JPS63165595A - Dual-wire papermaking apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The invention particularly relates to a two-wire papermaking apparatus.

More specifically, the present invention provides so-called lightweight coated grade paper (e.g., lightweight coated stock paper or coated stock paper), e.g.
This invention relates to a two-wire paper making machine for forming at high speeds of 500 feet/minute or more. More specifically, the present invention relates to a two-wire papermaking apparatus in which the forming wire forms a curved forming area.

[Conventional technology]

Currently, lightweight wave ff (IJIc) grade paper is made on paper machines that utilize Nagatsuna Shogi forming areas. While Fourdrinier paper machines can produce this grade of paper at relatively high speeds, for example on the order of about 3000 feet per minute, single Fourdrinier forming wires produce products known in the market as double-sided sheets.

[Problem that the invention seeks to solve]

Such sheets differ in appearance and surface properties such as wire marks and proportions of fines and fillers on both surfaces. IJc grade paper generally has a rating of about 30-4
It is in the range of 8 grams per square meter and is typically used for magazine paper. Over the past few years, there has been a significant increase in the demands on such papers to have equal coating properties and printability on both sides of the sheet.

In other words, it is necessary to make the gi web as one-sided as possible. In a Fourdrinier paper machine, water is drained in only one direction during the forming process, so the distribution of fines, fibers, and fillers is not equal on both sides of the web. Moreover, since the wire marks the bottom of the web,
In a paper web formed using a papermaking machine of the rope-making type, the quality deteriorates due to differences in properties on both sides.

In addition, even with a separate two-wire paper forming machine, it is not possible to form IJC grade paper in a sufficiently stable state due to the arrangement structure of various elements. There are issues regarding the method of drainage, the duration of the dewatering process, the order of placement of the dewatering elements on each side of the forming area, and the shape of the forming area itself.

That is, fines and fillers greatly affect the overall quality of the coated paper sheet, but in the conventional two-wire papermaking machine, the removal rate of fines and fillers in the early stage of the forming process is too high. If they are removed, they cannot be added back to the forming web in a subsequent process, nor can the removed portions be fully compensated for, such as by supplying an excessive amount of coating material.

However, if strong removal hydraulic forces are not applied to the paper web during the early stages of the forming process, it is possible to retain the fines and fillers, but in doing so it is possible to produce the paper web at an economical rate. becomes impossible.

[Means and effects for solving the problems] The present invention solves the above-mentioned problems when producing LWC grade paper with surface characteristics as uniform as possible. The forming wires converge (close to each other) with the paper stock in between. The valve raw material sandwiched between the forming wires in this way is sent to the perforated forming roll, where it is transferred to the second forming wire on the forming roll. Some of the water is removed inwardly, and some water is also removed outwardly through the first forming wire by centrifugal force.
The initial forming of each side of the paper web is an important process, and in this method, the initial forming is delicately controlled, a predetermined state is maintained with forming rolls, and the water removal rate and amount of water removed through both forming wires is controlled. can be processed so that they are almost equal.

In the subsequent web forming process, the travel path is gently curved from the point where both forming wires converge on the forming rolls to the downstream point of the last forming element acting on either forming wire. It has a meandering shape.

The shape of the forming wire movement path and the forming area is determined by the outer periphery of the forming roll through which both forming wires pass together,
and a curved path on a plurality of subsequent molding elements. The curved passage is convex toward the center of one loop-formed wire;
It is convex with respect to the center of the other looped forming wire, thereby creating a "serpentine" shape.

Between the ends of the serpentine (S-shaped) forming path, suction pressure is applied to one or both sides of the web with varying degrees of pressure. Such pressure can also be exerted on the underside of the forming wire by multiple foil blades,
It can also be effected by a perforated cover box connected to a suction source, thereby allowing water to drain into the box through the shaped wire. Thus, by providing an initial suction structure and a curved foil box or a perforated cover box, in combination with which the deflector blades are placed outside the convex curved passage section of the co-travelling forming wire, Water can be removed to the desired extent from both sides of the web during the forming process while retaining a high proportion of fines and fillers to produce the desired one-sided nib.

