Process for eliminating so-called stain rings on the rolls of a calender and corresponding paper-refining unit

摘要

On a calender downstream of a coating machine, a steam spray pipe (6) associated with a scraper (7) is provided for removing stain rings (5) formed by coating material settling on the roll. The steam spray pipe can be divided into a plurality of zones (11,12,13) which can be charged separately. When a stain ring (5) has formed, steam is passed against the roll (1) in the zone concerned and, after a short period of action, the scraper (7) is applied to the roll (1) in order to remove the softened stain ring (5). <IMAGE>