Abstract: 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).

Abstract: 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 (C10, C20) 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 (10) for the bottom layer and a wire (20) 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 (C10, C20) 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.

Abstract: 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).

Abstract: 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 (C10, C20) 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 (10) for the bottom layer and a wire (20) 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 (C10, C20) 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.

Abstract: The invention relates to a forming section (2) for forming a fibrous web (W). The forming section (2) comprises a first forming fabric (3) arranged to run in a loop supported by guide elements (4) and a second forming fabric (5) arranged to run in a loop supported by guide elements (4). The second forming fabric (5) is arranged so in 5 relation to the first forming fabric (3) that the two forming fabrics (3, 5) converge towards each other to form an inlet gap (6) into which stock can be injected. A forming roll (7) is arranged within the loop of the second forming fabric (5) to guide the second forming fabric (5) into the inlet gap (6) and to guide the first and the second forming fabric (3, 5) along a part of their path which is common to both the first and the second 10 forming fabric (3, 5) and which begins at the inlet gap.

Abstract: The invention relates to a forming section (2) for forming a fibrous web (W). The forming section (2) comprises a first forming fabric (3) arranged to run in a loop supported by guide elements (4) and a second forming fabric (5) arranged to nm in a loop supported by guide elements (4). The second forming fabric (5) is arranged so in 5 relation to the first forming fabric (3) that the two forming fabrics (3, 5) converge towards each other to form an inlet gap (6) into which stock can be injected. A forming roll (7) is arranged within the loop of the second forming fabric (5) to guide the second forming fabric (5) into the inlet gap (6) and to guide the first and the second forming fabric (3, 5) along a part of their path which is common to both the first and the second 10 forming fabric (3, 5) and which begins at the inlet gap.

Abstract: A forming section has a lower wire loop (11), which constitutes a single-wire section (T) following a breast roll (12). A first dewatering zone (Z1) has at least one stationary, first forming shoe (40) followed by a pulsating strip cover (50). 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 (30) 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.

Abstract: A multi-layer web formation section has two successive wire units (300, 310) with a common wire (11). A first headbox (100) supplies fiber pulp to the first wire unit (300) forming a first partial web (W1). A second headbox (110) supplies a new fiber pulp layer to the forward end of the second wire unit (310) atop the first partial web. A first non-pulsating dewatering zone (Z1b) in the forward end of a two-wire stretch of the second wire unit (310) has a first formation shoe (200b) with a curved cap (201) placed on the side of the new layer having openings (202) extending through the cap (201) with an under-pressure (P) affecting therethrough. A two-wire stretch of the second wire unit (310) has a second pulsating dewatering zone (Z2b) formed by fixed dewatering lists (210b), between which there are gaps (220b) and an under-pressure (Pb) affecting in these.

Abstract: A multi-layer web formation section has at least two successive wire units (300, 310). First and second headboxes (100, 110) supply pulp suspension jets to the forward end of the first wire unit (300) and the second wire unit respectively to form a first partial web (W1) and a second partial web (W2) which are joined at a joint (N1) between the second wire unit (310) and a bottom wire (11). A first non-pulsating dewatering zone (Z1b) in the forward end of a two-wire stretch of the second wire unit (310) is formed by a fixed formation shoe (200b) having a curved cap (201) placed against one side, having openings with an under-pressure applied. A two-wire stretch of the second wire unit (310) has a second pulsating dewatering zone (Z2b), formed by fixed dewatering lists (210b) in the cross machine direction with gaps (220b) therebetween with an under-pressure (Pb) applied.

Abstract: A forming section has a lower wire loop (11), which constitutes a single-wire section (T) following a breast roll (12). A first dewatering zone (Z1) has at least one stationary, first forming shoe (40) followed by a pulsating strip cover (50). 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 (30) 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.

Abstract: A forming section of a paper or board machine 10 in the forming section of a paper or board machine has a cover 36 having an outlet groove 20 between a suction zone 18 of circular holes and an outlet edge 40. A wire comes to the cover area from an inlet edge 38 and leaves from an outlet edge 40. The outlet groove 20 is essentially in the cross-machine direction of the cover 36. 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.

Abstract: Fibrous stock is supplied by a paper or board machine headbox (1) between looped forming wires (11, 12). Water is removed in a two part first dewatering zone (Z1), the first part formed by a suction forming roll engaging a forming wire (12) and the second part formed by a fixed forming shoe engaging opposite a forming wire (11). The wires (11, 12) are guided so the first dewatering zone causes essentially non-pulsating dewatering in the stock. Water is removed in a second dewatering zone (Z2) formed by fixed dewatering blades (21) on the other side of the wires (11, 12) and supported against the stock therebetween (21) and on the opposite side of the wires (11, 12) by dewatering blades (24), loaded in a controlled manner against the fixed dewatering blades (21) at gaps (22) between these so that pulsating dewatering is caused in the second zone (Z2).