In addition to the double-sidedness mentioned above, there have been long-standing problems with pinhole elimination and wrinkle control when producing IJc grade papers. Pinholes are a common problem in all lightweight grades of paper, and streaks and streaks are common when paper is produced on two-wire forming machines where the length of the unsupported section of the forming wire in co-running conditions exceeds 6 feet. tends to cause problems.

Of course, the elimination of pinholes and wrinkles is a very important requirement when producing magazine paper, and streaks can occur if the drainage rate of the web differs in different parts of the machine direction.
As a result, the thickness of the web wound on the reel is non-uniform (generally large), but the occurrence of such streaks and pinholes can be significantly reduced with the apparatus of the present invention. To achieve such an effect, in the molding area,
The path of the reshaped wire is curved into a gentle S shape,
In combination with such a structure, the wire is intermittently supported at narrow intervals by shoes that guide the forming wire,
Dewatering on the forming rolls is done slowly at the initial stage.

The initial drainage step on the forming rolls exposes the stock to a relatively constant pressure over a period of time, and the subsequent drainage step on the shoe exposes the stock to pulsating pressure from the foil blades. By combining these steps, it is possible to carry out dehydration in a desired order and form, retain fines and fillers on the surface of the web, and perform dehydration treatment that allows fibers to be molded in good condition from the web. Become.

It is therefore an object of the present invention to provide a two-wire paper forming device that controls duplexity, especially in the production of IJC grade papers.

Another object of the present invention is to provide a two-wire paper forming apparatus in which a substantially equal amount of filler remains on both sides of the web.

A further object of the present invention is to provide a two-wire paper forming apparatus that produces no or very few streaks in the paper web after production.

A further object of the present invention is to provide a two-wire paper forming apparatus in which initial dewatering is performed on the forming rolls and subsequent dewatering is performed in a serpentine forming area.

The present invention is characterized by providing a novel curved two-wire forming area.

The present invention has the advantage of producing high quality IJIc grade paper at high speed.

〔Example〕

Next, the present invention will be explained in more detail based on illustrated embodiments.

In FIG. 1, the headbox 14 has its nozzle 18
The paper stock jet 16 is disposed in such a manner that it is sprayed generally horizontally toward the first endless forming wire 10. The wire lO is passed over the introduction guide roll 26 and moved generally horizontally over a short distance, and the stock jet 6 is sprayed from the nozzle 18 toward the horizontal portion. The second endless forming wire 12 is hooked across the surface of the forming roll 20, and the area where the first and second wires move together (in an overlapping state) is at the lowest end of the outer peripheral surface of the forming roll 20. It starts from the neighborhood. This forming roll has a relatively large diameter (approximately 60 inches) and an open surface structure, specifically a porous structure with a number of holes extending through the outer surface, or a plurality of cracks or cracks in the outer surface. It has a slotted structure covered with fine mesh wire. That is, the outer surface of the forming roll has a water-permeable structure that allows water discharged from the stock to move inwardly into the interior of the roll and removed along the roll axis.

In this embodiment, the suction box 22 is arranged inside the forming roll 20, and the starting point of its suction area is located at the point where the first and second forming wires 10.12 extend tangentially to the roll and overlap on the roll surface. It is located at the starting point. This suction box 22 extends downstream from the starting point by an angle of approximately 90-100 degrees, at the end of which the co-traveling first and second forming wires separate from the forming rolls and move within the forming area. Move further downstream.

A plurality of deflector foils 21 are arranged inside the first forming wire 10 to cover the surface of the forming roll 20. These deflector foils are placed exactly adjacent to the inner surface of the first forming wire and are adapted to receive water that is centrifugally thrown past the wire and from its underside. The water received by this foil 21 is collected by the saveall 27 and the loop-shaped first
removed from the open end of the forming wire.

In the region where the first and second forming wires jointly extend in a generally vertical direction, a first dewatering shoe 34 is provided inside the first forming wire 10 at a portion downstream of the roller 20 by a small distance. In this embodiment, the surface of the first dewatering shoe contacts the forming wire running together on its porous surface and guides the wire while bending it. It is concavely curved inwardly (in other words, outwardly convexly curved), and when pressed against the wire, it pushes the wire outward into the curved path, and its tension causes water to shoo. It is being squeezed inward. The surface of the first dewatering shoe has a porous or open structure so that water squeezed inward from the first forming wire is collected into a removal box. The shape of the shoe surface can be set in various ways.

