JPH08208299A - Production of wood chip cement board - Google Patents

Abstract

PURPOSE: To produce a wood chip cement board having a bending strength comparable to that of a board produced from paper-making chips by subjecting wood chips produced from building waste wood to a specific treatment, mixing the chips with cement and water and hardening by a prescribed method. CONSTITUTION: Wood chips produced from building waste wood are steamed preferably at 150-200 deg.C for 5-15min and cut to obtain wood pieces. The wood pieces are mixed with cement and water and the mixture is placed on a formwork and cured in a compression-molded state. The cement may be replaced with a cement composition composed of Portland cement, alumina cement, anhydrous gypsum and/or hemihydrate gypsum and lime. As necessary, an aqueous solution of aluminum sulfate is scattered to the wood pieces to improve the adhesive strength of cement to the wood piece.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a wood chip cement board.

[0002]

2. Description of the Related Art A conventional method of manufacturing a wood chip cement board is described in Japanese Patent Publication No. 59-13476.
The mixture composed of the cement composition was placed on a mold and cured in a pressure-molded state. As a wood piece used in the method for manufacturing the wood piece cement board, a wood piece obtained by cutting a wood chip of a coniferous tree such as cedar or cypress that is usually used for papermaking is used.

[0003]

Recently, in view of the exhaustion of resources, it is desired to reuse the waste wood once used in the building, and such waste wood is preferable because it is inexpensive. However, when the inventor cuts this waste wood into wood pieces and uses the wood pieces to manufacture wood piece cement boards, it was found that the bending strength was reduced by about 10% as compared with ordinary wood piece cement boards. . In pursuit of this cause, the waste wood once used in the building is not only one kind of wood but various kinds of wood are mixed in a wide variety, so it is especially harder than hardwoods such as cedar and cypress, for example It is thought that this is because cherry blossoms and oaks are mixed. Further, as a result of continuous research by the present inventor, a method for producing a wood chip cement board having a bending strength comparable to that of a conventional wood chip cement board by using waste wood was completed. That is, an object of the present invention is to provide a method for producing a wood chip cement board having a bending strength comparable to that of a conventional wood chip cement board by using waste wood.

[0004]

The present invention has been made in order to achieve the above-mentioned object, and the invention according to claim 1 is to cook wood chips made from construction waste wood and then to make the wood chips. Is cut to produce wood pieces, and a mixture of wood pieces obtained by mixing cement and water on the wood pieces, cement, and water is placed on a mold and cured in a pressure-molded state.

According to the second aspect of the present invention, after wood chips made from waste construction wood are cooked, the wood chips are cut to produce wood chips, and the wood chips are made of Portland cement,
A mixture of alumina cement, anhydrous gypsum or (and) hemihydrate gypsum, a cement composition consisting of lime and water, wood chips,
Place a mixture of cement composition and water on the mold,
It is cured in the state of being pressure-molded.

[0006] According to the third aspect of the present invention, wood chips produced from construction waste wood are cut to produce wood chips, and the wood chips are sprinkled with an aqueous solution of aluminum sulfate in which aluminum sulfate is dissolved in water. Are mixed, and a mixture of the wood chips, cement, aluminum sulfate, and water is placed on a mold and cured in a state of being pressure-molded.

The invention according to claim 4 is the method for producing a wood chip cement board according to claim 1 and claim 2,
The conditions for steaming are 150 to 200 ° C. for 5 to 15 minutes, and the ratio of wood chips to cement or cement composition is wood chips 5.
-30 parts by weight, cement or cement composition 70-9
It is 5 parts by weight.

The invention according to claim 5 is the method for producing a wood chip cement board according to claim 3, wherein the ratio of wood chips to aluminum sulfate and cement is 5 to 30 parts by weight of wood chips and 5 to 10 parts by weight of aluminum sulfate. Parts, 70 to 95 parts by weight of cement.

