Steam treatment assembly for moving paper web has steam box defined by end-ribs in contact with the moving web

摘要

In a papermaking process a paper web passes over a steam jet (4) box whose lateral limits are defined by transverse ribs (10, 11) that prevent escape of the steam from the steam compartment (12). The transverse ribs are in contact with the moving web. The transverse ribs have an anti-wear coating on the edge in contact with the moving web. The coating is non-porous plastic or metal e.g. aluminium oxide layer or aluminium oxide ceramic material. The rib width is 12 to 15 mm.