Valmet Corporation

Valmet Oy

Valmet Paper Machinery Inc.

Metso Paper Inc.

Jorma Laapotti

Mikko Karvinen

Juhani Pajula

Reima Kerttula

Samppa J Salminen

Antti Poikolainen

Ari Puurtinen

Mika Viertola

Pertti Heikkil&auml;

Nils Soderholm

Janne Puustinen

Heikki Kaasalainen

Kari Juppi

Antti Komulainen

Juha Lipponen

Antti I Ilmarinen

Antti Kuhasalo

Heikki Ilvespaa

Juha Kaihovirta

Juha Kivimaa

Matti Kurki

Riku Pihko

Petter Honkalampi

Markku Lyytinen

Veijo Miihkinen

Reijo Jokinen

Olli Tapio

Pekka Taskinen

Petteri Halme

Tatu Halonen

Martti Hipsimaki

Jukka Kinnunnen

Jukka Kinnunen

An arrangement is disclosed for controlling the web in a press section of a paper of board machine wherein the press section includes a press nip and two fabrics arranged to travel through it. In addition, the press section includes a suction roll with a suction apparatus fitted after the press nip. The suction apparatus includes at least one suction case, which is arranged in a closing throat and/or an opening throat formed by one of the fabrics and the suction roll. The suction case is also arranged before and/or after the suction roll in the edge of the fabric in order to create a suction effect in a narrow edge area of the web.

Arrangement for controlling the web in a press section of a paper or board machine

A method and an apparatus for web threading in a drying section of a paper machine or the like. A leader () and a so called run-down strip are formed by cutting in the web coming to the drying cylinder in the drying section. An underpressure box () is arranged at the opening gap between the drying cylinder () and the drying wire, on that side of the wire which is away from the web, whereby this box can direct against the web an underpressure which is controllable in the machine's cross direction. The underpressure box creates an underpressure region (') between the leader and the underpressure box, the region having an underpressure pat the detachment point, i.e. in the area where the wire is detached from said drying cylinder (), which underpressure is sufficient to detach the leader from said drying cylinder. A protection zone is created between the underpressure region created at the leader and the run-down strip, which protection zone has a barrier () in order to maintain the underpressure pin the underpressure region.

Method and apparatus for web threading in a drying section of a paper machine or similar

Printing paper or paperboard of 30-200 g/m grammage is made in a machine with a wet section, press section and drying section. The web passes through a roll press with a double-felted roll-press nip, then in a shoe press with an extended single or double-felted shoe-press nip, and pressed in a deflection-compensating roll press, having a double-felted roll-press nip and open press rolls. The web travels at at least 1,200 m/min.; is subjected in the roll-press nip to a linear load from 100 to 300 kN-m and a specific pressure from 5 to 15 MPa; and is subjected in the shoe-press nip to a linear load from 500 to 1,500 kN/m and a specific high pressure from 4 to 13 MPa, to obtain a dewatered web with a dry-solids content of at least 38 percent after the roll-press nip and at least 45 percent after the shoe-press nip.

Method and machine for manufacturing printing paper or paperboard

A paper or board machine having a double-felted first press nip and a double-clothed second press nip. According to the invention the first press nip has a suction roll with suction zone, the downstream end of which is situated downstream of the press nip, the top felt being separated from the bottom felt at a point before the downstream end of the suction zone. The bottom felt of the first press nip carries the web to the second press which has a top felt which carries the web from the bottom felt of the first press nip to the second press nip, which is an extended press nip. A pickup suction roll is arranged in the top felt loop of the second press for transfer of the web from the bottom felt of the first press to the top felt of the second press. The latter bottom felt leaves the suction roll at the downstream end of the suction zone and is provided in its loop with suction boxes situated at a point before the transfer of the web to the top felt of the second press. Heat-supply devices are arranged outside the two top felts at points where one side of the web is exposed and the other side adheres to the top felts.