According to the invention of claim 1 or 2,
Wood chips made from construction waste wood are cooked. The cooking conditions differ depending on the quality of the construction waste wood, but as described in claim 4, it is usually cooked at 150 to 200 ° C for 5 to 15 minutes. Good. The cement used in the invention according to claim 1 is an appropriate cement such as Portland cement, alumina sensene, blast furnace cement, or a cement composition in which, if necessary, an appropriate additive such as a hardening accelerator or a hardening retarder is added to this cement. However, a normal Portland cement or a cement composition comprising Portland cement, alumina cement and anhydrous gypsum or / and hemihydrate gypsum, or lime as described in the second aspect of the invention is preferable.

In the invention according to claim 1, a piece of wood,
A mixture of cement and water is placed on a mold and pressure-molded. The ratio of the wood chips to the cement depends on the type of cement and may be appropriate. As described in claim 4, the ratio of wood chips to cement is 5 to 30% by weight of wood chips and 70 to 95% by weight of cement, and a mixture obtained by adding an appropriate amount of water thereto is preferable.

When a cement composition comprising portland cement, alumina cement, anhydrous gypsum or (and) hemihydrate gypsum, or lime is used as the cement according to the invention of claim 2, as described in claim 4, A mixture in which the ratio of wood chips to cement composition is 5 to 30% by weight of wood chips and 70 to 95% by weight of cement composition, and an appropriate amount of water is added thereto, is preferable.

[0012] When the wood chips are sprinkled with an aqueous solution of aluminum sulfate and mixed with cement as in the invention of claim 3, the ratio of wood chips, aluminum sulfate and cement is wood chips as described in claim 5. 5 to 30% by weight, aluminum sulfate 5 to 10% by weight, cement 65 to 80% by weight,
A mixture of water in which aluminum sulfate is dissolved and other water if necessary is preferably added to this.

[0013]

In the method of manufacturing a wood chip cement board according to claim 1 and the method of manufacturing a wood chip cement board according to claim 2, since wood chips prepared from waste wood are cooked, no reason can be clarified. A good wood chip cement board can be produced. When the inventor speculates the reason for this, it takes several months for the cement to fully set. Since conventional waste wood is hard, even if it is cured in a state where pressure is applied to a mixture of wood chips made from this waste wood and cement or the like, it is not yet sufficiently cured, and thus pressure-molded. It is considered that when the pressure is removed afterwards, the wood pieces swell and the adhesion between the wood pieces and the cement deteriorates, and the bending strength of the wood piece cement plate decreases, but when the waste wood is cooked, the wood pieces become softer, so pressure molding is performed. Even if the pressure is removed after that, it is considered that the adhesiveness of the cement becomes the same as in the production of the conventional wood chip cement plate, and the bending strength of the wood chip cement plate does not decrease.

Further, in the method for producing a wood chip cement board according to the third aspect of the present invention, since a wood piece is sprinkled with an aqueous solution of aluminum sulfate, a wood chip cement board having good bending strength can be produced for any reason, although it cannot be determined for any reason. To guess inventor this reason, aluminum is lime and normal temperature rapidly react one with calcium sulfoaluminate hydrate (3CaO · Al ₂ O ₃ · is cement cured product in the cement sulfate
3CaSO ₄ .32H ₂ O) is produced. Therefore,
When aluminum sulphate aqueous solution is sprinkled on wood chips and mixed with cement, crystals of calcium sulphoaluminate hydrate are produced on the wood surface, resulting in an increase in the bond strength between cement and wood chips, and bending strength of wood chip cement plates. Is expected to improve. Further, in claims 4 and 5, since the wood chips and the cement and the cement composition (and aluminum sulfate) are used in the optimum ratio, a very good wood chip cement board can be manufactured.

