JP2022118558A - Small wooden flakes for wooden boards and method for producing the same - Google Patents

Abstract

Kind Code: A1 A wood board A having high strength, excellent dimensional stability and surface properties, and easy to manufacture can be obtained.
SOLUTION: A wooden board A is formed by laminating a large number of small wooden flakes 1, 1, . Each of the small wooden flakes 1, 1, . Only one type having a fiber orthogonal direction dimension d2 (width) along the orthogonal direction of 40 mm or less is used.
[Selection drawing] Fig. 3

Description

TECHNICAL FIELD The present invention relates to a wooden board composed of a large number of small wooden flakes, and relates to a small wooden flake used for the wooden board, and a method for producing the same.

As an existing wooden board, plywood of South Seas such as lauan plywood is well known and widely used. However, in recent years, it has become difficult to obtain plywood made of plywood from the South Seas due to the depletion of raw materials and the prevention of environmental destruction.

Plywood made from domestic coniferous trees poses no problem in terms of raw material depletion, but its surface properties are insufficient, so it is limited to applications that require special strength.

OSB, PB (particle board), and MDF also pose no problem in terms of raw materials. However, although OSB has high strength, its surface properties are not sufficient. PB is inexpensive, but lacks dimensional stability and strength. Although MDF has good surface properties, it does not have sufficient dimensional stability. In addition, OSB, PB, and MDF have a drawback in that their densities are higher than those of plywood made from South Sea wood.

Thus, at present, there is no wooden board that satisfies a plurality of factors such as strength, weight, surface properties, and dimensional stability in addition to the stability of raw materials.

As examples of this type of wooden board, conventionally, those shown in Patent Documents 1 to 4 have been proposed. The wood boards disclosed in Patent Documents 1 and 2 are provided with a core layer in which a large number of wooden flakes are assembled, and a surface layer laminated on at least one surface thereof and in which a large number of wooden flakes are assembled. is. In the wood board of Patent Document 1, the absolute value of the thickness of the wood flakes in the core layer is 0.50 to 1.50 mm, and the absolute value of the thickness of the wood flakes in the surface layer is 0.08 to 0.60 mm. is proposed.

On the other hand, in the technique disclosed in Patent Document 3, a fiber mat is pressure-bonded to the surface of plywood, OSB, laminated wood, or the like, and this fiber mat is compressed to produce a high-density fiber layer, thereby increasing the base material. It is used to fill in the dents on the surface.

In addition, in the decorative floor material disclosed in Patent Document 4, a moisture-proof film having a moisture permeability of 7 g/m ² for 24 hours or less is laminated on the back surface of a wooden base material such as MDF. Even if a low decorative sheet is attached, warping and bending due to the magnitude of dimensional change are suppressed.

JP-A-7-47514 JP-A-7-76004 JP 2019-31104 A JP 2019-107894 A

However, in the wood boards disclosed in Patent Documents 1 and 2, the thickness and size of the wooden flakes constituting the wood board are different between the surface layer and the core layer, and therefore, two types of wood boards are used at the time of manufacture. It is necessary to prepare wood flakes, which inevitably requires time and effort for manufacturing and management. In addition, the wooden board using the wooden flakes described in the above-mentioned patent document has unevenness on the surface, and cannot ensure the surface smoothness that can be used as, for example, a base material for floors.

In addition, the wooden board of Patent Document 3 not only requires time and effort to secondary process the base material, but also has a double structure of the base material and the fiber layer, so it is possible to reduce the thickness of the board. There are limits. In addition, it is not possible to suppress dimensional change due to moisture absorption.

Furthermore, in the decorative material of Patent Document 4, the secondary processing of the base material is not only time-consuming, but also the width of the base material that can be used is restricted by the width of the moisture-proof film.

The present invention has been made in view of the above problems, and its object is to provide a wooden board having a structure in which a large number of wooden flakes are laminated, by improving the wooden flakes themselves so as to obtain wooden flakes of one size. To obtain a wood board having high strength, excellent dimensional stability and surface property and easy to manufacture by using chisel.

In order to achieve the above object, the present invention uses wood flakes whose size including thickness is limited to a very small range in contrast to cutting pieces that are commonly used as OSB constituent materials. Small wooden flakes, whose size is further limited to a minute range, are used as the constituent material. Then, the large number of small wooden flakes are stacked together to form a wooden board.

