JPH0565633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hybrid wire part and two
The present invention relates to a paper layer forming device that can be used for sheet wire type wire parts, etc.

(Prior Art) FIGS. 5 to 7 show examples of configurations of conventional hybrid wire parts. In FIG. 5, the raw material 1 ejected from the head box is dehydrated to some extent and is placed on the lower wire 2 and reaches the lead-in suction box 5, and then the lead-in roll 4
The upper wire 3 guided by the two wires overlaps, and the raw material is sandwiched between the two wires. On the lead-in sanction box 5, water is dehydrated by downward vacuum pressure and also by pressure generated by the tension and curvature of the upper wire 3. After passing the lead suction box, the white water remaining on the upper wire 3 is sucked up by the autoslice at the top of the upwardly facing dehydrator 6, and is dehydrated in the following suction box.

Also, due to the tension and curvature of the lower wire 2, white water oozes out to the lower wire 2 side at this part.
This is scraped off by the centrifugal force and the tip of the transfer box 7 after passing through the dewatering device. The transfer box 7 is a type of curved suction box, and functions to dewater downward, separate the upper wire 3 and the raw material, and reliably retain the raw material on the lower wire 2 side. The raw material is then further dehydrated by a flat suction box 8 and a suction couch roll to form a paper web, which is then transferred to a press part.

In FIG. 6, a dewatering roll 9 is used in place of the upward suction box in FIG. 5, and a forming shoe 10 is provided after the lead-in suction box 5 to provide dehydration and dispersion effects.
Further, in FIG. 7, a lead-in open roll 11 is used instead of the lead-in suction box, and a forming shoe 12 is provided on an upwardly inclined part.
A dewatering roll 13 is provided on the lower wire 2 side.

The hybrid wire part represented by this configuration can greatly enhance the dewatering capacity of a single wire fourdrinier paper machine, and
The dispersion of raw materials can also be improved, and double-sided properties can also be improved. This is mainly due to the pressure fluctuations and vibrations that are applied to the raw material by the upward suction box 6 and the batten plates with many foil-shaped cross sections used in the forming shoes 10 and 12, as well as the behavior of white water during dewatering. This is thought to be due to the effect of

However, this effect also largely depends on where the device constituting the upper wire 3 is placed in the lower wire 2 process. Naturally, the closer this position is to the head box, or in other words, the lower the concentration of the raw material, the greater the effect.
The concentration when it overlaps with the raw material is said to be about 1.5 to 2% or less. Therefore, the raw material concentration in the head box at this time does not exceed this, and is normally operated at 0.5 to 0.6% (fiber content only), and rarely exceeds 1%.

In this way, in conventional methods, dispersion is promoted by the side effects of dehydration, so as dehydration progresses, the concentration of the raw material increases, and the dispersion effect decreases significantly.
Diversification effects cannot be accumulated. In particular, raw materials that have been dehydrated by these devices are concentrated near the wires on the device side, and fiber mats grow, so if excessive action is applied, the fiber mats may even break.

Therefore, the arrangement of the dewatering equipment must be arranged in consideration of the balance between the dewatering power and the dispersion effect during dewatering.
As a result, when the content exceeds about 2%, it is difficult to disperse the raw material in the wire part, and an apparatus with high dispersion effect has been desired.

(Problems to be Solved by the Invention) Fiber dispersion basically proceeds due to relative motion between the fibers and between the fibers and the white water in which they are suspended.

The present invention solves problems such as difficulty in dispersing conventional raw materials in wire parts by maximizing the movement of white water to promote dispersion.
The present invention aims to provide a paper layer forming apparatus that can also handle high-concentration raw materials.

(Means for Solving the Problems) Therefore, the present invention provides a paper layer forming apparatus in which two wires running with a raw material sandwiched therebetween are supported in a polygonal shape by a plurality of convex portions.
The plurality of convex parts after the first one form a wedge space between the wire and the height which is large behind the apex of the convex part and decreases in height according to the running direction of the wire. The flat surface on the front side of the wire separates from the wire at a steep angle from the apex of the end of the same surface in the running direction, and if there is a subsequent convexity, it directly intersects with the flat surface on the front side of the apex of the subsequent convexity. The surface behind the apex is uniform across the width of the wire, and the plurality of convex portions are integrated to form a saw-blade-like uniform cross section. This is a means for solving problems.

(Function) In the above configuration, the supporting point of the wire is placed at the rear end of each element, and the area in front of this supporting point is a wedge-shaped space that narrows as the wire runs. The white water that has been dehydrated to the dehydration shoe side is returned to the raw material side to restore the fluidity of the raw material and bring about a dispersion effect, and this action is repeated and accumulated for the number of convex portions.

