Metso Paper Inc.

Valmet Corporation

Valmet Technologies Oy

Valmet Technologies, Inc.

Valmet Ab

Metso Automation Oy

Antti Poikolainen

Ari Puurtinen

Samppa J Salminen

Jorma Snellman

Mika Viertola

Kari Lamminmäki

Jorma Laapotti

Jyrki Jaakkola

Ari Linsuri

Juhana Lumiala

Pertti Heikkil&auml;

Juan Cecchini

Janne Puustinen

Kari Räisänen

Michael H Odell

Reijo Pietikäinen

Juha Kivimaa

Hannu Korhonen

Antti Leinonen

Karl-Johan Tolfsson

Seppo Kiviranta

Lauri Verkasalo

Hannu Lepomäki

Pertti K Heikkilä

Erkki Partanen

Janne Lappi

Jeffrey C Irwin

Sami Anttilainen

Aimo Närväinen

Petri Jetsu

Michaell Odell

Pasi Turpeinen

Heikki Ilvesp Aa

Kari Raisanen

Jukka Muhonen

Janne Laakso

Marko J Moilanen

Teuvo Virkkunen

Hannu Turpeinen

Samppa Ahmaniemi

Juan Carlos Cecchini

Kari RÄISÄNEN

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 forming section has a lower wire loop (), which constitutes a single-wire section (T) following a breast roll (). A first dewatering zone (Z) has at least one stationary, first forming shoe () followed by a pulsating strip cover (). The first forming shoe has leading and trailing edges and underpressure affecting through holes of the cover. The holes are openings or slots substantially in the longitudinal direction of the machine, whereby non-pulsating dewatering is applied on the stock travelling on top of the lower wire. A pulp suspension jet is fed from a headbox () at an impact point after the shoe leading edge. The cover is straight at least in the area between the impact point of the pulp suspension jet and the trailing edge. The impact of the pulp suspension jet on the forming wire is thus better controlled in a better way, increasing production speed.

Forming section

A multi-layer web formation section has two successive wire units () with a common wire (). A first headbox () supplies fiber pulp to the first wire unit () forming a first partial web (W). A second headbox () supplies a new fiber pulp layer to the forward end of the second wire unit () atop the first partial web. A first non-pulsating dewatering zone (Z) in the forward end of a two-wire stretch of the second wire unit () has a first formation shoe () with a curved cap () placed on the side of the new layer having openings () extending through the cap () with an under-pressure (P) affecting therethrough. A two-wire stretch of the second wire unit () has a second pulsating dewatering zone (Z) formed by fixed dewatering lists (), between which there are gaps () and an under-pressure (Pb) affecting in these.

Multi-layer web formation section

A multi-layer web formation section has at least two successive wire units (). First and second headboxes () supply pulp suspension jets to the forward end of the first wire unit () and the second wire unit respectively to form a first partial web (W) and a second partial web (W) which are joined at a joint (N) between the second wire unit () and a bottom wire (). A first non-pulsating dewatering zone (Z) in the forward end of a two-wire stretch of the second wire unit () is formed by a fixed formation shoe () having a curved cap () placed against one side, having openings with an under-pressure applied. A two-wire stretch of the second wire unit () has a second pulsating dewatering zone (Z), formed by fixed dewatering lists () in the cross machine direction with gaps () therebetween with an under-pressure (Pb) applied.

A forming section of a paper or board machinein the forming section of a paper or board machine has a coverhaving an outlet groovebetween a suction zoneof circular holes and an outlet edge. A wire comes to the cover area from an inlet edgeand leaves from an outlet edge. The outlet grooveis essentially in the cross-machine direction of the cover. The suction zone accomplishes non-pulsating dewatering, and the outlet groove accomplishes pulsating dewatering. The non-pulsating suction zone first accomplishes good retention, and after this formation is improved on the outlet groove. When pulsating dewatering takes place in the same direction as non-pulsating dewatering and immediately after non-pulsating dewatering, the web formed has a particularly good formation potential. Potential marking caused by non-pulsating dewatering can also be removed efficiently by means of pulsating dewatering taking place on the same side.

Dewatering element having non-pulsing dewatering followed by pulsing dewatering

Fibrous stock is supplied by a paper or board machine headbox () between looped forming wires (). Water is removed in a first dewatering zone (Z) formed with a fixed forming shoe () having a curved surface against which a wire () is supported while the opposite wire () is unsupported in the area of the shoe (). Water is removed in a second dewatering zone (Z) formed by fixed dewatering blades () on the other side of the wires () and supported against the stock therebetween () and on the opposite side of the wires () by dewatering blades (), loaded in a controlled manner against the fixed dewatering blades () at gaps () between these so that pulsating dewatering is caused in the second zone (Z). The wires () are guided so the shoe () causes essentially non-pulsating dewatering in the stock.

