Calendering normal stresses

Example 15.1 The Significance of Normal Stresses We consider the calender geometry of Fig. 6.22 (shown here) and make the same simplifying assumptions as in Section 6.4, but instead of a Newtonian or Power Law model fluid, we assume a CEF model that exhibits normal stresses in viscometric flows. By accepting the lubrication approximation, we assume that locally we have a fully developed viscometric flow because there is only one velocity component vx, which is a function of only one spatial variable y. 

Fig. 15.8 Calculated and measured differences of the primary normal stresses in the calender gap for two different planes y(x=o) — Hq/2. [Reprinted by permission from D. Mewes, S. Luther, and K. Riest, Simultaneous Calculation of Roll Deformation and Polymer Flow in the Calendering Process, 7nr. Polym. Process., 17, 339-346 (2002).]...

The conversion of thermoplastic polymers to finished products is normally accomplished upon the application, at high temperatures, of high shear stresses on viscous polymer melts, e.g. during extrusion. Kneading, mixing, and calendering are further manufacturing techniques used in com-... 

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