For example, there are the following two forms.

That is, in one example, as shown in FIGS. 7a and 7b, a plurality of foil blades 46 are mounted parallel (and preferably!) to the cross-machine direction to achieve the desired curvature in the flow direction (feed direction). state (or radius of curvature). In the other example, as shown in FIGS. 8a and 8b, a plurality of holes 48 are formed through the curved surface at narrow intervals.

In FIG. 1, formed wires 10 and 1 in a joint running state
2 runs further upwards from the shoe 34 and comes into contact with the surface of the second dewatering shoe 36. In this embodiment, the second dewatering shoe is similar to the first dehydrating shoe and the loop the second dewatering shoe being concave toward the inside of the second forming wire (in other words, convexly curved outwardly); Biasing the co-travelling patterning wires outwardly on the curved surface to create a desired amount of wire tension and to encourage water to pass through the second wire and into the second dewatering shoe. It looks like this. The curved porous surface of the second dewatering shoe 36 can have a variety of structures, including the foil blade structure and porous cover structure used for the first dewatering shoe surface.

In this embodiment, the first and second dewatering shoes 34 and 36 are curved in a convex shape 9 toward the forming wire, and can each be connected to a negative pressure source to drain water from the forming wire into the shoe. It looks like this. However, these shoes can also be used without external suction forces, especially in the case of a foil surface construction. In this case, save all 40
．． 41 will be installed alongside them to collect and remove water from the shoes.

After the forming wire 10.12 has passed through the second dewatering shoe 36 in co-running mode, it contacts the surface of the couch roll 24 and changes direction. The couch roll 24 has a built-in suction box 25, and when the first forming wire 10 leaves the second forming wire 12 and heads toward the guide roll 28 nearby, the wet web is transferred to the second forming wire by the suction box 25. It is designed to remain on the surface of 12. After passing through the guide roll 28 and a plurality of other guide rolls, the loop-shaped first forming wire returns to the introduction guide roll 26 and repeats the web forming process.

The web on the surface of the second forming wire 12 moves downward from the couch roll 24 and is exposed, and in this state the pickup felt 50 contacts the web W.

Because the web has a greater affinity for felt than the forming wire 12, the web is stripped from the forming wire 12 and fed to the inlet of subsequent sections of the papermaking machine, where it undergoes compaction, drying, and finishing operations. After being applied, it is wound up into a roll to form the final product or a product for further processing such as coating.

The perforated or open surfaces of the first and second dewatering shoes 34,36 may be provided with slots or holes or a combination of both, and may be formed with a plurality of closely spaced parallel foil blades. It is also possible to provide a suction source to draw the water inwardly from the continuous forming wire with the desired force, or it is possible to omit the use of such a suction source. The first and second dewatering shoes can also be arranged inside the first and second forming wires by suitably combining such specific structures into structures other than those shown.

In this regard, the designation of the dewatering shoes ("first" and "second") remains the same as before, regardless of whether they are located inside the first and second forming wires, The dewatering shoe closest to it on the downstream side is called the first dewatering shoe, and the next dewatering shoe downstream of the first dewatering shoe is called the second dewatering shoe, and the designation is independent of the forming wire surrounding the shoe. .

Also, for ease of explanation, in the various embodiments shown in FIGS. 2-6, corresponding elements are labeled with the same numerals with different suffixes.

In FIG. 2, first and second dewatering shoes 34a and 36a connected to negative pressure sources 42a and 44a, respectively, are arranged inside the first forming wire, and both surfaces are convex outward. The curved running path is formed by bending the shaped wires that are running together. Since the first and second dewatering shoes are both located inside the first forming wire, some amount of water is forced outwardly from the first forming wire and inward from the inner surface of the second forming wire. To do so, multiple deflectors (
Deflection) A foil 38a is placed inside the second forming wire in a non-contact state, blocking water as if it were pushed out by centrifugal force and keeping it away from the forming area.
It is designed to be discharged into a.