[0015]

Next, embodiments of the present invention will be described. (Example 1) Wood chips obtained by crushing architectural waste wood with a hammer mill are washed with water to remove metals, and then steamed in saturated steam at 175 ° C for 10 minutes. The wood chips thus obtained were cut with a ring type flaker and a hammer mill to produce wood chips. 200 parts by weight of this wood piece and 500 water
After adding 500 parts by weight of Portland cement and passing through a mixer to mix well, the mixture is placed on a molding frame, a template is placed on the mixture, and 30 kg is cold pressed. The pressure was applied at a pressure of / cm ^{2, and} the material was held and cured for 2 days under this pressure to be cured, decompressed, and dried at 100 ° C. for 24 hours to obtain a wood chip cement board.

Comparative Example 1 Wood chips obtained by crushing construction waste wood with a hammer mill were washed with water to remove metal, and then the wood chips were cut with a ring type flaker and a hammer mill to produce wood chips. . 200 parts by weight of this wood piece with 5 parts of water
00 parts by weight, then Portland cement 500
After adding parts by weight and passing through a mixer to mix well, this mixture was placed on a molding frame, a template was placed on this, and pressure was applied with a cold press at a pressure of 30 kg / cm ² , and this addition was performed. Hold and cure for 2 days under pressure to cure,
After decompressing, it was dried at 100 ° C. for 24 hours to obtain a wood chip cement board.

Comparative Example 2 Wood chips were produced by cutting cedar and cypress chips for papermaking with a ring type flaker and a hammer mill. To 200 parts by weight of this wood piece, 500 parts by weight of water was added, and then 500 parts by weight of Portland cement were added. After passing through a mixer and mixed well, this mixture was placed on a molding frame, and a mold was added from above. A plate is placed and pressed with a pressure of 30 kg / cm ^{2 by} a cold press, and in this pressed state, it is held and cured for 2 days to be cured, and after decompressing, 1
It was dried at 00 ° C. for 24 hours to obtain a wood chip cement board.

The bending strength of the wood chip cement board thus obtained was measured, and the results shown in Table 2 were obtained. On the other hand, when the springback degree of a mixture of wood chips, cement and water obtained by mixing wood chips with cement and water was measured, the results shown in Table 1 were obtained.

[0019]

[Table 1]

[0020]

[Table 2]

The springback degree shown in Table 1 was measured by the following method. A piece of wood 650g, Portland cement 1700g, water on the lower pressure plate of the press (upper and lower plate pressure area = 34cm x 44cm) in which the upper pressure plate is fixed and the lower pressure plate moves upward by hydraulic pressure. 1
A mixture of 020 g was placed on a substantially uniform thickness, the lower pressure plate was moved upward, and the mixture was allowed to stand for 15 minutes while being pressurized at 30 kg / cm ² , and was placed between the upper pressure plate and the lower pressure plate. After measuring the distance (L ₁ ), move the lower pressure plate down and stop when the pressure becomes 0 kg / cm ² , and measure the distance (L ₂ ) between this upper pressure plate and the lower pressure plate. Then, the spring back degree is calculated by the following formula, and the average value of four times is set as the spring degree of this piece of wood. Spring degree = L ₁ / L ₂

The bending strength shown in Table 2 was measured by the following method. 15cm × 20cm Wood piece cement board with a thickness of 15mm is placed with a fulcrum distance of 15cm.
The bending strength is calculated by pressurizing at a speed of mm / min until the wood chip cement board is broken, and the bending strength is calculated. The average value of 20 times is taken as the bending strength of this wood chip cement board.

As can be seen from Table 1, the wood pieces obtained by steaming construction waste wood have a weaker springback and softness than the wood pieces not cooked. Further, as can be seen from Table 2, the bending strength of the wood chip cement board using wood chips obtained by steaming construction waste wood (Example 1) is more than the bending strength of the wood chip cement board using non-steaming wood chips (Comparative Example 1). It is found that it is about 10% stronger, and is almost the same as the wood chip cement board (comparative example 3) using wood chips used for conventional papermaking.

