JP2603881B2 - Composite plate and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a composite board used as a building material or a member for furniture, and a method for producing the same.

<Prior art and its problems> Wood boards, which are generally called sawn timber, plywood, and veneer laminates (LVL, LVB), are used in a wide variety of applications as architectural and furniture components. Since it has a fiber direction, it expands and contracts with the absorption and release of water, and particularly has a large expansion rate in a direction perpendicular to the fiber direction and lacks dimensional stability. Further, since there is a conduit hole on the surface, there has been a problem that it is necessary to perform a base treatment such as a sealer treatment and a sealing treatment at the time of processing such as surface painting and paper sticking.

Recently, due to the depletion of high-quality wood, such wood boards have tended to increase in price. For this reason, wood chipboards made by bonding small pieces of wood have attracted attention as a material that is inexpensive and suitable for effective use of resources. Has been done.

However, since the wood chipboard is obtained by bonding wood chips, the surface is very rough, and it is difficult to apply makeup to the surface. In general, it is necessary to apply a thick decorative sheet to perform surface makeup, which is expensive. In addition, the surface peel strength is low, and since it is a collection of wood chips with individual fiber directions, expansion and contraction due to absorption and release of moisture is remarkable, and peeling and cracking of the decorative sheet attached to the surface for makeup purpose Easy to occur. Furthermore, since a large amount of an adhesive such as a urea resin and a phenol resin is used when attaching a decorative sheet material, a strong formalin odor remains, and when used for furniture, etc., this formalin odor remains in the furniture. Was.

As an improvement of such a wood chip board, there is known a so-called three-layer board in which the wood chips of the surface layer are fine and thin, and the wood chips of the center layer are coarse. When compared with a single-layer wood chipboard, the three-layer board has a certain degree of smoothness on the surface and can contribute to an improvement in bending strength. It is not possible to eliminate the general disadvantages. Furthermore, if the wood chips in the surface layer are made short (fine) and thin in order to enhance the smoothness of the surface layer, the binding force due to the entanglement between the wood chips becomes small, and in order to maintain the same bending strength, There was a problem that a large amount of adhesive was required.

<Means for Solving the Problems> In view of such a situation, the present invention has been devised after elaborate devising for the purpose of solving the above-mentioned problems in wood chipboard.

That is, according to the present invention, at least on the surface, a wood fiber layer in which a nonflammable inorganic compound is filled, adhered, or fixed to the inside and / or the inner wall surface of the wood fiber and / or the outer periphery of the wood fiber is disposed. And a wood chip layer laminated on the wood fiber layer. Such a wood fiber layer may be provided on both front and back surfaces, and a wood chip layer may be provided between the wood fiber layers on the front and back surfaces to form a composite board. The wood chip layer is a wood chip layer in which a non-combustible inorganic compound is filled, adhered, or fixed to the inside of the cell hole and / or the inner wall surface of the cell hole and / or the outer peripheral portion of the wood fiber in the wood chip. be able to.

The method for producing a composite board according to the present invention is obtained by fibrillating wood, and comprises a non-combustible inorganic compound in the cell pores and / or the inner wall surface of the cell pores and / or the outer periphery of the wood fiber. A wood fiber mat layer formed by adding an adhesive to wood fibers filled or adhered or adhered or fixed is disposed on both front and back surfaces, and between these front and back wood fiber mat layers, wood is cut. It is characterized in that the wood chips are laminated so that a wood chip mat layer obtained by adding an adhesive to the wood chips is arranged, and then pressed and integrally bonded.

The composite board according to the present invention has, for example, the structure shown in FIG. 1 and has the wood fiber layers 1a and 1b on which the front and back surfaces have been made nonflammable.
Are arranged, and the wood chip layer 2 is arranged between the front and back wood fiber layers 1a and 1b to be laminated and integrated.

The wood fiber layers 1a and 1b are, for example, lauan, kapole, chestnut,
After chipping hardwood such as poplar or softwood such as pine, cedar, cypress, etc., the wood fiber obtained by defibrating in accordance with a conventional method is used to obtain the inside of the cell pore and / or the inner wall of the cell pore and / or It is composed of non-combustible wood fibers obtained by performing a non-combustible treatment by filling, adhering, or fixing a non-combustible inorganic compound to the outer periphery of the wood fibers.

