Valmet Corporation

Juhani Saari

Stefan Kuni

An arrangement and method for calendering a board web including a calender providing a hot and hard calendering nip formed by two calender rolls and through which the board web passes. At least one of the calender rolls is arranged to be heated to such a temperature that the surface layer of the board web placed at the side of this roll reaches its vitrification temperature in the calendering nip. A film press is arranged directly before the calendering nip in the direction of transfer of the board web and includes a film press nip through which the board web is passed. The film press nip is arranged to transfer a liquid layer onto the face of the board web so as to moisten the board web. The board web is transferred from the film press nip into the calendering nip while the surface layer of the web is at the moisture level determined by the film press in view of producing a controlled moisture gradient.

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Tampere, Finland

Juhani Saari