In the present specification, the term "cut piece" refers to a piece cut from raw wood for OSB applications and generally used as a constituent material of OSB. The "woody flake" according to the present invention is cut from raw wood in the same way as the "cut piece", but refers to a thin piece that is outside the normal thickness range of the "cut piece" and smaller than that. . The "woody flakes" according to the present invention refer to flakes smaller than the "woody flakes" within the same thickness range as the "woody flakes".

Specifically, the first invention is directed to the above small wooden flakes used for a wooden board in which a large number of small wooden flakes having front and back surfaces along the fiber direction are laminated in an aggregated state and bonded together. be.

The wood flakes are characterized by having a thickness of 0.05 to 0.35 mm, a fiber direction dimension along the fiber direction of 40 mm or less, and a fiber orthogonal direction dimension along the direction orthogonal to the fiber direction of 40 mm or less. and The thickness, length and width of the wood flakes are all average values.

In the first invention, the wooden board is constructed by laminating a large number of small wooden flakes in an aggregated state and bonding and integrating each of the small wooden flakes with a thickness of 0.05 to 0.35 mm along the fiber direction. It is a flake with a fiber direction dimension of 40 mm or less and a fiber orthogonal direction dimension of 40 mm or less along a direction orthogonal to the fiber direction.

In this way, wood boards are made by crushing wood flakes having a specific thickness (for example, obtained in a wood flake manufacturing process) in the direction of the fibers of the wood flakes and in the direction perpendicular to the fibers. The thickness of the small wooden flakes is extremely thin and is within a narrow range of 0.05 to 0.35 mm. The variation in thickness is small and the thickness is uniform. In addition, since the length and width of the small wooden flakes are also within a certain range, the wooden board is made homogeneous by gathering the small wooden flakes of uniform size within a certain range. As a result, not only does the strength of the wood board increase, but warpage due to moisture absorption and desorption is less likely to occur, and good dimensional stability comparable to that of plywood made of South Sea wood can be obtained. In addition, since a large number of small wooden flakes are uniform in size, the surface of the wooden board does not have large irregularities unlike ordinary OSB, and the wooden board has excellent surface properties. In addition, since a large number of small wooden flakes of uniform size are collected and laminated, the production thereof is facilitated. In this specification, the surface property of a wooden board refers to the surface property of a wooden board adjusted to the product thickness by a #150 grit sander, for example.

A second invention is a small wooden flake for a wooden board according to the first invention, wherein the small wooden flake has a thickness of 0.15 to 0.25 mm, a fiber direction dimension of 20 mm or less, and a fiber orthogonal direction dimension of 5 mm. It is characterized by having the following elongated shape. This further improves the dimensional stability and surface properties of the wooden board.

A third invention is a method for manufacturing small wooden flakes for a wooden board according to the first or second invention, which manufacturing method comprises a wooden flake manufacturing step for cutting raw wood to produce wooden flakes; and a small wooden flake manufacturing step of pulverizing the wooden flakes obtained in the wooden flake manufacturing step to form small wooden flakes smaller than the wooden flakes.

In the third aspect of the invention, in the wooden flake production process, raw wood is cut to produce wooden flakes, and then in the wooden flake production process, the wooden flakes are pulverized into small wooden flakes smaller than the wooden flakes. is formed. Since the small wooden flakes are produced through the two-step process in this manner, the small wooden flakes can be easily produced.

A fourth aspect of the invention is characterized in that, in the method for producing small wooden flakes for a wooden board according to the third aspect, in the step of producing small wooden flakes, the wooden flakes are pulverized so as to split along the fiber direction. In this way, the woody flakes can be smoothly split to easily form uniform small woody flakes within the target size range, thereby further facilitating the production of the small woody flakes.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a large number of small wooden flakes having front and back surfaces along the fiber direction are laminated in an aggregated state and bonded together to form a wooden board. The thickness of the wooden flakes was set to 0.05 to 0.35 mm, and the dimensions in the fiber direction and the fiber orthogonal direction were set to 40 mm or less. As a result, a large number of small wooden flakes are uniform in size with little variation, and the strength of the wooden board can be increased. It is possible to easily manufacture a wooden board.

