To coat a moving paper/cardboard web on both sides, a coating is applied indirectly to one side to give a shallow penetration depth, and coated indirectly on the other side with a greater penetration depth

摘要

To apply a coating to both sides of a moving paper or cardboard web (14), a coating is applied initially to one side (14a) by an indirect application so that the coating medium penetrates through the web by a given depth (T1). The web passes through a drying stage before the other side (14b) of the web is coated indirectly for the coating to penetrate by a second depth level (T2), which is greater than the penetration from the first coated side. The web passes through a further drying stage. The penetration of the first coating is a maximum of 50% of the web thickness (D) and preferably 20-35%. The penetration of the second coating is 55-75% of the web thickness.