The wood chip layer 2 uses wood chips that have been cut and crushed using small-diameter wood, sawn wood, raw wood cores, wood chips and the like as raw materials.
If necessary, it is composed of wood chips that have been made non-combustible in the same manner as wood fibers.

The method for producing a composite plate of the present invention will be described below with reference to FIG. The wood fiber production line and the wood chip production line produce wood fibers and wood chips to which an adhesive is added, respectively, and the wood fiber layer mat to which the adhesive is added is arranged on the front and back surfaces, After laminating the wood chip layer mat between the front and back wood fiber layer mats, the composite board of the present invention is manufactured by pressing and bonding and integrally molding. Hereinafter, each step will be described in detail.

Wood fiber production line For example, one or more species of softwood such as pine, cedar, toga, cypress, or hardwood such as lauan, kapole, apiton, cruin, chestnut, poplar, willow, etc. This is steamed under high-temperature and high-pressure steam to be defatted and softened, and then defibrated by a defibrating device to obtain wood fibers.
This wood fiber has a length of 1-30mm and a thickness of 2-300μ
Most of them are of the degree. This wood fiber is in the form of a bundle of several to several tens of cell holes made up of wood cells and conduit holes or temporary conduit holes, and the cell wall around the fiber is torn or cracked. Often do. In addition, as the wood fiber, bayas obtained by cutting sugar cane, corn stalks, coconut shells and the like into chips, and then defibrating the chips can be used.

The obtained wood fiber is thrown into a drying device to have a water content of 7
Adjust so that it is about 15%.

The voids such as cell pores and conduit pores of the dried wood fiber are filled with a non-flammable inorganic compound, or the non-flammable inorganic compound is fixed or adhered in a layer along the inner wall of the cell pore, and further, the wood fiber is The non-combustible inorganic compound is fixed or adhered to the outer peripheral portion to perform the non-combustible treatment. This non-combustibility treatment can be performed, for example, by the following steps. That is, the wood fiber is converted into an aqueous solution of a water-soluble inorganic salt (hereinafter referred to as “first liquid”).
) Is sufficiently immersed in the substrate for impregnation. At this time, it is effective to forcibly accelerate the impregnation by applying a reduced pressure or a chemical pressure. Further, the wood fiber is made to have a high water content state without drying, or after being dried, immersed in water or warm water to absorb water and made it saturated, and then immersed in the first liquid for diffusion and impregnation. Is also good. As the first liquid, MgCl ₂ ,
MgBr ₂ , MgSO ₄ .H ₂ O, Mg (NO ₃ ) ₂ .6H ₂ O, AlCl ₃ , AlBr ₃ , Al _{2
(SO 4) 3, Al (} NO 3) 3 · 9H 2 O, CaCl 2, CaBr 2, Ca (NO 3) 2,
Examples include aqueous solutions of ZnCl ₂ , BaBr ₂ , BaCl ₂ .2H ₂ O, Ba (NO ₃ ) _{2 and the} like. By immersing and impregnating the wood fibers in the first liquid, the ions of the inorganic salt of the solute enter the cell pores of the wood fibers by diffusion.

Next, a dewatering process is performed to remove an excess of the first liquid. The dewatering process is performed by means such as centrifugal dewatering or showering, washing with a pile of water, etc., and removal of excess first liquid causes excessive generation of nonflammable inorganic compounds on the surface of the wood fiber. And to improve the diffusion and impregnation of the aqueous solution to be subsequently impregnated. Further, it is possible to prevent the generation of the nonflammable inorganic compound in a free state that is not attached or fixed to the wood fiber.