FIG. 1 is a cross-sectional view of a wooden board according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the main part of the wooden board. FIG. 3 is an enlarged perspective view schematically showing the small wooden flakes according to the embodiment of the present invention. FIG. 4 is a diagram showing a manufacturing process of a wooden board. FIG. 5 is an enlarged cross-sectional view showing a state in which a wooden board is hot-pressed from a mat, which is an aggregate of small wooden flakes. FIG. 6 is a diagram showing the characteristics of wooden boards in comparison with boards of other materials.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following descriptions of the embodiments are merely exemplifications in nature, and are not intended to limit the invention, its applications, or its uses at all.

FIG. 1 shows a wooden board A according to an embodiment of the present invention. This wooden board A has a density of 500 to 800 kg/m ³ and a thickness of 3 to 12 mm, for example. Among them, the thin type wooden board A with a thickness of 3 mm or more and less than 6 mm is used as an inner wall material for a loading platform of a vehicle such as a truck, a base material for a cushion floor installed indoors, a decorative surface material, and an interior decoration. It is constructed as an interior material such as a building material (riser board, etc.). A medium-thickness type wooden board A having a thickness of about 6 to 12 mm is used, for example, as a soundproof floor base material, a floor base material for shoes, an entrance fixture, and the like. Thus, the wooden board A is used as a substitute material for the existing plywood for baseboards. This wooden board A will be described in detail.

The wooden board A, as enlarged in FIG. The wood flakes 1, 1, . . . have one kind of thickness.

The feature of the present invention resides in the wooden flakes 1 forming the wooden board A. As shown in FIG. 3, the thickness t of the wooden flake 1 is 0.05 to 0.35 mm (0.05 mm or more and 0.35 mm or less). , preferably 0.10 to 0.30 mm (0.10 mm or more and 0.30 mm or less), more preferably 0.15 to 0.25 mm (0.15 mm or more and 0.25 mm or less), still more preferably 0.15 ~0.20 mm (0.15 mm or more and 0.20 mm or less). The characteristics of the wooden board A are determined by the small wooden flakes 1, 1, . . . The thickness of the wooden flakes 1 is an average value. In other words, the small wooden flakes 1 according to the present invention are strands (also referred to as cut pieces in the present invention) that are used as elements (constituent materials) of general OSBs and generally have a thickness of 0.6 to It is about 1.5 mm, but the thickness is thinner than that.

The small wood flakes 1 have fibers 1a, 1a, . It has an elongated shape (strip shape) longer than When the fiber direction dimension d1 is the length and the fiber orthogonal direction dimension d2 is the width, the length d1 is 40 mm or less, preferably 35 mm or less, more preferably 30 mm or less, even more preferably 25 mm or less, still more preferably 10 to 20 mm ( 10 mm or more and 20 mm or less). Also, the width d2 is 40 mm or less, preferably 15 mm or less, more preferably 0.5 to 5 mm (0.5 mm or more and 5 mm or less). Both the length d1 and the width d2 of the wooden flakes 1 are average values. In other words, the small wooden flakes 1, 1, ... according to the present invention are generally 110 mm in length along the fiber direction of the cut piece used as a constituent material of general OSB (150 to 250 mm in the long one). about 1/3 of the length), and the width is generally 15 to 25 mm (long ones are about 1/3 of the length), but the size is smaller than that. Moreover, although not shown, the small wooden flakes 1 according to the present embodiment are obtained by crushing wood flakes (also referred to as post-cut wood flakes) that have been cut from a raw wood, as described later. In order to define something different from the wood flakes after cutting, the wood flakes after cutting are referred to as "small wood flakes".

The species of wood used for the small wooden flakes 1, 1, . . . is not particularly limited. For example, fir materials such as cedar, cypress, Douglas fir, etc., acacia, aspen, poplar, pine (hard pine, soft pine, radiata pine, etc.), birch, rubber (rubber tree), etc., but are limited to these tree species. In addition, various tree species can be used. Various tree species include Todomatsu, Japanese larch, Ezo spruce, Sawara, Hiba, Kaya, Japanese hemlock, Maki, various pine, paulownia, maple, birch (white birch), vertebrate, beech, oak, fir, oak, oak, camphor, zelkova. Japanese timber such as American cypress, American cypress, American cedar, American fir, spruce, hemlock, redwood, etc., Agathis, Terminalaria, Rawan, Meranti, Juncon, Camerele, Calampayan, Amberoi, Melina, Teak, Apiton Any material can be used, such as South Sea timber such as sengonglaut, balsa, cedro, mahogany, lignum vita, acacia manguum, Mediterranean pine, bamboo, sorghum, and chamelele.

