JPH11293578A - Dry type fiber opening of waste paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry type method for safely and efficiently opening the fibers of waste paper, while preventing the occurrence of a fire due to static electricity. SOLUTION: The fibers of waste paper are opened, while the relative humidity of an atmosphere in an area (a fiber-opening area) for opening the fibers of the waste paper is controlled within a prescribed range so that the water content of the waste paper (fiber-opened waste paper) after the opening of the fibers is 8-12 wt.% based on dry waste paper. Fine water drops having particle diameters of <=50 μm are supplied into the fiber-opening area 5 to control the relative humidity of the atmosphere. Air having a relative humidity preliminarily controlled by mixing outer air with fine water drops having particle diameters of <=50 μm may be supplied into the fiber-opening area 5 to control the relative humidity of the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for defibrating waste paper, and more particularly, to a method for dry defibration of used paper such as magazines, corrugated cardboard, newsprint, and OA paper.

[0002]

2. Description of the Related Art In recent years,
Used paper, such as magazines, corrugated cardboard, newsprint, and OA paper, discharged from factories, offices, or general households, is widely used for applications such as formwork, wall, floor, and waterproofing materials for civil and architectural use. It is supposed to be.

[0003] When used paper is used for the above purposes, it is usually necessary to perform a treatment (fibrillation treatment) for loosening the used paper into a fibrous form. In addition, as a method of defibrating waste paper, it is roughly classified into a wet defibration method in which water is added to swelled waste paper, and swelling is performed by stirring.For example, after roughly crushing waste paper, a predetermined interval is used. By pressing used paper between the multiple blades arranged in the above, the used paper is crushed by impact, and the part is further entangled with other used paper or rubbed together to break down the fibers by the dry defibration method There is.

[0004] The above-mentioned dry defibration method has a merit that, unlike the wet defibration method, there is no need for a step of removing water after defibration, and is attracting attention. From scraping used paper in the process,
Since static electricity is easily generated and a fire may be caused depending on defibration conditions such as relative humidity in the atmosphere, a dry defibration method with higher safety has been required.

[0005] The present invention meets the above requirements,
An object of the present invention is to provide a method for dry-fibrillating waste paper safely and efficiently by preventing the occurrence of fire due to static electricity.

[0006]

In order to achieve the above object, a method for defibrating waste paper according to the present invention (claim 1) is a dry defibration method for defibrating waste paper in a dry state to obtain a fibrous form. In the above, the relative humidity in the atmosphere in the area where the used paper is defibrated (defibrated area) is set so that the moisture content of the used paper after defibration (defibrated waste paper) is 8 to 12% by weight on a dry basis. This is characterized in that the defibration is performed while controlling in the range.

According to a second aspect of the present invention, there is provided a dry defibration method for waste paper, wherein the relative humidity in the atmosphere is adjusted by supplying fine water droplets having a particle size of 50 μm or less into the defibration region. It is characterized by.

[0008] In a third aspect of the present invention, in the dry fibrillation method for waste paper, air whose relative humidity is adjusted in advance by mixing external air with fine water droplets having a particle size of 50 µm or less is mixed with the fibrillation area. It is characterized in that the relative humidity in the atmosphere is adjusted by being supplied to the inside.

Further, according to a fourth aspect of the present invention, the relative humidity in the atmosphere in the defibration region is 55%.
It is characterized by the above.

[0010]

According to the present invention (claim 1), in the dry defibration method of waste paper, the waste paper is defibrated so that the moisture content of the defibrated waste paper (defibrated waste paper) is 8 to 12% by weight on a dry basis. Since the defibration is performed while controlling the relative humidity in the atmosphere in the region where the defibration is performed (the defibration region) within a predetermined range, the water content (8 to 12% by weight) of the defibrated waste paper and the atmosphere From the equilibrium relationship with the relative humidity, the relative humidity in the atmosphere is kept in a range where static electricity is hardly generated. Therefore, by setting the inside of the defibration region to an atmosphere in which static electricity is unlikely to be generated, the occurrence of fire due to static electricity can be prevented, and the dry paper defibration can be performed safely and efficiently.

