Patent ID: 6730192
Filing Date: 2004-05-04
Classification: D21F

Abstract:
A method for manufacturing printing paper or paperboard with a grammage of 30-200 g/m2 in a paper or paperboard machine, cormprising a wet section, a press section and a drying Section, in which mcthod a web, formed in thc wet section, is pressed in a roll press with a double-felted roll-press nip and, thereafter, in a shoe press with an extended single or double-felted shoe-press nip, wherein:the web is pressed in a deflection-compensating roll press, having said doublefelted roll-press nip and open press rolls; the machine is operated at a web speed of at least 1,200 m/min.; the web in said roll-press nip is subjected to a linear load ranging from 100 to 300 kN/m, and a specific pressure ranging from 5 to 15 MPa; and the web in said shoe-press nip is subjected to a linear load ranging from 500 to 1,500 kN/n, and a spedfic presurc ranging from 4 to 13 MPa; and to obtain a dewatered web with a dry-solids content of at least 35 percent, preferably at least 38 percent, after the roll-press nip and at least 45 percent after the shoe-press nip.