FI120239B - A web forming machine and a method in a web forming machine - Google Patents

Description

Web forming machine and method in web forming machine Banfominingsmaskin ocli föjfarande i en banformningsmaskin

5 TECHNICAL FIELD

The invention relates to a forming machine according to the preamble of claim 1.

The invention also relates to a method according to the preamble of claim 9,

BACKGROUND OF THE INVENTION

15 The forming machine comprises paper, board, tissue and pulp machines. In the context of this application, a special slide press of a press section of a rib forming machine refers to a press in which opposing press members form only one press nip. The press nip of a stand-alone press may be a roll nip or a long nip. In contrast to the stand-alone press, there is a center roll press, where the center roll forms a press nip with at least two • · 20 other rolls. The press nipples of the center roll press may be roll nipples and / or long. känippejä.

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The function of the press section is to remove water from the web and make the loan symmetrical, • ·. 1 2 1. wherein the absorption and roughness properties of both sides of the web are symmetric.

• · · 25; ’J2. The open passages after the center roll of the compact press and the single press cause 3; reduce breaks and limit the speed of the press section. In a closed • · · conveyor belt. Missing points and track dusting become a problem in 1. export. Also, the conveyor belt • · · does not achieve the best smoothness and dry matter content of the web.

• · * · 1 30 When using a thermal roller as a center, its temperature cannot be raised very high.

2 · 3 · M · 2 because of its low solids content, it easily folds into the hot roller.

FF Palent 0868567 shows a press section shown in Fig. 5 having a three nip 5 center roller press and a subsequent separate fourth chuck press. Also, the third nip is a long nip, the Kcskit and the counter roll of the fourth long nip can be heated roll rolls. as the center roll temperature is raised.

M patent 92941 discloses a suction nipple between a shoulder and a heated central roll. In the transfer event, there is a suction glass clamp against the center roller, so that the track cannot be tightened during transport by means of a pullocron. The web will then remain loose and will easily exhibit defects in the transfer region, particularly since the web is adhered to a mouthwash, air-impermeable, high adhesion roll. The dry solids content of the web is relatively low with the roll roll, whereby the adhesion of the roll to the roll roll becomes a problem when the temperature of the roll roll is raised.

The 20 FJ Patent Application 20055055 discloses a press section shown in Fig. 6 with a three-nip center roller press followed by a separate fourth long nip press. A transfer belt is fitted around the center roller and the fourth long nip press. The web is moved from the center roll transfer price to a fourth long nip press press felt with a separate fabric strip. After the fourth long nip press, there is a drying section with ... 25 horizontal blow-drying followed by vertical blow-drying, with a loose belt ci, not very good quality of the surface of the web, and no finishing. * Can provide extra heat with transfer belt.

1 Fl Patent Patent Application 885737 discloses a center roller roller with a strap arranged around the center roller and formed as a loop for a plurality of guide and tension rollers. , with the help of sldos.

• · • · · “Kama is created between the pick-up felt and the lower felt in the first squeeze nipple between the first imulcla and the first groove roll with the si si! for pick-up felt support. The web is then moved across the surface of the Piek-up felt over the suction sector of the first suction cup to the purlins formed between the first suction cup and the Middle East. In one of the second pin nip, the web is moved to the surface of the central rotating tape 5 and further to the third pin belt nipple formed between the touch roll and the second groove roll on the tape surface. After the third purge adhesive, the web is moved on the surface of said tape to a transfer point formed between the tape and the second suction cup. At the transfer point, the web is transferred to a drier, dryer, circulating a second suction tea. All press nipples are tclanipps. The tape should be such that air can pass through it. in order to utilize the Piek-up technique for transferring the web from the press section to the drying section. As a result, the tape is perforated. A suitable metal, for example steel, which can withstand high temperatures may be used as a tape mat, but it is also conceivable that various plastics, polymers and the like are suitable as tape materials.

15

Fl patenl 81625 discloses the use of a thin, heat-conductive, endless, heated tape in a press nip. The strip forms an extended compression zone with the suction cup. The increase in the dry solids content of the web using the suction nipple and fabric tension of the rolls is quite small. Since the dry solids content of the web 20 is relatively low after the nip, the web must be on the surface of the heated tape for a long time before the web can be removed from the tape in a controlled manner without causing damage to the loan. The machine thus cherishes a lot of space in the machine direction, which makes it expensive.

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Fl patch 81626 discloses a method for using a thin, heat conductive, endless, heated tape in a press nip. The web sticks to the strip at the purlins • · ·. ···. and the web is guided forward with the tape until so much is removed ···. *. water so that the web comes off of the tape itself. The increase in dry solids content of the web using the roller nipple is · · · '!!. * So that the web must be in the heated tape • · long before the solids content is high enough to release the web from the tape.

