JPH0687637A - Production of woody cement molded goods - Google Patents

Abstract

PURPOSE:To provide a woody cement molded goods excellent in strength and durability at a relatively low cost by minimizing the effect of a hardening inhibitor eluted from a wood fine chip. CONSTITUTION:A cement coated wood chip made by forming a cement hardened film on the surface of the wood fine chip is previously produced by mixing the wood fine chip and a high speed cement or super high speed cement with water and curing to harden. The woody cement molded goods are obtained by adding to uniformly mix a cement and water to the cement coated wood chip and curing to harden after molding.

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 wood cement molded product.

[0002]

2. Description of the Related Art A wood cement molded article is known as a building material having excellent fire resistance, workability and durability. The wood cement molded product is manufactured by kneading wood particles such as wool and wood chips, Portland cement and water, press-molding the mixture, and then curing and curing.

[0003] However, depending on the type of wood chips used, a large amount of cement hardening-inhibiting substance is included, so that the curing time becomes long and the strength of the product is lowered. Careful selection of the type of wood chips to avoid this will naturally lead to higher product prices.

In order to solve the above-mentioned problems, a method of mixing and molding ultra-rapid cement, wood chips and water (Japanese Patent Publication No. 55-14827), Portland cement, alumina cement, anhydrous gypsum and / or A method has been proposed in which a cement composition containing hemihydrate gypsum (quick cement), wood chips and water are mixed and molded (Japanese Patent Publication No. 59-18339).

[0005]

These methods using rapid hardening cement or ultra-fast hardening cement improve the productivity by hardening the cement before the hardening inhibitor in the wood chips elutes and by heat hardening. This is the purpose. In these methods, it is possible to cure in a short time (5 to 15 minutes) by heating and pressing, so that the productivity is significantly improved.

However, these rapid-hardening cements and ultra-quick-hardening cements are more expensive than general Portland cements, and this leads to an increase in product price, so that they are practically difficult to use.

[0007]

DISCLOSURE OF THE INVENTION The present invention aims to eliminate the drawbacks of these conventional methods, and in particular, minimizes the effects of hardening inhibitors that are eluted from wood chips, and is excellent in strength and durability. The purpose is to provide a cement molded product at a relatively low cost.

That is, the present invention provides a method for producing a wood cement molded product by molding and curing a kneaded product containing wood chips, cement and water, in which wood chips, rapid hardening cement or ultra-rapid hardening cement, and water are mixed. By pre-manufacturing a cement-coated wood piece in which a cement hardened coating is formed on the surface of the wood strip by curing and hardening, cement and water are added to the cement-covered wood piece to form a uniform mixture, and then cured. It is characterized by being hardened.

In the practice of the present invention, a cement-coated wood chip comprising a wood chip, a quick-hardening cement or a super-hardening cement, and water for curing and curing to form a cement-hardening coating on the surface of the wood chip. Are manufactured in advance.

The cement used in the production of the cement-coated wood chips is a quick-hardening cement or a super-fast-hardening cement except for ordinary Portland cement. Of course, these mixed cements may be used. Further, a curing accelerator may be further added. Calcium chloride, water glass, aluminum chloride, ferric chloride and the like are known as hardening accelerators.

In the production of cement-coated wood chips, water may be added to the wood chips and the mixture may be stirred, and then powdered rapid hardening cement or ultra-rapid hardening cement may be added and mixed. Hard cement or ultra-rapid cement may be added.

[0012] As described above, since the rapid hardening cement or the ultra-quick hardening cement is used for the production of the cement-coated wood chips, the cement hardening is completed and the cement hardening film is formed on the surface before the cement hardening inhibiting components in the wood chips are eluted. It is possible to eliminate the influence of the cement hardening inhibiting component formed on the molded article.

The cement-coated wood chips obtained are then mixed with cement and water. The method of adding and mixing may be carried out by adding water to the cement-coated wood chips and then mixing them, or by mixing cement and water to prepare a cement slurry and then adding and mixing the cement-covered wood chips thereto. good. Alternatively, the cement-coated wood chips may be wetted with water, then the cement powder is added and mixed, and further an appropriate amount of water may be added and mixed.

As the cement used in this step,
Any of various cements such as ordinary Portland cement, rapid hardening cement, ultra-quick hardening cement and thermosetting cement can be selected and used. Further, the same curing accelerator as described above may be further added.

When ordinary Portland cement is used, it is naturally cured. A slowing agent may be added to adjust the usable time of the slurry.

Depending on the cement used, it can be hardened by hot pressing.

In the wood cement molded product thus obtained, the wood chips, which have low mechanical strength by themselves, are reinforced by the formation of the cement hardened coating film to fulfill the function as an aggregate and to prevent the hardening inhibitory component. To prevent elution.

[0018]

[Function] The hardening inhibitor is sealed by the cement hardening film existing on the surface of the wood chips, and the influence on the structure which gives the structural strength of the molded product is prevented.

[0019]

[Example] A cement coated with a hardened cement coating, which was added by adding a quick-hardening cement in a weight ratio of 1: 0.5 to 1 and an appropriate amount of water to wood chips and mixing and curing for 4 hours. A coated piece of wood was obtained.

The weight ratio to the cement-coated wood chips is 1:
0.5-2 rapid-hardening cement and an appropriate amount of water are added and mixed, and the mixture is sprinkled to form a mat of the mixture.
100 ° C., pressure 10 to 25 lkg / cm ² , clamping time 5
Heating and pressing in ~ 20 minutes, specific gravity 0.8 ~ 1, bending strength 12
A wood chip cement board of 0 to 200 kg / cm ² was obtained.

The wood chip cement board obtained has a bending strength of 10 to 10 as compared with the wood chip cement board obtained by the conventional method.
It was improved by 20%.

The structure of this cement board is schematically shown in FIG. The wood chips 1 are coated with a hardened cement coating 2 to form cement-coated wood pieces, and a cement matrix 3
Many are mixed in.

[0023]

According to the method of the present invention, since the wood chips are previously coated with the cement hardening coating, the influence of the hardening inhibitor can be minimized.

Since rapid hardening cement or ultra-quick hardening cement is used as the cement for covering the wood chips, it is possible to
That is, before the hardening inhibitor elutes from the wood chips, the cement coating covering the wood chips is hardened and formed, and hardening inhibition is not substantially caused.

Although rapid-hardening cement and ultra-fast-hardening cement are more expensive than ordinary Portland cement, they are used to form a cement-hardening coating that covers the surface of wood chips, and form the matrix of the molded article. Normal Portland cement can be used for the part, which does not significantly increase the product cost.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of the structure of a wood cement molded product manufactured by the method of the present invention.

[Explanation of symbols]

 1 Wood strip 2 Cement hardening film 3 Cement matrix

Claims (2)

[Claims] 1. A method for producing a wood cement molded product by molding and curing a kneaded material containing wood chips, cement and water, wherein the wood chips, the rapid hardening cement or the super quick hardening cement, and water are mixed and cured. A cement-coated wood piece is formed in advance by hardening so that a cement hardened film is formed on the surface of the wood strip, and cement and water are added to the cement-coated wood piece to form a uniform mixture, followed by curing and curing. A method for producing a wood cement molded product characterized by: 2. The method for producing a wood cement molded product according to claim 1, wherein a cement hardening accelerator is added to wood chips, Portland cement and water in the production of the cement-coated wood chips.