FI112673B - Multilayer web forming device - Google Patents

Description

1112673

MONIKERROSRAIN FORMNINGSANORDNING -FLERSKIKTSBANAN

The present invention relates to a multilayer web machine (multi-web web forming machine). More particularly, the present invention relates to a multilayer web device for forming a top layer on a bottom layer.

In Bel Bond ^^ top wire reformers, the pulp can be dewatered upwards, resulting in smoother surface properties.

Specifically, when pulp is injected from the headbox onto a four-drill wire, the dewatering takes place downwards so that the fibrous web remains on the upper surface of the wire. The fibrous web is then transferred to a press section where the dewatering of the formed web is continued.

15

The aforementioned downward dewatering makes the resulting web uneven in surface properties. The Bel Bond ^^ unit is a top wire unit having a looped top wire cooperating with a four-dierier wire so that the wires surround the forming section.

20

The pulp is dewatered upwardly through the forming member so that the resulting formed web has more uniform surface properties.

j ''; Instead of forming a multilayer web, the base layer is initially formed by fourdri-; *. A second headbox is placed * on the 25 sternal wire and immediately before the Bel Bond ^^ with the upper wire.

';' Although said arrangement has proved successful in forming a multilayer web, the top layer still tends to break during the subsequent compression step 30.

: ', Specifically, when injecting pulp from another headbox under the overhead wire, • 11: tends to form a fiber mat which causes the low-consistency pulp to:., Remain trapped under the non-fiber material, resulting in _ .. web breakage.

35;,: Patent publications FI-92728, FI-94880, FI-, 'representing prior art. 98540, FI-72761, FI-84637 and WO-A-9009481. The differences between the present invention and the prior art are more fully apparent from the appended claims.

The present invention seeks to solve the above problem by smoother dewatering of the surface layer 5, which results in a more uniform pulp consistency in the "Z" direction.

Thus, it is a primary object of the present invention to provide a multilayer web device which avoids the aforementioned disadvantages of the above device and which constitutes a significant advance in the multilayer web forming technique.

Another object of the present invention is to provide a multilayer web device that prevents the resulting web, particularly heavy webs, from breaking.

It is another object of the present invention to provide a multilayer fabric device including a suction slot that aids in upward dewatering.

Other objects and advantages of the present invention will become apparent to those skilled in the art from the description contained herein, together with the accompanying drawings.

20

The present invention relates to a multilayer web device for forming a top layer on a bottom layer. The web includes a looped bottom forming wire *: * for receiving the base layer. Above the lower wire, there is a co-operative loop forming wire formed therebetween to form; ·. 25 a substantially horizontal forming member having first and second ends.

'* · <The pivoting rod has a curved surface disposed below the lower forming wire and upstream of the first end of the forming member for guiding the lower wire. A second headbox is positioned near the pivot bar so that the mass sprayed from the second headbox toward the first end of the forming member rests on the base layer 30 while the mass sprayed from the second headbox forms the top layer.

:, A curved dewatering shoe is located below the bottom wire and adjacent to the first end of the forming member. The center of curvature of the curved shoe is located below the bottom wire si- '. that part of the water of the topsheet is ejected through the upper wire.

'Τ 35 i, ·; Above the top wire and immediately downstream of the dewatering shoe is a *, 1: suction means that collects some of the water upstream of the top wire.

5 3 112673

An inverted suction box is located downstream of the suction slot and opposite to the dewatering shoe on the opposite side of the upper fabric. The box has a curved surface with a center of curvature located above the upper wire.

On the curved surface, a plurality of dewatering strips are located in the machine direction, spaced apart. Each strip extends in the transverse direction of the machine so that the strips are positioned between the curved surface and the upper wire to guide past the upper wire's curved surface.

With respect to the strips, a plurality of dewatering foils are disposed on the opposite side of the wires so that the consistency of the surface-forming mass increases as it passes through the forming part, while maintaining the consistency of the surface layer in the "Z" direction so as to prevent breakage of the resulting web.