Example 2 Wood chips obtained by crushing construction waste wood with a hammer mill were washed with water to remove metal, and then 1
Cook in saturated steam at 75 ° C for 10 minutes. The wood chips thus obtained were cut with a ring type flaker and a hammer mill to produce wood chips. 500 parts by weight of water was added to 200 parts by weight of this wood piece, and then a cement composition comprising 395 parts by weight of Portland cement, 52.5 parts by weight of alumina cement, 31.5 parts by weight of anhydrous gypsum, and 21 parts by weight of lime, After passing through the mixer and mixing well,
This mixture is placed on a molding frame, a template is placed on it, and the pressure is 30 kg / cm ² with a cold press at 93 ° C.
At 15 ° C for 15 minutes to cure and decompress, then 10
It dried at 0 degreeC for 24 hours, and obtained the wood chip cement board.

Comparative Example 3 Wood chips obtained by crushing construction waste wood with a hammer mill were washed with water to remove metal, and then the wood chips were cut with a ring type flaker and a hammer mill to produce wood chips. . 200 parts by weight of this wood piece with 5 parts of water
00 parts by weight, then Portland cement 395
Parts by weight, 52.5 parts by weight of alumina cement, anhydrous gypsum 3
Cement composition consisting of 1.5 parts by weight and 21 parts by weight of lime was added and mixed well by passing through a mixer, and then this mixture was placed on a molding frame, a template was placed on it, and cold pressed. At a pressure of 30 kg / cm ² and a temperature of 93 ° C. for 15 minutes to cure and decompress, and then at 100 ° C. for 2 minutes.
After drying for 4 hours, a wood chip cement board was obtained.

Comparative Example 4 Cedar and cypress chips for papermaking were cut with a ring type flaker and a hammer mill to produce wood chips. To 200 parts by weight of this wood piece, 500 parts by weight of water was added, and then, a cement composition consisting of 395 parts by weight of Portland cement, 52.5 parts by weight of alumina cement, 31.5 parts by weight of anhydrous gypsum, and 21 parts by weight of lime, After passing through a mixer to mix well, the mixture was placed on a molding frame, a template was placed on the mixture, and pressed with a cold press at a pressure of 30 kg / cm ² and a temperature of 93 ° C. for 15 minutes. After hardening and decompressing, it was dried at 100 ° C. for 24 hours to obtain a wood chip cement board.

The springback degree of the mixture of wood chips, cement and water and the flexural strength of the wood chip cement board obtained by the above method were measured by the same method as in Example 1,
The results shown in Table 3 and Table 4 were obtained.

[0028]

[Table 3]

[0029]

[Table 4]

As can be seen from Table 3, the wood chips obtained by steaming construction waste wood have weaker springback and softer than those of non-steamed wood chips. Further, as can be seen from Table 4, the bending strength of the wood chip cement board using wood chips obtained by steaming construction waste wood (Example 2) is more than the bending strength of the wood chip cement board using non-steaming wood chips (Comparative Example 3). It is found that it is about 10% stronger and is almost the same as the wood chip cement board (comparative example 4) using wood chips used for conventional papermaking.

Example 3 Wood chips obtained by crushing construction waste wood with a hammer mill were washed with water to remove metal, and then 1
Cook in saturated steam at 75 ° C for 10 minutes. The wood chips thus obtained were cut with a ring type flaker and a hammer mill to produce wood chips. An aqueous solution prepared by dissolving 50 parts by weight of aluminum sulfate in 500 parts by weight of water is sprinkled on 200 parts by weight of this piece of wood. Next, 500 parts by weight of Portland cement was added to a mixture of the wood chips, aluminum sulfate and water, and the mixture was passed through a mixer to mix well, and then the mixture was placed on a molding frame, and a template was put on the molding frame. Was placed, and the mixture was held and cured for 2 days under a pressure of 30 kg / cm ² with a cold press to cure, and after decompressing, it was dried at 100 ° C. for 24 hours to obtain a wood chip cement board.