Machine for manufacturing paper or board

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

The invention relates to a former-press section ( ) of a paper machine and to a method of transferring a web from a former to a press section. Between the former section ( ) and the press section ( ) there is a pre-press zone (PP) which removes water from the web (W) and through which the web (W) is passed as a closed draw from the former section ( ) to the press section ( ). The upper wet wire ( ) or the equivalent transfer wire ( A) of the former section ( ) is passed through the pre-press zone (PP), the web (W) being passed on the lower face of said wire into and through the pre-press zone (PP). Inside the loop of the upper wet wire ( ) or of the equivalent transfer wire ( A) and/or inside the loop of the lower wet wire ( ) there are transfer devices ( ) based on the use of a pressure difference. The transfer devices ( ) are arranged to operate in connection with threading or an operational malfunction such that the web (W) is separated from the upper wet wire ( ) or the equivalent transfer wire.

Former-press section in a paper machine and method for transfer of the web from the former to the press section

A method and apparatus for producing paper or board, according to which the paper or board web is transferred continuously supported through a drying section of a paper or cardboard machine and both sides of the web are treated with a treating agent on a long nip applicator included with the drying section of the machine. The web is transferred from the last press nip of the press section to the first dryer of the dryer section with a continuous loop-like support member, for example, by a transfer belt, transfer felt or one of the press felts of the press section. The web is advantageously dried in the drying section with a blow unit on a porous drying felt by blowing hot air on the web with impingement dryers, and the drying felt may be cooled.

Method and apparatus for handling paper or cardboard webs

A press section of a paper making machine for dewatering a paper web (W) formed in a preceding forming section in which dewatering felts ( ) are applied to both surfaces of the paper web (W) as the paper web (W) travels in a closed draw from the forming section through a first extended nip press (NP ), thereby drawing a substantial amount of water simultaneously and symmetrically from both surfaces of the paper web (W). The upper felt ( ) transports the paper web (W) from the first extended nip (NP ) to a smooth surfaced center roll ( ) where the paper web (W) passes through at least one roll nip (N , N ) or extended nip (NP &prime;, NP &prime;). The center roll ( ) is positioned at an elevation higher than the first extended nip (NP ) thereby reducing the length of the press section. In a second roll nip (N ), a press fabric ( ) is substituted for the upper felt ( ) to efficiently remove additional water. Additional extended or roll nips (NP , N , N , N ) may be interposed between the center roll ( ) and the succeeding drying section, between the forming section and the first extended nip (NP ), or between the first extended nip (NP ) and the center roll ( ).

Press section of a paper making machine employing an extended nip press

Method and device in a paper machine for transfer of the web from the former section to the press section

A method for transferring a paper web in high-speed paper machines having a press section arranged between a web former and a dryer section. In the press section, there is one or more press nip zones dewatering the web, at least the last one of which is an extended nip through which at least two press fabrics that receive water are passed. The web is passed between the press fabrics through the last extended-nip zone so that the draining of water out of the web takes place through both faces of the web. After the last extended-nip zone, the web follows one of the fabrics passing through the last extended-nip zone by the effect of a difference in pressure avoiding rewetting of the web. The fabric carrying the web is passed through a gently loaded transfer nip zone in which the web is transferred onto a transfer surface more adhesive than the face of the fabric. The web is transferred on this transfer surface as a closed draw onto the drying wire or equivalent in the dryer section following after the press section.

Methods for transferring a web in a paper machine from a two-felt press

An arrangement and method for transferring a paper web in high-speed paper machines having a press section arranged between a web former and a dryer section. In the press section, there is one or more press nip zones dewatering the web, at least the last one of which is preferably an extended nip through which at least two press fabrics that receive water are passed. The web is passed between the press fabrics through the last extended-nip zone so that the draining of water out of the web takes place through both faces of the web. After the last press nip zone, the web follows one of the fabrics passing through the last extended-nip zone by the effect of a difference in pressure avoiding rewetting of the web. The fabric carrying the web is passed through a gently loaded transfer nip zone in which the web is transferred onto a transfer surface more adhesive than the face of the fabric. The web is transferred on this transfer surface as a closed draw onto the drying wire or equivalent in the dryer section following after the press section.