• · · * # 30 The machine thus requires a lot of machine direction space, which makes it expensive.

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SUMMARY OF THE INVENTION

The object of the present invention is to provide a web forming assembly having a high speed and high quality compression hinge solution built around a central roller and possibly also a crill putter, particularly suitable for repeating the puris-5 tmosa.

The web forming cell according to the invention is essentially characterized in that it is presented in the characterizing part of claim 1.

ALREADY

The method according to the invention is essentially characterized by what is stated in the characterizing part of claim 9.

In the solution of the invention, the borrowed export is tracked using a simple heated roller belt roller with a central roller and possibly also a crill spur. As the dry solids content of the web reaches about 55%, the contact of the web with the metal belt is reduced and the web a very easily detaches from the metal belt. In the triple nipple t

In the SymPress B center press, the dry solids content of the web after the third nip • · · i * · at 1200 m / min is about 53-55%. Using a heated metal belt * * 20 around the center roll and the heated fabrics will increase the dry solids content of the web after the third nip • * · * ·: *, the web will come off the metal belt quite easily. ! · Even at much higher speeds.

From the first heated belt loop, the web is picked on a separate transfer wire ... 25 killc, on whose surface the web is moved forward in the process. A separate transfer wire web provides the necessary tension difference to the web and reverses the direction of web travel so that the web can be transferred to the scuravail.

• ♦ • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · • ♦ · '♦' · For example, SC with scouring values · Speed is in the range 1900-2500 m / min, ethinylamine (clanip line load is 20-150 kN / ιη, second roll nip line load is 80-160 kN / m and third and fourth long nip line loads are in the range 1200-1600 kN / m. The dry solids content of the web after the press section is then in the range 56-62%.

5 If necessary, the heated metal belt can be coated with a suitable coating and / or an anti-fouling agent can be applied to the surface of the metal belt and / or the web to ensure release of the web from the heated metal air.

The invention will now be described in detail with reference to various embodiments of the invention shown in the figures of the accompanying drawings, the details of which, however, are by no means narrowly limited.

BRIEF DESCRIPTION OF THE FIGURES

Figure I schematically illustrates a web forming configuration according to the invention. Figure 2 shows you diagrams! a modification of the web form shown in Fig. I;

Fig. 3 schematically illustrates another modification of the forming machine shown in Fig. 1.

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DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 1 schematically illustrates a web forming concept according to the invention.

The press section here comprises a press clamp and a crill press which scours it.

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The web W is picked up in the pick-up pen 9 at pick-up point P with a pick-up suction roll 12 After pick-up point P, the web W is first brought in with water • · · · · 1 * · on the underside of the receiving pickup felt 10, and thereafter in a direct run between the pickup felt 10 and the water receiving pinching felt 20, in a substantially horizontal plane, After the press nip NO, the web W is held on the outer surface of the first upper felt 10 with the vacuum applied in the suction sector 11 of the squeegee nipple 11 and is introduced into the first press nip N1 of the center flap, which is a single felt tea nip. The roll below the first press belt N1 is a squeegee nipple 11 acting as a top nipple for the pinch nipple NO, and the upper roll is a central roll 31 surrounded by a first metal air felt 30 which is heated by the first 10 sets of heaters 32. on the outer surface of the first metal belt 30 to the second punch nip NP1 of the center path press, which is a single felt end nipple. The lower roll NPI of the second roll press is the contact roll roll 31 and the top roll is a first long stretch 41 formed by a flexible hose jacket within which is a pressurized shoe loaded with hydraulic pressure medium to provide the necessary press pressure on the first upper felt 40 The NPI thus forms the first long nip of the press section.

After the second mandrel pin NPI of the center path press, the web W is introduced on the outer surface of the first • · ·, *.:. * Metal belt 30 with a downwardly running run to the first • · ·, *. A transfer point SI formed between the first metal belt 30 and the first transfer belt. The first metal belt 30 may be supported and its vibrations prevented by at least one ... 25 sliding means mounted inside the first metal belt 50, which may consist of a low-friction support means 33. The lubricated contact surface may be used in the support means. with a first metal belt 30.