According to the principles of the invention, the forming roll forming area 23a is
Although it is formed over an angular range covered by the suction box 22a on the outer periphery of the forming roll, such a range 23a extends from the front wall of the suction box 22a in the circumferential direction! It can be changed by making the P1 clause flexible. In that case, the introduction guide roll 26a and the headbox nozzle 18a are adjusted correspondingly to move the nozzle around the circumference of the forming roll, so that the amount of water drawn from the stock between the wires on the forming roll is adjusted accordingly. be adjustable. This adjustment is made in relation to the amount and rate of dewatering in the first and second dewatering shoes 34a, 36a, and the total amount of dewatering through both the first and second drawing wires and the amount of water accompanying the water. Effectively balance wind, fine, fiber, and filler removal amounts.

In FIG. 3, first and second dewatering shoes 34b.

36b are respectively arranged inside separate forming wires, the first dewatering shoe being attached to the inside of the second forming wire, and the second dewatering shoe being attached to the inside of the first forming wire. The re-drying shoe also has a convex curved surface that contacts the inside of the corresponding wire. These surfaces may be provided with a plurality of foil blades, similar to other embodiments of the dewatering shoe, or may be formed by a cover with a plurality of holes cut through the surface.

The forming area 23b of the forming roll 20b may be significantly smaller than in the case described above, and the suction force exerted thereon may be significantly smaller, thereby reducing the initial forming roll displacement and increasing the roll displacement versus foil. - The blade displacement ratio can also be changed to a desired value. Also, similar to the embodiment shown in FIG. 2 (i.e., non-contact structure with the wire), the deflector 38b is disposed inside the second forming wire in a state facing the surface of the convex curved wire, and its position is In this method, water ejected from the inner surface of the second forming wire due to centrifugal force during the forming process is received and its direction is changed.

In the embodiment shown in FIG. 4, the forming range 23c increases to a range of about 100 degrees.
The forming wire is tangentially separated from the surface of the forming roll at a point approximately 100 degrees away from the bottom edge of the outer circumference of c.

In the embodiment shown in FIG.
d is divided into a plurality of subchambers 19.119, 219.319, allowing for greater control over the range and degree of suction applied to the web during forming. That is, the introduction guide roll 26d is adjusted in the direction indicated by the double-headed arrow 52d, and one or more suction chambers 19, 119, 219, 319 can be eliminated or added as required.

In the embodiment shown in FIG. 6, a non-rotating shoe 26e is used in place of the introduction guide roll. In this example,
A ceramic surface is formed on the shell 26e over which the first wire moves smoothly.

With this type of structure, the deflection of the support guide 26e can be controlled more accurately than in the case described above, and all vibrations associated with roll rotation can be comprehensively eliminated, so depending on the device,
This type of structure is preferable because it allows the angle of the throat (passage section) to be changed over a wide range.

In the operating state, the first forming wire 10 is guided past the adjustable introduction guide roll 26 onto the forming roll 20 . The guide roll 26 is adjustable in the direction of the double-headed arrow 52 and is formed between the throat 19 (i.e., the first forming wire 12 and the second forming wire 12 that contacts the forming roll 20 upstream of the first forming wire 19 ). The shape and position of the passageway entrance section can be changed. (preferably, but not necessarily, in a state where the second forming wire is in contact with the surface of the forming roll), an area where the first and second forming wires converge (approach each other) near the surface of the forming roll. is called the throat 19 as is well known, and the nozzle 1 of the head box 14 is connected to the throat 19 at the throat 19.
8 jets the stock stream into the throat near the forming rolls.

In the present invention, the term "stock" is used to refer to the slurry of water and fibers that is conveyed from the headbox to the forming wire. Dewatering of the slurry is accomplished by draining water out of one or both of the forming wires, and as the stock moves downstream, the slurry is dewatered and the fiber density and dryness increases. In other words, as long as the orientation of the fibers and the movement of fibers and fines continue, the slurry will remain a "stock".
in a state. Ultimately, the paper stock becomes a web W.

Immediately after the throat area, the stock is conveyed onto the forming roll area 23 of the forming rolls, where it is subjected to gentle suction pressure inwardly through the second forming wire and from the inside to the outside of the first forming wire. It receives a slight centrifugal force towards.

