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The coating of Newtonian liquids onto a roll rotating at low speeds
Author(s) -
Tharmalingam S.,
Wilkinson W. L.
Publication year - 1978
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760181506
Subject(s) - meniscus , dimensionless quantity , materials science , mechanics , capillary action , capillary number , newtonian fluid , momentum (technical analysis) , radius , curvature , inertia , radius of curvature , coating , composite material , classical mechanics , optics , physics , geometry , mean curvature , mathematics , incidence (geometry) , finance , mean curvature flow , computer science , economics , computer security
A theoretical treatment is presented for the prediction of the rate at which a liquid is entrained by a roll which is rotating partially submerged in a Newtonian liquid, and also for the prediction of the variation in the thickness of the film around the roll. The method involves the integration of the momentum equation after neglecting inertia forces in the dynamic meniscus region and the matching of the surface curvature with that derived for the static meniscus region near the liquid surface. The resulting equation allows the prediction of the relationship between a dimensionless film thickness parameter, T , and the capillary number, Ca , as a function of the radius of the roll, the withdrawal angle and the position of the roll periphery. The liquid flux on the roll can also be predicted.