Further, according to the present invention, since the moisture content of the defibrated waste paper is kept in a predetermined range, for example, when using the defibrated waste paper as a raw material for a wood-based board, a stable quality raw material is supplied. This makes it possible to simplify the process of manufacturing a wood-based board (for example, an adhesive compounding process, a board forming process using a hot press method, etc.), and to provide a wood-based board with economically stable quality. Can be manufactured. In addition, when used for purposes other than the raw material of the wood-based board, it is possible to supply high-quality defibrated paper having a stable water content, which is advantageous.

Further, the dry defibration method of the used paper according to claim 2 is as follows.
The relative humidity in the atmosphere is adjusted by supplying fine water droplets having a particle size of 50 μm or less into the defibration region, so that fine water droplets having a large surface area are efficiently evaporated in the defibration region. In addition, it is possible to suppress and prevent a rise in the ambient temperature, and to quickly adjust the relative humidity in the ambient atmosphere, so that the present invention can be made more effective. Note that the present invention does not exclude the case where external air is supplied into the defibration region together with the fine water droplets,
Such a configuration is also included in the scope of the present invention.

Further, as in the dry fibrillation method for waste paper according to the third aspect, by mixing the external air with fine water droplets having a particle size of 50 μm or less, air in which the relative humidity is adjusted in advance is introduced into the fibrillation area. Also by supplying, it is possible to quickly adjust the relative humidity in the atmosphere.

Further, as in the dry fibrillation method for waste paper according to the fourth aspect, by setting the relative humidity in the atmosphere to 55% or more, generation of static electricity in the fibrillation region is surely suppressed.
Thus, the present invention can be made more effective.

Hereinafter, the operation of the present invention will be described in more detail by taking as an example a case where the relative humidity is adjusted by supplying fine water droplets having a particle size of 50 μm or less into the defibration region.

When fine water droplets having a particle size of 50 μm or less are supplied into the defibration region, the fine water droplets evaporate quickly. As a result, the heat generated due to the power supplied at the time of defibration is absorbed, and the rise in the ambient temperature is suppressed within a predetermined range. By keeping the rise in the ambient temperature in a certain range, the decrease in the relative humidity due to the rise in the ambient temperature is suppressed, and the relative humidity in the atmosphere after the defibration is set within a range of, for example, 60 to 75%. It is possible to adjust and the relative humidity is kept within the above range,
The water content of the defibrated waste paper can be 8 to 12% by weight on a dry basis.

The relative humidity in the atmosphere is 60 to 75%.
Thus, the generation of static electricity is prevented, and the waste paper can be dry-fibrillated safely and efficiently without causing a fire. In addition, the particle size of the fine water droplet is 50
Since it is not more than μm, it is possible to prevent adverse effects due to collision with equipment, condensation, and aggregation.

Hereinafter, when defibration is performed under the conditions of the present invention, absorption of heat generated during defibration, ambient humidity, ambient temperature,
The moisture content of the defibrated waste paper will be further described.

[Absorption of Heat Generated During Fibrillation] The increase in the ambient temperature due to the heat generated due to the power supplied during the fibrillation is absorbed by the evaporation of the fine water droplets, and the evaporation of the fine water droplets causes the increase in the atmosphere. As the moisture increases, the absolute humidity rises.

[Ambient Humidity after Fibrillation] The relative humidity in the atmosphere after the temperature rise is suppressed within a predetermined range by adjusting the amount of the fine water droplets added, is changed by the seasonal humidity change (the raw material to be equilibrated by the seasonal humidity change). The water concentration of the waste paper changes)
By controlling to a certain range, the moisture content of the defibrated old paper can be kept in a predetermined range (8 to 12% by weight on a dry basis) while preventing generation of static electricity. That is, when the moisture content of the defibrated waste paper is set to 8 to 12% by weight, the relative humidity becomes 55% or more, which is suitable for preventing generation of static electricity.

