Kemira Oyj

Valmet Technologies Oy

Valmet Technologies, Inc.

Metso Paper Inc.

Juan Cecchini

Antti Poikolainen

Matti Hietaniemi

Mikko Virtanen

Reijo Pietikäinen

Juha Kivimaa

Kimmo Strengell

Hannu Lepomäki

Kari Lamminmäki

Teuvo Virkkunen

Pekka Hilden

Vesa LUHTAMÄKI

Petteri Soini

The invention relates to a method for forming a three-layer board web, preferably a folding box board (FBB) or a solid bleached (sulfate) board (SBS), in a forming section () comprising a multilayer headbox () and a forming unit (). In the method the layers of the three-layer board web are first formed of pulp suspension in the multilayer headbox () and fed to only one forming unit (), a gap former where the pulp suspension from the multilayer headbox is fed to a gap between lower and upper wires for water removal and for joining the layers of the three-layer board web and where water is first removed by a non-pulsating forming shoe ().

Method of forming a three-layer board web and a forming section of forming a three-layer board web

A method for forming a multi-ply fiber web in which least part of the sizing of the multi-ply fiber web is provided by applying sizing agent in the form of foam by a curtain type application device (C, C) in between at least two layers of the multi-ply fiber web in the forming section. The invention also relates to a forming section for a multi-ply fiber web having at least one twin-wire forming part formed between a wire () for the bottom layer and a wire () for the top layer of the multi-ply fiber web, where the layers are joined, and the treated layers combined. The forming section has a curtain type application device (C, C) for applying sizing agent in the form of foam in between two layers of the multi-ply fiber web in the forming section of a multi-ply fiber web production line.

Method for sizing a multi-ply fiber web and a forming section for a multi-ply fiber web

A method is disclosed for increasing strength properties, preferably burst strength and SCT strength, of a paper or board product. The paper or board product is manufactured from a fibrous web produced by a multilayer headbox, where an aqueous layer is formed between at least a first and a second fibre layer formed from fibrous stock suspension(s), and where feed water for the aqueous layer includes at least one cationic polymer. The method of the invention includes adding an anionic additive selected from a group comprising anionic synthetic organic polymers, anionic polysaccharides, and any of their combinations to the feed water before formation of the aqueous layer.

Method for increasing the strength properties of a paper or board product

Growing community of inventors

Jyväskylä, Finland

Juan Cecchini