A first transfer wire 50 is arranged around the first transfer suction roll 51. The web • · · · "'W is picked up at the first transfer point SI by the first transfer suction 51 51 ...

on the outer surface of the first wire mesh 50 supported on the web by moving ··· * · * * 30 to a second transfer point'S2 formed by the inside of the first wire mesh 50 and the second transfer die of the lower felt 60 62. The web W is picked up at the 7 parasitic transfer point S2 in the suction section of the second displacement suction 62 on the outer surface of the lower felt 60, which support is then transferred to a different pressurized nip NP2 which is a single-nail press nip. The upper clamp of the nip press nip NP2 is one of the clamps da 71 surrounded by a second metal belt nipple 70 which is heated by a second heating device 72. providing the necessary clamping pressure to the web W running between the lower felt 60 and the second metal belt 70. The press nip NP2 of the barbell press thus forms a second long nip of the press section.

10

After the separate press nip NP2, the W is moved in the support of the second metal belt 70 to the third transfer point S3 formed between the second metal belt 70 and the third transfer suction roll 81 inside the drying fabric 80 of the first drying unit DJ. The second paddle belt 70 may be supported and its vibrations prevented by at least one slider mounted inside the second metal belt 70, which may consist of a low-friction support means 73. The lubricated contact surface 73 with the second metal belt 70 may be used. The web W is picked up at the third transfer point S3 in the suction section 81 of the third transfer suction roll.

A drying unit D1 on the outside of the drying wire 80 supported by a web W

. 20 is passed through a first drying unit D1. In the first drying unit D1, the web W is dried by a straight or curved, substantially horizontal overhead blowing unit 83 having vacuum members 84 such as suction cups and control boxes 85 which are! are preferably suction or deep-groove so-called Disk rolls.

After the first drying unit D1, the web W is moved at the fourth transfer point 90. The second transfer point S4 is formed by a control blade 82 of the first drying unit D1 and a second drying unit 80. Between the guide blade 91 of the drying fabric 90 of the fryer D2, in the parasitic drying unit D2 the web • · W is dried by a vein, or by curved, substantially vertical bale blowing units • · 93 93, 94. The inside of the second drying unit D2 8 vacuum devices such as suction cups 95 and guide slots 96, which are preferably suction cups or so-called Disk rollers with deep grooves.

After the second drying unit D2, the web W is transferred by a drying wire 90 of the second drying unit D2 to the surface of the first drying cylinder 101. From this first drying cylinder, the web W is picked up on the drying wire 100 of the first cylinder drying group R1, the support of which is fed to the first reverse suction filter 102 of the first drying group R1, which has a running component 103.

After the 10 transfer point SI, the steam transfer box 52 may be used against the first transfer nozzle 51. The dry matter content of Raman W is relatively high at the first transfer point SI and the first screen nozzle 51 efficiently absorbs steam into the web W, good profiling capability, a vacuum means, e.g., a blowing simulator, can be placed inside the lower felt press 60 through the press nip 60 through the nip press nip 60, e.g.

A blower simulator 92 may be placed inside the second dryer fabric 90 just prior to the fourth transfer point S4 to ensure attachment of the web W to the other dryer fabric (). 90 in the fourth transfer site S4.

The solution can also use press fabric 10, 20, 40, and 60 to effectively fabricate and repair fabric lifters that reduce fabric wear, resulting in: • · · · · Higher solids content and longer life of the fabrics with a smaller press section • · * ·· * / application choke. Such a tissue engineer is disclosed in Applicant's Patent Application No. 20065498.

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The solution may also employ a technique for guiding the splint loops 10, 20, 40, 00 whereby the fabric is tightened and guided only by changing the position of one and the same roll relative to the fabric. Such an arrangement is disclosed in Applicant 11 Patent No. 116399.

5

The puncture portion may be covered with an air-conditioned hood 200, whereby the process is more efficient as the heat escapes to the data center. Warm fabrics also contribute to the dry solids content of the web and dry air can be brought near the web to enhance evaporation by the press member.

10

The first 30 and second 70 heated metal belts form a simple closed loop around the two rolls 31, 34, 71, 74 alone. Also, the first transfer wire 50 forms a similar simple closed loop around two rolls 51, 53.

15

The first and second metal belts 30, 70 are air-impermeable, smooth surface metal belts.