Regarding the physical properties of the small wooden flakes 1, the density is preferably 250 kg/m ³ or more, more preferably 300 kg/m ³ or more, more preferably 800 kg/m ³ or less, more preferably 500 kg/m ³ or less, and still more preferably. is 400 kg/m ³ or less. When the density is 250 kg/m ³ or less, the thickness of the mat required to form the wood board A with the same density and strength is increased, and the press pressure related to the hot press treatment in the press molding process is reduced. need to raise.

Although the density of the small wooden flakes 1 may exceed 800 kg/m ³ , it is difficult to obtain such small wooden flakes 1 easily. That is, the upper limit of the density is not limited to 800 kg/m ³ and may be a higher value as long as the small wood flakes 1 exceeding 800 kg/m ³ can be easily obtained.

Also, the moisture content of the small wooden flakes 1 is preferably about 2 to 20%, more preferably 2 to 8%. If the water content is less than 2%, softening takes a long time in the hot press treatment in the press molding process, and the pressing time becomes long, which may reduce the strength.

Moreover, if the moisture content of the small wooden flakes 1 exceeds 20%, it takes time to heat and compress in the same hot-pressing process, and there is a risk that the hardening of the adhesive will be hindered and the strength will decrease. .

A large number of small wooden flakes 1, 1, . However, the orientation of the fiber direction is not essential, and the fiber direction may be randomly oriented. The fiber direction (longitudinal direction) being oriented in the reference direction means that the fibers 1a, 1a, . . . In other words, the fiber directions of the oriented wooden flakes 1, 1, . . . are parallel to each other. Some of the small wooden flakes 1, 1, . . . may include small wooden flakes 1, 1, .

Next, a method for manufacturing the wooden flakes 1 will be described with reference to FIG. At the same time, a method for manufacturing the wood board A from the wood flakes 1 will also be described with reference to FIG. The method for manufacturing the wooden flakes 1 includes a wooden flake manufacturing step P1 and a wooden flake manufacturing step P2. Further, the manufacturing method of the wooden board A further includes an adhesive application step P3, a mat forming step P4, and a heat pressing step P5.

(Wood flake manufacturing process P1)
If necessary, raw wood such as logs and thinned wood is cut short and the bark is removed. A large number of cut pieces (wood flakes after cutting) are formed which are thinner and smaller than the cut pieces normally used. It can also be formed from offcuts, waste materials, and waste pallet materials generated at construction sites and the like. A common cutting device is used. The thickness of the cut piece is adjusted by the speed at which the raw wood is fed into the cutting machine. The wood flakes (wood flakes after cutting) formed by this cutting are different from the small wood flakes 1 constituting the wood board A of the embodiment and are larger in size.

At this time, each wood flake is cut so that the fibers appear linearly on the front and back surfaces, and the cut thickness is the thickness t of the small wood flake 1 . This is because, in subsequent steps, the thickness t of the small wooden piece 1 basically does not change from the thickness of the wooden piece after cutting, and the thickness of the wooden piece after cutting becomes the thickness t of the small wooden piece 1 as it is. be.

(Wood flake manufacturing process P2)
Next, the woody flakes after cutting (woody flakes after cutting) are pulverized using a pulverizer that does not use blades, such as a hammer mill, pin mill, or jet mill, or a pulverizer that uses blades, such as a knife flaker or cutter mill. , smaller than the size of the wooden flake immediately after cutting (the wooden flake after cutting) in the direction orthogonal to the fiber, and small wooden flakes 1, 1, . . . constituting the wooden board A are formed. At this time, when the wooden flakes after cutting are pulverized in the width direction so as to split along the fiber direction (longitudinal direction), elongated small wooden flakes 1, 1, . . . can be produced. In other words, if a force (impact) is applied along the fiber-perpendicular direction to the wood flake after cutting, it is difficult to break, but if a force is applied parallel to the fiber direction, the wood flakes are easily broken. Even if the wooden flakes are curled after cutting, they are divided into flat pieces by pulverizing them.

The direction of the force applied to the cut wooden flakes is not limited to the direction parallel to the fiber direction. When a force is applied in random directions to the wood flake after cutting, the wood flake after cutting usually cracks from the portion where the force is weaker (easier to crack in the direction where the force is weaker). The force that connects the fibers of the wood flakes after cutting (the force in the direction perpendicular to the fibers) is overwhelmingly weaker than the force in the direction of the fibers. ), after cutting, the wooden flakes are split along the fiber direction and shortened in the direction orthogonal to the fibers, and elongated small wooden flakes 1, 1, . . . are obtained.