The forming roll forming range is generally determined by an angle corresponding to the arcuate distance of the suction box 22, and the upstream end of the range extends tangentially to the forming roll with the first and second forming wires touching each other. position, and its downstream end is
This is the position where both forming wires are tangentially away from the forming rolls.

In the embodiments of FIGS. 2, 4, 5, and 6, the forming range of the forming rolls can be increased or decreased (i.e., the angle can be increased or decreased) as desired; Thereby, for example, a single suction box 22 (FIG. 2)
One or more partial chambers 19.11 of a suction box (FIG. 5) with a compartmented structure can be formed by forming a long molding area 23 on top.
It is also possible to form short molding areas on the 9.219.319 and to vary the degree of suction pressure exerted on the individual subchambers. In either case, a controlled and gentle suction pressure is applied in the forming area of the forming rolls, thereby removing water inwardly from the second forming wire and retaining the ash, fines and other fillers appropriately. Facilitates the formation of webs.

Introductory guide 26 can be comprised of a roll or a stationary curved structure, such as the ceramic foil-like surface 26e of FIG. for example, in the direction of the double-headed arrow 52, thereby changing the position where the first forming wire 10 extends tangentially and contacts the slurry covering the second forming wire on the forming roll 20. You can also. In this structure,
The position of the headbox and its nozzle 18 can be varied circumferentially around the surface of the forming roll, as desired, as shown in FIGS. 4 and 5. This changes the time that the slurry is exposed to the forming area of the forming rolls and changes the effect of gravity on the initial dewatering action on the forming rolls. In this case, the amount of drainage around the forming rolls also changes.

After passing through the forming rolls with the slurry sandwiched between them, both forming wires are fed onto the convex curved surface of the first dewatering shoe 34 such that the direction of curvature of the path of movement of the stock is aligned with the movement on the forming rolls. The direction of curvature of the passage is opposite. The outwardly convex curved surface of the first dewatering shoe can also be formed by a plurality of foil blades (FIGS. 7a, 7b) with the same blade contact area on the inside of the forming wire;
It is also possible to form a plurality of blades having different plate contact areas with respect to the forming wire. Furthermore, as shown in FIGS. 8a and 8b, the first dewatering shoe may be provided with a porous arcuate surface having a plurality of holes or slots. Similarly, any form can be adopted for the second dewatering shoe.

Furthermore, if necessary, the first dewatering shoe can be connected to a suction source such as pump 42a (FIG. 2), and the suction connection structure can also be eliminated. If a suction structure is not adopted, a suitable saveall 40°41 (Fig. 1) is provided to recover and remove water scooped out from the forming wire by the pump pulsating pressure action of the foils of the first and second dewatering shoes. conduct.

As shown in FIG. 2, on the downstream side of the first dewatering shoe,
Inside the second forming wire on the convexly curved forming wire travel path, one or more deflector foils 38a are disposed in contact-free proximity to the inner surface of the second forming wire; It is also possible to receive and deflect water that splatters outwardly from the second forming wire due to centrifugal force as it bends over the surface of the second dewatering shoe 36a. The water thus removed from the second forming wire by centrifugal force is recovered by the saveall 39a.

In all constructions, both forming wires are connected to forming rolls 20
The robots move together in a convex curved path from the to the couch roll 24. In the structure shown in FIG. 2, both forming wires reach above the second dewatering 36a.

The shoe 36a can employ either a foil or perforated cover structure, similar to the embodiment described above in connection with the first dewatering shoe 34a. Further, the water in the formed wire in the co-running state can be discharged through the second dewatering shoe only by the pulsating pressure action of the foil blade pump, or by the action of this action and the suction pressure action by the suction pump 44a. You can also do it. This vacuum pump 44a can also be connected to another porous cover structure. After leaving the second dewatering shoe, the forming wire is guided onto the surface of couch roll 24. The couch roll 24 is provided with a suction box 25, and the web W, which has been almost completely formed, is held on the second forming wire 12 by the suction box 25, and the first forming wire 10 is separated from the web and passed through a plurality of guide rolls. It is guided onto the first of the rolls 28 and is supported by those rolls 28 to move in an endless loop trajectory. The second forming wire 12 similarly moves in an endless loop trajectory. The web W is peeled off from the surface of the second forming wire by a pink-up felt 50 and sent to a downstream processing step.