Next, a compound liquid that reacts with the first liquid to generate a water-insoluble incombustible inorganic compound (hereinafter, referred to as “second liquid”)
Is added to the wood fiber using a blender, spray or the like, or the wood fiber is impregnated with the second liquid to impregnate the wood fiber. As in the case of the first liquid, the impregnation of the second fiber with the wood fibers can be promoted by the decompression or pressure treatment. As the second liquid, NaCO ₃ , H ₂ SO ₄ , (N
_{H 4) 2 CO 3, Na} 2 SO 4, (NH 4) 2 SO 4, H 2 PO, Na 2 HPO 4, (NH 4) 2 H
PO ₄ , H ₃ BO ₃ , NaBO ₂ , NH ₄ BO _{2 and the} like are exemplified. The second liquid is applied or immersed in the cell pores of the wood fibers so that the second liquid
The liquid is diffused and impregnated, and the first liquid and the second liquid react in the wood fiber to generate a nonflammable inorganic compound. The resulting non-combustible inorganic compounds include magnesium phosphate, calcium phosphate, barium phosphate, aluminum phosphate, magnesium borate, magnesium carbonate, calcium carbonate,
Examples thereof include calcium compounds such as zinc phosphate, barium carbonate, calcium nitrate, and barium nitrate, magnesium compounds, aluminum compounds, barium compounds, lead compounds, zinc compounds, and silicate compounds. For example, when barium chloride is used as the first liquid and ammonium hydrogen phosphate is used as the second liquid, barium cation and phosphoric acid anion react to form barium phosphate and barium hydrogen phosphate. Is done.

After the completion of the reaction, the excess second liquid is removed by dewatering by means of centrifugal dewatering or washing with water such as showering or soaking. The immersion treatment and the liquid removal treatment of the second liquid may be repeatedly performed as necessary. After the deliquoring treatment, it is dried to a water content of 25% or less, preferably 7 to 15%.
Since this incombustible inorganic compound is water-insoluble, it is filled or adhered or adhered to the inside of the cell pore or the inner wall of the cell pore of the wood fiber after drying, and also adhered or fixed to the outer periphery of the wood fiber. As a result, the non-combustible inorganic compound is present in a form that blocks or fills voids and cracks that appear on the surface of the wood fiber.

It is preferable that the non-combustible inorganic compound is mixed at a rate of 33% by weight or more based on the wood fiber. If the amount is less than this, sufficient fire protection performance cannot be obtained. In order to increase the reaction efficiency between the first liquid and the second liquid, the addition and mixing of the second liquid is preferably performed in a heated atmosphere, particularly at a temperature of 40 ° C. or higher, more preferably 50 ° C. or higher. In addition, the first liquid and the second liquid are put into a warm water state, and the wood fiber is immersed in the first liquid and the second liquid.
When electric or mechanical vibration is applied by ultrasonic waves or a vibrator at the time of immersion of the liquid, diffusion and reaction of the processing liquid into the wood fibers can be performed well. The order of treatment with the first liquid and the second liquid does not matter, and the treatment with the second liquid may be performed first.

Thus, the noncombustible inorganic compound is fixed to the inside of the cell pore or the inner wall surface, and the noncombustible inorganic compound is also fixed or adhered to the outer peripheral portion thereof, so that the noncombustible wood fiber is obtained.

Next, the non-combustible wood fiber is put into a mixing device, and an adhesive is added and adhered. In the mixing device, optional additives such as a water generating agent and a smoke reducing agent can be simultaneously mixed as needed. Further, when the same type or different types of non-combustible inorganic compounds produced by the reaction of the first liquid and the second liquid are mixed into the adhesive and used, the fire prevention performance can be further improved. The adhesive is preferably a synthetic resin adhesive such as a urea resin adhesive, a phenol resin adhesive, a melamine resin adhesive, an epoxy resin adhesive, an isocyanate / vinyl acetate resin adhesive, or a modified resin thereof. Used for

The non-combustible wood fibers to which the adhesive is attached are put into a hot air duct, and are dried while being transported by air. The blowing speed at this time is about 15 to 20 m / sec, but can be adjusted over a wide range depending on the specific gravity of the wood fiber, the feeding amount, the processing capacity of the preceding and following steps, and the like.
With this hot air conveyance, the water content of the wood fibers is about 6 to 15%.

The dried wood fibers are conveyed to forming devices 3a and 3b (FIG. 3).

Wood chip production line A small piece of wood is obtained by cutting and crushing small-diameter wood, sawn wood, sawn wood core, waste wood chips and the like as raw materials, and then secondary crushing as necessary. The obtained small pieces of wood are sorted and adjusted to a uniform size and shape, and dried until the water content becomes 6 to 15%.

