JP3515099B2 - Method for producing wood-based composite material - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood-based composite obtained by binding wood-based materials with a binder, and a method for producing the same. 2. Description of the Related Art Slender pieces of wood material (chips) having a binder attached thereto are aligned in the longitudinal direction, are laminated, form a mat, and the mat is pressed and heated. It is known that wood-based composites can be obtained. Woody
The bending strength is increased by orienting the material pieces (chips) (for example, Patent Document 1). Examples of the woody material obtained by binding the above wood pieces with a binder include a particle board, an MDF, and a hard board. However, the above-mentioned wood-based material is a renewable resource material because the used wood material pieces are composed of plant resources, but the binder is generally a phenol resin, a melamine resin, a urea resin, an isocyanate resin, or the like. These petroleum resins are not renewable natural resources, and cannot be said to be recyclable materials. A wood mat formed by laminating a mixture of an elongated wood material piece and a binder while orienting the mixture in one direction is placed on a conveyor such as a belt conveyer, and is sent to a press machine. Although it is conveyed, there has been a problem that the orientation is disturbed by the vibration during the conveyance, the lamination is broken, and the physical properties of the molded article are deteriorated. [Patent Document 1] Japanese Patent Application Laid-Open No. 63-107507 (first
SUMMARY OF THE INVENTION [0005] The object of the present invention is to eliminate the problems of conventional wood-based structural materials, to be able to be sufficiently used as structural materials, and to make all the constituent raw materials from natural resources. To provide a method for producing a wood-based composite material. SUMMARY OF THE INVENTION The present invention provides a dismantling waste material,
Pallet wood, thinned wood, offcuts generated during sawing, fuel and
Recycled materials such as wood materials used as raw materials for paper broke down
Crushed by crusher, length is 20 ~ 150mm, thickness is
Using wood material pieces classified to 1 to 15 mm,
Add a curing agent to the piece and tannin alone or tannin as the main agent
Adhesive natural consisting of tannin adhesive used in combination
Mixed with the binder of the material component to form a long and thin piece of wood.
The wood mat is made by laminating the hand in one direction.
The wood mat is placed on a conveyor and pressed.
The wood mat is heated by a press machine.
It is characterized in that for coupling with each other woody material pieces by pressure
Manufacturing method of wood-based composite material . [0007] The binder is composed of a natural product component, and examples thereof include those obtained by purification, extraction, modification and the like from the natural product component or the natural product. Specifically, gelatin, casein glue, soy glue, glue, protein adhesives such as albumin, starch, dextrin, rice paste, starch adhesives such as glucomannan, animal adhesives such as chitin and chitosan, cellulose Adhesives, lignin adhesives, tannin adhesives and the like. These adhesives may be used alone or in combination. [0008] In particular, tannin-based adhesives are preferred because they are components extracted from natural wood, so they have good affinity with wood material pieces , have moderate tackiness, and have high strength when cured. . Tannin-based adhesive may be used to cure by heating or the like used in tannins alone, in the Application for which durability is required, combined aldehyde compound and isocyanate compound, a crosslinking agent such as epoxy Is preferred. The tree species from which the tannin-based adhesive is extracted is not particularly limited, but those extracted from radiata pine, black wattle, mimosa, quebracho, and chestnut are preferred. When the tannin extracted from wood is solid, it can be used by dissolving or dispersing it in water or an organic solvent as needed. The tackiness of a binder made of a natural component having tackiness means a property in which pieces of wood material that come into contact with each other are difficult to peel or move due to sticking of the binder. In the inclined ball tack test described in JIS Z 0237, it is preferable that the ball number at an inclination of 30 degrees shows a numerical value of 2 inches or more. [0010] As a raw material species of the above-mentioned wood material pieces, cedar,
Examples include conifers such as hinoki, pine, spruce, and fir, and broadleaf trees such as birch, apiton, sengonglaut, and aspen. Plant materials such as bamboo and kouriang can be included in addition to these trees. Examples of usable forms include raw materials such as logs of the above tree species, thinned wood, scrap materials generated at factories and house construction sites, waste pallet materials discarded after transporting members, demolition waste materials generated during building demolition, and the like. Is mentioned. In particular, recycled materials such as demolition waste materials, waste pallet materials, thinning materials, offcuts generated during lumbering, and wood materials used as fuels and raw materials for papermaking are preferred. As a method of processing the above-mentioned raw material into an elongated piece of wood, there are a hammer mill, a uniaxial crusher for crushing wood by rotating a roll with a blade on its surface, and a biaxial or multiaxial structure having a rotating blade meshed. A crusher such as a shaft crusher is used, but a rotary cutter which cuts veneer into chopsticks and turns it into a stick, and a flaker which turns a log or the like with a rotary blade into a strand and the like can also be used. In particular, when a recycled material is used as a raw material, a crusher is preferable in that foreign materials are easily mixed and the durability of the blade is high. [0013] Since the long and thin wood pieces obtained by the above method vary in size, a predetermined size wood piece is obtained by the classification step. As a classification method at this time,
There are a roller screen method, a vibrating mesh method, a wind selection method, and the like, and these may be used as needed. An elongated wood piece has a length of 20 to 150 mm and a thickness of 1 to 15 mm. [0014] It is preferable that the classified elongate wooden material pieces are adjusted to have a predetermined moisture content. By keeping the water content constant, there is no quality variation of the molded product during production.