As seen in all examples, the forming area forms a gently meandering path from point 30. The first and second forming wires converge at the above point 30 on the forming roll and leave the forming roll at point 32 from the second dewatering shoe. During this transfer process, both forming wires are supported by the surfaces of the forming rolls and the surfaces of the first and second dewatering shoes, so that no unsupported structure transfer path is created for more than a few feet in any part. Furthermore, as shown in the embodiment of FIG. 3, only one forming wire contacting deflector 38b is required to remove drainage from forming wire 12b.

In the embodiment shown in FIGS. 2 and 3, the first and second dewatering shoes 34, 36 are located inside the first and second forming wires.
The layout structure is different. Although the actions of the shoes 34 and 36 are the same, it is necessary to change the combination of cover and foil structure depending on the operating conditions, and specifically, the position of the shoe, the machine speed, and the specific paper to be manufactured. The combination structure is changed depending on the quality grade, etc.

In the embodiment shown in FIGS. 1, 2, and 3, the forming area is formed from a point 30 on the forming roll to a point 32 before the couch roll forms a gentle reverse bend. , in that region, the co-travelling forming wire passes a portion of the forming roll surface and the surfaces of the two convex curved dewatering shoes.

The stock is first exposed to a constant and relatively low drainage pressure over a wide range on the surface of the forming roll. To that extent, the fines and fillers are retained within the stock that is being formed into a gi web.

The co-running forming wires then move to the first dewatering shoe, whereupon the stock is most preferably exposed to relatively high rapidly fluctuating pulsating pressures by the set of foil blades. Here, the formation of fibers within the paper web takes place.

Finally, the co-running forming wire moves onto the second dewatering shoe, which is most preferably a set of foil blades. Here, the degree of fiber formation is further increased as the wire is reversely curved.

Thus, the discharge pressure on the forming rolls is a constant low pressure over a wide range, which reduces the degree of disruption of the individual fiber arrangement during the forming process, and at the same time increases the degree of retention of fines and fillers. . Approximately 30-40% of free water is removed from the stock on the forming rolls.

On the dewatering shoe, the non-water content is increased to promote fiber formation. Approximately 60-70% of free water is removed from the feedstock. In this case, most of the fines and filler are retained because there is less water to carry them away from the web.

Due to the constant relatively low pressure exerted over a wide area in the initial path of the stock on the forming rolls and the short-period relatively high pulsating pressure exerted on the dewatering shoe, special pressure conditions are created. is formed. This facilitates water removal and increases filler retention and fiber shaping in the web during forming, achieving the objective of producing double-sided high quality LWC paper sheets.

In any of the embodiments shown in FIGS. 1 to 4, the arrangement structure is generally vertical, but the position of the entire forming apparatus including each part from the forming roll 20 to the couch roll 24 may be changed.
? , and while maintaining a gently curved molding region between points 30 and 32, the molding region can be set in any orientation in the range from vertical to horizontal, as required. Similarly, devices with various deformation and adjustment structures other than those described above may be constructed based on the present invention.

