Process and apparatus for the treatment of a paper or board web

摘要

In a process to apply a coating (5) to e.g. a paper or cardboard web (2), the coating is discharged by a curtain coating assembly (4) and the web then advances via a steam jet discharge (11) station (10) to a broad nip calander (12). The glazing process is effected in an online process together with application of the coating. The broad nip has a length of 40 to 100 mm for coated graphic paper grades and 100 to 200 mm for coated carton grades. The paper or carton is glazed between two drums at a temperature of 170 to 250C and at a pressure of 20 MPa. The paper residence is 0.8 to 50 ms following exposure to steam for 10 to 100 ms. Also claimed is a commensurate assembly.