Patent ID: 6869505

Claim:
A method for calendaring an uncoated board web for manufacture of board grades White Lined Chipboard (WLC) and Folding Box Board (FBB) in a long nip shoe calendar, the method comprising the steps of: passing the web at a first speed through a long nip shoe calender having a long nip formed between a shoe roll and a thermo roll, the long nip having a length such that the dwell time of the web within the nip is greater than 10 ms, and applying a nip pressure below 3 MPa, and wherein a surface temperature of the thermo roll is greater than 200° C., and wherein a calender belt having a hardness of below 100 ShA is used on the shoe roll; and moisturizing the board web surface to be pressed against the thermo roll before the nip by spraying atomized water onto said board web surface in an amount of 1-20 g/m 2 such that the time of action of the water before the nip is about 0.1-2 s.