15

In a more detailed embodiment of the present invention, the pivoting rod must be positioned so that the second headbox can be located very close to the bottom wire so that the mass injected from the second headbox is injected substantially parallel to the bottom wire between the pivot bar and the dewatering shoe.

20

In one embodiment of the present invention, the curved surface of the pivot bar is ceramic.

· '; The curved dewatering shoe also includes a plurality of spaced bars 25 spaced apart in the machine direction. Every rod is. *, transverse and the rods include the upstream rod.

The dewatering shoe also includes a suction box which is in fluid communication with the spaces formed between adjacent rods.

30: The mass is injected from the second headbox so that the mass collides with the bottom layer at a distance upstream of a plurality of rods spaced apart; loving.

In one embodiment of the present invention, the drainage shoe has a radius of curvature: · ·: of between 12 and 18 meters.

4, 112673

The suction nozzle means is an auto-slice containing lip means for guiding a portion of the water ejected from the surface layer through the upper wire. The self-contained slit also includes a collection container means associated with lip means for collecting said portion of water.

5

In a more detailed embodiment of the present invention, the suction means comprises a plurality of suction slots spaced apart in the machine direction, each suction slot having an adjustable lip. The suction means also include an arrangement of a collection container positioned above each lip such that when operated by the device, the water discharged from the upper layer through the upper layer by the tensioning of the wires and the converging wire wedge is removed through the suction lining due to the fiber mat forming on the side.

15 The radius of curvature of the inverted suction box is greater than the radius of curvature of the dewatering shoe.

Each list of dewatering lists is located at a distance from the adjacent dewatering list. The distance is greater than the distance between the bars of the dewatering shoe.

":; Each foil in the foil set is disposed between adjacent strips in a plurality of dewatering strips, such that the strips and foils exert dewatering pressure pulses on the multilayer web: ', as the web passes between the strips and foils.

:,. More specifically, the foils interact with the molds and are positioned opposite the molds to the machine length of the suction box starting from the most upstream mold.

30: In another embodiment of the present invention, the foils cooperate with the moldings and are positioned opposite the moldings and the one upstream of the suction box; down the list.

35 Each dewatering foil contains a pair of threaded rods that are one-way * ·; and spaced apart and close to the other end of the foil.

5, 112673

Another pair of threaded rods are spaced apart and parallel to the opposite end of the foil.

In cooperation with the pair of rods, there is a support member such that the support and the rods 5 can be vertically aligned with each other.

In cooperation with one pair of rods, a second support member is provided so that the second support and the other rods can be vertically aligned with each other.

The foil bar having first and second ends is arranged such that the first end of the foil bar is mounted on the first bracket and the other end is mounted on the second bracket so that the foil bar can be vertically adjusted. The bearings allow rotating position of the foil rod relative to the bottom wire. Underneath the foil bar is pneumatic tube means for loading the foil bar against the bottom wire.

15

It will be apparent to one skilled in the art to modify and modify the present invention based on the following detailed description. However, such modifications and modifications are within the spirit and scope of the invention as defined in the appended claims.

Fig. 1 is a side view of a multilayer grinder of the present invention, Fig. 2 is a side view of a second embodiment of the present invention. ·; of multilayer,. Fig. 3 is a side view of a multilayer ribbon according to yet another embodiment of the present invention, '! i. ' Figure 4 is an enlarged view of the self-acting slot shown in Figure 1, Figure 5 is a side view of a preferred embodiment of the present invention.

; Like parts are denoted by like reference numerals throughout the present invention:. cat in embodiments.

'1' 35 Fig. 1 is a side elevation view of a multilayer web device of the present invention generally designated by reference numeral 10 and forming a bottom layer V of a surface layer 12; on top of it.

6 112673

The ribbon 10 includes a loop-shaped lower wire 16 on which the bottom layer 14 is received.

Cooperating with and above the lower wire 16, there is a looped upper wire 18 such that the wires form a generally horizontally located forming part 20 having a first 22 and a second end 24.

