JP2001213657A - 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: A ground powder of the woody cement board to which the woody cement board waste reinforced by woody fiber 2 is ground by a shock grinder is utilized to a part of raw material of the woody cement board. The ground waste powder contains crude powder 1A containing fibrilized woody fiber 2A, and fine powder 1B with a large active surface area.

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 waste wood from the wood cement board is poor in hardenability, and has a small particle size, so that the wood fiber is short-sheared. 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 waste material of a wood cement board using a wood fiber material (2) as a reinforcing material is obtained by using an impact type crusher. A wood cement board containing a crushed waste wood material obtained by fibrillating and pulverizing the wood fiber substance (2A) contained in the wood waste, and a wood cement board waste material using the wood fiber substance (2) as a reinforcing material Using an impact type crusher, the wood fiber material (2A) contained in the waste material is fibrillated, and the crushed waste material is added to the raw material mixture containing cement and the wood fiber material (2). The present invention provides a method for producing a wood cement board in which a mat is formed by forming a mat by dewatering and forming the slurry and curing and curing the mat. Further, the pulverized waste material is a pulverized waste material of a wood cement board that has not been autoclaved and has been cured under normal pressure, and it is preferable that the pulverized waste material contains at least 50% by weight of a wood fiber substance with little deterioration. .

[0005]

When a wood cement board waste material containing wood fiber material such as slag cement perlite board is crushed by an impact crusher such as a hammer mill, the crushing process is first performed as a so-called primary crushing step as shown in FIG. A lump (1) containing wood fiber material (2) such as pulp is formed. In the lump (1), the portion where the wood fiber material (2) is present is softer than the other portions, so that it is difficult to be finely pulverized, and it is easy to divide at this portion. As shown in FIG. 2, in a state where the lump (1) is divided into a plurality of coarsely pulverized materials (1A, 1A) as a so-called secondary pulverization step, the wood fiber material (2A, 2A) is torn. This gives rise to fluff (21A) (fibrillation). The portion where the wood fiber material (2) does not exist is almost inorganic and hard, so that it is finely pulverized into a finely pulverized product (1B). In the above-mentioned waste material pulverized material, most of the coarsely pulverized material (1A) holds the wood fiber material (2), and 50% by weight or more of the wood fiber material (2) is mainly made of the wood fiber material with little deterioration. The particle size is more than 300 μm, especially 30 μm
It is contained in an amount of at least% by weight.

The coarsely pulverized material (1A) having the fluff (21A) formed at various places on the surface as described above is mixed with the raw material of the wood cement board to obtain a fine powder of raw material such as cement or the above-mentioned finely pulverized waste material (1B). ) Is trapped in the fluff (21A), and when the wood cement board is manufactured by the papermaking method, the leakage of the raw material fine powder during the papermaking is prevented, so that the papermaking band such as felt is clogged. It becomes cloudy and improves the papermaking property, that is, the productivity.

Further, the fuzz (21A) formed from the surface of the coarsely pulverized material (1A) is strongly entangled with the fuzz (21A) of the wood fiber material in the raw material or other coarsely pulverized material (1A). The fluff (21A) is reduced by the coarse pulverized material.
Since it is formed radially from (1A) in a random direction, the reinforcing effect due to the entanglement of the fluff (21A) has no directionality, and the strength of the product is improved in any direction.
Therefore, the fibrillation of the wood fiber material (2) is usually performed in a beating step in a slurry, but in the present invention, only the grinding step, in other words, the wood fiber material (2) is obtained by a dry method.
Can be fibrillated. If a pulverized waste material of a wood cement board that has not been autoclaved and is pressure-cured at normal pressure is used, the wood fiber material in such a pulverized waste material is in a living state, that is, a state having tensile strength with little deterioration, The trapping property and the entanglement property at the time of papermaking exhibit almost the same effect as the properties of a wood fiber material used for manufacturing a wood cement board, so-called beaten virgin pulp. On the other hand, the unreacted components of the cement remaining in the wood cement board waste material are exposed on the surface of the finely pulverized waste material (1B), so it is active and reacts with the cement and silicic acid-containing substances in the raw material. Hardens to contribute to the strength of the product.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [Wood Cement Board Waste] Wood cement board waste used in the present invention is a board containing wood fiber material such as slag cement perlite board, and trimming waste discharged from the wood cement board manufacturing process as described above. Or waste materials resulting from repair or removal of buildings using wood cement boards. The above-mentioned waste material is desirably a normal pressure cured product which has not been autoclaved. In the above normal pressure cured product, the wood fiber material is less deteriorated, and the effect almost equivalent to that of virgin pulp remains.

