Pressure distribution in a two-roll mill.

Abstract

An asymmetric pressure distribution in a pair of rolls rotating at equal and unequal speed for Newtonian fluid was obtained by lubrication model analysis and was compared with experimental values. The work was carried out with a pair of rolls of radius /?=8.2cm in the range of fluid viscosity \i=1.5-15Pa s, half of minimumnip clearance h0 =35-390/an, meanroll speed um=0.26-1.56m/s and roll speed ratio Nr=0.5-1. The experimental pressure profiles and force separating rolls are well represented by the calculated values in the region of N'ca (=fiuf(R/h0)2/y)<2.5 x 107, where y is liquid surface tension. In the range of 7Vc'a>2.5 x 107, the absolute values of the minimum pressure decrease with increasing N 'ca. The theoretical pressure distribution can be well corrected by considering that the liquid film separating point predicted by the theory comes near to the minimumnip.

Measurement of pressure distribution in a deformable nip of counter-rotating rolls

“…Although good agreement was found between the theoretical and experimental results, the model was suitable for predicting the maximum positive pressure in the nip, but not in the subambient region. Murakami et al (1985) reported the development of a model for the prediction of pressure based on lubrication theory. They were capable of predicting the pressure between counterrotating rolls at low speed with Newtonian fluids.…”