JP2001213656A - Woody cement board and method of manufacturing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woody cement board to which a woody cement board waste is recycled. SOLUTION: Ground powder A to which the woody cement board waste reinforced by woody fiber 2 is ground by a impact mill and the ground powder ground by a milling grinder are utilized to a part of a raw material of the board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood cement board using waste wood cement board effectively and a method for producing the wood cement board.

[0002]

2. Description of the Related Art A wood cement board using a wood fiber material as a reinforcing material is used as a building material such as an outer wall material and a roof material. Trimming waste discharged from the process of manufacturing the wood cement board, or waste material generated by repairing or removing buildings using the wood cement board has been conventionally ground and used for landfilling. It has been proposed to effectively use the pulverized waste material as a part of a raw material for a wood cement board. For example, Japanese Patent No. 259392
In No. 6, the waste material was treated with a pulperizer to a particle size of 35 to 30.
It is disclosed that the mixture is pulverized to a range of 0 μm and added to a raw material slurry for a wood cement board.

[0003]

The above-mentioned wood cement board waste material is poor in hardenability, and has a small particle size and is crushed, so that the wood fiber material is short-sheared and has no entanglement effect. No reinforcement effect can be expected, and conventionally, the wood cement board was only used as a filler as a raw material, and thus the amount of addition was limited, and a large amount of wood cement board waste could not be effectively used.

[0004]

According to the present invention, as a means for solving the above-mentioned conventional problems, a pulverized material obtained by pulverizing a waste wood cement board using a wood fiber material as a reinforcing material by using an impact type pulverizer. Of wood cement board containing wood and wood cement board containing wood material and wood fiber material as reinforcing material containing material and pulverized material pulverized by attrition type pulverizer A wood-cement board in which a pulverized product obtained by a pulverizer is added to a raw material mixture containing cement and a wood fiber substance to form a slurry, and the slurry is subjected to papermaking dehydration molding to form a mat and cure and harden the mat. Is provided.
The particle size of the pulverized product by the above-mentioned impact type pulverizer is mainly 850.
３００300 μm, and the particle size of the pulverized product by the attrition mill is preferably 300 μm or less.

[0005]

[Function] When a crushed material (1) of wood cement board as shown in Fig. 1 is finely crushed by an impact type crusher such as a hammer mill, a portion where wood fiber material (2) such as pulp exists is found. Because it is softer than the other parts, it is easy to split at this part. Then, as shown in FIG. 2, in a state where the pulverized material (1) is divided into two pulverized materials (1A, 1A), the wood fiber material (2A, 2A) is torn to generate fluff (21A) (FIG. 2). Fibrillation). The ground product (1A) is mainly 850 to 300
The particle size is μm, preferably 2 mm or less.
Further, the pulverized product (1A) is pulverized with a pulverizing pulverizer such as a ball mill to have a particle size of 300 μm or less, preferably 100 to 30 μm.
In the case of a finely pulverized product having a particle size of μm, which is a so-called rehydratable particle size, not only the divided surface of the pulverized material in which the unreacted cement and silica components inside are pulverized but also the surface of the pulverized material which has been ground. And the surface of the pulverized material is activated.

[0006] A pulverized material using an impact type pulverizer (hereinafter referred to as a pulverized material A) in which fluff (21A) is formed at various places on the surface, and a pulverized material having a surface activated by grinding are provided. (Hereinafter referred to as crushed material B) is mixed with the raw material of the wood cement board. In the crushed material A, the fine powder of the raw material such as cement is trapped in the fluff (21A), and the wood cement board is manufactured by the papermaking method. In this case, the leakage of the raw material powder during papermaking is prevented, so that clogging of the papermaking band such as felt is unlikely to occur, and the papermaking property, that is, the productivity is improved. Reacts with the cement, silicic acid-containing substance or pulverized material A contained in the raw material, and re-hardens.
The mutual reaction and re-hardening also improve the strength of the product.

Further, the fluff (21A) formed from the surface of the pulverized material A is tightly entangled with the woody fiber material in the raw material or the fuzz (21A) between the pulverized material A and the mat or product. It contributes to strength improvement, but the fluff (2
1A) is radially formed from the pulverized material (1A) in a random direction, so the reinforcing effect by the entanglement of the fluff (21A) is not directional, and the strength of the mat or the product is increased in any direction. Also improve.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. (Wood cement board waste material) The wood cement board waste material used in the present invention is a board material containing wood fiber material such as slag cement perlite board, and the board material is preferably a normal pressure cured product that has not been autoclaved. As described above, it is trimming waste discharged from the wood cement board manufacturing process, or waste material generated by repair or removal of a building using the wood cement board. The above waste material is usually 40 to 20 mm by a crusher such as a twin-screw crusher.
It is pulverized into coarse pulverized material (1) of about the size. In the present invention, the above coarsely pulverized product (1) is pulverized by an impact pulverizer such as a hammer mill or an impact mill or a pulverization pulverizer such as a vertical mill or a roller mill. The pulverized material pulverized by the impact type pulverizer is mainly pulverized into a pulverized material A having a particle size in a range of 850 to 300 μm, preferably 2 mm or less. During the above-mentioned pulverization, fibrillation of the wood fiber material (2A) occurs as described above, and the pulverized material A in which fuzz (21A) is radially formed from the surface in a random direction as shown in FIG. can get.