[Effects of the Invention] The present invention provides a two-wire paper making device in which the first and second
As explained above, by forming a meandering movement path in which both wires run together with the web sandwiched between the first and second dewatering shoes on the downstream side of the forming roll partially surrounded by the forming wire, , the stock is first dewatered by a relatively low pressure on the surface of the forming roll, and then dewatered in the meandering path by a relatively high pulsating pressure of short periods by a dewatering shoe, thereby facilitating water removal. , the degree of retention of filler and the degree of forming of fibers in the web during forming are increased, and paper with high quality on both sides can be produced.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing a molding area of an embodiment of the present invention;
FIG. 2 is a schematic side view of another embodiment of the invention in which the first and second forming shoes are arranged inside the first forming wire;
The figure is a side view of still another embodiment of the present invention in which the first forming shoe is arranged inside the second forming wire and the second forming shoe is arranged inside the first forming wire, and FIG. Forming according to yet another embodiment of the invention in which the position of the initial contact point of the first forming wire and the headbonx nozzle are located downstream of the forming rolls compared to the embodiments of FIGS. FIG. 5 is a side view of the forming roll similar to FIG. 4 with the position where the first forming wire contacts the forming roll and the headbox nozzle located further downstream of the forming roll surface; FIG. 6 is a side view of the forming roll in which the first forming wire is guided onto the forming roll by a non-rotating guide, and FIGS. 7a and 7b are dewatering shown in FIGS. 1 to 3, respectively. Figures 8a and 8b are front and side views of the foil box of the shoe, respectively, of the perforated cover structure of the dewatering shoe shown in Figures 1-3. 10.-first forming wire, 12-second forming wire,
14- Head box, 16- Stock jet, 19
- Throat, 20- Forming roll, 21- Deflector foil, 23- Forming range, 24- Couch roll, 34
．． 36-One theory Mizushu agent Patent attorney Akira Sakama and 3 other people FIG, 2

Claims (1)