Moreover, even if there are wood knots in the wood thin piece after cutting, the knots are more fragile than the other portions, so the knots are pulverized into powder and removed in the later sorting process.

In this way, instead of only one step of cutting raw wood, by adding a crushing step after that and going through a two-step process, it is possible to cut wood flakes that are thinner and smaller than the cut pieces to the required size. can easily produce high-strength small wooden flakes 1, 1, . . .

The small wood flakes 1, 1, . . . obtained in the pulverization step are passed through a sieve or the like to sort out (classify) the size of the small wood flakes 1, 1, . As a result, the large number of small wooden flakes 1, 1, . . . are finer and uniform in size and shape. The small wooden flakes 1 are manufactured as described above.

Specific manufacturing conditions in the wooden flake manufacturing step P2 are described below.
(1) Using a hammer mill with a diameter of 320 mm, the cut wooden flakes were pulverized at 1125 rpm (about 1130 m/min) for several seconds (for example, about 1 to 3 seconds). After that, it was screened through a mesh of Φ20 mm, and those that passed through the mesh were designated as small wooden flakes 1, 1, . . . As a result, small wooden flakes 1, 1, . . . which were fine and uniformly uniform in size and shape were obtained.
(2) Using a hammer mill with a diameter of 540 mm, the cut wooden flakes were pulverized at 1500 rpm (about 2545 m/min) for several seconds (for example, about 1 to 3 seconds). After that, it was sorted through a mesh of Φ15 mm, and those that passed through the mesh were designated as small wooden flakes 1, 1, . . . As a result, the small wooden flakes 1, 1, . . . were obtained which were slightly finer than the small wooden flakes 1, 1, .
(3) Using a hammer mill with a diameter of 200 mm, the cut wooden flakes were pulverized at 2000 rpm (1256 m/min) for several seconds (for example, about 1 to 3 seconds). After that, it was screened with a mesh of Φ10 mm to Φ20 mm, and those that passed through the mesh were designated as small wooden flakes 1, 1, . . . As a result, small wooden flakes 1, 1, .

(Adhesive application step P3)
In the manufacturing process P2 of the wooden flakes 1, 1, . . . , a large number of small wooden flakes 1, 1, . , 1, . . . In the first adhesive application step P3, the wooden flakes 1, 1, . . . As the adhesive, for example, an isocyanate-based adhesive can be used, and in addition, for example, an amine-based adhesive such as a phenol resin, a urea resin or a melamine resin, or a natural-based adhesive may be used. Also, a commonly used water repellent agent may be used together with the adhesive.

(Mat forming step P4)
Next, as shown on the left side of FIG. 5, a large number of small wooden flakes 1, 1, . A mat A1 of small wooden flakes 1, 1, . . . For example, when forming a wooden board A with a thickness of 4 mm, the small wooden flakes 1, 1, 1 and 1 with a thickness t of 0.2 mm are arranged so that the thickness (height) of the mat A1 is about 40 mm. pile up.

(Thermal pressing process P5)
Then, the mat A1 is carried into a hot press device and set between the hot plates, and the mat A1 is subjected to hot press processing at a predetermined pressure and temperature by the hot press device to be compressed, and the adhesive is cured. molded together. Thus, the wooden board A shown in FIG. 1 is formed.

At this time, as shown in FIG. 5, the exemplified mat A1 having a thickness of about 40 mm is compressed into a wooden board A having a thickness of 4 mm, for example, and the thickness is compressed to 1/10. The pressing temperature for hot pressing is not particularly limited, but is, for example, 100 to 180.degree. The press pressure for the hot press treatment is, for example, 2 to 4 N/mm ² and the press time is, for example, 1 to 2 minutes. The pressing time varies depending on the thickness of the wooden board A, and may be completed in less than 1 minute or may be completed in 2 minutes or more. Also, a preliminary heat treatment using a heating device may be performed before the hot pressing treatment using the hot pressing device.

In addition, since the small wooden flakes 1, 1, . Variation in the strength of the wooden board A is eliminated. In other words, in a strand board that uses large strands (cutting pieces), for example, an uneven mat containing knots causes thin and low-strength portions partially (spots), resulting in variations in strength, but this is eliminated. Moreover, the thinner the wooden flakes 1, 1, . . . In general, a strand board using large strands (cutting pieces) can increase the strength. It combines the homogeneity and strength of Board A.