Forming of a paper or board web in a twin-wire former or in a twin-wire section of a former

A web is formed between two wire loops (), in a wire section of a paper or board machine, in connection with which dewatering elements () are placed and in which water is drained from a stock suspension from between the two wires (). In the region of a twin-wire zone, a suction roll () is placed within one wire loop and a suction box () having a curved surface is situated in opposed relationship with the suction roll () on the wire loop. After the suction box (), the web is guided, due to the effect of a vacuum of the suction roll (), forwards on the surface of the wire loop of the suction roll ().

Arrangement for a wire section of a paper or board machine

At the end of the twin wire zone of a paper machine former, a suction box () inside the upper wire loop () has a curved lid (') opposite a roll () within the lower wire loop (). The lid is curved in a run situation so the tension of the upper wire () reduces the normal force between the wire () and the lid (&#x2032;) caused by the underpressure of the suction box. The underpressure keeps the web mainly off from the roll () and the lower wire () while being adhered to the underside of the upper wire () and conforming to the curved shape of the lids. Members (&#x2032;) are provided for making the web follow the lower wire () in a break situation for conducting it to the broke handling system.

Arrangement in the wet end of a paper machine

Suction box in a paper machine including a vacuum chamber, a deck or a number of substantially U-section holders open toward a wire and ribs arranged in the deck or the holders so that they can be loaded against the wire. At least in a running situation, the deck of the suction box is curved or the ribs are arranged to provide a curve run of the wire so that the wire tension of the curved run over the deck or ribs serves to lower a normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck or ribs.

Suction box in a paper machine

A method in a paper machine for transferring a paper web from a wet wire in a former section to a pick-up fabric or an equivalent transfer fabric of a press section, including the steps of forming a pick-up point on the wet wire and separating an edge strip from at least one edge of the web prior to the pick-up point by means of at least one cutting device. The method further includes separating the web from the wet wire and passing the web onto the pick-up fabric at the pick-up point. The method also includes applying a pressure difference to the at least one edge strip through the wet wire or the pick-up fabric at or after the pick-up point to cause the at least one edge strip to either follow the wet wire or become separated from the pick-up fabric after the pick-up point and to be placed in a broke system arranged beneath the paper machine.

Device in a paper machine for transfer of the web from the former section to the press section

A sample collecting device takes samples from the white water drained from the web through the wire in the wire part, at a number of points in the cross direction of the web. An analyzer analyses the samples and forms a retention profile for controlling the paper machine. The device for measurement and regulation of the retention profile comprises means for measurement of the retention profile across the web width from different points of width of the web. The headbox comprises ducts passing to different points of width of the headbox to pass a flow of liquid containing a retention agent in the headbox into connection with the stock flow to regulate the retention profile across the web width. The ducts have valves which are regulated on the basis of the retention profile data for regulating the retention agent into duct flow.

Method and device for measurement of the retention profile and for control of the retention in a paper/board machine

The invention relates to a headbox ( ) for a paper/boardmaking machine. The headbox ( ) including a stock flow header ( ) and, following the stock flow header, a piping system such as an inlet pipe manifold, and/or a turbulence generator ( ) and a tapered slice ( ), wherefrom the stock is passed onto the forming wire (H ). The construction of said headbox further includes a flow header (J) for a dilution liquid the flow header having connected thereto an inlet channel (S ), a return pipe (S ) and outlet channels (D , D , D , . . . ) that are distributed over the full length of said flow channel for passing the dilution water to control valves (V , V , . . . ) and, therefrom, further to different points along the cross-machine width of the headbox so as to mix with the stock delivered from the stock flow header ( ) in order to control the consistency of the stock to a desired value, thus accomplishing the control of the web basis weight profile in cross-machine direction over the headbox. The dilution water flow header (J) is structured to accomplish mixing of the dilution water flow (L ) so as to make the consistency of the dilution water flow (L ) homogeneous both along the entire length of the flow header (J) and in cross sections of the flow taken in planes perpendicular to the longitudinal axis of the flow header.

Headbox for a paper or board making machine

A suction box in a paper machine including a vacuum chamber, a deck or a number of substantially U-section holders open toward a wire and ribs arranged in the deck or the holders so that they can be loaded against the wire. At least in a running situation, the deck of the suction box is curved or the ribs are arranged to provide a curve run of the wire so that the wire tension of the curved run over the deck or ribs serves to lower a normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck or ribs. A method in a suction box in a paper machine, wherein a vacuum is formed in a vacuum chamber of the suction box and, during formation of the vacuum, the deck and/or the ribs is/are pressed against the wire. At least in a running situation, the curve form of the deck of the suction box or the position of the ribs is such that the tension of the wire running over the deck or ribs lowers the normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck/ribs.

Suction box in paper machine and method in the suction box in a paper machine

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Jyväskylä, Finland

Antti Poikolainen