The method, paper machine and base paper for the manufacture of a simple paper coated with lwc quality

摘要

A method, a paper machine and a base paper for the manufacture ofLWC printing paper which is coated once. The paper machine comprises a headbox (100), a gap former (200), a press section (300) which comprises at least one extended nip press, a pre-dryer section (400) in which a web (W) is dried applying at least cylinder drying (R1-R7), a pre-calender (500) in which the web (W) is pre-calendered, at least one portion which is formed of a coating station (600) and an after-dryer section (700) and in which the web (W) is coated on both sides applying a film coating method or a non-contact coating method and dried applying at least contact-free drying (710), an end calender (800) in which the web (W) is calendered, and a reel-up (900) in which the web (W) is reeled. The pre-calender (500) is a calender which is provided with at least one nip (NEl, NE2) and in which both surfaces of the web are in contact with a calendering backup surface having a surface temperature of at least 200 °C, advantageously at least 250 °C, the total length of the nip or nips of the pre-calender is in a range of 15-600 mm, advantageously in a range of 30-600 mm, the linear load of each nip is in a range of 50-500 kN/m, advantageously in a range of 100-400 kN/m, and the moisture content of the web before the first nip of the pre-calender (500) is in a range of 5-20 %, advantageously in a range of 6-15 %.