Furthermore, the small wooden flakes 1, 1, . Even if the small wooden flakes 1, 1, . . . contain a relatively large amount of moisture, even if they are hot-pressed, steam generated by the evaporation of the moisture smoothly escapes from the mat A1. That is, as shown on the left side of FIG. 5, a large number of minute voids exist between the mutually adjacent wooden flakes 1, 1, . . . in the mat A1. The voids communicate not only in the fiber direction and the fiber orthogonal direction of the small wooden flakes 1, 1, . . . but also in the thickness direction, and are three-dimensionally continuous. Therefore, punctures are less likely to occur when pressurization of the wooden board A is stopped.

Through these steps, a wooden board A having a density of 500 to 800 kg/m ³ and a bending Young's force of 3.5 to 7.0 GPa is formed. As shown in the right side of FIG. 5, this wooden board A has (remains) a large number of three-dimensionally continuous small voids therein. Therefore, the wooden board A is also excellent in air permeability.

In the manufacturing method of the wooden board A, as another step, after the hot pressing step P5, the wooden board A is cured to an equilibrium moisture content, and then the front and back surfaces are ground with a sander to adjust the final thickness. You may provide a process. A commonly used sander can be used, for example, #150 sander. By going through this finishing process, a wooden board A with even better surface properties can be obtained.

The wooden board A preferably has a surface root mean square height Sq of 0.005 to 0.015 μm or an arithmetic mean surface height Sa of 0.002 to 0.007 μm. The surface of the wooden board A refers to the surface of the wooden board A after the finishing process, for example, the surface of the wooden board A adjusted to the product thickness with a #150 sander. The root-mean-square height Sq and the arithmetic mean height Sa are surface roughness parameters representing the surface properties defined in ISO25178. That is, the wooden board A has excellent surface properties by controlling the parameters Sq and Sa, which specify the surface properties, within specific ranges.

The root-mean-square height Sq is a parameter corresponding to the standard deviation of the distance from the average plane, and corresponds to the standard deviation of height. Therefore, the smaller the value of the root-mean-square height Sq on the surface of the wooden board A, the smaller the variation in the size of the irregularities on the surface, and the better the surface properties. Specifically, if the thickness t of the small wooden flakes 1, 1, . . . , and the thickness t of the wooden flakes 1, 1, . . . 008 μm or less, the surface roughness of which is comparable to that of MDF, which has excellent surface properties.

The arithmetic mean height Sa represents the mean of the absolute values of the height differences of each point with respect to the mean plane of the surface. Therefore, the smaller the value of the arithmetic mean height Sa on the surface of the wooden board A, the less large unevenness the surface has and the more excellent the surface properties. Specifically, if the thickness t of the wooden flakes 1, 1, . . . If the thickness t of the wooden flakes 1, 1, ... is 0.25 mm or less (preferably 0.20 mm or less), the arithmetic mean height Sa on the surface of the wooden board A is 0.002 μm or more and 0.005 μm or less. The surface roughness of the wooden board A is even better than that of MDF, which has excellent surface properties.

The surface properties of the wooden board A are not limited to the root mean square height Sq and the arithmetic mean height Sa. It may be specified by the indicated maximum height Sz, kurtosis Sku, or the like.

Therefore, the above embodiment can provide the following effects. The wood board A has an extremely thin thickness t, an average value of 0.05 to 0.35 mm, a fiber direction dimension d1 (length) along the fiber direction of 40 mm or less, and a thickness along the direction perpendicular to the fiber direction. A large number of small wooden flakes 1, 1, .

That is, the single-layer wooden board A is composed of only one type of small wooden flakes 1, 1, ..., and the thickness t of the small wooden flakes 1, 1, ... is extremely thin, with an average value of 0.05. Since the thickness is within a narrow range of 0.35 mm, the thickness t of the large number of small wooden flakes 1, 1, . . . In addition, since the fiber direction dimension d1 (length) and the fiber orthogonal direction dimension d2 (width) of the small wooden flakes 1, 1, . . . The small flakes 1, 1, . . . gather together and become homogeneous. Therefore, not only does the strength of the wood board A increase, warping due to moisture absorption and desorption is less likely to occur, and good dimensional stability comparable to that of plywood made of plywood from the South Seas can be obtained. In addition, since many small wooden flakes 1, 1, . . . Excellent for In addition, since a large number of small wooden flakes 1, 1, .

