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 (300) comprising a multilayer headbox (100) and a forming unit (200). In the method the layers of the three-layer board web are first formed of pulp suspension in the multilayer headbox (100) and fed to only one forming unit (200), 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 (37, 39).

The invention relates to a use of a water-soluble polymer product comprising amphoteric polyacrylamide, which has neutral or cationic net charge at pH 7, a weight-average molecular weight of 2,500,000-18,000,000 g/mol and a total ionicity of 4-28 mol-%. The polymer product is used for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres. The invention relates also to a method for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres, as well as to produced paper or board.

A method of and an arrangement for adding at least one additional stock component to an approach flow system (30) of a fiber web machine by mixing the at least one additional stock component to a fibrous stock such that the stock flow is equalized (50) and the at least one additional stock component is introduced to the stock flow by injection mixing (80).

The invention relates to a use of a water-soluble polymer product comprising amphoteric polyacrylamide, which has neutral or cationic net charge at pH 7, a weight-average molecular weight of 2 500 000-18 000 000 g/mol and a total ionicity of 4-28 mol-%. The polymer product is used for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres. The invention relates also to a method for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres, as well as to produced paper or board.

Equipment for manufacturing a fiber structure in the present disclosure includes: a defibrator configured to pulverize and defibrate a fiber material containing fibers; a transport pipe through which a defibrated material defibrated by the defibrator is transported; a melting-material mixing section configured to mix a melting material into the defibrated material transported through the transport pipe; a fibrous-web forming machine configured to accumulate the defibrated material in which the melting material is mixed and form a fibrous web; a sheet supply section configured to supply a shape-maintaining sheet to the fibrous web; and a heating-and-compression mechanism configured to compress the shape-maintaining sheet and the fibrous web between planar plates and heat the shape-maintaining sheet and the fibrous web to a temperature equal to or higher than a temperature at which the melting material softens.

A method of and an arrangement for adding at least one additional stock component to an approach flow system (30) of a fiber web machine by mixing the at least one additional stock component to a fibrous stock such that the stock flow is equalized (50) and the at least one additional stock component is introduced to the stock flow by injection mixing (80).

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 (300) comprising a multilayer headbox (100) and a forming unit (200). In the method the layers of the three-layer board web are first formed of pulp suspension in the multilayer headbox (100) and fed to only one forming unit (200), which only one forming unit is a gap or combi type twin-wire former, for water removal and for joining the layers of the three-layer board web and water is first removed by a non-pulsating forming shoe (37, 39). The invention also relates to a forming section for forming a three-layer board web, preferably a folding box board (FBB) or a solid bleached (sulfate) board (SBS), which forming section comprises a multilayer headbox (100) and a forming unit (200). The forming unit consist of only one forming unit (200) for water removal and for joining the layers of the three-layer board web and that the one forming unit (200) is a gap or combi type twin-wire former and first water removal means comprises a non-pulsating forming shoe (37, 39).

Methods and apparatuses for producing a zoned and/or layered substrate are described. A method can include providing a first supply of fibers, providing a second supply of fibers, and providing a headbox. The headbox can include a machine direction, a cross-direction, and a first cross-directional divider that separates a first zone of the headbox from a second zone of the headbox in a cross-directional manner. The method can further include transferring the first supply of fibers and the second supply of fibers to the headbox. The method can also include transferring the first supply of fibers and the second supply of fibers through the headbox to provide the substrate.

A system for forming a facer includes a hydroformer that receives a first fluid and a second fluid. A first fluid line is configured to deliver the first fluid to a first inlet pipe and a second fluid line configured to deliver the second fluid to a second inlet pipe. The first fluid line includes a first fiber source that stores a first type of fibers and a first thick stock pump that pumps the first type of fibers to the first inlet pipe. The second fluid line includes a second fiber source that stores a second type of fibers and a second thick stock pump that pumps the second fluid to the second inlet pipe. The first fluid and second fluid are simultaneously poured or delivered onto a porous belt or surface to form the facer.

Methods and apparatuses for producing a zoned and/or layered substrate are described. A method can include providing a first supply of fibers, providing a second supply of fibers, and providing a headbox. The headbox can include a machine direction, a cross-direction, and a first cross-directional divider that separates a first zone of the headbox from a second zone of the headbox in a cross-directional manner. The method can further include transferring the first supply of fibers and the second supply of fibers to the headbox. The method can also include transferring the first supply of fibers and the second supply of fibers through the headbox to provide the substrate.