[Scope of Claims] 1. The first and second loop-shaped forming wires are arranged so as to move in a common passage in a state facing each other in a part of their length, and the throat formed by both forming wires is In a two-wire papermaking machine equipped with a head box for spouting a stock stream to a paper stock; a forming roll is arranged inside a loop-shaped second forming wire, and the forming roll receives water from the paper stock that has passed through the second forming wire. providing a porous surface for passing through; a couch roll disposed inside the looped second forming wire downstream of the forming roll; a wire guiding means disposed inside the looped first forming wire; first and second dewatering shoe means configured to guide the first forming wire to form a converging throat with the second forming wire in the vicinity of the forming roll, both located inside the first forming wire; Alternatively, the first dewatering shoe means is arranged inside one of the forming wires;
A second dewatering shoe means is provided on the downstream side of the forming roll and upstream of the couch roll, with the second dewatering shoe means disposed inside the other forming wire; A two-wire paper making apparatus characterized in that a meandering movement path is formed for the first and second forming wires to run together with the forming rolls in the forming area extending to the front. 2. The wire guiding means is adjustable so that the position where the first forming wire contacts the slurry on the second forming wire around the forming roll can be changed. The two-wire paper making device described in Section 1. 3. The two-wire paper making apparatus according to claim 1, wherein the forming roll is provided with a suction box, and the box limits the forming area on the surface of the forming roll where the stock moves. 4. The two-wire paper making apparatus according to claim 3, wherein the size and position of the forming roll suction box are adjustable. 5. The suction box is partitioned so that different suction pressures can be applied to a plurality of different positions inside the outer periphery of the forming roll. Wire paper making equipment. 6. The two-wire paper making apparatus according to claim 1, wherein the first dewatering shoe is arranged inside the first forming wire. 7. The two-wire paper making apparatus according to claim 6, wherein the second dewatering shoe is disposed downstream of the first dewatering shoe and inside the second forming wire. 8. The two-wire paper making apparatus according to claim 1, wherein the first dewatering shoe is disposed inside the second forming wire. 9. A two-wire papermaking apparatus according to claim 8, characterized in that the deflector foil means is disposed downstream of the first dewatering shoe and inside the second forming wire. 10. The two-wire paper making apparatus according to claim 1, wherein both the first and second dewatering shoes are arranged inside the loop-shaped first forming wire. 11. Both the first and second dehydration shoes are connected to the loop-shaped first
Claim 1, characterized in that deflector foil means is disposed inside the forming wire, and deflector foil means is placed inside the second forming wire in contact with the first wire to remove water from the wire. 2. The two-wire papermaking device according to item 1. 12. Foil blade means is provided on one or both of the first and second dewatering shoes, the foil blade means being brought into contact with an adjacent forming wire, and a convex curvature directed toward the forming wire by the foil blade means; A two-wire papermaking apparatus according to claim 1, characterized in that a surface is formed to allow water to be discharged inwardly from the forming wire. 13. Providing a perforated cover on one or both of the first and second dewatering shoes, the perforated cover contacting an adjacent forming wire and forming a convex curved surface towards the forming wire by means of the foil blade; 2. The two-wire paper making apparatus according to claim 1, wherein water is discharged inward from the forming wire. 14. In a two-wire papermaking apparatus for forming a paper web from a stock stream ejected from a headbox nozzle; a forming roll and a couch roll are provided; loop-shaped first and second forming wires are connected to the forming roll in a section; at least one of the first and second forming wires is provided with a first and second dewatering wire; the shoes in contact, thereby causing the first
and draining water from a corresponding one of the second forming wires; pressing surfaces of the first and second dewatering shoes against one or both of the first and second forming wires, thereby; A two-wire papermaking device for forming a paper web, characterized in that a curved forming region is formed by a forming wire in a range from a starting point on the forming roll to a point before the forming wire reaches the couch roll. 15. Foil blade means is provided on one or both of the first and second dewatering shoes, and the foil blade means is brought into contact with an adjacent forming wire to form a convex curved surface toward the forming wire. A two-wire paper making apparatus according to claim 14. 16. A patent claim characterized in that one or both of the first and second dewatering shoes is provided with a porous cover, and the porous cover is brought into contact with an adjacent forming wire to form a convex curved surface facing the forming wire. A two-wire papermaking apparatus according to item 14. 17. A suction pressure source is provided in one or both of the first and second dewatering shoes to promote the intrusion of water from the paper stock into the shoe through the corresponding forming wire. 2 as set forth in claim 14
Wire paper making equipment. 18. The forming roll is provided with a forming area through which at least one forming wire passes, in which water is slowly removed from the stock through the corresponding forming wire. 15. The two-wire papermaking device according to item 14. 19. Providing an introduction guide means for selectively positioning the first forming wire with respect to the second forming wire on the forming roll, thereby selecting the position of the throat between the two forming wires in a co-traveling state; 15. The two-wire paper making device according to claim 14, wherein the two-wire paper making device is configured to determine the amount of paper. 20. The two-wire papermaking apparatus according to claim 19, characterized in that the introduction guide means is provided with a stationary curved surface whose position is adjustable. 21. A deflector foil means is provided at the water receiving position, and is arranged on the inside of one of the loop-shaped forming wires and on the side extending convexly toward the deflector foil means. A two-wire papermaking apparatus according to scope 14. 22. Claim characterized in that the second forming wire is engaged with the surfaces of both the forming roll and the couch roll, and the deflector foil means is located inside the first forming wire opposite the forming area of the forming roll. A two-wire papermaking apparatus according to item 14. 23. Disposing deflector foil means inside the forming wire located outside the dewatering shoe, thereby forming a convex curved travel path to receive water centrifugally displaced from the adjacent forming wire; 15. A two-wire paper making apparatus according to claim 14. 24. In a two-wire papermaking apparatus for forming a paper web from a stock stream emerging from a headbox nozzle; a forming roll having a forming area and a couch roll having a suction box are provided; loop-shaped first and second The forming wires are arranged to converge near the forming area of the forming roll to form a stock receiving throat and diverge on or downstream of the suction box in the couch roll; the first dewatering shoe is connected to the second forming wire; the first dewatering shoe having an outwardly convex curved surface extending toward the second forming wire, the surface being formed by a plurality of laterally extending foil blades; a first dewatering shoe downstream of the first forming wire, the second dewatering shoe having an outwardly convex curved surface extending toward the first forming wire, the second dewatering shoe having an outwardly convex curved surface extending in a plurality of lateral directions; forming a foil blade; the forming roll and the first and second dewatering shoes form a serpentine curved forming area extending from the forming roll forming area to before the couch roll;
The stock is first exposed to a relatively constant wide range suction pressure, then to a rapidly fluctuating pulsating pressure, which promotes web fines and filler retention at an early stage, and then A two-wire papermaking device for forming a paper web, characterized in that the web is in a drainage state to promote fiber formation. 25. The two-wire paper making apparatus according to claim 24, wherein the forming range of the forming roll is adjustable and the suction pressure applied to the throat can be changed. 26. The first forming wire for the second forming wire on the above forming area.
Introducing guide means for selectively determining the position of the forming wires is provided, whereby the throats are selectively determined and the state of drainage from both forming wires is adjusted. A two-wire papermaking apparatus according to Scope 25.