Enhancing Paper Properties on Supercalenders, 2002 Technology Summit Proceedings

B. Vyse, T. H. Steele, P. Neill, G. Geub & T. Makinen

While on-line supercalendering is not new, there has been a recent dramatic increase in the number of commercial applications, especially on high speed, uncoated specialty grade machines. These applications have re-awakened an interest in CD and MD gloss and CD caliper improvements, not just with the on-line supercalender applications but also on conventional supercalenders. Perhaps this latter interest is driven by a desire to improve the quality and productivity of the conventional supercalender installation. De-bottlenecking the mill through supercalender optimization is a term heard often, along with the desire to improve operating efficiencies to compete with on-machine calendering. Many applications, on- and off-machine, are seeking quality improvements that require additional control mechanisms, such as external roll heating.

The use of steam and induction energy to allow increased speed and improved CD profiles is well known in the conventional 2 or 4 nip hot soft calender application and is easily applied to the on- and off-line supercalender. This paper will review the technology, application, and results from a wide range of recent induction energy and steam box applications on coated and uncoated grade supercalenders, both of the on- and off-machine variety.