JP2000044315A - Production of composite cement plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing composite cement plate excellent in mechanical strengths, heat insulating properties and sound insulating properties while suppressing production cost of an unit, and capable of being utilized as a backing material for a roof, a wall or the like, having high retentivity of a vis, a concrete panel or the like. SOLUTION: Chaff 4 and chips 6 of wood in the proportion of 30-40 wt.% chaff and 70-60 wt.% chips of the wood are mixed with a cement base 8, and the obtained mixture is inserted into a prescribed frame mold. A compression force within the range of 3-10 kg/cm2 is added to the mixture in the thickness direction to provide a compressed body in a plate shape, and the obtained compressed body is hardened and dried to provide the objective composite cement plate 2.

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 composite cement board suitable as a base material for roofs and walls, a control panel, and the like.

[0002]

2. Description of the Related Art As described in JIS, a wool cement board is a board material obtained by mixing wood wool and a cement paste and then compression molding. Also, a wood chip cement board using a wide and long wood piece in the fiber direction in place of the wood wool is also known in Japanese Utility Model Laid-Open No. 1-87135, and together with the wood wool and wood strip described above, Compared to these, a thin wood chip cement plate obtained by mixing a fine wood chip (a wood chip similar to a planar chip to be described later) with a cement paste and then compressing the same is also disclosed in Japanese Utility Model Publication No. 6-16900.
It is known in the publication. Further, the wood chip cement board is also as specified in JIS.

[0003]

Problems to be Solved by the Invention Wood chips (wood wool, wood chips, wood chips, etc.) including these wood wool cement boards, wood chip cement boards, wood chip cement boards, wood chip cement boards, etc.
A wood cement board made by mixing and compressing one or more of wood chips including planar chips) with cement paste increases mechanical strength such as bending strength and tensile strength, and is lightweight and heat insulating. It is widely used as a base material for roofs and walls, and as a building material under ceilings and tatami mats because of its excellent properties and sound insulation.

[0004] By the way, the wood cement board is prepared by mixing a wood piece into a cement paste with high accuracy and uniformity in order to make the entire board uniform mechanical strength, or a wood piece in order to improve heat insulation and sound insulation. If a plate is formed into a curl and an air pocket is provided inside the board, a special mixing device and a wood chip manufacturing device are required, and the number of manufacturing processes is increased. There is a risk that it will.

The present invention has been made in view of the above circumstances, and has excellent mechanical strength, heat insulation and sound insulation while suppressing the manufacturing unit price, and further has a high holding power for screws, such as a base material for roofs and walls. It is an object of the present invention to provide a method for producing a composite cement board that can be used as a panel or a control panel.

[0006]

In order to solve the above-mentioned problems, a method for producing a composite cement board according to claim 1 is characterized in that rice husks and wood pieces are prepared by mixing rice husks 30% by weight%: wood pieces 70% to rice hulls 40%. : Blended with a cement paste in a mixing range of 60% of wood pieces, the mixture is packed in a predetermined mold, and pressure is applied in the thickness direction of the mixture to produce a plate-like compressed body. Further, it is a method of forming the compressed body by curing and drying.

[0007] According to a second aspect of the invention, in the manufacturing method of a composite cement board according to claim 1, wherein the compressive force applied to the thickness direction of the mixture, the range of 3kg / cm ² ~10kg / cm ² Set to.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a composite cement board according to the present invention.

The composite cement board 2 is manufactured by mixing rice hulls 4, wood pieces 6 and cement paste 8, compressing the mixture, and hardening and drying the whole. The structure shown in FIG. It is formed continuously.

[0010] Mixing ratio of rice husk 4 and wood pieces 6 (% by weight)
Is 30% of chaff: 70% of wood pieces to 40% of chaff: 6 pieces of wood
0% (the sum of the weight ratios is set to 100% in these ranges).

The mixture comprising the rice hulls 4 and the wood pieces 6 is uniformly mixed with the cement paste 8 to form a mixture,
The mixture is filled in a predetermined mold. Here, the mixing ratio (weight ratio%) of the composition and the cement paste 8 is 40% of the composition: 60% of the cement paste to 30% of the composition: 70% of the cement paste (the sum of the weight ratios in these ranges is 10%).
0%).

In the thickness direction of the mixture, 3 kg / c
A composite cement having a bulk specific gravity of 0.6 to 1.5 is obtained by applying a compressive force in the range of m ^{2 to} 10 kg / cm ² to produce a plate-like compact and curing and drying the compact for a predetermined time. A plate 2 is formed.

As shown in FIG. 2, the rice hulls 4 produced by threshing the rice are hulls wrapping rice, cilia 4a are present on the outer surface, and bowl-shaped shell spaces 4b are inside. Is provided. And all the rice hulls 4 are formed from the same kind of rice, and therefore have a substantially uniform shape.