The pivoting rod 26 has a curved surface 28 disposed downstream of the lower forming wire 16 and upstream of the first end 22 of the forming member 20 for guiding the lower wire 16.

A second headbox 30 is disposed adjacent the pivot bar 26 so that the mass 32 sprayed from the second headbox 30 towards the first end 22 of the forming member 20 rests on the bottom layer 14, while the mass 32 injected from the second headbox 30 forms the topsheet 12.

Below the bottom wire 16 and near the first end 22 of the forming member 20 is a curved dewatering shoe 34. The center of curvature of the curved dewatering shoe 34 is located below the bottom wire 16 so that a portion of the water indicated by arrow 36 is ejected upstream 18.

; Above the upper wire 18 and immediately downstream of the dewatering shoe 34 are located suction means generally designated by reference numeral 38, which collect said; '. 25 parts of water 36 upward from top wire 18.

>. Immediately downstream of suction cavity 38 and upstream of dewatering shoe 34! A reversed suction box, generally designated 40, is disposed on the opposite side of '18. The box 40 has a curved surface 42 having a center of curvature located above the upper rib 18.

: ,,. · On a curved surface 42 are spaced in a machine direction MD spaced apart; . a set of dewatering lists 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55 and 56. Each. ·. the strips 44-56 extend in the transverse direction of the machine so that the strips 44-56 are between the curved surface 35 and the wire 18 for guiding the upper wire past them.

Fig. 2 is a side view of another embodiment of the present invention having a multilayer web device generally designated 10A.

The web device 10A is substantially similar to the device shown in Figure 1 except that the web device shown in Figure 2 further includes a plurality of dewatering foils 58, 59, 60 and 61 disposed with respect to strips 44A to 56A on opposite sides of wires 16A and 18A such that the consistency of the forming mass increases as it passes through the forming member 20A, while the consistency of the topsheet 12A remains uniform in the "Z" direction so that the resulting web is not broken.

As shown in Figs. 1 and 2, the pivot bar 26, 26A must be adjusted to permit positioning of the second headbox 30, 30A close to the lower wire 16, 16A, so that the mass 32, 32A injected from the second headbox 30, 30A is substantially injected. , 26A, and in the direction of the bottom wire 16, 16A between the drainage shoe 34, 34A.

The curved surface 28, 28A of the pivoting rod 26, 26A is made of ceramic material.

Fig. 3 is a side view of yet another embodiment of the present invention. Figure 3 illustrates a multilayer web machine generally designated 10B, including all essential features of the embodiment shown in Figure 1. However, generally, the curved dewatering shoe indicated by reference numeral 20B at 34B includes a plurality of spaced bars 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76 and 77 are machine direction MD spaced apart. Each bar, '': for example, bar 62 is transverse to the machine, and spaced apart bars' '' include a bar 62 upstream.

25, ···, More specifically, the dewatering shoe includes a suction box 78 which is a color; . in fluid communication with spaces formed between adjacent bars such as bars 62 and 63.

The mass 32B injected from the second headbox 30B collides with the bottom layer 14B • · 'upstream of a plurality of bars 62 to 67 spaced apart. near rod 62.

, ·, The drainage shoe 34B has a radius of curvature of between 12 and 18 meters.

Figure 4 is an enlarged view of the suction means 38 shown in Figure 1. As shown in Figure 4, the suction means 38 includes a self-acting slit 80 including a lip means 82 shown in Figure 4 for guiding a portion of water 36 'from the topsheet 12. The self-acting slot 80 also includes collecting means 84 associated with lip means 82 for collecting said portion of water 36 'therein.

As shown in Figure 4, the self-acting slot 80 more precisely includes a plurality of slots 86, 87, 88, 89 and 90 spaced apart in the machine direction, each slot 86-90 including lip 82, 92, 93, 94 and 95, respectively.

