An efficient and simple numerical technique is presented for analyzing nonisothermal nip flow of viscous liquids. It has been applied on calendering to calculate the design parameters as well as the interaction effects between roller characteristics, operation conditions, and material properties. Viscous heating is shown to drastically change the mechanics near the nip exit if the rollers rotate at different speeds. Consequences for scaling‐up and model experiments are indicated.

No abstract

The squeezing flow of a printing ink in the nip between rotating rollers is investigated. A numerical analysis is used which takes into account the viscoelastic nonlinear behavior of the deformable roller. Contributions from the central creeping flow zone to tack reading are calculated and compared with experiments for three different rubbers on the measuring roller. The said zone only contributes a minor fraction to the tack force. Nevertheless the effect of roller characteristics on performance can be understood on the basis of the creeping flow theory. Slip is found to be an important element in quality considerations of tackmeters. Its effect on tack is investigated theoretically and experimentally. The flow pattern is so complicated that no simple scaling-up procedure can be formulated.Systematic experiments show a vehicle-related effect which might be associated with fluid elasticity.