JP3015987B2 - Manufacturing method of wood cement molding - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a wood cement molded product. [0002] Wood cement moldings are known as building materials having excellent fire resistance, workability and durability. BACKGROUND ART A wood cement molded product is manufactured by kneading a piece of wood such as wood wool or a piece of wood, Portland cement and water, press-molding the mixture, and then curing and curing. [0003] However, depending on the type of wood chips used, the curing time is prolonged and the strength of the product is reduced due to the large amount of cement hardening inhibitor. Careful selection of wood strips to avoid this will naturally lead to higher product prices. [0004] In order to solve the above-mentioned problems, a method of mixing and mixing ultra-rapid hardening 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 semi-hydrated gypsum (rapidly hardened cement), wood chips and water are mixed and molded (JP-B-59-18339). [0005] The method using these rapid-hardening cements or ultra-rapid hardening cements involves hardening the cement before the hardening inhibitor in the wood chips elutes, and improving the productivity by heat hardening. The purpose is to improve. In these methods, curing can be performed in a short time (5 to 15 minutes) by heating and pressing, so that productivity is greatly improved. However, these quick-hardened cements and ultra-fast-hardened cements are more expensive than ordinary Portland cements and cause an increase in the price of the products. An object of the present invention is to eliminate the disadvantages of these conventional methods, and in particular, to minimize the effect of hardening inhibitors eluted from wood chips and to reduce the strength and durability. An object of the present invention is to provide an excellent wood cement molded product at a relatively low cost. That is, the present invention relates to a method for producing a wood cement molded product by molding and hardening a kneaded product containing wood chips, cement and water, wherein a wood chip, a rapidly hardened cement or an ultra-rapidly hardened cement and water are mixed. A cement-coated wood piece in which a cement hardened film is formed on the surface of the wood piece by curing and hardening is formed in advance, and cement and water are added to the cement-coated wood piece, uniformly mixed and molded, and then cured. It is characterized by being cured. In practicing the present invention, a cement-coated wood piece having a hardened cement film formed on the surface of the wood piece by mixing wood chips, rapid-hardening cement or ultra-hard cement, and water and curing and hardening. Is manufactured in advance. The cement used in the production of cement-coated wood chips is a rapidly hardened cement or a super-hardened 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 curing accelerators. In the production of cement-coated wood chips, water is added to the wood chips and stirred, and then powdered hardened cement or ultra-rapid hardened cement may be added and mixed. Hard cement or ultra-rapid hardening cement may be added. [0012] As described above, since hard cement or ultra-rapid hardening cement is used in the production of cement-coated wood chips, cement hardening is completed before the cement hardening inhibitory component in the wood chips elutes, and a cement hardened film is formed on the surface. It can be formed and can eliminate the influence of the cement setting inhibitory component in the molded article. [0013] The resulting cement-coated wood pieces are then mixed with cement and water. The method of addition and mixing may be mixed by adding water after mixing the cement with the cement coated wood chip, or by mixing the cement and water to adjust the cement slurry and then adding and mixing the cement coated wood chip. good. Alternatively, a cement-coated wood piece may be wetted with water, then cement powder may be added and mixed, and then an appropriate amount of water may be added and mixed. The cement used in this step includes:
Any one of various cements such as ordinary Portland cement, rapid-hardened cement, ultra-fast-hardened cement, and hot-hardened 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. The useable time of the slurry can be adjusted by adding a retarder. Depending on the cement used, it can be hardened by heating and pressing. In the wood cement molded product thus obtained, wood fragments having low mechanical strength are reinforced by the formation of a cement hardened film, and function as an aggregate. To prevent elution. The hardening inhibiting substance is sealed by the cement hardening film present on the surface of the wood piece, and the influence on the structure which gives the structural strength of the molded article is prevented. EXAMPLE A rapidly hardened cement in a weight ratio of 1: 0.5 to 1 and an appropriate amount of water were added to wood pieces, mixed, cured for 4 hours, and covered with a hardened cement film. Obtained cement-coated wood chips were obtained. The weight ratio of cement-coated wood chips is 1:
0.5-2 hardened cement and an appropriate amount of water are added and mixed, and the mixture is formed into a mat of the mixture by using a spraying device.
100 ° C., pressure 10 to 25 lkg / cm ² , pressing 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 obtained wood chip cement board has a flexural strength of 10 to 10 compared to the wood chip cement board obtained by the conventional method.
It was improved by 20%. The structure of the cement plate is schematically shown in FIG. The wood strip 1 is covered with a cement hardened coating 2 to form a cement-coated wood piece, and a cement matrix 3
Many are mixed in. According to the method of the present invention, the influence of the hardening inhibitor can be minimized because the wood chips are preliminarily covered with the cement hardened film. [0024] Since cement used for coating wood chips is hardened cement or ultra-rapid hardened cement, it can be used in a short time.
In other words, before the hardening inhibitor elutes from the wood chips, the cement coating covering the wood chips is hardened and hardly inhibited from hardening. [0025] Rapid-hardened cement and super-hardened cement are more expensive than ordinary Portland cement, but they are used to form a hardened cement coating on the surface of wood chips and form a matrix of the molded article. Since normal Portland cement can be used for the part, the product cost does not increase significantly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of the structure of a wood cement molded product manufactured by the method of the present invention. [Explanation of Signs] 1 Wood strip 2 Cement hardened film 3 Cement matrix

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C04B 28/02 C04B 18/26 C04B 20/10

Claims (1)

(57) [Claims] In a method for producing a wood cement molded product by molding and hardening a kneaded product containing wood chips, cement and water, a wood chip is prepared by mixing wood chips, rapid-hardening cement or ultra-rapid hardening cement, and water and curing. A wood material characterized in that a cement-coated wood piece in which a cement hardened film is formed on the surface of a strip is previously produced, and cement and water are added to the cement-coated wood piece, uniformly mixed and molded, and then cured and hardened. Manufacturing method of cement molding. 2. The method for producing a wood cement molded product according to claim 1, wherein a cement hardening accelerator is added to the wood chips, Portland cement and water in producing the cement coated wood chip.