[Adjustment of moisture content of defibrated waste paper] Since the defibrated waste paper has a small wire diameter and a large surface area, the moisture content quickly becomes equilibrium with the relative humidity in the atmosphere (depending on the quality of the defibrated waste paper. And the moisture content value equilibrium with the relative humidity in the atmosphere is different).

Therefore, in winter, by making the relative humidity in the atmosphere after fibrillation larger than the relative humidity of the outside air, the water content of the old paper is made larger than the water content equilibrium with the relative humidity of the outside air. can do.

Specifically, for example, when the relative humidity of the outside air is 5
0%, the relative humidity in the atmosphere after defibration is 70%.
By adjusting to ~ 75%, the moisture content of the defibrated waste paper is
The water content (9 to 10% by weight) can be higher than the water content (for example, 6 to 7% by weight) in equilibrium with the relative humidity of the outside air.

In summer, by making the relative humidity in the atmosphere smaller than the relative humidity of the outside air, the moisture content of the defibrated waste paper can be made smaller than the moisture content in equilibrium with the relative humidity of the outside air. it can.

Specifically, for example, when the relative humidity of the outside air is 7
When it is 5 to 80%, fine water droplets and air are supplied to the defibration region so that the relative humidity in the atmosphere after defibration becomes 60 to 70%, and a certain rise in the atmosphere temperature is allowed. By adjusting the relative humidity and temperature of the atmosphere,
The moisture content of the defibrated waste paper is set to a moisture content (1) smaller than the moisture content (for example, 13 to 14% by weight) in equilibrium with the relative humidity of the outside air.
0 to 11% by weight).

The relative humidity can be adjusted to 60 to 70% without supplying fine water droplets and air. In this case, however, the supply amount of waste paper may not be balanced. However, by supplying fine water droplets and air as in the present invention, it is possible to reliably control the water content in the used paper after fibrillation in the range of 8 to 12% by weight. However, in practice, the supply amount of fine water droplets and external air should be determined in consideration of the supply amount of waste paper raw material, the moisture content of the waste paper raw material, the amount of air flowing in from the outside, the relative humidity of the atmosphere, etc. Is desirable.

As described in claim 3, by mixing the external air with fine water droplets having a particle size of 50 μm or less, air whose relative humidity has been adjusted in advance is supplied into the defibration region to control the relative humidity in the atmosphere. Even when the humidity is adjusted, the same operation and effect as in the above case can be obtained.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be shown and features thereof will be described in more detail.

FIG. 1 is a schematic diagram showing a main configuration of a dry fibrillation apparatus used for carrying out a dry fibrillation method of waste paper according to an embodiment of the present invention.

This dry defibrating device includes a defibrillator body 1 for defibrating waste paper in a dry manner, a quantitative feeder 2 for supplying coarsely pulverized waste paper to the defibrillator body 1, and a defibrillator body 1. Driving means (electric motor) 3 for rotationally driving the defibrating blade 1a and external air mixed with fine water droplets (water droplet mixed air) in the mixer 4 are used in a defibration region (used paper is defibrated) in the defibrillator main body 1. Air supply line 6 for supplying air to the area 5 to be processed, a separator 7 for separating the defibrated waste paper (defibrated waste paper) from the atmospheric air, and a separator 7 for separating the defibrated waste paper with the atmospheric air. A transport line 8 for feeding, a humidity detecting means (hygrometer) 9 disposed on the transport line 8 for detecting the relative humidity in the atmosphere after the fibrillation, and a waste paper separated by the separator 7. Moisture meter for measuring moisture content (eg infrared moisture meter 10) and an exhaust blower 11 which is disposed downstream of the separator 7 and sucks the atmospheric air from the defibrating machine main body 1 through the separator 7. The supply amount of the fine water droplets and the external air is controlled in accordance with the detection result of the moisture content of the used defibrated waste paper. In the above-described dry defibrating device, external air flows into the defibrating machine main body 1 as the used paper is supplied from the fixed amount feeding device 2.