Figure 2 shows you diagrams! a modification of the embodiment 20 shown in Fig. 1, wherein the pinch nip NO of the roller track and the associated pre-press nip 21 are used; **; and e. Railia W is moved directly into the pick-up • · · • · * ”. * From point E on the pick-up felt 10 to the first press nipple between the kcskitclan 31 and the press suction roll 1 i NL Otherwise, the embodiment shown in FIG. 1,... 25, ···. Figure 3 is a schematic, i.e. another variant of the direct · · ··· shown in Figure 1. *. format.sla, where the criDispress NP2 that scripts the track press is omitted. The web is then moved from the first transfer roll 50 directly to the first drying fabric. In other respects, the embodiment shown in Figure 3 corresponds to the embodiment shown in Figure 1 * · * * 30

In Figure i, the pre-press nip NO, which may be an iclanip (ai longer is formed between the press suction roll 11 and the pre-press nip 21, the pre-press nip NO could also be formed for picking up the web VV between pick-up point P and the press suction roll 11

5

The Applicant markets the press section of Figure 1 and 2 under the trade name SymPress BH V and the press section of Figure 3 under the brand name SymPress B.

In the embodiments shown in Figures I and 2, a vctocroll web \ V transfer is used on both sides of the last press nip NP2. Before the last press belt nip NP2, so W is moved at the second transfer point S2 by a press (acting on the second screen nip 62 acting on the underside of web W) and after the last press nip NP2, web W is moved at a third transfer point S3 by a third transfer nip 81. -J5 downward on the mandrel nipple underneath the last press nip 60. The asymmetric dewatering of the last press nip causes a greater concentration of fines on the underside of the web W, but this asymmetry of fines is compensated by a · the web W is released from the tissue in contact with the upper surface of the web W. The result is thus a symmetrical web W in this respect.

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In the embodiments shown in the figures, the transfer of the web at the points of the transfer suction rolls is used, but of course the transfers can also be made with the transfer suction boxes.

The claims which follow, within the scope of the inventive idea * * # 1 # ... # as defined by the invention, may be varied and departed from the foregoing by way of example only.

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Claims (16)