As shown in FIG. 3, the wood piece 4 is elongated in the fiber direction, has a width of about 3 to 5 mm, and has a width of 50 to 50 mm.
Wood wool having a length of about 400 mm, wood chips (not shown) which are wider (about 1 cm) than the wood wool, and whose cross section in the width direction is arc-shaped, or planar chips 4 which are canna waste of electric canna. It is. In addition, the dimensions of the wood wool and wood strips are
It is not limited to the above numerical values.

Here, the present inventor conducted a test on the mechanical properties, heat insulation properties and sound insulation properties of the bending strength and tensile strength of the composite cement board 2 of the above embodiment, and the results shown in Table 1 were obtained. .

In this test, the mixing ratio of the rice husks 4 and the wood pieces 6 was calculated as follows:
0%: a range of 40% of wood pieces, a mixture ratio of this composition and cement paste is 30% by weight of a composition: 30% of cement paste, 70% of cement paste, a compressive force of 8 kg / cm ² , and a plurality of composite cement boards 2 are prepared. Manufactured.

[0017]

[Table 1]

According to the above test results, when the mixing ratio of the rice husks 4 and the wood pieces 6 is in the range of 30% by weight% of the rice husks: 70% of the wood pieces to 40% of the rice husks: 60% of the wood pieces, the heat insulating and sound insulating properties are obtained. And the composite cement board 2 with increased bending strength and tensile strength is obtained.

This factor will be described with reference to FIG. 1. If the mixing ratio is in the range of 30% of rice husk: 70% of wood pieces to 40% of rice husk: 60% of wood pieces in weight%, the thickness direction and the board width direction The rice husks 4 are interposed between the pieces of wood 6 that are entangled in layers, and the cilia 4a on the outer surface of the rice hulls 4 increase the adhesive force to the cement paste 8, so that the cement paste 8 becomes an effective reinforcing material. Thereby, the composite cement board 2 with increased bending strength and tensile strength is obtained. Further, since there are a plurality of shell spaces 4b of the rice hulls 4 into which the cement paste 8 does not enter and an air pool is provided by these shell spaces 4b, heat insulation and sound insulation are also improved.

However, if the mixing ratio of the rice hulls 4 exceeds 40%, the layered entanglement of the wood pieces 6 is reduced and the reinforcing function is weakened, so that the heat insulation and sound insulation are good, but the bending strength is high. And the tensile strength decreases. Also,
When the mixing ratio of the rice husks 4 is less than 30%, the air pool formed by the rice husks 4 is reduced, so that the bending strength and the tensile strength are good, but the heat insulation and the sound insulation are reduced. .

Next, a screw pull-out test was performed on the composite cement board 2 of the above embodiment, and the results shown in Table 2 were obtained. In addition, this test was performed for the rice husk 4
The composition ratio of rice hulls is 40% by weight%: wood pieces 60%, the mixture ratio of this composition and cement paste is 30% by weight of composition: 70% cement paste, and the compressive force is 1 kg / cm ^2. A plurality of composite cement boards 2 were manufactured by changing to １４14 kg / cm ² . Then, a screw having a body having a diameter of 2.5 mm and a length of 50 mm was screwed into the plurality of composite cement boards 2, and a pull-out test was performed. Note that a nail pulling force tester (product number MKS200) manufactured by Maeda Metal Industry Co., Ltd. was used as a screw pull-out measuring device.

[0022]

[Table 2]

According to the above test results, the compressive force was 3 kg / cm ²
The composite cement board 2 with a range of 10 kg / cm ^{2 to} 35 kg / cm ²
It exhibits a high screw pull-out force of 38 kg. This is because when the compression force to produce a composite cement board 2 in the range of ^{3kg / cm 2 ~10kg / cm 2} , and mixed in elastically deformable cement paste 8 chaff 4 and wood pieces 6 with each other, the composite cement When the body of the screw enters the inside of the plate 2, the rice hulls 4 and the wood pieces 6 located around the body of the screw exert an elastic restoring force toward the body of the screw. To generate tightening force. With this tightening force, a pulling force of 35 kg to 38 kg at which the screw cannot be easily removed can be obtained, and the holding force of the screw increases.

Here, the composite cement plate 2 having a compression force of less than 3 kg / cm ² has less chaff 4 and wood pieces 6 around the screwed screw body, and has a smaller screw body. 25kg ~
The pull-out force is as small as 30 kg. Also,
The adhesive force of the rice husk 4 to the cement paste 8 is reduced, and the rice hull 4 is easily peeled off, and the quality of the composite cement board 2 may be deteriorated.

In the composite cement plate 2 having a compressive force exceeding 10 kg / cm ² , the rice hulls 4 and the wood pieces 6 are densely mixed with the cement paste 8 in a state where they cannot be elastically deformed. Even if the part penetrates, the rice husks 4 and the wood pieces 6 do not exert an elastic restoring force toward the body of the screw, and
The pull-out force is as small as 1 kg.