On the other hand, the pulverized material pulverized by a pulverizer such as a vertical mill or a roller mill is finely pulverized into a pulverized material B having a particle diameter of 300 μm or less, preferably 100 to 30 μm.

In the present invention, the pulverized material obtained by the above-mentioned impact-type pulverizer is separated into coarse particles and fine particles by sieving or the like, or is separated into low specific gravity components and high specific gravity components by air classification. The fine or low specific gravity component may be pulverized by an impact-type pulverizer to obtain a pulverized product A, and the fine particles or the high specific gravity component may be pulverized by a grinding pulverizer to obtain a pulverized product B.

The waste material contains unreacted active substances such as unreacted CaO, SiO ₂ and Al ₂ O ₃ which are uncured components of the cement.
Not a small amount of curability remains in the waste material. Therefore, if the above-mentioned waste material is finely pulverized to a particle size of 300 μm or less, particularly 100 to 30 μm by a grinding-type pulverizer, the active substance is exposed on the surface of the pulverized material B, so that the reaction activity is increased, and such a waste material is increased. The remaining curability can be effectively used, and the strength of the product can be further improved.

Further, when the pulverized material obtained by the above-mentioned impact-type pulverizer is classified by air, the obtained pulverized material A contains a large amount of wood fiber material, so that the reinforcing effect of the wood fiber material can be used effectively. In addition, since a large amount of the above-mentioned inorganic active substance remains in the obtained crushed material B, a crushed material B having a higher reaction activity can be obtained.

In order to set the particle size of the crushed material A and the crushed material B within the above range, a sieve having a predetermined diameter may be set in an impact-type crusher or a crusher-type crusher and sieved. . In the present invention, the crushed material A and the crushed material B are usually 8: 2 to
They are mixed in a 2: 8 weight ratio. The mixed and crushed products A and B can be added to the raw material in an amount of about 10 to 60% by weight. However, if the amount exceeds 60% by weight, the strength of the product may be reduced.

[Cements] The cements used in the present invention include, for example, cements such as Portland cement, jet cement, blast furnace cement, fly ash cement, alumina cement, and blast furnace slag, fly ash, diatomaceous earth, and volcanic ash. And the like, and silica silicate reactants such as silica sand and silica stone powder.

[Additives] In the present invention, in order to reinforce the strength of the cement board product, or to enhance the hardening property of the above-mentioned pulverized cement board waste material, pulp fibers, waste paper defibrated materials, wood fiber bundles are further added. Wood fiber materials such as wood, wood chips, wood flour, etc., and reinforcing fiber materials such as organic fibers such as polyester fiber, polyamide fiber, acrylic fiber, acetate fiber, polyethylene fiber and polypropylene fiber, and inorganic fibers such as glass fiber, carbon fiber and ceramic fiber. And / or one or more of silicic acid-containing substances such as silica powder, silica fume, perlite, mica, dolomite, wollastonite, glass powder, siliceous clay, bentonite, etc. Good. The reinforcing fiber material and the silicic acid-containing substance are each added in an amount of 30% by weight or less. If the added amount exceeds 30% by weight, the effect of reinforcing the cement board product and the effect of strengthening the hardenability are saturated, and the cement board waste material recycling rate is reduced. In addition to the above components, if desired, a cement hardening accelerator such as calcium chloride, magnesium chloride, magnesium hydroxide, aluminum sulfate, sodium aluminate, water glass and the like, and a water repellent such as a fatty acid metal salt, wax, paraffin, and silicon are added. May be done.

[Manufacture of Wood Cement Board] In order to manufacture the wood cement board of the present invention, first, the crushed materials A and B (coarse crushed material (1)), If possible, the raw material further added with the above-mentioned reinforcing fiber material and / or a silicic acid-containing substance may be used.
A wet method in which a slurry dispersed in water at a solid concentration of about 15% by weight is subjected to paper-forming dewatering by a paper machine such as a Nutsche-type paper machine, a fourdrinier-type paper machine, a round-mesh-type paper machine, and a mat is formed, or The mat is formed by a dry method in which the raw material is sprayed on a template in a water-containing state of 60% by weight or less and the mat is formed.

