JPH0593381A - Apparatus for forming sheet of paper - Google Patents

Abstract

PURPOSE:To obtain an apparatus, capable of feeding a specific paper stock to a vat, feeding water at a prescribed flow rate, forming sheets of paper while overflowing the water, contributing to improvement in global environment and excellent in recycling of pulp. CONSTITUTION:The objective apparatus 58 for forming sheets of paper is designed to rotate a cylindrical cylinder mold 60 around a shaft in a vat 68 while feeding a paper stock prepared by disaggregating pulp into the vat 68, suck the above-mentioned disaggregating pulp onto the surface of the cylinder mold 60 and form sheets of paper. In the apparatus, the paper stock 66 obtained by disaggregating the pulp using multilayered paper containing layers of metallic foils such as aluminum is fed to the vat 68 and water is simultaneously fed at a prescribed flow rate to form the sheets of paper while overflowing the water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a papermaking apparatus for making pulp from a stock solution obtained by disintegrating pulp with pulper or the like from waste paper.

[0002]

2. Description of the Related Art In recent years, environmental problems on a global scale such as global warming have been highlighted, and it has become an international concern to investigate the cause and take countermeasures. For example, if the amount of paper used continues to increase as it is, the amount of garbage will increase accordingly, and incineration will cause a large amount of carbon dioxide to be emitted, further spoiling the destruction of the natural environment.

On the other hand, in recent years, the amount of paper used has been increasing due to the popularization of office automation equipment and the development of various paper products, and it is difficult to suppress the amount of pulp used. Therefore, the recycling of used paper is drawing attention, and efforts are being made to recycle used paper into usable paper. Recycled waste paper has been used for many years. Paper containers, such as milk cartons, use high quality pulp, and it is very valuable to recycle paper products for various uses from them.

A typical system for carrying out such a treatment is to put waste paper as a raw material into a pulper, stir the waste paper and a predetermined chemical in the pulper to disintegrate the pulp, and carry out several steps. After that, the paper is sent to a paper making device to make paper.

By the way, some paper containers are made of multilayer paper having a metal layer such as aluminum foil.
A typical one of such multi-layered paper is five layers of polyethylene and aluminum foil in addition to paper. By providing a layer of aluminum foil inside the container in this way, the contents can be sealed in the same manner as canned goods, so that oxygen and light are completely shielded. Therefore, when the product is sterilized and filled in such a container, it can be stored for a long period of time. Taking advantage of these advantages, this kind of container is widely used as a container for juice, long-life milk, liquor, coffee and the like.

The multi-layered paper used for such milk packs also contains a large amount of pulp as described above. Therefore, it is desirable that such used multi-layered paper is also recycled and reused by the conventional waste paper recycling system.

[0007]

However, when a paper container having a layer of aluminum foil is tried to be recycled by a system using a conventional papermaking machine, the recycled paper contains crushed aluminum foil. It remained as it was and could not be put to practical use. Although much effort has been made in the past to remove this aluminum foil to enable the recycling of multi-layer paper, so far no satisfactory results have been obtained. Therefore, the multilayer paper containing the metal foil contains many pulp raw materials, but the pulp has not been recycled.

Therefore, the treatment of such a paper container becomes a problem. In the case of such a container, even if incinerated, only the part other than aluminum burns, and if the aluminum is forcibly burned to a high temperature, the incinerator itself may be damaged. In addition, the method of incineration is the release of carbon dioxide,
It is not preferable from the viewpoint of resource reuse. Furthermore, although the method of burying in the ground was also adopted, aluminum does not easily decompose in the ground, leading to new environmental damage. For this reason, in Europe and America, there is a movement to ban the use of paper containers containing aluminum foil.

The present invention has been made based on the above circumstances, and even when a multilayer paper containing a metal foil such as aluminum is used as a raw material, it does not contain unnecessary substances such as aluminum foil and has high purity. It is an object of the present invention to provide a papermaking device that can obtain recycled paper.

[0010]

Means for Solving the Problems The present invention for achieving the above object is to rotate a cylindrical cylinder in the vat around an axis while supplying a liquid in which the pulp is disintegrated to the vat, In a papermaking apparatus for making paper by suctioning the disintegrated pulp on the surface of the cylinder, a stock solution in which pulp is disintegrated from a multilayer paper including a layer of metal foil as a raw material is supplied to the vat, and It is characterized in that water is supplied at a flow rate to cause paper overflow while overflowing.