The waste material is pulverized by an impact type pulverizer such as a hammer mill. As described above, the waste wood pulverized material contains 50% by weight or more of a living fiber material in a living state, that is, a state having a tensile strength, and has a particle size of 300 μm.
In particular, 600 μm or more is contained in an amount of 30% by weight or more. At the time of the above-mentioned pulverization, as described above, in the coarsely pulverized product (1A), the fibrous material (2A) occurs, and fuzz (21A) is formed radially in a random direction from the surface as shown in FIG. Is done.

[0010] The above-mentioned waste material contains unreacted active substances such as unreacted CaO, SiO ₂ and Al ₂ O ₃ which are uncured components of cement.
The waste material still has a considerable amount of curability. The finely pulverized product (1B) has a particle size of 60 μm or less, and is 50% by weight.
The above has a large active surface area because the particle size is 30 μm or less, and therefore, the curability remaining in such waste material can be effectively used. In the present invention, the pulverized waste material (1A, 1B) can be added to the raw material up to about 60% by weight. However, if the amount exceeds 60% by weight, the strength of the product may be reduced.

[Cements] Examples of the cements used in the present invention include cements such as Portland cement, jet cement, blast furnace cement, fly ash cement, alumina cement and the like, blast furnace slag, fly ash, diatomaceous earth, volcanic ash and the like. And a calcium silicate reactant such as silica sand and silica stone powder.

[Other Additives] In the present invention,
In order to reinforce the strength of cement board products or to enhance the hardenability of the above-mentioned cement board waste materials, wood fiber substances such as pulp fibers, waste paper defibrated materials, wood fiber bundles, wood chips, wood flour, polyester One or more kinds of reinforcing fiber materials such as fibers, polyamide fibers, acrylic fibers, acetate fibers, organic fibers such as polyethylene fibers, and polypropylene fibers, and inorganic fibers such as glass fibers, carbon fibers, and ceramic fibers; and / or silica powder; Silica fume,
One or more of silicic acid-containing substances such as shirasu balloon, perlite, mica, dolomite, wollastonite, glass powder, siliceous clay, bentonite and the like may be added. The reinforcing fiber material and the silicic acid-containing substance are each added in an amount of 30% by weight or less. When the amount of these additives is 3
When the content exceeds 0% by weight, the effect of reinforcing the cement board product and the effect of enhancing the hardening property are saturated, and the cement board waste material recycling rate decreases. In addition to the above components, if desired, calcium chloride, magnesium chloride, magnesium hydroxide,
Cement hardening accelerators such as aluminum sulfate, sodium aluminate, and water glass, and water repellents such as fatty acid metal salts, wax, paraffin, and silicon may be added.

[Manufacture of Wood Cement Board] In order to manufacture the wood cement board of the present invention, the above-mentioned cements and the above-mentioned pulverized wood cement board waste materials (1A, 1B) may further contain the above-mentioned reinforcing fiber material and / or A slurry obtained by dispersing a raw material mixture containing a silicic acid-containing substance or the like in water at a solid content of about 5 to 15% by weight is subjected to a paper machine such as a Nutsche machine, a fourdrinier machine, and a round mesh machine. Forming is performed by a wet method of forming a mat by dewatering the paper.

The cement in the raw material mixture is usually 30 to
80% by weight, wood cement board waste is usually added in about 4 to 60% by weight, reinforcing fiber material is usually added in about 4 to 10% by weight, and silicic acid-containing substance is usually added in about 4 to 10% by weight.

