Mathematical modelling of the reverse and metering roll coating flow of Newtonian fluids

✍ Scribed by H. Benkreira; M.F. Edwards; W.L. Wilkinson

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 495 KB
• Volume: 37
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(82)80162-0

✦ Synopsis

Ah&act-A mathematical model of the reverse and metering roll coating flow of Newtonian fluids is presented. It is based on the lubrication approximation and simple physical notions regarding the separation region. These physical notions discard the effect of surface tension on the dynamics of the system. The results of this model give the dimensionless net flux through the nip, AL, as a function of the speed ratio, r, and the radius ratio r, This function is a weak one over the range of r, and r, normally encountered in reverse and metering roll coating operations and is in good agreement with experimental data[l] obtained previously. The results of this present study have also been related to the findings from a previous analysis of forward roll coating [2]. L = qLJMU (4)

where AU is the difference of the linear speeds of rolls and ho the minimum gap between the rolls. Ho and Holland's theoretical value of hr ( = 2/3) is seemingly in good agreement with restricted data for two liquids of equal viscosity and very slightly different density. Despite the obvious technological impact of these systems, no other experimental or theoretical studies have been published in the literature.