Comparative Example 5 Wood chips obtained by crushing construction waste wood with a hammer mill were washed with water to remove metals, and then the wood chips were cut with a ring type flaker and a hammer mill to produce wood chips. . 200 parts by weight of this wood piece with 5 parts of water
00 parts by weight, then Portland cement 500
After adding parts by weight and passing through a mixer to mix well, the mixture is placed on a molding frame, a template is placed on the mixture, and the mixture is pressed with a cold press at a pressure of 30 kg / cm ^2. After holding and curing for 2 days to cure and decompress, 1
It was dried at 00 ° C. for 24 hours to obtain a wood chip cement board.

The bending strength of the wood chip cement board thus obtained was measured, and the results shown in Table 5 were obtained.

[0034]

[Table 5]

As can be seen from Table 5, the bending strength (Example 3) of the wood chip cement board obtained by sprinkling aluminum sulfate on wood chips obtained from construction waste wood was a wood piece not sprinkling aluminum sulfate. It can be seen that the bending strength of the wood cement board (Comparative Example 5) is approximately 10% stronger.

[0036]

As is apparent from the above description, the first aspect of the present invention is as follows.
In the method for producing a wood chip cement plate according to the above and in the method for producing a wood chip cement plate according to claim 2, since wood chips made from waste wood are steamed, wood chips made from the chips used for papermaking are used. It is possible to produce a wood chip cement board that has approximately the same bending strength as the cement board. In this way, waste wood can be used, which is an extremely valuable invention.

Further, in the method for manufacturing a wood chip cement board according to the third aspect, since the wood chips are sprinkled with an aqueous solution of aluminum sulfate, a wood chip cement board having good bending strength can be manufactured, and therefore the chips used for papermaking. It is possible to manufacture a wood chip cement board having substantially the same bending strength as a wood chip cement board using the wood chips prepared from In this way, waste wood can be used, which is an extremely valuable invention. Further, in the inventions of claims 4 and 5, since wood chips and cement (and aluminum sulfate) are used in the optimum ratio, an extremely good wood chip cement board can be produced, which is preferable.

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Claims (5)

[Claims] 1. A wood chip made from waste construction wood is steamed and then cut to produce a wood chip, and a wood chip, which is a mixture of cement and water, and a mixture of cement and water is used as a formwork. A method for manufacturing a wood chip cement board, which is characterized in that the wood chip cement board is placed on and cured in a state of being pressure-molded. 2. Wood chips made from construction waste wood are steamed, then the wood chips are cut to produce wood pieces, and the wood pieces are made of Portland cement, alumina cement, anhydrous gypsum or (and) hemihydrate gypsum, lime. A method for producing a wood chip cement board, which comprises mixing a cement composition consisting of the above with water and placing a mixture consisting of the wood chips, the cement composition and water on a mold, and curing the mixture under pressure molding. 3. A wood chip produced by cutting off construction waste wood is cut to produce a wood chip, and an aluminum sulfate aqueous solution in which aluminum sulfate is dissolved in water is sprinkled on the wood chip. Cement is further mixed to obtain the wood chip, cement. A method for producing a wood chip cement board, which comprises placing a mixture of aluminum sulfate and water on a mold and curing the mixture in a pressure-molded state. 4. The method for producing a wood chip cement board according to claim 1 or 2, wherein the steaming condition is 150 to 2
A method for producing a wood chip cement board, which is 5 to 15 minutes at 00 ° C., and the ratio of wood chips to cement or cement composition is 5 to 30 parts by weight of wood chips and 70 to 95 parts by weight of cement or cement composition. . 5. The method for manufacturing a wood chip cement board according to claim 3, wherein the ratio of wood chips to aluminum sulfate to cement is 5 to 30 parts by weight of wood chips, 5 to 10 parts by weight of aluminum sulfate, and 70 to 95 parts by weight of cement. And a method for manufacturing a wood chip cement board.