(Example) Examples of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show examples of the present invention.

First, in FIG. 1, the raw material 20 that has been dehydrated at the front part of the wire part on the wire 21 is transferred to
4 and is sandwiched between the upper wire 22 guided by the lead-in roll 23. The upper surface of the dewatering shoe 24 supports the wire with a moderate curvature, and is configured such that the lower wire 21 is first bent downward little by little, and then the upper wire overlaps halfway. The white water dehydrated in the dehydration show 24 is removed by a deflector or auto slice 25, etc.
The raw material 20 and the upper and lower wires 22 pass between the pairs of fiber dispersion shoes 26 and 27 and are subjected to a dispersion action.

The dispersed raw material 20 is transferred to an upward dehydrator 28
The wire 2 is rapidly dehydrated in a downward suction box 29 called a transfer box.
1 and separated from the upper wire 22.
Thereafter, as in the conventional method, it is dehydrated to a predetermined concentration in a suction box or suction couch roll and sent to a press part.

Next, FIG. 2 shows an embodiment different from FIG. 1. In this embodiment, the fiber dispersion shoes 26 and 27 are the same as the case shown in FIG.
A dehydration shoe 30 having the same configuration as the dehydration shoe 24 is provided on the upper wire 22 side behind the dehydration shoe 6 and 27. In this dewatering shoe 30, the dispersion effect is improved and at the same time, the dehydrated white water is directed toward the lower wire 21 side, so there is no need for complicated sabors around the rolls as shown in FIG. 6, and the overall structure is also improved. It becomes very simple. The curvature of the dehydration shoe 30 should be several times to ten times smaller than the curvature of the dehydration roll in order to improve the paper quality (to reduce the displacement of the wire before and after the bend) and to reduce frictional resistance. Since the dehydration power is reduced, a larger transfer box 31 is provided.

With such a configuration, the structure on the upper wire 22 side becomes very simple and at the same time there is no heavy object, so even a conventional single wire Fourdrinier paper machine can be easily modified, and a large formation improvement effect can be expected. I can do it.

Next, the dewatering shoes 24 and 30 will be explained with reference to FIGS. 3 and 4. First, dehydration step 2 in Figure 3
4, the dehydration shoe 24 supports the two wires 21 and 22 running with the raw material 20 sandwiched in between a plurality of polygonal convex portions 34, and at least the second and subsequent wires of these convex portions 34 The plurality of convex portions 34' form a wedge space 33 with the wire 21, which has a large height behind the apex of the convex portion 34' and whose height decreases in accordance with the running direction of the wire 21. If there is a flat surface A in front of the apex of the convex portion and a vertex C at the end of the same surface A in the running direction, away from the wire 21 at a steep angle, and there is a subsequent convex portion 34'',
Consisting of a flat surface A' in front of the apex of the subsequent convex portion 34'' and a surface B behind the apex C that directly intersects,
The surfaces A, B, A' before and after this vertex C are the wire 21
are uniform across the width direction, and these plurality of convex portions 3
4, 34', and 34'' are integrated to form a sawtooth-like uniform cross section.Furthermore, the tip 32 of the dewatering shoe 24 forms an acute angle to scrape off the white water on the lower surface of the lower wire 21 and remove the raw material 20. The lower wire 21 is guided to the upper surface of the dehydration shoe 24.The upper surface of the dehydration shoe 24 has a sawtooth cross section so as to have a plurality of recesses that form wedge spaces 33 between the wire 21 and the wire 21 from the middle. , the wire is supported by the convex portion 34 in an arc shape (polygonal shape if you look closely).

The dehydrated white water passes through the lower wire 21 due to pressure, its own weight, etc., and enters the wedge space 33 of the recess.
The raw material 20 advances in the same direction as the wires 21 and 22, approaches the convex portion 34, and is pushed back toward the raw material 20 again, at the same time wetting the wire and the surface of the convex portion, acting as a lubricant for the contact portion.

On the other hand, the raw material 20 that has advanced on the wire 21
has a free surface until the upper wire 22 overlaps, and the higher the concentration of fibers at that time, the faster the fibers tend to become flocs (agglomeration of fibers). The raw material 20 is finely agitated by the fluctuations, the movement of white water, and the vibrations, and the local flow where the fibers tend to aggregate is broken and uniformly dispersed again.

This phenomenon can be easily confirmed by comparing the state of the raw material passing over a plate with a slight curvature and the state of the raw material when many grooves are cut in this plate at right angles to the running direction of the wire. .