Therefore, the composite cement board 2 of the present embodiment has a rice hull 30
%: Wood piece 70% to rice husk 40%: wood piece 60 in a range of 60%, the wood pieces 6 are entangled in layers in the thickness direction and the board width direction, and the rice husks 4 are interposed between the wood pieces 6. Further, the cilia 4a on the outer surface of the rice hull 4 increase the adhesive force to the cement paste 8 and become an effective reinforcing material of the cement paste 8, so that the composite cement plate 2 having increased bending strength and tensile strength is obtained. In addition, the above-described rice husk 4
And the mixing ratio of the wood pieces 6, there are a plurality of shell spaces 4b of the rice hulls 4 into which the cement paste 8 does not enter. Since the air spaces are provided by these shell spaces 4b, the heat insulation and the sound insulation are good. Become.

Furthermore, a compressive force when manufacturing a composite cement board 2 in the range of ^{3kg / cm 2 ~10kg / cm 2} , mixed with the cement paste 8 as chaff 4 and wood piece 6 is elastically deformed relative to one another When the body of the screw is screwed into the composite cement plate 2, the rice husk 4 and the wood piece 6 located around the body of the screw exert an elastic restoring force toward the body of the screw. Screw holding force increases.

Then, the composite cement plate 2 of the present embodiment
Uses rice husks 4 which are agricultural by-products, so that the cost of raw materials can be reduced. The rice husk 4 is almost uniform in size, and has a cilia 4a having an increased adhesive force to the cement paste 8 and a bowl-shaped shell space 4b in which an air pocket of the composite cement plate 2 is provided. Therefore, special equipment for manufacturing high-quality boards like the wood cement boards shown in the prior art is not required, and the number of manufacturing steps does not increase. Can be greatly reduced.

Although not shown, the chaff 4 and the wood pieces 6
In addition, when the composite cement board 2 is manufactured by blending elastic pieces made of synthetic rubber such as ethylene-vinyl acetate copolymer (EVA), natural rubber, and styrene-butadiene rubber, the holding power of the screw can be further increased. it can.

Further, if pearlite is mixed in addition to the rice hulls 4 and the wood pieces 6, the weight of the composite cement board 2 can be further reduced. In addition to the rice husks 4 and the wood pieces 6, if the incinerated ash of the used cement board is mixed,
At the same time, the cost of raw materials can be reduced.

Further, since the surface of the rice hull cement board obtained by mixing the rice hulls 4 and the cement paste 8 has a smooth finish, the above-mentioned composition comprising the rice hulls 4 and the wood pieces 6 is uniformly mixed with the cement paste 8. When the mixture obtained by mixing the rice husks 4 and the cement paste 8 is layered on the mixture thus formed to form a composite cement board,
A cement board with an improved appearance can be obtained.

[0032]

As described above, according to the method for manufacturing a composite cement board according to the first aspect, since rice hulls, which are agricultural by-products, are used, the cost of raw materials can be reduced. And the rice hulls are almost uniform in size, and moreover, they have a cilia that increases the adhesion to the cement paste and a bowl-shaped shell space that provides an air pocket for the manufactured composite cement. The need for special equipment for producing high-quality boards like the wood cement boards shown in the prior art is unnecessary, and the number of manufacturing steps is not increased. be able to.

Further, in the present invention, the mixing ratio of rice husk and wood pieces is 30% by weight% of rice husks: 70% of wood pieces to 40% of rice husks:
By setting the range of the wood pieces to 60%, the wood pieces become entangled in layers in the thickness direction and the board width direction, and rice hulls are interposed between the wood pieces, and the cilia on the outer surface of the rice hulls are cemented. Since the adhesive strength to the paste is increased to be an effective reinforcing material for the cement paste, a composite cement board having increased bending strength and tensile strength can be manufactured.

In addition, by setting the mixing ratio of the rice hulls and the wood pieces as described above, there are a plurality of rice husk shell spaces into which the cement paste does not enter, and an air pocket is provided by these shell spaces. Good.

On the other hand, according to the second aspect of the invention, when the compressive force in the range of 3kg / cm ² ~10kg / cm ² to produce a composite cement plates, as chaff and wood piece is elastically deformed relative to one another When mixed with cement paste and screwed into the composite cement plate, the rice husk and wood pieces located around the screw exert an elastic restoring force toward the screw,
It is possible to obtain a composite cement plate having an increased screw holding force.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an internal structure of a composite cement plate of the present invention.

FIG. 2 is a view showing a shape of chaff according to the present invention.

FIG. 3 is a view showing a wood piece according to the present invention.

[Explanation of symbols]

 2 composite cement board 4 rice hull 4a cilia 4b shell space 6 wood piece 8 cement paste

Claims (2)

[Claims] 1. Rice husk and wood pieces are crushed by weight in a
%: 70% of wood pieces to 40% of rice hulls: 60% of wood pieces are mixed into a cement pace, and the mixture is packed in a predetermined mold, and the compressive force is applied in the thickness direction of the mixture. In addition, a method for producing a composite cement board, wherein a plate-like compact is produced, and the compact is hardened and dried. ^2. The method for producing a composite cement board according to claim 1, wherein a compressive force applied in a thickness direction of the mixture is set in a range of 3 kg / cm ^{2 to} 10 kg / cm ² .