Each slot 86-90 includes a collecting container 84, 97, 98, 99 and 100 respectively located above the respective lip 82 and 92-95. The arrangement is such that, when the apparatus is operated, the tapered wedge 102 formed between the bottom wire 16 and the wires 102 water 36 'discharged from the surface layer 12 through the upper fabric 18 is removed through the suction means 38 so as to prevent the lower consistency of the mass from being trapped with the suction means 38 of the surface layer 12 on the back side of the upper fabric 18.

In each of the embodiments shown in Figs. 1-3, the radius of curvature of the inverted suction box 40 is greater than that of the dewatering shoe 34.

Each list of dewatering set 44B-56B, for example 44B, is at a distance D from adjacent dewatering list 45A, as shown in Figure 2. The distance D is greater than the distance d between the rods 62 and 63 'of the dewatering shoe 34B shown in Figure 3.

J. In the embodiment shown in Fig. 3, each .1 · 'of the foil set 58B, 59B, 60B and 61B. foil is disposed between adjacent moldings of dewatering set set 44B-56B, such that: moldings 44B-56B and foils 58B-61B apply dewatering pressure pulses to the multilayer web as the web passes between the molds and foils.

Fig. 5 is a side view of a preferred embodiment of the present invention, which is much similar to the embodiment shown in Fig. 3. However, it does: * foils 58C, 59C, 60 and 61C interact with lists 44C, 45C, 46C and 47C

• and located opposite lists 44C to 47C from list 44C upstream

, ', Beginning with the machine length of the suction box 40C.

35: As shown in the embodiment of Figure 3, the foils 58B to 61B are cooperating

'. : with lists 44B - 56B and located opposite lists 44B - 56B and suction box 40B

9 112673 from upstream list 44B downstream to downstream list 56B.

In the embodiment shown in Figure 2, the foils 59-61 are disposed upstream of the drainage shoe 5 34A and opposite the self-acting slot 80.

During operation of the device of the present invention, in all the embodiments shown in Figures 1-3 and 5, and as most obviously shown in Figure 4, the mass forming the topsheet 12 collides with the upper wire 18 in the vicinity of the leading lip 82 of the slot 86.

10

The lips 82 and 92-95 are positioned such that, as the upper fabric 18 passes the lips 82 and 92-95, the radius of curvature of the upper fabric 18 at the automatic slot 80 is approximately 15 meters.

In addition, water accumulating inside the Bel Bond1M fabric 18 due to the tensioning of the lower fabric 16 and the tapered wedge 102 102 is removed.

No vacuum is applied inside the collection tanks 84 and 97-100.

The object of the present invention is to increase the consistency of the incoming mass evenly throughout the stock without forming a fiber mat outside the Bel Bond3 ^ wire 18 so that a lower consistency is not trapped beneath the base layer 14. The present invention avoids the web breakage that occurs in existing solutions. with weights.

t l '. 25 The self-acting slot unit 80 and the leading guide roller before it are also fully adjustable bog, '·. to optimize ritual properties.

The present invention also includes an arrangement such as that shown in Fig. 5, which does not have a self-opening slot with only a suction slot 30 for upward drainage within the upper wire loop.

I I t 'In addition, the upstream part of the curved surface of the inverted suction box, i.e., the part ·; opposite the foils are, the radius of curvature is about 15 meters, while the reverse of the suction box, "·. the rest of the curved surface has a radius of curvature of about 5 meters.

,! 35: In addition, in another embodiment of the present invention, a reversed box. ; the portion close to the opposing foils is flat while the rest of the curved 10 1 12673 surface is curved.

Various embodiments of the present invention allow for uniform dewatering of the surface layer in the multilayer fin so that the consistency of the surface-forming mass increases through the forming part while maintaining the consistency of the surface layer in a "Z" direction so as to avoid breaking the resulting web.

