NUMERICAL-CALCULATION OF THE COATING PROC ESS BETWEEN 2 ROLLS RUNNINGIN THE SAME DIRECTION

Rotating rolls are used to apply liquids as thin films to paper or oth er materials which are utilized as films. In this contribution a numer ical method is applied which solves the pulse balance with the support of FEM, taking free surfaces into consideration. The coupled energy e quation is solved on the basis of the Boundary Element Method (BEM). i nfluential physical units are summarized in the friction number the ca pillary number the Reynolds number; the Stokes number and the length r atio. The influence of the physical entities is investigated and the c alculated pressure-, velocity-, tension-, and temperature fields are d isplayed graphically. A temperature gradient superimposed to the curre nt between the roll surfaces permits an additional influence on the cu rrent field and the coating thickness. The results of the numerical ca lculations are summarized in an empirical approximation equation.