JP7064630B1 - Wood laminated board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wood laminated board having high strength, excellent dimensional stability and further improved surface properties. SOLUTION: A wood laminated board A is formed by integrating a first wood layer B and a second wood layer C laminated on both sides thereof, and the first wood layer B is a front and back surface along a fiber direction. A large number of first wood shards are laminated and bonded together in an aggregated state, and the first wood shard has a thickness of 0.05 to 0.35 mm and a fiber direction dimension along the fiber direction of 40 mm or less. The dimension of the second wood material layer C along the direction orthogonal to the fiber direction is 40 mm or less, and a large number of second wood pieces having front and back surfaces along the fiber direction are laminated and adhered in an aggregated state. Integrated, the second wood flakes are smaller than the first wood flakes. [Selection diagram] Fig. 1

Description

The present invention relates to a wood laminated board.

South Sea plywood such as Lauan plywood is well known and widely used as an existing wood board. However, in recent years, it has become difficult to obtain South Sea plywood in terms of preventing the depletion of raw materials and environmental destruction, and replacement with other wood boards is being attempted.

Plywood made from domestic coniferous trees has no problem in terms of raw material depletion, but its surface properties are not sufficient, so it is limited to applications that specialize in strength.

OSB, PB (particle board), and MDF also have no problem in terms of raw materials. However, although OSB has high strength, its surface property is not sufficient. PB is cheap, but its dimensional stability and strength are not sufficient. Although MDF has good surface properties, it does not have sufficient dimensional stability. Further, OSB, PB, and MDF have a problem that the density is higher than that of South Sea lumber plywood.

As described above, the current situation is that there is no wood board that satisfies a plurality of factors such as strength, weight, surface property, and dimensional stability in addition to the stability of the raw material.

As an example of this kind of wood board, those shown in Patent Documents 1 to 4 have been proposed conventionally. The wood board shown in Patent Document 1 and Patent Document 2 includes a core layer in which a large number of wood flakes are assembled, and a surface layer in which a large number of wood flakes are laminated and laminated on at least one surface thereof. 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. Has been proposed.

On the other hand, in the technique shown in Patent Document 3, a fiber mat is pressure-bonded to the surface of plywood, OSB, laminated lumber, etc., and the fiber mat is compressed to produce a high-density fiber layer, thereby forming a base material. I try to fill in the dents on the surface.

Further, the floor decorative material shown in Patent Document 4 has a structure in which a moisture-proof film having a moisture permeability of 7 g / ^m for 2.24 hours or less is laminated on the back surface of a wood base material such as MDF, so that the front surface is moisture-permeable. Even if a low decorative sheet is attached, the warp and towing due to the magnitude of the dimensional change are suppressed.

Japanese Unexamined Patent Publication No. 7-47514 Japanese Unexamined Patent Publication No. 7-76004 Japanese Unexamined Patent Publication No. 2019-31104 Japanese Unexamined Patent Publication No. 2019-107894

However, in the wood boards shown in Patent Documents 1 and 2, not only the size but also the thickness of the wood flakes constituting the wood board are different between the surface layer and the core layer, and therefore, 2 at the time of manufacture. It is necessary to prepare different types of wood flakes, and it is inevitable that manufacturing and management will be troublesome. In addition, the wood board using the wood flakes described in the patent document has irregularities on the surface, and it is not possible to secure surface smoothness that can be used as a base material for floors, for example.

Further, the wood board of Patent Document 3 not only takes time and effort for secondary processing of the base material, but also has a double structure of the base material and the fiber layer, so that the thickness of the board is reduced. There is a limit. In addition, it is not possible to suppress dimensional changes due to moisture absorption.

Further, in the decorative material of Patent Document 4, not only is it time-consuming because it is a secondary processing of the base material, 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 these points, and an object thereof is high strength and dimensional stability that can be easily manufactured by applying an improved technique to a wood board having a structure in which a large number of wood flakes are laminated. The purpose is to further improve the wood board having excellent surface properties so that a wood laminated board having further improved surface properties can be obtained.

In order to achieve the above object, in the present invention, a wood piece whose size including the thickness is limited to a minute range is used with respect to the cut piece normally used as a constituent material of OSB, and the wood piece is used. Two types of wood shards whose size is further limited to a minute range are used as constituent materials, and each wood layer in which these wood shards are laminated in an aggregated state is laminated and integrated to have a core layer and a front and back layer. As a laminated board, a wood material layer composed of two types of wood small pieces, which are smaller in size, was arranged on the front and back layers of the wood laminated board.

In addition, in this specification, a "cut piece" is a piece cut from raw wood for OSB use, and is usually used as a constituent material of OSB. The "wooden flakes" according to the present invention are those cut from raw wood in the same manner as the "cut pieces", but refer to thin and smaller flakes outside the normal general thickness range of the "cut pieces". .. The "wooden flakes" according to the present invention refer to flakes smaller than the "wooden flakes" in the same thickness range as the "wooden flakes".

