JP2652774B2 - Manufacturing method of inorganic plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a cement-based inorganic plate mainly used for construction.

[0002]

2. Description of the Related Art Conventionally, an inorganic plate in which a wood reinforcing material such as a piece of wood, wool, or wood pulp is mixed with cement has been provided as a building plate such as an outer wall material or an inner wall material. As a method for producing the above-mentioned inorganic plate, a molding material obtained by mixing a wood-based reinforcing material with a cement-based inorganic powder such as cement has been recently sprayed on a mold plate to form a mat, and the mat is heated and pressed to be primarily cured. A dry method in which a product is manufactured and then the primary cured product is demolded and cured to finally cure the product is awarded. According to the dry method, an inorganic plate having a three-dimensional uneven pattern on its surface can be easily manufactured, and such an inorganic plate has been highly evaluated as an outer wall material.

[0003]

However, in the above-mentioned conventional dry production method, although the hardening of the cement-based inorganic powder is promoted by heating and pressing, it takes 10 to 10 days to reach the demolding after pressing. It requires a long period of time, the efficiency of use of templates is low, and productivity is very low.To cope with mass production, a large number of templates are required and investment in templates is large. (For example, JP-A-54-48821). The reason why it takes a long time before demolding after pressing is that cement-based inorganic powders require a long time for hydration and hardening, and when demolded in a short time, the molding material causes springback. It is mentioned that a molded article having a desired shape cannot be obtained. Particularly in some tree species such as larch, yellow lauan, etc., when a cement hardening inhibitor such as saccharides contained in wood acts on the cement inorganic powder, it inhibits the hardening of the cement inorganic powder. Further, the curing time is delayed, and the curing often becomes poor, making molding impossible. However, from the viewpoint of effective use of wood resources, it is desirable to use wood scrap generated from the demolition of buildings as a wood reinforcing material. However, the wood scrap is diverse and often includes the tree species containing a large amount of the sugars. Therefore, it is difficult and very troublesome to sort out and remove only such a tree species.
Furthermore, even if it is the same tree species, there is a problem that the sugar content differs between the core material and the sapwood, and the time from press molding to demolding varies greatly. For this reason, there has been a long-awaited demand for a method of manufacturing an inorganic plate that shortens the time from press forming to demolding and keeps it substantially constant irrespective of the type of wood reinforcing material, core material, or sapwood.

[0004]

According to the present invention, as a means for solving the above-mentioned conventional problems, a cement-based inorganic powder 40 is used.
The water content of the molding material obtained by mixing 2 to 15 parts by weight of the cementitious inorganic powder with 100 to 70 parts by weight of the cementitious inorganic powder is 40 to 70 parts by weight, 20 to 35 parts by weight of the wood reinforcing material,
Step 1 of adjusting the weight to 60% by weight, Step 2 of forming a mat by spraying the molding material on a template, Step 3 of pressing and matting the mat to perform primary curing by spraying steam, and Primary cured mat. And a final curing step of curing in a water-containing state, and a method for producing an inorganic plate comprising the above steps 1, 2, 3, and 4.

[Cement-based inorganic powder] The cement-based inorganic powder used in the present invention is a hydraulic inorganic powder containing calcium silicate as a main component. For example, Portland cement, or blast furnace cement in which blast furnace slag is mixed with Portland cement,
There are fly ash cement mixed with fly ash, silica cement mixed with a silica substance such as volcanic ash, silica fume, and clay, alumina cement, blast furnace slag, and the like.

[Wood reinforcement] Wood reinforcement, wood wool, wood chips, wood fiber, wood pulp, wood fiber bundle, etc. are used as wood reinforcement in the present invention. A material containing lignocellulose as a main component such as fiber, bacas, fir, rice straw, etc. may be mixed. Preferred wood reinforcements are wood chips of 0.5 to 2.0 mm in width, 1 to 20 mm in length, 20 to 30 aspect ratios (length / thickness), 0.1 to 2.0 mm in diameter, and 2 to 35 mm in length. And / or bent and / or bent wood fiber bundles.

[Aggregate] In the present invention, an aggregate, particularly a lightweight aggregate, may be added in addition to the cement-based inorganic powder and the wood reinforcing material. As the lightweight aggregate, inorganic foams such as pearlite, shirasu balloon, expanded shale, expanded clay, calcined diatomaceous earth, fly ash, coal waste, and crushed foam concrete are used. The lightweight aggregate is usually added in an amount of 30 parts by weight or less based on the total solid content of the mixture.

Furthermore aluminum sulfate if desired in the [third component] above composition, magnesium sulfate, calcium sulfate, curing accelerator and waxes such as aluminate compounds, waxes, paraffins, surfactants, waterproofing agents such as silicon Or a water repellent may be added.

