Date of Award

12-1991

Degree Name

Master of Science

Department

Chemical and Paper Engineering

First Advisor

Dr. Nicholas G. Triantafillopoulos

Second Advisor

Dr. James E. Kline

Third Advisor

Dr. Raymond L. Janes

Access Setting

Masters Thesis-Open Access

Abstract

In this study the total dynamic force (TDF) acting on the blade was determined at three different web speeds. The objective was to compare quantitatively the experimental results with the predictions of existing models to show whether or not any of these models predict coat weight development. The existing models include the lubrication theory, impact model, lateral force, and combinations of these models.

Under the conditions investigated, the estimated TDF was in good agreement only with the impact force (sum of impulse and hydrodynamic forces) model of blade coating. The impulse force accounted for 94% of the TDF and, therefore, was considered the dominant contributor to coat weight development. Data suggested that the momentum change of coating layer entering the blade tip region has been counted twice in the original proposed model. If lubrication flow alone was considered at the blade tip, the hydrodynamic lift could contribute maximum 30 to 48% of the TDF. Finally, the recently proposed lateral force at the nip was calculated to be only 6 to 7% of TDF.

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