Next, a method of dry-fibrillating waste paper using this dry-fibrillation apparatus will be described. First, the coarsely pulverized waste paper is quantitatively supplied from the quantitative feeder 2 to the defibrator main body 1. At this time, the defibrating blade 1a in the defibrating machine main body 1 is rotated by the driving means 3. In addition, air mixed with water droplets to which fine water droplets are added and mixed at a predetermined ratio is supplied from the air supply line 6 for humidity control to the defibrating machine main body 1.
And the relative humidity in the atmosphere in the defibration region 5 is set to 60
~ 75% (atmospheric temperature: 10-40
° C). The relative humidity and the atmosphere temperature are such that the moisture content of the defibrated waste paper (defibrated waste paper) (that is, the moisture content equilibrated with the relative humidity and the ambient temperature) is 8 to 12 on a dry basis.
The condition is that the weight% is obtained. However, the value of the moisture content that is equilibrium with the relative humidity in the atmosphere differs depending on the quality of the defibrated waste paper. While maintaining the above relative humidity and ambient temperature, the used paper is defibrated in the defibrator main body 1. Then, the defibrated waste paper (defibrated waste paper) is sent to the separator 7 together with the atmosphere air to be separated from the atmosphere air, and the defibrated waste paper is collected. The atmospheric air is exhausted to the outside via the exhaust blower 11. In this embodiment, the supply of the fine water droplets and the external air is adjusted according to the result of the humidity detection by the humidity detecting means 9 and the result of the detection of the moisture content of the defibrated waste paper by the moisture meter 10, whereby the defibration is performed. The water content of the used paper is reliably controlled in the range of 8 to 12% by weight.

As described above, air is mixed by adding and mixing fine water droplets at a predetermined ratio, and defibrating while adjusting the relative humidity in the atmosphere in the defibration region 5 to a predetermined range. Thus, the generation of static electricity can be prevented, and the used paper can be dry-fibrillated safely and efficiently.

That is, according to the method of the above embodiment,
Fine water droplets having a particle size of 50 μm or less supplied into the defibrating region evaporate quickly, and absorb heat generated due to the power supplied from the driving means 3 during defibration. As a result, a decrease in the relative humidity due to an increase in the ambient temperature is suppressed and prevented, the relative humidity in the atmosphere after fibrillation is kept in the range of 60 to 75%, and the moisture content of the fibrillated waste paper is reduced relative to the atmosphere. It becomes 8 to 12% by weight which is equilibrium with humidity and temperature. Therefore, the generation of static electricity can be prevented, and the waste paper can be dry-fibrillated safely and efficiently without causing a fire.

Further, the moisture concentration in the raw waste paper, which becomes equilibrium changes due to the change in the seasonal humidity, is controlled by controlling the relative humidity in the atmosphere after the temperature rise is prevented by adjusting the amount of fine water droplets added. Thus, the water content of the defibrated waste paper can be adjusted within a predetermined range.

For example, in winter, by making the relative humidity in the atmosphere after fibrillation larger than the relative humidity of the outside air, the moisture content of the fibrillated waste paper can be made higher than the moisture content in equilibrium with the relative humidity of the outside air. Can be bigger.

In summer, by making the relative humidity in the atmosphere smaller than the relative humidity of the outside air, the moisture content of the defibrated waste paper can be made smaller than the moisture content in equilibrium with the relative humidity of the outside air. it can. Therefore, it is possible to prevent the moisture content from fluctuating depending on the season, and to obtain a fibrillated waste paper of stable quality. In addition, the present invention
It can be widely applied not only when the humidity fluctuates due to seasonal changes, but also when the humidity in the atmosphere fluctuates due to weather changes and various other reasons, thereby making it safe and efficient. The used paper can be defibrated to obtain a defibrated used paper having a stable moisture content.