After the obtained wood chip is subjected to a non-combustible treatment by the same method as that for the wood fiber, if necessary, an adhesive is added and mixed. The adhesive used at this time may be the same as the one added and mixed with the wood fiber. The wood chips to which the adhesive has been applied are dried as necessary, and then conveyed to the forming device 4 (FIG. 3).

Forming-Hot pressing The wood fibers and wood chips conveyed to the forming devices 3a, 3b, 4 by the respective production lines are deposited on the conveyor 5 as shown in FIG. 3, and the front and back layers are made of the wood fiber layer 1a. , 1b and a three-layer mat 10 having a wood chip layer 2 at the center. After the three-layer mat 10 is cut into an appropriate size by the cutting machine 6, it is sent to the hot press machine 8 by the conveyor 7,
The composite plate of the present invention is manufactured by hot pressing.

Further, the composite board of the present invention produces a wood fiber board from the wood fiber which has been made non-combustible in the above-described manner, and if necessary, manufactures a wood chip board from the wood chip which has also been made non-combustible. After laminating these wood fiber boards and wood chipboard with a urea resin-based, phenolic resin-based or water-based vinyl urethane-based adhesive at least on the front surface or front and back sides so that the wood fiber boards are arranged, hot It can also be manufactured by pressing and bonding with a press.

In the composite board obtained by bonding and integrating the wood fiber board and the wood chipboard, the wood fiber layer has a specific gravity of 4.0 or less (soft fiber board) by adjusting the temperature, pressure and time of the heat and pressure in the manufacturing process, It can be arbitrarily selected from 0.4 to 0.8 (medium fiber board) and 0.8 or more (hard fiber board). Similarly, in the wood chip layer, the specific gravity is adjusted to about 0.3 (light wood chip board), 0.4 to 0.8 (medium wood chip board) and 0.8 by adjusting the temperature, pressure and time of the heat and pressure during the manufacturing process. ~ 1.05
(Hard wood chipboard) can be arbitrarily selected. Therefore, for example, a hard fiberboard having a specific gravity of 0.8 or more is used as the front and back wood fiber layers 1a and 1b, and a specific gravity of 0.4 is used as the intermediate wood chip layer 2.
~ 0.8 medium wood chipboard is selected, and these are laminated and integrally formed into a composite board, when an external force is applied to the surface, the compressive strength of the high specific gravity wood fiber layer 1a on the front side and the back side Combined with the tensile strength of the wood fiber layer 1b and the binding force of the wood fiber layer, an excellent bending Young's modulus (rigidity) can be obtained, and a lightweight and strong composite board can be obtained. in this way,
The composite board according to the present invention, by freely selecting the specific gravity of the wood fiber layer and the wood chip layer, and further adjusting their thickness,
A composite plate having strength and weight required according to the application can be obtained.

<Example> Production of wood fiber Radiata pine chips were degreased and softened by boiling at 160 ° C and 7 kg / cm ² for 5 minutes. The chips were defibrated by a defibrator type refiner, and the obtained wood fibers were dried.

The wood fiber was immersed in a 30% aqueous barium chloride solution for 10 minutes, subjected to diffusion treatment, and then drained. This was dried with hot air to adjust the water content to 7%. The wood fiber is put into a blender, and a 40% aqueous solution of ammonium phosphate is added and mixed, and water-insoluble barium phosphate and barium hydrogen phosphate are added to the inside of pores such as cell holes of the wood fiber or the outer periphery of the wood fiber. After the incombustible inorganic compound was formed, it was drained, washed with water, and dried with hot air to a water content of 6%. The weight increase rate of the wood fiber by this non-combustible treatment was 40%.

The non-combustible wood fiber was put into a blender, and a 4% wax sizing agent and a 10% phenol resin adhesive were added and mixed in the blender based on the amount of the wood fiber, and then conveyed to a forming device.

Production of wood chips Raw radiata pine wood and waste materials were put into flakers to obtain flake-shaped wood chips. After drying this wood chip, it was sorted to obtain a suitable flake-shaped wood chip. After subjecting this wood chip to non-combustible treatment in the same way as for wood fiber,
The mixture was put into a continuous mixer, and 1% of a wax sizing agent and 8% of a phenol resin adhesive were added to and mixed with the amount of wood chips in the mixer, and then conveyed to a forming device.