Claims (11)

11 112673 A multilayer web forming device for forming a surface layer on a base layer, said web comprising: receiving a bottom loop forming fabric (16) on top thereof, 10 top forming web forming fabric (18) cooperating with and above said bottom section generally 20) for determining between the first and second ends (22, 24) of the forming member 15, a second headbox (30, 30B) located above said lower wire (16) such that the forming head (20) of the second headbox (30, 30B). the mass sprayed towards the first end (32) is arranged to rest on the bottom layer (14, 14B), which mass sprayed from the second headbox (30, 30B) forms a surface layer (12), 20 a curved dewatering shoe (34, 34B) located below the bottom wire (16). and near the first end (22) of the forming member (20), the curved shoe (34, 34B) the center of curvature is located below the bottom wire (16) such that a portion of the water of the surface layer is ejected through the upstream (18) ;; 25 suction means (38) disposed above the upper wire (18) and in relation to the dewatering shoe (34) immediately downstream of said portion of water (36). 30 inverted suction boxes (40) located immediately downstream of the suction means (38) and opposite to the dewatering shoe (34, 34B) on the opposite side of the upper fabric (18) 12 112673, wherein the box (40) is curved a surface (42) with a center of curvature above the top wire (18), a plurality of dewatering molds (44B - 56B, 44C - 56C) spaced apart along the arcuate surface (42) in the machine-5 direction at each block (44B - 56B, 44C to 56C) extending in the transverse direction of the machine with strips disposed between the curved surface (42) and the upper fabric (18) for guiding the upper fabric therethrough, and a plurality of dewatering foils (58B-61B, 58C-61C) foiled within 44B to 56B, 44C to 56C) on the opposite side of the wires (16, 18) such that the consistency of the mass forming the surface layer increases during passage of the forming part, characterized in that the inhaler further comprises a pivot bar (26) having a curved surface (28) located beneath the lower forming wire (16) and upstream of the first end (22) of the forming section (20) for guiding the lower wire (16); located near the pivot bar (26, 26A), and 20; , 'that each foil of the plurality of foils (58B-6IB, 58C-61C) is disposed between a plurality of adjacent lists of dewatering lists (44B-56B, 44C-56C), apply dewatering pressure pulses to the multilayer · · · strip as the web passes through the strips and foils: 1: 25, while maintaining the consistency of the top layer in the “Z” direction to withstand the resulting web breakage, The multilayer web device according to claim 1, characterized in that the swinging bar (26) is arranged so that the second headbox can be positioned: very close to the lower wire so that the mass 13 112673 injected from the second headbox is injected substantially from the swinging shoe parallel to the underside of the wire. Multilayer web machine according to claim 1 or 2, characterized in that the curved surface of the pivoting bar (26) is ceramic. A multilayer webbed device according to claim 1, 2 or 3, characterized in that the curved dewatering shoe (34, 34B) further comprises a plurality of spaced bars (62-77) spaced apart from each other in the machine direction 10 (MB). in the transverse direction, wherein the spaced apart rods include an upstream rod (62). A multilayer web device according to claim 4, characterized in that the dewatering shoe (34, 34B) further comprises a suction box (78) which is in fluid communication with the spaces formed between adjacent rods. A multilayer web device according to claim 4, characterized in that the mass injected from the second headbox (30, 30B) collides with the bottom layer (14): near the upstream rod (62). The multi-layer web device according to claim 1, characterized in that the radius of curvature of the drainage shoe (34, 34B) is in the range of 12 to 18 meters. A multilayer web device according to claim 1, characterized in that the radius of curvature of the inverted suction box (40) is greater than that of the dewatering shoe 1; the radius of curvature. ... 9. A multilayer web machine according to claim 4, characterized in that '' 30 each dewatering strip is disposed relative to the adjacent dewatering strip; : for a cause greater than the distance between adjacent rods of the drainage shoe (34, 34B). 14 1 12673 Multilayer web machine according to claim 1, characterized in that the foils (58C - 61C) cooperate with the moldings (44C - 47C) and are located between the moldings starting from the upstream mold (44C) on the machine length of the suction box (40C). 5 The multilayer web device according to claim 1, characterized in that the foils (58B-61B) cooperate with the moldings (44B-56B) and are located between the molds and downstream of the mold (44B) upstream of the suction box to the downstream mold ( 56B). iti '15 1 12673