[Alkali metal silicate] The alkali metal silicate used in the present invention includes lithium silicate, potassium silicate, sodium silicate and the like. Preferred alkali metal silicates include potassium silicate and sodium silicate which are inexpensive and readily available. The molar ratio _{Si O 2 / Na 2 O =} 2~4 desired silicate and an alkali metal in said alkali metal silicate, Si O ₂ / K
₂ O = 3-4.

[Manufacture of Inorganic Plate] In order to manufacture the inorganic plate of the present invention, usually, a predetermined amount of the above composition is mixed to prepare a molding material. In this case, the cement-based inorganic powder 40 to 70
Parts by weight, 20 to 35 parts by weight of the wood reinforcing material, and the alkali metal silicate are added and mixed at a ratio of 2 to 15% by weight based on 100 parts by weight of the cement-based inorganic powder. Is added to adjust the water content to 40 to 60% by weight (step 1). As a preferable preparation method, the above-mentioned wood reinforcing material and the above-mentioned alkali metal silicate salt diluted with water are mixed to allow the alkali metal silicate salt to penetrate into the wood reinforcing material, and then the above-mentioned cement-based inorganic powder and aggregate, etc. Is added and mixed. The molding material thus prepared is sprayed on a template to form a mat (step 2). Next, the periphery of the mat is sealed with a seal frame material and pressed, and steam is injected and heated to accelerate the curing reaction of the mat, and the size and specific gravity of the mat are regulated by the seal frame material. The mat is primarily cured while retaining the water vapor inside the seal frame material (step 3). The pressure of the steam applied in the heating and pressing is 0.12 to 0.30 MPa, and the injection time is usually 2 to 3.
The pressing pressure is usually 2 to 5 MPa, and the pressing time is usually 2 minutes or more, but preferably 2 to 15 minutes in consideration of productivity. If the steam injection time is less than 2 seconds, the primary curing of the mat becomes insufficient, and the demolding workability tends to deteriorate, and the strength and freeze-thaw resistance of the obtained product may not be satisfied. In this case, the primary cured material of the mat may burst, so in this case, before releasing the primary cured product, maintain the pressure-tightened state.Open the pressure reducing valve etc. to reduce the internal pressure of the mat in the seal frame material. It is necessary to gradually lower to prevent the primary cured product from bursting. The primary cured product of the mat obtained after the pressing is cured in a water-containing state (step 4). To cure the primary cured product in a water-containing state, it is preferable to coat the primary cured product with a water-impermeable film in order to prevent evaporation of water. When the water content of the primary cured product is small, water immersion is performed or water is sprayed. When water is sprayed, the primary cured product is preferably covered with a water-impermeable film in order to prevent evaporation of water. The curing time is usually 7 to 15 days, and the primary curing is finally cured by the curing. After the curing, the product is subjected to a surface treatment if necessary through a drying process to obtain a product.
Except for the above embodiment, in the pressing step, the steam may be jetted from the back surface of the mat, or may be jetted from both the front and back surfaces. The inorganic plate of the present invention may have a two-layer structure or a three-layer structure. In the case of a two-layer structure, first, a molding material in which a wood reinforcing material having a fine particle diameter is mixed is sprayed on a template, and then a molding material in which a wood reinforcing material having a large particle diameter is mixed thereon is molded. A mat having a two-layer structure is formed by spraying on a board, and the mat is heated and pressed to form a surface layer portion having a dense structure using a molding material in which a wood reinforcing material having a fine particle diameter is mixed. A back layer having a rough structure is formed by a molding material mixed with a wood reinforcement having a large diameter. Furthermore, in the case of a three-layer structure, a molding material in which a wood reinforcing material having a fine particle diameter is mixed is further sprayed thereon to form a three-layer structure mat, and the mat is heated and pressed to obtain the above-described particle diameter. The layer made of the molding material in which the wood reinforcing material having a large particle size is mixed is used as the core layer portion, and the layer made of the molding material in which the wood reinforcing material having a small particle diameter is mixed is used as the back layer portion. When a three-layered structure is formed, two mats having the two-layered structure may be stacked and heated and pressed. In this case, the mat is laminated so that layers of a molding material mixed with a woody fiber having a large particle diameter are in contact with each other.