Mat forming, hot pressing On a screen conveyor, a first wood fiber forming device, a wood chip forming device, and a second wood fiber forming device are installed in this order from the downstream side in the conveying direction of the conveyor. The wood fibers and wood chips were dropped on the upper surface to form a continuous three-layer mat in which wood fibers / wood chips / wood fibers were sequentially deposited from the surface side.

After cutting this mat to its specified width and length,
It is put into a hot press and hot pressed at 200 ° C for 5 minutes.
The front and back wood fiber layers are each 5 mm, the center wood chip layer is 15 mm,
A composite plate having an overall thickness of 25 mm and a size of 3 ′ × 6 ′ was obtained.

The specific gravity of the wood fiber layer in the obtained composite board is 0.7, the specific gravity of the wood chip layer is 0.5, and the specific gravity of the entire composite board is
0.6.

<Effect of the Invention> Since the composite board according to the present invention uses inexpensive wood chips, and a wood fiber layer is provided on one or both sides of the wood chip layer,
The surface is smooth and good cosmetic properties are obtained. Further, it is excellent in surface peel strength, and can solve problems such as expansion and contraction caused by water absorption and moisture absorption of the wood chipboard. Further, since the wood fibers in the wood fiber layer are subjected to the non-combustible treatment, they are not deteriorated or carbonized by heat, and there is no possibility of ignition for a long period of time. Therefore, it is widely used as a building material or furniture / building member even in places where fire is used, such as in kitchens.
By similarly treating the wood chips in the wood chip layer with non-combustible material, the fire protection performance can be further improved.

In the method for manufacturing a composite board according to the present invention, when a wood fiber board and a wood chipboard manufactured in advance are laminated and bonded to form a composite board, the specific gravity and thickness of each board can be arbitrarily determined in each manufacturing process. Since it can be adjusted, it is possible to easily obtain a composite plate having a weight and strength according to the application.

In addition, the composite board manufactured by the method of adding an adhesive to the wood fiber and the wood chip, forming the laminated mat by hot forming, and forming the laminate mat by hot pressing, in addition to bonding (entanglement) between the wood fibers, Since the bonding between the wood fiber and the wood chip occurs, and the wood fiber layer and the wood chip layer are manufactured simultaneously as a single plate, a very large bonding strength between the layers can be obtained. Further, the thickness of the wood fiber layer and the wood chip layer can be freely adjusted by adjusting the amount of wood fiber and wood chip dropped from the forming machine when forming the mat.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of a composite plate according to the present invention, and FIG.
FIG. 3 is a process diagram showing a method for producing a composite plate according to the present invention, and FIG.
The figure is a side view schematically showing an example of equipment for performing the steps after the forming in FIG. DESCRIPTION OF SYMBOLS 1a, 1b: wood fiber layer, 2: wood chip layer, 3a, 3b, 4: forming device, 8: hot press machine, 10: three-layer mat

Claims (4)

(57) [Claims] At least on the surface, a wood fiber layer in which a nonflammable inorganic compound is filled, adhered or fixed to the inside and / or the inner wall surface of the wood fiber and / or the outer peripheral portion of the wood fiber is disposed. And a wood chip layer laminated on the wood fiber layer. 2. A wood fiber layer in which a nonflammable inorganic compound is filled or adhered or fixed to the inside and / or the inner wall surface of the wood fiber and / or the outer periphery of the wood fiber. A composite board comprising a wood chip layer disposed between the wood fiber layers on the front and back sides. 3. The wood chip layer is filled, adhered or adhered to a cell hole and / or an inner wall surface of the cell hole and / or an outer peripheral portion of the wood chip in the wood chip. The composite board according to claim 1, wherein the composite board is a wood chip layer. 4. A wood fiber obtained by fibrillating wood, wherein a non-combustible inorganic compound is filled or adhered to the inside of the cell pore and / or the inner wall surface of the cell pore and / or the outer periphery of the wood fiber. The wood fiber mat layers formed by adding an adhesive to the fixed wood fibers are arranged on both front and back surfaces, and between these front and back wood fiber mat layers, wood chips are obtained by cutting wood. A method for manufacturing a composite board, comprising laminating wood chip mat layers to which an agent has been added, and then pressing and bonding to integrate.