A web forming machine, wherein the press section comprises at least two compact press nips (N1, NP1) formed by three rolls (11,31,41) such that the first 5 single-press press nips (N1) are formed by a press nip roll (11) and between the center roll (31) and the second single-felt press nip (NP1) formed between the center roll (31) and the first press roll (41), wherein the press fabric on the side of the press suction roll (11) is a water-picking felt (10) and a first press roll ), the first water-absorbing upper felt (40), a first metal belt loop (30) is disposed about the central roll (31), on the surface of which the web (W) is gripped by said first single-felt press nip (N1); after the second single felt press nip (NP1) at the first transfer point between the transfer suction roll (51) and the first metal belt loop (30) ( SI) for the fabric (50) rotating the first transfer suction roll (51), characterized in that the first press roll is a first long nip roll (41), the first metal belt loop (30) consists of an air-impermeable, smooth-faced metal belt. , and the fabric surrounding the transfer suction roll (51) is the first transfer fabric (50) supported: · *: the web (W) is moved forward in the process. ·: ··: 20 ϊ A web forming machine according to claim 1, characterized in that the first metal belt loop (30) has only a central roll (31) and a first guide roll (30), wherein: the first metal belt loop (30) is adapted to pass around only two ···: f>: rolls. 25 ·· «Y ί A web forming machine according to claim 1 or 2, characterized in that within the first transfer wire loop (50) there is only a transfer suction roll (51) and a second guide roll:. *, (53), wherein the transfer wire loop (50) is arranged to pass around only two rolls. ··· · • · · · · ·. ·. 30 A forming machine according to any one of claims 1 to 3, characterized in that • · · • ♦ # I. the web forming machine comprises a two felt pre-press nip (NO) formed between • said press suction roll (11) and a pre-press roll (21), wherein is a pick-up blanket (10). The forming machine according to any one of claims 1 to 4, characterized in that, after said second single felt press nip (NP1), the web forming machine comprises a separate press having a single felt press nip (NP2) formed between a second press roll (71) and a second long nip roll (61). the second longitudinal nip roll (61) of the single-press single nip press nip (NP1) is a water receiving lower felt (60) to which the web (W) is transferred by a first transfer wire (50) and a second silk screen within the first transfer wire (50). 62) at the second transfer point (S2). A forming machine according to claim 5, characterized in that a second heated (72) metal belt loop (70) is disposed around said second press roll (71) of the single-press press nip (NP2) of said single press, the surface of which is gripped in the single press press nip and from which surface Taina (W) is moved after the single-press press nip (NP2) of the single press into a third transfer suction roll (81) between the third ·· ·: transfer shaft (81) and the second metal belt loop (70). a rotating first drying unit (D1) for a first drying wire (80), the support of which moves the web (W) forward in the process. ··· · • • • • • • • i A forming machine according to claim 6, characterized in that the first drying unit (D1) is a drying unit with a straight or curved horizontal blowing drying unit (83), the web (W) being moved first (>!). supporting the first dryer wire (80) through the first dryer unit (D1) and: further, the inner guide roll (82) of the first dryer wire (80) and the second guide wire (91) of the second dryer wire (90) of the second drying unit (D2). ··· 30 at the fourth transfer point (S4) to the second drying unit (D2) for the second drying wire (90). A forming machine according to claim 7, characterized in that the second drying unit (D2) is a drying unit with straight or curved vertical blow drying units (93, 94), wherein the web (W) is moved in support of the second drying wire (90) by the second drying unit (D2). and further to the first drying cylinder (101), from which the web (W) is transferred to the drying wire (100) of the first cylinder drying group (R1). A method in a web forming machine, the method of which at least two compact press nipples (191, NP1) are formed in press section 10 formed by three rolls (11, 31, 41) such that a first single felt press nip (N1) is formed 31) and a second single-felt press nip (NP1) is formed between the center roll (31) and the first press roll (41), wherein a pick-up felt (10) is used as a press fabric side of the first press suction-15 lane (11) of the first single felt press nip a first water-receiving top felt (40) is used as a press fabric on the first press roll (41) of the second press nip (NP1), a first metal belt loop (30) is imaged around the center roll (31); ) and from which the web (W) is moved from the second press nip (NP1) *: **: 20 after the first transfer suction roll (51) and the first metal belt loop (30) at the first transfer point (S1), for the • · I l: fabric (50) orbiting the first transfer suction roll (51), characterized in that the first • · l a long nip roll (41), the first metal belt loop (30) being an air-impermeable, smooth-surface metal belt heated by a heating device (32) and a first transfer wire (50), which is wound in a support by ··· X ϊ the web (W) is moved forward in the process. ··· • · ···> The method according to claim 9, characterized in that the pre- · · · · · · · · · · · · · · · · · · · · · a staple metal belt loop (30) to disable the center roll (31) and the first steering ··· .1. 30 baffles (34), wherein the first metal belt loop (30) passes through the guide rolls of only two rollers. mana. • · · • · · · · 14 Method according to Claim 9 or 10, characterized in that a first transfer wire loop (50) is rotated to rotate the transfer suction roll (51) and the second guide roll (53). Thus, the first transfer wire loop (50) passes under the control of only two rolls. 5 Method according to one of Claims 9 to 11, characterized in that a double felt pre-press nip (NO) is provided between said press suction roll (11) and the pre-press roll (21), wherein the press fabric on the pre-press roll (21) is a pre-press felt (20) and The (11) sided press fabric is a pick-up felt 10 (10). Method according to one of Claims 9 to 12, characterized in that after the second press nip (NP1) a separate press is formed, the single-felt press nip (NP2) being formed between the second press roll (71) and the second long nip roll (61). ) as a press fabric on the side of the second long nip roll (61), the water receiving lower felt (60) is supported on which the web (W) is moved by the first transfer wire (50) at the second transfer point (S2) between the second transfer suction roll (62) and the first transfer wire (50). • · · • · · • • • *: **: 20 A method according to claim 13, characterized in that: providing a second heater around a second press roll (71) of the press nip (NP2) of the single press; a metal belt loop (70), the surface of which is gripped by a web (W) in a • • IJ press nip (NP2), and from which a web (W) is displaced after a separate press press nip • ♦ · (NP2) and a third transfer belt roll (81); (70) to a first drying wire (80) of a first drying unit (D1) rotating a second transfer suction roll (81), which supports the web ···: J (W) being moved forward in the process. 1 · • · ♦ • · «• · ·. ** ·. Method according to claim 14, characterized in that the web (W) M »30 is dried in the first drying unit (D1) with a straight or curved horizontal direction. with an overhead drying unit (83) wherein the web (W) is moved within the support of the first drying fabric (80) through the first dryer unit (D1) and further to the inner guide roll (82) of the first dryer wire (80) and the second dryer wire loop of the second dryer unit (D2). (90) at a fourth transfer point (S4) between the inner guide roller (91) to the second drying line (90) of the second drying unit (D2). 5 Method according to Claim 15, characterized in that the web (W) is dried in the second drying unit (D2) by straight or curved vertical blow-drying units (93, 94), whereby the web (W) is moved in the support of the drying fabric (90) of the second drying unit (D2). through the second drying unit (D2) and further to the first drying cylinder (101), from which the web (W) is transferred to the drying wire (100) of the first cylinder drying group (R1). f · · · ♦ ♦ ♦ ♦ • • ♦ ♦ · · · · · ♦ ♦ ♦ ♦ · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · To · · · · · • · · · ·· · · 16