[0011]

A molding material comprising a mixture of a cement-based inorganic powder, a wood reinforcing material, an alkali metal silicate, and, if desired, an aggregate, particularly an inorganic foam, is formed as a mat on a mold plate. When the mat is pressed and water vapor is injected, the mat is rapidly heated to the inside, and the alkali metal silicate rapidly reacts with the cement-based inorganic powder. That is, the alkali metal components (Li ₂ O, K ₂ O, Na ₂ O, etc.) of the alkali metal silicate accelerate the hydration hardening of the cement-based inorganic powder, and the silicic acid component (SiO ₂ ) The cement-based inorganic powder reacts with the lime (CaO) of the cement-based inorganic powder and hardens the cement-based inorganic powder as a whole even if the wood-based reinforcing material contains a cement-hardening inhibitor such as a saccharide. Proceed smoothly. Since the mat which has been primarily cured in this way has a sufficient primary strength for the demolding operation, it can be demolded by pressing for a short time (preferably 2 to 15 minutes). When the aqueous alkali metal silicate solution is first infiltrated into the wood reinforcing material, the above-mentioned reaction is performed with the cement-based inorganic powder around which the aqueous alkali metal silicate solution is present from the wood reinforcing material by pressing. . In this case, when the wood reinforcement contains a cement hardening inhibitor, the surface of the wood reinforcement is coated with the alkali metal silicate when the aqueous solution of the alkali metal silicate is penetrated into the wood reinforcement. In this state, the elution of the cement hardening inhibitor contained in the wood reinforcing material is prevented, so that the hardening of the cement inorganic powder proceeds more smoothly.

[0012]

【Example】

[Embodiment 1] FIGS. 1 to 5 show one embodiment of a process for producing an inorganic plate of the present invention. In FIG. 1, a mold plate (1) is conveyed by a conveyor (2) in the direction of an arrow, and a mold release agent is sprayed from a spray nozzle (3) on a mold surface of the mold plate (1). 1) is introduced into the forming device (4) by the conveyor (2). The forming device (4) includes a forming chamber (5) and a blower chamber (7) in which a blower (6) provided at an outlet of the forming chamber (5) is provided.
The forming chamber (5) is opposed to the blowing chamber (7).
A reverse blower (8) provided at the entrance of the hopper, and a hopper (9) provided at the ceiling of the forming chamber (5);
Molding material supply conveyor (10) connected to the hopper (9)
And a molding material supply sieve (11) installed on the conveyor (10)
Consists of

The molding material R is sprayed from the sieve (11) onto a conveyor (10) and is supplied to a hopper of a forming chamber (5).
From (9) into the forming chamber (5),
It is scattered and deposited on the template (1) introduced by the conveyor (2) into the forming chamber (5). At this time, air is blown from the blower (6) of the blower chamber (7) to the inlet side, the molding material R is selected by air, and the molding material R in which the wood reinforcing material having a fine particle diameter is mixed is placed on the lower side. The molding material R in which the wood reinforcing material having a large size is mixed is set to the upper side. At this time, the reverse air is blown to the outlet side by the reverse air blower (8). So that In this way, a mat (12) having a dense structure on the lower side and a coarse structure on the upper side is formed, and the mat (12) is trimmed to a predetermined size, if necessary, and then the pressing device shown in FIG. Introduced in 13).

The pressing device (13) includes a platen (15) installed on a base (14) and a lower pressure plate (heat plate) mounted on the platen (15). 16), a movable plate (18) attached to the lower end of the hydraulic cylinder (17), an upper pressure plate (19) which is a hot plate attached below the movable plate (18), A steam injection plate (20) mounted below the pressure plate (19),
A seal frame member (22) which is a seal means disposed below the steam injection plate (20) and suspended by a link (21).
And a frame (23) that supports the hydraulic cylinder (17) and guides the movable plate (18). The above steam injection board (20)
As shown in FIG. 3, is a main body (24), a steam pipe (25) inserted into the main body (24), and a number of nozzles which are inserted from the steam pipe (25) and open on the lower surface of the main body (24). It consists of a pipe (26).

The mat (12) formed by the above-mentioned forming device (4) is introduced into the pressing device (13) and set on a lower pressing plate (16) as shown in FIG.
As shown in the figure, the lower pressurizing plate (16) and the upper pressurizing plate (19) are pressed together and the periphery thereof is sealed with a seal frame (22).
As described above, the pressing pressure in this case is usually 2 to 5 MPa. Then, when the predetermined pressure is reached, steam is injected from the steam injection plate (20) to the mat (12) through the steam pipe (25) and the nozzle pipe (26). As described above, the pressure of the steam is 0.12 to 0.30 MPa, and the injection time is usually 2 to 10 seconds. In this case, a releasable net or mat, such as a glass fiber net coated with Teflon resin, may be interposed between the mat (12) and the steam jet plate (20) so that steam can pass through. Further, instead of the sealing frame member (22), a sealing means such as a rubber belt or a heat-resistant adhesive tape may be used for sealing.

[0016] By the steam injection to the mat (12), as described above, the reaction between the cement-based inorganic powder and the alkali metal silicate hardens smoothly, and the primary strength is reduced in a short time (usually within 5 minutes). And the demolding work becomes easier. As described above, the primary strength of the mat (12) is improved in a short time during the press forming, and the demolding operation is facilitated, so that the upper pressing plate (19) of the pressing device (13) is raised. The mold is opened, and the primary curing mat (27) shown in FIG. 5 is removed from the mold plate (1).