Specifically, the first invention is intended for a wood laminated board in which a second wood layer laminated on both sides of a first wood layer and a first wood layer is integrated. The first wood material layer is formed by laminating a large number of elongated first wood small pieces having front and back surfaces along the fiber direction in an aggregated state and adhering and integrating them to form the first wood material layer. The thickness of one wood piece is 0.05 mm or more and 0.35 mm or less between the front and back surfaces , the length along the fiber direction is 40 mm or less, and the width along the direction orthogonal to the fiber direction is 15 mm. It is as follows. Further, the second wood material layer is formed by laminating a large number of elongated second wood material flakes having front and back surfaces along the fiber direction in an aggregated state and adhering and integrating them to form the second wood material layer. The second wood flakes are characterized by being smaller than the first wood flakes in the same thickness range as the first wood flakes .

In the first invention, in the wood laminated board, the first wood material layer and the second wood material layer arranged on both sides thereof are laminated and integrated. The thickness of the front and back surfaces of the first wood material layer is 0.05 mm or more and 0.35 mm or less , the length along the fiber direction is 40 mm or less, and the width along the direction orthogonal to the fiber direction is 15 . A large number of elongated first wood pieces having a size of mm or less are laminated in an aggregated state and are formed by adhesive integration. The thickness, length and width of the first wood flakes are all average values. In addition, the second wood material layer is composed of a large number of second wood pieces having an elongated shape smaller than the first wood pieces in the same thickness range as the first wood pieces and laminated in an aggregated state by adhesive integration. ing.

As described above, the wood laminated board has two sizes in which the wood flakes having a specific thickness obtained in the P1 step described later are crushed in the fiber direction and the fiber orthogonal direction of the wood flakes in the P2 step and the P3 step also described later. It is composed of wood flakes, and these wood flakes are extremely thin and fit within a narrow range of 0.05 to 0.35 mm (same thickness range), so many wood flakes are thick. The variation is small and the thickness is uniform. Further, since the length and width of the wood flakes are also within a certain range, the wood laminated board becomes homogeneous by gathering the wood flakes having the same size within a certain range. Therefore, local defects and variations in density are extremely reduced, and stable strength of the wood laminated board can be developed. In addition, warpage due to moisture absorption and desorption is less likely to occur, and good dimensional stability comparable to that of South Sea plywood can be obtained. In addition, the second wood layer composed of a large number of second wood small pieces, which is smaller in size than the first wood small pieces in which a large number of wood small pieces are arranged in a uniform size, forms both sides of the first wood layer. Since it is laminated on the wood laminated board and becomes the front and back layers of the wood laminated board, the surface of the wood board does not have large irregularities unlike the normal OSB, and the surface property of the wood laminated board can be further improved. It has excellent surface properties. Further, the wood laminated board is an aggregate in which a large number of second wood flakes of uniform size are assembled, an aggregate in which a large number of first wood flakes of uniform size are assembled, and the second wood flakes. Since the aggregates in which the flakes are assembled are laminated and integrated in order, the production thereof becomes easy.

According to the second invention, in the wood laminated board of the first invention, the first wood flakes have an elongated shape having 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 improves the dimensional stability of the first wood material layer. Further, since the surface property of the first wood material layer is improved, the surface property (particularly smoothness) of the second wood material layer formed on the first wood material layer is further improved. This makes it possible to improve the dimensional stability and surface properties of the wood laminated board.

A third aspect of the invention is characterized in that, in the wood laminated board of the first or second invention, the second wood flakes have at least one dimension of length and width smaller than the first wood flakes. ..

According to the fourth invention, in the wood laminated board of any one of the first to third inventions, the second wood flakes have a thickness of 0.15 to 0.25 mm, a length of 10 mm or less, and a width of 2 mm. It is characterized by having the following elongated shape.

In these third and fourth inventions, the surface property of the second wood material layer is further improved. That is, the surface properties of the wood laminated board can be further improved.

In the fifth invention, in the wood laminated board of any one of the first to fourth inventions, the ratio of the thickness of each second wood layer to the entire wood laminated board is 5% or more and 40% or less. It is characterized by. This makes it possible to achieve both the strength and surface properties of the wood laminated board.

The sixth invention is characterized in that, in the wood laminated board of any one of the first to fifth inventions, the density of the first wood material layer and each second wood material layer is 250 to 800 kg / m ³ . do. This further increases the strength of the wood laminated board.

As described above, according to the present invention, the wood laminated board is laminated and integrated so that the second wood layer is arranged on both sides of the first wood layer, and the first wood layer is made of fiber. A large number of first wood small pieces that have front and back surfaces along the direction, have a thickness of 0.05 to 0.35 mm, and have a fiber direction dimension and a fiber orthogonal direction dimension of 40 mm or less, and are uniform in size with little variation. It is assumed that the flakes are laminated in an aggregated state and bonded and integrated, and the second lumber layer is formed by laminating and adhering and integrating the second lumber strips smaller than the first wood strips in an aggregated state. As a result, the strength of the wood laminated board can be increased, and the good dimensional stability equivalent to that of South Sea plywood and the excellent surface property equivalent to that of MDF can be obtained, so that the wood laminated board can be easily made. Can be manufactured.