[0011]

According to the present invention, the multi-layered paper containing a layer of aluminum foil is used as a raw material according to the above constitution, and when the stock solution disintegrated with the pulper is supplied to the vat, water is supplied at a predetermined flow rate. It was confirmed that by overflowing, the amount of aluminum strips contained in the recycled paper was significantly reduced as compared with the case where water was not supplied. The predetermined flow rate is appropriately about 1/3 of the volume of the stock solution. Further, even if the metal foil containing a metal layer other than aluminum is used as the raw material, it is considered that the amount of metal contained in the recycled paper can be extremely reduced by the same principle.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a flow of a process of regenerating pulp from a paper container such as processing waste by a pulp regenerating system using a paper making machine according to an embodiment of the present invention,
FIG. 2 is a cross-sectional view of laminated paper used as a raw material in this example,
FIG. 3 is a schematic sectional view of the pulper 20 into which a used paper container as a raw material is initially charged, FIG. 4 is an enlarged sectional view of the impeller and the vicinity of the screen shown in FIG. 1, and FIG. Sectional drawing, FIG. 6 is a schematic sectional drawing of a papermaking apparatus. In this system, the cross-section of the raw material is shown in Figure 2.
As shown in, a paper container made of laminated paper of three kinds and five layers including a layer of aluminum foil shall be used. As shown in the figure, this laminated paper comprises a polyethylene layer 10 having a thickness of about 15 to 20 microns, an aluminum foil layer 12 having a thickness of about 9 microns, and a polyethylene layer 14 having a thickness of about 15 microns from the inside.
Layer 1 of base paper (pulp) of about 310 to 340 g / m ²
Each layer consists of a layer 18 of polyethylene of 6 and 15 microns.

About 1 kg of raw material, about 5 kg of caustic soda and 20 kg of sodium hypochlorite are added to the pulper 20 shown in FIG. Here, caustic soda is for disintegrating pulp, and sodium hypochlorite is for bleaching pulp. Inside the tank 22 of the pulper 20, as shown in FIG. 3, there are an impeller (rotating blade) 24 for stirring the stock liquid, and a stainless steel screen 26 having a large number of holes under the impeller 24. It is provided. As shown enlarged in FIG. 4, the impeller 24
The distance between the back side of the and the screen 26 is significantly smaller than that of the conventional pulper, and is about 2 mm. By narrowing the gap between the impeller and the screen in this way, a turbulent flow is generated in the space between them, and the pulp that has settled on the screen can be wound up on top of the impeller without passing through the screen. It can be promoted and the screen can be prevented from clogging.

In the pulper 20, the raw materials and the above-mentioned chemicals are charged, the temperature is maintained at about 40 ° C., and the impeller 24 is set at about 1
The pulp is disintegrated by rotating with a 50 horsepower motor and stirring the raw materials and chemicals for about 1 hour. The pulp thus disintegrated passes through a screen having a large number of holes 30 having a diameter of 1 to 4 mm provided below the impeller. On the other hand, most of the aluminum foil and polyethylene are taken out as unnecessary substances from the gate valve 28 provided on the side surface of the tank.

By performing the treatment with the pulper 20 in this manner, about 99.1% of the aluminum foil can be removed. However, the aluminum foil finely crushed by the impeller 24 together with the pulp has holes 3 in the screen.
Pass 0. Therefore, the amount of aluminum still mixed in is too large for recycling this pulp as a usable paper.

The pulp that has passed through the screen 26 of the pulper 20 enters a beating refiner 34 through a porcher 32 as shown in FIG. This beaten refiner has a structure similar to that of a stone mill, and further disintegrates pulp disintegrated with a pulper.

The pulp discharged from the beating refiner 34 passes through a porcher 36 and enters a screen device 38 for removing dust. The screen device 38, as shown in FIG.
The impeller 40 is rotated, and the pulp raw material supplied from the left side is pressurized and passed through a screen (product name FN screen) 42 having slit holes with a diameter of 15/1000 inches. At this time, a large amount of water is supplied from the side of the impeller 40 to dilute the stock solution. This causes large strips of aluminum foil that cannot pass through the screen 42 to be washed off the surface of the screen and sent continuously to the tail screen 44 from the side of the screen device by overflow.

The stock solution that has passed through the screen device 38 is sent to the retention porch 48 through the washer 46, where
For example, the stock solution is retained for about 10 hours. This retention porter has a volume of 50 cubic meters, and a propeller is provided inside the retention porter. The propeller is rotated during the retention to stir the stock solution. Hold stock solution 4
By staying at 8, the progress of processing by the operation of this system and the working time zone of the worker can be adjusted.

The stock solution that has passed through the retention porch 48 is sent to the screen device 54 through the porch washer 50 and the machine chest 52. The size of the hole of the screen device 54 is smaller than that of the screen device 38 in the preceding stage of the retention porch 48 and is 10/1000 inch, but the other configurations are the same as the screen device 38.
Therefore, also in this case, a large amount of water can be used to efficiently remove the unwanted substances attached to the front side of the screen. The removed unwanted matter is sent to the tail screen 56.