After the upper wires 22 sandwich the raw material 20, there is no free surface, and the movement of the fibers in particular is restricted in the thickness direction. Upper wire 22
The material is pressed toward the lower wire 21 by the tension and the curvature in the running direction, and pressure is generated on the material.
For this reason, raw materials are dehydrated rapidly,
The white water dehydrated to the lower wire 21 side is in the wedge space 3
Because it is pushed back to the raw material side by the action of 3,
Overall, water is dehydrated only from the upper wire 22 side.

Here, the difference between the embodiment of the present invention and conventional dehydration is explained by the movement of white water on the lower wire 21 side and the growth of fiber mats on the upper wire 22 side, which is farthest from the shoe that provides the dehydration effect. It is in the point of doing.

In the case of the conventional method (excluding dehydration shoes with a flat top surface), in most cases, including the lead-in box shown in Figure 5, the raw material when dehydration is applied,
We expect and utilize the dispersion effect caused by the movement of white water, but at this time, the concentration of raw materials and the formation of fiber mats also occur on the dehydration equipment side, and at least the concentration of raw materials near the wire will always increase during the next operation. It's going up a little. For this reason, even if the same effect is given, it must be transmitted to the entire raw material through the concentrating section where the fluidity has decreased on the dehydrator side, and the dispersion effect will rapidly decrease, and on the other hand, an excessive effect will be concentrated and formed. It may directly destroy the fiber mat.

On the other hand, in the case of the dewatering shoe 24 in the embodiment of the present invention, since the dewatering shoe 24 is concentrated from the upper wire 22 side, the action of the dehydrating shoe on the lower wire 21 side does not break the fiber mat, and the fiber mat enters the wedge space 33. Because the white water flows back and is diluted again, the dehydration shoe side maintains the highest fluidity, and the most white water passes through the raw material section in the thickness direction.On the other hand, the raw material on the dehydration shoe side makes two round trips each time it passes through the convex part. He will be affected by the movement of Hakusui in the second round.

In addition, when the lower wire 21 contacts the dewatering shoe protrusion 34 and bends, and the upper wire 22 bends at a predetermined curvature, pressure is generated. Since it is pushed back to the side and tries to push up the upper wire 22, the pressure rises slowly and takes a long time. Due to these actions, the dispersion effect on raw materials is
At the same time, it is greatly improved compared to the conventional method.
Since the impact caused by the dehydration shoe is also alleviated, the yield of raw materials is also improved. In addition, in the case of a dehydration shoe with a flat top surface, the concentration of raw materials occurs on the upper wire side as in the present invention, but the dehydration direction of white water is one-way to the upper wire side, so the dispersion effect is very small. .

Further, the dehydration shoe 30 shown in FIG. 4 has the same structure as the dehydration shoe 24 but is arranged in the opposite direction for exclusive use of dehydration. In this case, the two wires head toward the dehydration show with the raw material sandwiched between them from the beginning. Further, the above effect can be enhanced by providing ventilation or water passage holes 35 in the recessed portion of the dewatering shoe 24.

In the case of Fig. 3, if a small amount of water is sent into the recess from the hole 35, it will be pushed into the raw material side together with white water by the action of the wedge space 33, and the concentration of the entire raw material can be diluted. Not only can the considerable difference in concentration between before and after the show be intentionally reduced, but the dispersion effect is further enhanced by increasing the amount of white water due to dilution. Furthermore, by sending liquids containing chemicals, fillers, etc. through the water injection hole, it becomes possible to add or add these liquids to the raw materials using the wire part.

The raw material dilution function in this wire part is
This is something that conventional equipment cannot do without, and by adding this function, it will create room for considering dispersion and dewatering separately in the processing method of raw materials in the wire part. Incidentally, in the case of the usage shown in FIG. 4, this effect can of course be added, and conversely, the water passage hole can be enlarged to drain excess white water from the recess.

Moreover, in FIG. 3, if the upper and lower sides are considered upside down and the raw material is placed on the upper wire 22 side in the figure, the air flow that has accompanied the lower wire 21 on the dehydration shoe 24 will be , raw material 20 and lower wire 2
There is a possibility that the material may be mixed into the raw material 20 in the eggplant wedge space 33 of 1. In such cases, conventionally, an open roll 11 is used without using a dehydration shoe or the like (Fig. 7), but it is recommended to provide a ventilation hole 35 to suck in the airflow that comes along with the lower wire 21. This problem can also be resolved.
That is, a dewatering shoe 24 provided with holes may be used instead of the open roll 11 shown in FIG. 7.