[Embodiments 2 to 16] Using the forming apparatus (4) and the pressing apparatus (13) of Embodiment 1, Tables 1 and 2 were used.
Inorganic plate samples 1 to 15 were manufactured under the compacting conditions shown in Tables 1 and 2 by using the molding material having the composition of Example 2 above
Table 1 shows the physical properties of the inorganic plate samples 1 to 15 manufactured in
And in Table 2.

[0018]

[Table 1]

[Comparative Examples 1 to 6] Using the forming material (4) and the pressing device (13) of Example 1, a molding material having the composition shown in Table 3 was used, and the inorganic material was obtained under the pressing curing conditions shown in Table 3. Plate samples 16 to 21 were produced. Table 3 shows the physical properties of the inorganic plate samples 16 to 21 manufactured in Comparative Examples 1 to 6.

[0020]

[Table 3]

[Discussion] Sample 16 of Comparative Example 1 uses a molding material to which no alkali metal silicate is added, and primary compaction is insufficient due to insufficient compression for 10 minutes, and the mold cannot be removed. Sample 17 of Comparative Example 2 in which the steam injection time was less than 2 seconds had insufficient product strength and freeze-thaw resistance, and Sample 18 of Comparative Example 3 in which the steam injection time exceeded 10 seconds Destruction occurs. Curing time is less than 7 days 5
The sample 19 of Comparative Example 4, which was a day, had insufficient strength and freeze-thaw resistance, and the sample 20 of Comparative Example 5, which had a compression time of 1 minute which was less than 2 minutes, had poor strength and freeze-thaw resistance. Enough
Sample 21 of Comparative Example 6 in which the alkali metal silicate was added in an amount exceeding 15 parts by weight and 16.7 parts by weight with respect to the cement-based inorganic powder had poor freeze-thaw resistance and cracked the product in layers. did. On the other hand, Sample 1 of Examples 2 to 16 of the present invention
No. to No. 15 are sufficiently large in both product strength and freeze-thaw resistance and show excellent physical properties.

[0022]

According to the present invention, since the pressing time can be greatly reduced in the present invention, the investment in the template can be greatly reduced, and the productivity decreases even if the inorganic plates are pressed one by one. If the inorganic plates are pressed one by one, it is possible to obtain a sheet having less variation in thickness than the conventional case where the inorganic plates are stacked and pressed. In the present invention, since the pressing time is shortened irrespective of the type of the wood reinforcing material, it is also possible to reuse the construction waste material as the wood reinforcing material. Thus, the present invention provides an extremely efficient inorganic material having a uniform thickness. Plates can be manufactured.

[Brief description of the drawings]

 1 to 5 show one embodiment of the present invention.

FIG. 1 is a process chart of mat forming.

FIG. 2 is a schematic view of a pressing device.

FIG. 3 is a schematic cross-sectional view of a steam injection board.

FIG. 4 is a schematic view of a pressing device in a pressed state.

FIG. 5 is a side sectional view of a molded product.

[Explanation of symbols]

 12 Mat 13 Pressing device 27 Primary curing mat

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C04B 18:26) (72) Inventor Shuichi Kawai 70-35 Fukakuya-Yaguchicho, Fushimi-ku, Kyoto-shi, Kyoto (72) Invention Person Dwight Agobourne Eusebio 1-04 Takabacho, Fushimi-ku, Kyoto-shi, Kyoto (56) References JP-B-55-36618 (JP, B2)

Claims (4)

(57) [Claims] 1 to 40 parts by weight of a cement-based inorganic powder, 20 to 35 parts by weight of a wood reinforcing material, and 2 to 15 parts by weight of an alkali metal silicate are mixed with 100 parts by weight of the cement-based inorganic powder. Step 1 of adjusting the moisture content of the molding material to 40 to 60% by weight, Forming a mat by spraying the molding material on a mold plate 2, Pressing the mat and spraying water vapor to cure it primarily. Step 3, a step of curing the primary-cured mat in a water-containing state and finally curing the mat; a method of manufacturing an inorganic plate comprising the above steps 1, 2, 3, and 4 2. The method according to claim 1, wherein an inorganic foam is further added to the molding material in an amount of 30 parts by weight or less. 3. The production of an inorganic plate according to claim 1, wherein the alkali metal silicate is one or more alkali metal silicates selected from lithium silicate, potassium silicate and sodium silicate. Method 4. The process according to claim 3, wherein the water vapor pressure in step 3 is 0.12 to 0.1.
30 MPa, the injection time is 2 to 10 seconds, the pressing time is 2 minutes or more, and the curing time in step 4 is 7 to
The method for producing an inorganic plate according to claim 1, which is for 15 days.