As described above, the coarsely pulverized wood cement board waste material (1A) captures raw materials such as cement, finely pulverized waste material (1B), and silicic acid-containing substances in the fluff (21A), as described above. When the wet method is applied to the mat forming, the drainage of the slurry is particularly improved. In the mat formed in this way, the coarsely crushed waste material is used.
The strength is reinforced by the strong entanglement effect of the fluff (21A) of (1A).

The mat is pressed at 20 to 60 kgf / cm ² by a roll press, a flat plate press or the like, and after the above-mentioned press, it 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 above primary curing,
The mat is secondarily cured. The secondary curing is usually 40-7.
Curing at 0 ° C for 12 hours or more under normal pressure or 140-180 ° C
Autoclave curing for 8 to 12 hours. If autoclaving is carried out for the secondary curing, the reaction between the finely ground waste material of the wood cement board in the mat (1A) or the finely ground waste material of the wood cement board (1A) and the silicic acid-containing substance is smoother. The mat hardens into a wood cement board.

[Embodiment] A pulverized material obtained by pulverizing a wood cement board waste material which has not been subjected to autoclaving and is produced by normal pressure curing with a hammer mill and a pulverized material obtained by pulverizing with a vertical mill are separately shown in Table 1. A slurry was prepared by mixing the raw materials at the mixing ratios shown in Table 1 below, and after papermaking dehydration molding, curing and curing were performed to obtain a wood cement board. The physical properties of the obtained wood cement board are as shown in Table 2.

[0018]

[Table 1]

[0019]

[Table 2]

According to Table 2, Comparative Examples 1, 2, and 3 using the crushed wood cement board waste material (vertical mill crushed material) containing the non-fibrillated wood fiber material used the fibrillated wood fiber. Example 1 according to the present invention using a crushed wood cement board waste material (hammer mill crushed material)
The flexural strength is much lower than that of 2, 3, and 4, the dimensional change rate of water absorption is large, the drainage during papermaking is poor, and there is a possibility that dewatering cracks may occur during pressing. In the case of Comparative Example 4 in which the pulverized hammer mill was used in an amount exceeding 60% by weight (70% by weight), the bending strength was reduced, the dimensional change in water absorption was increased, and the drainage during papermaking was poor. There is also a risk of dehydration cracking during pressing.

[0021]

The waste wood cement board of the present invention is pulverized by an impact-type pulverizer. In the process, the wood fiber material contained in the waste wood is fibrillated and the coarse pulverized material having fluff is produced. A finely pulverized material having a large surface area is obtained. When such a pulverized waste material is added as a part of a raw material for a wood cement board, a strong entanglement effect of the fluff of the coarsely pulverized material and a smoothness of the finely pulverized material are obtained. The product strength is improved by a proper curing reaction. Therefore, the amount of the waste material can be increased to approximately 60% by weight, and the effective use efficiency of the waste material 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 Lump 2 Wood fiber material 1A Coarsely pulverized material 1B Finely pulverized material 2A Wood fiber material after pulverization 21A Fluff

Claims (4)

[Claims] 1. A waste wood pulverized material obtained by fibrillating and pulverizing the wood fiber substance contained in the wood cement board using an impact type pulverizer using a wood cement board using the wood fiber substance as a reinforcing material. Wood cement board characterized by containing 2. The pulverized waste material is a pulverized waste material of a wood cement board which has not been subjected to autoclave curing and has been cured at normal pressure.
The wood cement board according to claim 1, which is contained in an amount of at least% by weight. 3. A crushed waste wood material obtained by fibrillating the wood fiber material contained in the waste wood material using an impact type crusher and pulverizing the wood fiber board waste material using the wood fiber material as a reinforcing material. A method for producing a wood cement board, comprising adding a raw material mixture containing cement and a wood fiber material to form a slurry, forming the mat by dewatering and forming the slurry, and curing and curing the mat. 4. The pulverized waste material is a pulverized waste material of a wood cement board which has not been subjected to autoclaving and has been cured under normal pressure.
The method for producing a wood cement board according to claim 3, wherein the wood cement board is contained in an amount of not less than% by weight.