Arrangement and method for transferring a web in a paper machine from a

A paper or board machine and a method for passing a paper or board web from a forming section to a press section in a paper or board machine wherein the web is carried on a first wire in the forming section or transferred to a first wire from a forming wire of the forming section. The web that runs on the first wire is made to adhere in a transfer and pre-press zone to an outside face of a transfer belt which is substantially non-water-receiving. The pre-press zone includes an extended nip defined by an extended-nip roll and a smooth-faced press roll, the extended-nip roll having a hose mantle and a press shoe arranged in a loop of the hose mantle. After this pre-press zone, the web is separated substantially immediately from the wire and passed on support of the transfer belt onto the next press fabric in the press section and/or into the next press nip. In the pre-press zone or zones, a substantial amount of water is removed out of the web substantially in one direction only, and, at the same time, the web is made to adhere reliably to the outside face of the transfer belt.

Method and machine for removing water from a paper or board web by

An arrangement and method for transferring a paper web in high-speed paper machines having a press section arranged between a web former and a dryer section. In the press section, there is one or more press nip zones dewatering the web, at least the last one of which is an extended nip through which at least two press fabrics that receive water are passed. The web is passed between the press fabrics through the last extended-nip zone so that the draining of water out of the web takes place through both faces of the web. After the last extended-nip zone, the web follows one of the fabrics passing through the last extended-nip zone by the effect of a difference in pressure avoiding rewetting of the web. The fabric carrying the web is passed through a gently loaded transfer nip zone in which the web is transferred onto a transfer surface more adhesive than the face of the fabric. The web is transferred on this transfer surface as a closed draw onto the drying wire or equivalent in the dryer section following after the press section.

Transfer of a web in a paper machine from a two-felt press nip to a

A press section in a paper machine through which a paper web has a closed and supported draw and a method and arrangement for compensating for elongation of the web in an equalizing press nip in the press section. The press section has at least two successive separate nips and dewatering of the paper web is carried out at least in the first one of these nips, preferably between two press fabrics that receive water. The last press nip in a running direction of the web is the equalizing press nip which may be separate from the preceding nip and in which no substantial dewatering is performed. The web may be passed through the equalizing press nip from the preceding dewatering press nip on a transfer belt substantially non-water-receiving. After the equalizing nip, the elongation of the paper web in the machine direction, which elongation takes place in the equalizing nip, is compensated for by a difference in speed of the transfer belt.

Press section with an equalizing nip for compensating for elongation of

A press section of a paper making machine for dewatering a paper web (W) formed in a preceding forming section in which dewatering felts (11, 28) are applied to both surfaces of the paper web (W) as the paper web (W) travels in a closed draw from the forming section through a first extended nip press (NP.sub.1), thereby drawing a substantial amount of water simultaneously and symmetrically from both surfaces of the paper web (W). The upper felt (11) transports the paper web (W) from the first extended nip (NP.sub.1) to a smooth surfaced center roll (30) where the paper web (W) passes through at least one roll nip (N.sub.1, N.sub.2) or extended nip (NP.sub.2 ', NP.sub.3 '). The center roll (30) is positioned at an elevation higher than the first extended nip (NP.sub.1) thereby reducing the length of the press section. In a second roll nip (N.sub.2), a press fabric (33) is substituted for the upper felt (11) to efficiently remove additional water. Additional extended or roll nips (NP.sub.2, N.sub.3, N.sub.0, N.sub.E) may be interposed between the center roll (30) and the succeeding drying section, between the forming section and the first extended nip (NP.sub.1), or between the first extended nip (NP.sub.1) and the center roll (30).

Growing community of inventors

Palokka, Finland

Jorma Laapotti