The crushed material A in the crushed wood cement board waste material
As described above, since the raw material powder is trapped in the fluff (21A), when the wet method is applied to the mat forming, the drainage of the slurry is improved. In the mat thus formed, the crushed material A
The strength is reinforced by the strong entanglement effect of the fluff (21A) of the resin, which makes it difficult to lose its shape.

The mat is pressed by a roll press, a flat plate press, or the like, preferably at a pressure of 30 kg / cm ² or more, and after the press, is subjected to primary curing if desired.
The mat may be embossed on the surface of the mat by using a template having a concave-convex pattern on the mold surface in the press. The primary curing condition is usually 60 to 90 ° C. for 5 to 12 hours. After the primary curing, the mat is secondarily cured. The secondary curing is usually carried out at 40 to 70 ° C. for 12 hours or more under normal pressure or at 140 to 180 ° C. for 6 to 12 hours. If autoclaving is performed on the secondary curing, the calcium silicate reaction, which is a hardening reaction involving the cement component and the silicic acid-containing substance (silica component) in the mat or the waste materials A and B of the wood cement board, becomes more effective. Performed smoothly, the mat hardens into a wood cement board.

[Example] 40% by weight of cement and pulp 5
50% by weight and 5% by weight of pearlite and slag cement pearlite board (normal pressure cured product containing wood fiber material) 50
The raw material mixture consisting of 7% by weight was made into a slurry having a solid content of 7% by weight, paper-formed by a fourdrinier paper machine, dewatered, and formed into a winding roll on a making roll. After the mat is flat-pressed, primary curing is performed at 80 ° C. for 10 hours and 60 hours.
A wooden cement board was obtained by carrying out secondary curing under normal pressure at 24 ° C. for 24 hours. The pulverized waste material was obtained by mixing a pulverized product A having a size of 350 to 600 μm and a pulverized product B having a size of 30 to 100 μm mainly in the mixing ratio shown in Table 1. Table 1 shows the physical property values of the obtained wood cement board.

[0020]

[Table 1]

According to Table 1, Examples 1, 2 and 3 using the mixture of the pulverized material A and the pulverized material B of the present invention have a specific gravity higher than Comparative Example 1 using only the pulverized material A As a result, an excellent wood cement board was obtained, in which the bending strength was greatly improved and the amount of flexure at the time of breaking was maintained substantially equal. Examples 1, 2, and 3 are slightly inferior in specific gravity and bending strength as compared with Comparative Example 2 using only the pulverized material B, but are much more excellent in the amount of flexure at break and in the formability.

[0022]

The wood cement board waste material of the present invention uses the crushed material A crushed by the impact type crusher and the crushed material B crushed by the attrition crusher together. In the process, the wood fiber substance contained in the waste material is fibrillated and fluffed, and the surface of the crushed material B is remarkably activated. Such a crushed mixed waste material is used as a part of the raw material of the wood cement board. When added, the product strength is improved by the strong entanglement effect of the fluff of the crushed material A, the capturing effect of the finely crushed material, and the excellent curability due to the surface activation of the crushed material B. Therefore, the amount of the waste material can be increased to approximately 60% by weight,
Effective utilization efficiency of waste materials is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a coarsely pulverized product.

FIG. 2 is an explanatory diagram of a finely pulverized material.

[Explanation of symbols]

 1 Coarse pulverized material 2 Wood fiber material 1A Pulverized material A 2A Wood fiber material after pulverization 21A Fluff

Claims (4)

[Claims] The present invention is characterized in that it comprises a pulverized material obtained by pulverizing a waste material of a wood cement board using a wood fiber material as a reinforcing material using an impact type pulverizer and a pulverized product obtained by pulverizing with a grinding type pulverizer. Wood cement board 2. The wood cement board according to claim 1, wherein the particle size of the pulverized product by said impact type pulverizer is mainly 850 to 300 μm, and the particle size of the pulverized product by said attrition type pulverizer is 300 μm or less. 3. A pulverized material obtained by pulverizing a wood cement board waste material using a wood fiber material as a reinforcing material by using an impact type pulverizer and a pulverized material obtained by pulverizing the material by a grinding pulverizer. A method for producing a wood cement board, comprising: adding a slurry to a raw material mixture containing the same to form a slurry, forming the slurry by papermaking dewatering and forming a mat, and curing and curing the mat. 4. The wood cement board according to claim 3, wherein the particle size of the pulverized product by the impact type pulverizer is mainly 850 to 300 μm, and the particle size of the pulverized product by the attrition type pulverizer is 300 μm or less. Manufacturing method