping it with an elastic wiper (length $L$, rigidity $B$) moved at a velocity $V$. The scraper is clamped vertically at a given distance above the substrate, and ${h}_{d} $ is maximal when the tip of the scraper is just tangent to the surface. We show experimentally and theoretically that this maximum thickness is ${h}_{\mathit{max}} \simeq 0. 33L \mathop{ (\eta V{L}^{2} / B)}\nolimits ^{3/ 4} , $ where $\eta $ is the liquid viscosity. The deposition law is found to be sensitive to the shape of the wiper: the film thickness can also be tuned by using wipers with a permanent curvature, and varying this curvature.

Type
Papers
Copyright
©2013 Cambridge University Press

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