The defibrated waste paper obtained as described above can be used as a suitable raw material for wood-based boards because the moisture content does not fluctuate greatly depending on the season and the quality is stable. For example, an aqueous solution of a polyisocyanate compound (MDI) is added to the defibrated waste paper having a water content of 8 to 12% by weight obtained as described above to obtain a water content of 30%.
After adjusting the content of the dry base polyisocyanate compound to be 5 to 15% by weight, the polyisocyanate compound is cured by a hot press method and the water content becomes 5 to 10% by weight. Until heating,
By pressing, formwork materials for civil engineering or construction,
It is possible to efficiently manufacture a wooden board having characteristics that can be used as a wall material, a floor material, and the like.

The defibrated waste paper obtained as described above can be widely used for the following applications in addition to the raw material of the wood-based board. It is used by spraying it on agricultural mulch fields, dry fields, etc. It has the effects of suppressing germination of weeds and suppressing changes in underground temperature. Asphalt mixed fiber for pavement road Asphalt is modified, and the effect of improving road durability is obtained. Wastewater treatment fiber Can be used as a coagulation aid, filtration aid, and the like. Dry mold as packing buffer. Harmless and cheaper than foamed styrene. Livestock fiber Instead of sawdust and rice husk, it is used as a litter for barns and a water conditioner for pig dung.

The present invention is not limited to the above embodiment, and various applications and modifications can be made within the scope of the invention.

[0040]

As described above, the dry defibration method for waste paper according to the present invention is used for defibration such that the moisture content of the defibrated waste paper (defibrated waste paper) is 8 to 12% by weight on a dry basis. Since the defibration is performed while adjusting the relative humidity in the atmosphere in the region, the generation of static electricity can be prevented, and the waste paper can be dry defibrated safely and efficiently. In addition, the defibrated waste paper obtained by the method of the present invention has a stable water quality without a large fluctuation in the water content depending on the season, and thus is mixed with a raw material for wood-based boards, an agricultural mulch material, and asphalt for paved roads. It can be widely used for fiber, waste water treatment fiber, dry mold as packing buffer, fiber for livestock and so on.

Further, the relative humidity in the atmosphere is adjusted by supplying fine water droplets having a particle size of 50 μm or less into the defibration region as in the method for dry defibration of waste paper according to the second aspect. In this case, fine water droplets having a large surface area can be efficiently evaporated in the atmosphere, and the relative humidity in the atmosphere can be quickly adjusted, whereby the present invention can be made more effective.

Further, as in the method of dry-type defibration of waste paper according to the third aspect, air whose relative humidity is adjusted in advance by mixing external air with fine water droplets having a particle size of 50 μm or less is supplied into the defibration region. This also makes it possible to quickly adjust the relative humidity in the atmosphere.

Further, as in the method of dry-type defibration of waste paper according to the fourth aspect, by setting the relative humidity of the defibration region to 55% or more, generation of static electricity in the defibration region is reliably suppressed. And the present invention can be made more effective.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a main part of a dry defibration apparatus used for performing a dry defibration method of waste paper according to an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 defibrillator main body 1a defibrating blade 2 quantitative feeder 3 driving means (electric motor) 4 mixer 5 defibration area 6 air supply line for humidity control 7 separator 8 transport line 9 humidity detecting means (hygrometer) 10 moisture meter 11 Exhaust blower

Claims (4)

[Claims] 1. A dry defibration method for defibrating waste paper into fibers by dry defibration, wherein the moisture content of the defibrated waste paper (defibrated waste paper) is 8 on a dry basis.
Dry defibration of waste paper, characterized in that the defibration is performed while controlling the relative humidity in the atmosphere in the region (defibration region) in which the waste paper is defibrated so as to be within 12% by weight. Method. 2. The dry defibration method for waste paper according to claim 1, wherein the relative humidity in the atmosphere is adjusted by supplying fine water droplets having a particle size of 50 μm or less into the defibration region. . 3. The relative humidity in the atmosphere is adjusted by mixing the external air with fine water droplets having a particle size of 50 μm or less to supply air in which the relative humidity has been adjusted in advance into the defibration region. The method for dry-fibrillation of waste paper according to claim 1, characterized in that: 4. The relative humidity in the atmosphere in the defibration area is 5
The dry defibration method of used paper according to claim 1, wherein the content is 5% or more.