Abstract: Fibrous stock is supplied by a paper or board machine headbox (1) between looped forming wires (11, 12). Water is removed in a first dewatering zone (Z1) formed with a fixed forming shoe (3) having a curved surface against which a wire (12) is supported while the opposite wire (11) is unsupported in the area of the shoe (3). Water is removed in a second dewatering zone (Z2) formed by fixed dewatering blades (21) on the other side of the wires (11, 12) and supported against the stock therebetween (21) and on the opposite side of the wires (11, 12) by dewatering blades (24), loaded in a controlled manner against the fixed dewatering blades (21) at gaps (22) between these so that pulsating dewatering is caused in the second zone (Z2). The wires (11, 12) are guided so the shoe (3) causes essentially non-pulsating dewatering in the stock.

Abstract: A web is formed between two wire loops (13, 14), in a wire section of a paper or board machine, in connection with which dewatering elements (12, 17, 15, 28) are placed and in which water is drained from a stock suspension from between the two wires (13, 14). In the region of a twin-wire zone, a suction roll (15) is placed within one wire loop and a suction box (16) having a curved surface is situated in opposed relationship with the suction roll (15) on the wire loop. After the suction box (16), the web is guided, due to the effect of a vacuum of the suction roll (15), forwards on the surface of the wire loop of the suction roll (15).

Abstract: A forming section of a paper or board machine 10 in the forming section of a paper or board machine has a cover 36 having an outlet groove 20 between a suction zone 18 of circular holes and an outlet edge 40. A wire comes to the cover area from an inlet edge 38 and leaves from an outlet edge 40. The outlet groove 20 is essentially in the cross-machine direction of the cover 36. 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.

Abstract: A multi-layer web formation section has two successive wire units (300, 310) with a common wire (11). A first headbox (100) supplies fiber pulp to the first wire unit (300) forming a first partial web (W1). A second headbox (110) supplies a new fiber pulp layer to the forward end of the second wire unit (310) atop the first partial web. A first non-pulsating dewatering zone (Z1b) in the forward end of a two-wire stretch of the second wire unit (310) has a first formation shoe (200b) with a curved cap (201) placed on the side of the new layer having openings (202) extending through the cap (201) with an under-pressure (P) affecting therethrough. A two-wire stretch of the second wire unit (310) has a second pulsating dewatering zone (Z2b) formed by fixed dewatering lists (210b), between which there are gaps (220b) and an under-pressure (Pb) affecting in these.

Abstract: A multi-layer web formation section has at least two successive wire units (300, 310). First and second headboxes (100, 110) supply pulp suspension jets to the forward end of the first wire unit (300) and the second wire unit respectively to form a first partial web (W1) and a second partial web (W2) which are joined at a joint (N1) between the second wire unit (310) and a bottom wire (11). A first non-pulsating dewatering zone (Z1b) in the forward end of a two-wire stretch of the second wire unit (310) is formed by a fixed formation shoe (200b) having a curved cap (201) placed against one side, having openings with an under-pressure applied. A two-wire stretch of the second wire unit (310) has a second pulsating dewatering zone (Z2b), formed by fixed dewatering lists (210b) in the cross machine direction with gaps (220b) therebetween with an under-pressure (Pb) applied.

Abstract: Fibrous stock is supplied by a paper or board machine headbox (1) between looped forming wires (11, 12). Water is removed in a first dewatering zone (Z1) formed with a fixed forming shoe (3) having a curved surface against which a wire (12) is supported while the opposite wire (11) is unsupported in the area of the shoe (3). Water is removed in a second dewatering zone (Z2) formed by fixed dewatering blades (21) on the other side of the wires (11, 12) and supported against the stock therebetween (21) and on the opposite side of the wires (11, 12) by dewatering blades (24), loaded in a controlled manner against the fixed dewatering blades (21) at gaps (22) between these so that pulsating dewatering is caused in the second zone (Z2). The wires (11, 12) are guided so the shoe (3) causes essentially non-pulsating dewatering in the stock.

Abstract: A web is formed between two wire loops (13, 14), in a wire section of a paper or board machine, in connection with which dewatering elements (12, 17, 15, 28) are placed and in which water is drained from a stock suspension from between the two wires (13, 14). In the region of a twin-wire zone, a suction roll (15) is placed within one wire loop and a suction box (16) having a curved surface is situated in opposed relationship with the suction roll (15) on the side of the other wire loop. After the suction box (16), the web is guided, due to the effect of a vacuum of the suction roll (15), forwards on the surface of the wire loop on the side of the suction roll (15).

Abstract: At the end of the twin wire zone of a paper machine former, a suction box (17) inside the upper wire loop (11) has a curved lid (17?) opposite a roll (18) within the lower wire loop (10). The lid is curved in a run situation so the tension of the upper wire (11) reduces the normal force between the wire (11) and the lid (17?) caused by the underpressure of the suction box. The underpressure keeps the web mainly off from the roll (18) and the lower wire (10) while being adhered to the underside of the upper wire (11) and conforming to the curved shape of the lids. Members (17a, 18?) are provided for making the web follow the lower wire (10) in a break situation for conducting it to the broke handling system.