The preferred water content is 0 to 14%. [0015] The classified and controlled moisture content of the elongated pieces of wood is mixed with the binder. The mixing amount of the binder is
The density of the wood material pieces, shapes, depending on the surface condition, usually based on the weight of the wood material pieces, preferably 1 to 20 wt%. Examples of the mixing means of the woody material pieces and a binder, a method of mixer put into mixing such as Henschel mixer and a binder wood material pieces and the like, if the binder is a liquid Ya on the conveyor Wood inside the drum blender
When a binder is attached to the surface of the wood piece by using an application means such as a spray on the piece , a structural material having uniform and stable strength can be obtained. The mixture of the wood material pieces and the binder is laminated while being oriented in a certain direction to form a wood mat. Specifically, it can be carried out by putting pieces of wood material into a mold and stacking them. The term “orientation in a certain direction” means that the fiber direction of the wood chip is oriented at an average angle of less than 20 degrees with respect to the longitudinal direction of the formed wood-based composite material. In order to orient in one direction, an orientation laminating apparatus such as a forming mold divided at a fixed interval or a disk orienter used in manufacturing an oriented strand board (OSB) or the like is used. After the formation of the mat, the mat is put into a press apparatus which can be heated and pressed and heated. Heating and pressurizing may be performed simultaneously, or may be performed after pressurizing,
Pressurization may be performed after heating. Examples of the press device include a method of transmitting heat to the inside by heat transfer from the surface of a piece of wood material such as a hot plate, and a method of directly heating the inside such as steam injection or high-frequency heating. (Example 1) A wood-based composite material was formed by the following manufacturing process. An elongated piece of wood material is obtained by cutting a board chip (crushed by a uniaxial crusher) purchased from a wood waste disposal company using a roller screen type wave roller screen device (manufactured by Taihei Co., Ltd.) with a thickness of 1 to 8 mm. Wood chips were classified. After adjusting the water content of the above-mentioned wood chips to 6%, a cellulose-based adhesive (trade name "Auro wood part adhesive", manufactured by Genro Chemical Industry Co., Ltd.) was used as a binder in an amount of 10% by weight based on the wood chips. Into a drum blender and mixed. Next, the blended binder and wood chips were removed by OSL.
Put into a forming machine (manufactured by Taiheisha Co., Ltd.) and form a forming mold (2000 mm long, 500 mm wide, 1 height)
00 mm). In the forming mold, a metal partition plate (thickness: 2 mm) was used, which was divided into 10 equal parts at 50 mm intervals, and oriented and laminated in one direction. Next, the forming mold and the partition plate were released, and the mat was put into a press. The die of the press machine is 2500 mm long, 500 mm wide and 150 mm high.
The press machine was a heat transfer type, and a 300 t press manufactured by Kawasaki Yuko was used. Pressing is performed at a heating temperature of 180 ° C. and a pressure of 3 MPa for 20 minutes, and the final shape of the molded product is 2000 mm × 500 m.
An mx 30 mm plate-shaped molded body was obtained. When the bending strength of the formed compact was measured, it was 25 MPa. (Example 2) The same as Example 1 except that a tannin-based adhesive was used as a binder. As a tannin-based adhesive, a curing agent (a mixed solution of 57% formaldehyde, 23% urea, and 20% water) was used in 6 parts with respect to 100 parts of a main agent (40% aqueous solution of natural tannin). JI tannin adhesive
Measured according to SZ 0237. The ball number was 5 inches. When transporting the wood chip mat to the press machine, it was transported on a trolley at a distance of about 10 m,
Due to the adhesive property, no noticeable disorder of the orientation and stacking collapse at the end portions occurred. When the bending strength of the formed compact was measured, it was 41 MPa. (Comparative Example) The same as Example 1 except that an isocyanate-based adhesive was used as a binder. The tackiness of the isocyanate-based adhesive was measured according to JIS Z 0237. The ball number was 2 inches. When transporting a wood chip mat to a press machine, if it is placed on a trolley for a distance of about 10 m, it will not be sticky, so the orientation will be disturbed over the entire mat, and significant stacking collapse will occur at the edges. Occurred. When the bending strength of the formed compact was measured, it was 33 MPa.
Met. According to the present invention, the recycled material is crushed by a crusher.
And classified long wooden pieces and tan which is a natural ingredient
Mix wood materials together with a binder consisting of a nin-based adhesive
To obtain wood-based composites of natural resource type using renewable resources as raw materials
In addition, the obtained wooden composite can have sufficient strength to be used as a structural material. In addition, if the binder having a tackiness made of a tannin-based adhesive is used , when the wood chip mat is conveyed to the press machine, no noticeable disorder of the orientation and the collapse of the stack at the edges occur.

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B27N 3/00-3/28

Claims (1)

(57) [Claims] [Claim 1] At the time of demolition waste material, waste pallet material, thinning material, lumber
Wood used as scrap material, fuel and raw materials for papermaking
Quality material and other recycled materials are crushed by a crusher and the length is 2
Wood that is classified into 0 to 150 mm and 1 to 15 mm in thickness
Using wood material pieces, the wood material pieces and tannin alone or with the main agent
Tannin-based adhesive combining hardening agent with tannin
Mixed with natural binders with natural adhesive properties
The long and thin pieces of wood are oriented in one direction in the longitudinal direction.
The wood mat is formed by stacking
Put the unit on the conveyor and put it into the press,
The wood pieces by heating and pressing
Method of producing wood-based composite material characterized by binding
Law .