首页   按字顺浏览 期刊浏览 卷期浏览 Reverse roll coating of non‐Newtonian liquids
Reverse roll coating of non‐Newtonian liquids

 

作者: D. J. Coyle,   C. W. Macosko,   L. E. Scriven,  

 

期刊: Journal of Rheology  (AIP Available online 1990)
卷期: Volume 34, issue 5  

页码: 615-636

 

ISSN:0148-6055

 

年代: 1990

 

DOI:10.1122/1.550145

 

出版商: The Society of Rheology

 

关键词: Reverse roll coating;Flow field in cylinder gap;Flow instabilities;Capillary number;NON−NEWTONIAN FLUIDS;COATINGS;SHEAR FLOW;DEPOSITION;STEADY FLOW;FLOW RATE;SOLUTIONS;ORGANIC POLYMERS;FILM FLOW

 

数据来源: AIP

 

摘要:

The essence of reverse roll coating is the rapid high‐shear flow in a small gap between two rigid cylinders rotating with opposed surface speeds. The flow field established in this gap, including the free surface locations and flow rate, is determined mainly by the balance of viscous and surface tension forces, as measured by the capillary number. Non‐Newtonian rheological behavior can strongly affect both the steady, uniform flow and the instabilities to which it is susceptible. Computed solutions of the governing equations indicate that flows of purely viscous liquids differ little from those of Newtonian liquids at the same capillary number, provided that the dimensionless force ratio is defined with the viscosity at the appropriate shear rate. Experiments with shear thinning but relatively inelastic algin solutions confirm this, with the exception that ribbing is strongly exaggerated, presumably by slight elasticity of the liquid. Experiments with highly elastic polyacrylamide solutions show that the coating thickness and the nature of the instabilities can be dramatically altered.

 

点击下载:  PDF (996KB)



返 回