The most cost-effective press roll cover - hard or soft grooved roll?

摘要

Since water can be removed more cost-effectively from the sheet at the press section than at the dryer section of a paper machine, the press rolls of any machine running faster than 1000 m/min have been grooved, rather than drilled, for more than a decade now. Sufficiently closely spaced grooving creates an efficient exit route for water, thereby clearly improving sheet dewatering compared to plain or simply blind-drilled press rolls.