The stock solution that has passed through the screen device 54 is sent to the paper making device 58. FIG. 6 is a schematic sectional view of the paper making device 58, and the liquid sent from the screen device 54 is supplied from the right side of this drawing.

In the papermaking apparatus shown in FIG. 6, the supplied stock material liquid 66 flows through the vat 68. This stock liquid 66
A vacuum suction unit 62 is provided at the central portion of the circular net 60 which is provided so as to be submerged by about half and to rotate, just along the central axis of the circular net. By vacuum suction by the vacuum suction unit 62, the stock solution 66 is attracted to the periphery of the net 60, and in parallel with this, when the net 60 is rotated in the direction of the arrow, the pulp fibers are surrounded by the net. Other liquids pass through the net 60. The thus-adsorbed pulp is wound on the couch roll 64 which is located above the cylinder 60 and is conveyed in synchronism with the rotation of the cylinder to obtain a sheet-like wet pulp or recycled paper.

For raw materials containing no aluminum,
In this way, a recycled paper can be obtained only by performing papermaking in the same manner as in the past. However, when a multilayer paper containing an aluminum foil is used as a raw material as in the present embodiment, a part of the aluminum foil is finely divided so as to pass through the screen in the pulper, and these are subjected to the above-mentioned steps, and then the papermaking machine 5
Reach up to 8. Therefore, the paper obtained by performing papermaking in the same manner as in the past contains fine aluminum powder exceeding the allowable value and cannot be put to practical use as it is.

As a result of considering such points, in the present embodiment, the net 6 is supplied to the stock liquid supplied from the screen device 54.
Add a large amount of water on the front side of 0 (feed water),
On the rear side of 0, the paper is made to overflow and discharged from the discharge port 70, and the papermaking process is carried out while circulating the stock solution 66 diluted with cutting water. Here, the amount of water to be added is, for example, about one third of the volume of the original stock solution. When the cylinder 60 was rotated in this state and vacuum suction was performed, a paper containing almost no aluminum was obtained. In an attempt, it was confirmed that the aluminum content increased from the time when the addition of water was stopped, when the papermaking was carried out in the same manner as the conventional method without water circulation.

In response to such experimental facts, the mechanism is that aluminum fine particles which are sucked and try to approach the net 60 are washed away from the vicinity of the net by additional convection water due to its large specific gravity. It is thought that it is because the circle cannot be approached for a certain distance.

By passing through several steps as described above, the aluminum foil suitable for each situation is removed at each step, but finally, the pulp which practically contains no aluminum is recycled. It is considered that the biggest cause is the overflow-type papermaking machine 58 introduced in the present invention.

[0026]

As described above, according to the present invention, water is added to cause overflow when a paper stock solution made from a multi-layer paper containing a layer of a metal foil such as aluminum is used as a raw material. It was confirmed that by circulating the stock solution in the papermaking machine, the content of metal strips contained in the obtained recycled paper was significantly reduced. As a result, it is possible to recycle more multilayer paper containing metal foil, which was previously discarded, so that more pulp can be reused and it is not necessary to bury the multilayer paper in the ground. Therefore, it is possible to provide a paper machine that can contribute to the improvement of the global environment.

[Brief description of drawings]

FIG. 1 is a diagram showing a flow of a process of regenerating pulp from a paper container such as processing waste by a pulp regenerating system using a paper making apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of laminated paper used as a raw material in an example of the present invention.

FIG. 3 is a schematic sectional view of a pulper.

FIG. 4 is an enlarged cross-sectional view showing the impeller and the vicinity of the screen shown in FIG.

FIG. 5 is a cross-sectional view of a screen device.

FIG. 6 is a schematic cross-sectional view of a papermaking device.

[Explanation of symbols]

 10, 14, 18 Polyethylene layer 12 Aluminum foil 16 Base paper layer 20 Pulper 22 Tank 24 Impeller 26 Screen 28 Gate valve 32, 36 Retaining porter 34 Refining refiner 38, 54 Screen device 46 Washer 48 Retaining porter 58 Papermaking machine 60 Yen net 62 Vacuum suction part 64 Couch roll 66 Paper stock liquid 68 Vat 70 Discharge port

Claims (1)

[Claims] 1. A cylindrical cylinder is rotated around an axis in the vat while supplying a liquid in which the pulp is disintegrated to the vat,
In a papermaking apparatus for making paper by suctioning the disintegrated pulp on the surface of the cylinder, a stock solution in which pulp is disintegrated from a multilayer paper including a layer of metal foil as a raw material is supplied to the vat, and A papermaking device characterized by supplying water at a flow rate and overflowing to make paper.