In particular, the average value of the thickness t of the small wooden flakes 1, 1, ... in the wooden board A is 0.15 to 0.25 mm, the average value of the fiber direction dimension d1 is 20 mm or less, and the average value of the fiber orthogonal direction dimension d2 is 5 mm or less, the dimensional stability and surface properties of the wooden board A are further improved.

FIG. 6 exemplifies the characteristics of the wooden board A according to the present invention in comparison with boards made of other materials. It is as large as lauan plywood, and is superior to lauan plywood in terms of anisotropy in dimensional stability and color tone and color uniformity in terms of surface properties. Moreover, compared with OSB, the wooden board A has uniform bending Young in the vertical and horizontal directions, and is excellent in anisotropy in dimensional stability, smoothness in surface properties, and color tone/color uniformity. That is, the wooden board A has high strength and excellent dimensional stability and surface properties.

In this way, by using the wooden board A, which has high strength, excellent dimensional stability and surface properties and is easy to manufacture, and constructing it as an interior material such as a floor material and a wall material, the interior material and the floor material can be easily manufactured. can be manufactured to

INDUSTRIAL APPLICABILITY The present invention is extremely useful because it is possible to obtain a wooden board which is composed of small wooden flakes of uniform size, has high strength, and has good dimensional stability and surface properties comparable to those of plywood made from South Sea wood. , with high industrial applicability.

A Wooden board A1 Mat P1 Wooden flake manufacturing process P2 Small wooden flake manufacturing process P3 Adhesive application process P4 Mat forming process P5 Heat pressing process 1 Small wooden flake 1a Fiber t Thickness d1 Fiber direction dimension (length)
d2 Fiber orthogonal direction dimension (width)

Specifically, the first invention relates to the above-mentioned small wooden flakes for use in a wooden board in which a large number of elongated small wooden flakes having front and back surfaces along the fiber direction are laminated in an aggregated state and bonded together. is the target.

The small wooden flakes have a thickness between the front and back surfaces of 0.05 mm or more and 0.35 mm or less , a length along the fiber direction of 10 mm or more and 40 mm or less, and a width along the direction perpendicular to the fiber direction of It is characterized by being 0.5 mm or more and 15 mm or less. The thickness, length and width of the wood flakes are all average values.

In the first aspect of the invention, the wooden board is constructed by laminating a large number of elongated small wooden flakes in an aggregated state and by bonding and integrating, and each wooden small flake has a thickness of 0.05 between the front and back surfaces. mm or more and 0.35 mm or less , a length along the fiber direction of 10 mm or more and 40 mm or less, and a width of 0.5 mm or more and 15 mm or less along the direction perpendicular to the fiber direction.

The second invention is the wooden flakes for the wooden board of the first invention, wherein the wooden flakes have an elongated shape with a thickness of 0.15 to 0.25 mm, a length of 20 mm or less, and a width of 5 mm or less. It is characterized by This further improves the dimensional stability and surface properties of the wooden board.

Claims (4)

The small wooden flakes used for a wooden board in which a large number of small wooden flakes having front and back surfaces along the fiber direction are laminated in an aggregated state and bonded together,
A wood board characterized by having a thickness of 0.05 to 0.35 mm, a fiber direction dimension of 40 mm or less along the fiber direction, and a fiber orthogonal direction dimension of 40 mm or less along the direction perpendicular to the fiber direction. Wood flakes. In the wooden flakes for the wooden board of claim 1,
A small wooden flake for a wooden board, characterized by having an elongated shape with a thickness of 0.15 to 0.25 mm, a fiber direction dimension of 20 mm or less, and a fiber orthogonal direction dimension of 5 mm or less. A method for producing wooden flakes for a wooden board according to claim 1 or 2,
A wooden flake manufacturing process in which raw wood is cut to make wooden flakes,
and a step of pulverizing the wooden flakes obtained in the step of producing wooden flakes to form small wooden flakes smaller than the wooden flakes. Production method. In the method of manufacturing the wooden flakes for the wooden board according to claim 3,
A method for producing small wooden flakes for a wooden board, wherein the small wooden flakes are pulverized so as to split along the fiber direction in the small wooden flakes manufacturing process.

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