(Effects of the Invention) Since the present invention is constructed as explained above in detail, the dispersion effect is greater than that in the case of dehydration using rolls or curved surfaces, and the misalignment between the two wires is small, so the strength in the paper thickness direction is increased. This produces strong paper. In addition, since the white water oscillates greatly within the two wires, the uniformity in the paper thickness direction is improved, and a paper web with good double-sided properties can be obtained. Furthermore, since the white water shakes greatly within the two wires, the fibers whose movement is restricted by both wires (especially long fibers) are dispersed in the plane direction, improving paper strength and producing paper with a light texture. you can get a fish. In particular, improving paper strength in the planar direction helps improve raw material concentration, which is currently a difficult problem.

Note that if a hole is made in the recessed portion, the above-mentioned effect can be further improved by pouring water. By using water injection and suction through the holes in this recess, it is possible to consciously change the concentration of the raw material on the wire. can be used instead of open rolls (overlapping one wire with another). Also dehydration roll,
By using it in place of an open roll for lead-in, it is possible to omit a white water treatment device such as a Sabor, which requires a complicated shape around the roll, and maintenance work such as cleaning the open roll can also be eliminated.

Furthermore, by using the dehydration shoe of the present invention in place of a lead-in suction box, it is possible to increase the dispersion effect, reduce frictional resistance due to the lubricating action of white water, and eliminate the need for a vacuum box, connecting piping, etc. It also becomes possible to add chemicals and fillers. Furthermore, the present invention has a structure in which the large upward suction box is reduced or omitted, or by omitting the sabor for white water treatment, the structure is simplified and the weight can be significantly reduced, making it possible to reduce the weight of the conventional single The top wire device (top unit) can be installed without significantly reinforcing the wire-type Fourdrinier paper machine and its foundation.

In addition, when the raw material sandwiched between two wires approaches the support point, dehydration always occurs from both wire surfaces, and conventionally this white water is removed immediately, and the main issue in developing this technology is to improve the removal efficiency. I came as.
In this conventional method, the fiber pine grows from both wire surfaces toward the center, and the fibers are dispersed by the movement of water at this time, but the fiber pine on the support point side passes through the support point immediately after growth. The impact weakens the structure of the pine, deteriorating the fiber yield, and creating a qualitative difference between the central part and the parts near the two wires.

In the case of the present invention, the white water seeping out to the support point side is pushed back to the raw material side by the wedge surface, so that the substantial fiber mat grows sequentially from the outer wire surface side to the support surface side. I'm going to go there.

For this reason, the amount of white water that promotes fiber dispersion passing through the fiber mat section is equivalent to two surfaces (double) compared to the conventional case, and the dispersion ability is doubled. It is possible to dehydrate while adding dispersion even at a location where the concentration is such that dehydration is performed while fixing the formation.

In addition, the action of the wire support point on the raw material begins before the support point (the apex of the convex part) comes into contact with the wire through the white water on the wedge surface. This also prevents damage to the pine and has the effect of minimizing the amount of fiber that passes through the pine and flows into the white water. Moreover, conventional dewatering equipment does not cause such a result even if used at a location where the concentration is such that the pine is torn apart.

In addition, the dehydration shoe of the present invention has a relatively simple structure and can have a thin cross-sectional thickness, so it does not require a large space like conventional curved suction boxes or dehydration rolls, and does not require vacuum equipment or white water treatment. Since no equipment is required, a simple and inexpensive top unit for a fourdrinier paper machine can be provided.

[Brief explanation of the drawing]

1 and 2 are side sectional views of wire parts showing embodiments of the present invention, FIG. 3 is a detailed view of the dewatering shoe in FIG. 1, and FIG. 4 is a detailed view of the dewatering shoe in FIG. 2. , FIG. 5, FIG. 6, and FIG. 7 are side sectional views showing conventional wire parts, respectively. Explanation of main parts of the figure, 20...raw materials, 21, 2
2... Wire, 24... Dehydration shoe, 33... Wedge space, 34... Convex portion.

Claims (1)

[Claims] 1. In a paper layer forming apparatus in which two wires running with a raw material sandwiched therebetween are supported in a polygonal shape by a plurality of convex portions, at least the second and subsequent convex portions are located at the apex of the same convex portion. A flat surface on the front side of the apex of the convex part that forms a wedge space between the wire and the height that is large on the rear side and becomes smaller in the running direction of the wire, and the end part of the same plane in the running direction. If there is a subsequent convex part that separates from the wire at a steep angle from the apex, it consists of a flat surface on the front side of the apex of the subsequent convex part and a surface behind the apex that directly intersects with the flat surface on the front side of the apex of the subsequent convex part. A paper layer forming device characterized by having a dewatering shoe whose surface is uniform across the width of the wire, and where a plurality of convex portions are integrated to form a sawtooth-like uniform cross section.