FIG. 1 is a cross-sectional view of a wood laminated board according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of the first and second wood material layers constituting the wood laminated board. FIG. 3 is an enlarged perspective view schematically showing the first woody flakes constituting the first woody material layer. FIG. 4 is an enlarged perspective view schematically showing the second woody flakes constituting the second woody material layer. FIG. 5 is a diagram showing a manufacturing process of a wood laminated board. FIG. 6 is an enlarged cross-sectional view showing a state in which a wood laminated board is thermally pressed from a mat which is an aggregate of a first wood piece and a second wood piece. FIG. 7 is a diagram showing the characteristics of a wood laminated board in comparison with a board made of another material.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are merely exemplary and are not intended to limit the invention, its applications or its uses.

<Wood laminated board>
FIG. 1 shows a wood laminated board A according to an embodiment of the present invention. As the wood laminated board A, for example, a board having a density of 500 to 800 kg / m ³ and a thickness of 3 to 12 mm is used. The thin type wood laminated board A having a thickness of less than 3 to 6 mm is, for example, an inner wall material for a loading platform used 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 building material ( It is constructed as an interior material such as a riser board). The medium-thickness type wood laminated board A having a thickness of about 6 to 12 mm is constructed, for example, as a soundproof floor base material, a floor base material for footwear, a entrance construction material, or the like to be installed indoors. As described above, the wood laminated board A is used as a substitute material for the existing plywood for the base plate. Further, since the wood laminated board A has the same surface properties as MDF, it can be suitably used for decorative thin plywood.

The wood laminated board A includes a first wood layer B and two second wood layers C and C, and the second wood layers C and C are laminated and integrated on both sides of the first wood layer B. It has been transformed. In other words, the first wood material layer B is interposed between the two second wood material layers C and C. That is, the first wood material layer B constitutes the core layer of the wood laminated board A, and the two second wood material layers C and C form the front and back layers of the wood laminated board A.

The ratio of the thickness of each second wood layer C to the entire wood laminated board A is preferably 5% or more and 40% or less, more preferably 8% or more and 30% or less, and further preferably 10% or more and 25% or less. be. That is, the second wood material layer C: the first wood material layer B: the second wood material layer C in the wood laminated board A is preferably 5: 90: 5 to 40:20:40, more preferably 8:84 :. It is 8 to 30:40:30, more preferably 10:80:10 to 25:50:25. By appropriately changing the ratio of the thickness of the first wood material layer B and each second wood material layer C, a wood laminated board A having both the strength required for the application and excellent surface properties can be obtained. ..

(1st wood layer)
As shown in an enlarged manner in FIG. 2, the first wood material layer B has a large number of first wood small flakes 1, 1, ... Therefore, a large number of first wood flakes 1, 1, ... Have one kind of thickness.

Explaining the first wood small piece 1, as shown in an enlarged manner in FIG. 3, the thickness t of the first wood small piece 1 is 0.05 to 0.35 mm (0.05 mm or more and 0.35 mm or less). Yes, 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), and further preferably 0. It is 15 to 0.20 mm (0.15 mm or more and 0.20 mm or less). The characteristics of the first wood material layer B, that is, the characteristics of the wood laminated board A are determined by the first wood small flakes 1, 1, ... Of the thin thickness t. The thickness t of the first woody flakes 1 is an average value. In other words, in the first wood thin section 1 according to the present invention, the strand (also referred to as a cutting piece in the present invention) usually used as an element (constituent material) of general OSB is generally 0 in thickness. While it is about 6 to 1.5 mm, it is a thin piece thinner than that.

Further, the first woody small piece 1 has fibers 1a, 1a, ... Due to a conduit, a temporary conduit, or the like, and the fiber direction dimension d1 in the direction along the fiber 1a is a fiber along the direction orthogonal to the fiber direction. It is an elongated shape (strip shape) longer than the orthogonal direction dimension d2. When the fiber direction dimension d1 is taken as the length and the fiber orthogonal direction dimension d2 is taken as the width, the length d1 is 40 mm or less, preferably 35 mm or less, more preferably 30 mm or less, still more preferably 25 mm or less, still more preferably 10 to 20 mm ( 10 mm or more and 20 mm or less). 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), and further preferably more than 2 mm and 5 mm or less. The length d1 and the width d2 of the first woody flakes 1 are both average values. In other words, in the first woody flakes 1, 1, ... According to the present invention, the cut pieces usually used as a constituent material of general OSB are generally 110 mm in length (about 150 to 250 mm in the long one). ), The width is 15 to 25 mm (about 1/3 of the length in the case of a long one), but the size is smaller than that. Moreover, although not shown, the first wood flakes 1 according to the present embodiment are smaller than the wood flakes as they are cut from the raw wood (also referred to as post-cut wood flakes). In the sense that it is different from the wood flakes after cutting, it is called "small wood flakes" for the wood flakes after cutting.

The tree species used for the first woody flakes 1, 1, ... Are not particularly limited, and for example, a South Sea tree or a broad-leaved tree may be used, or other tree species may be used. For example, fur materials such as sugi, cypress, and douglas fir, acacia, aspen, poplar, pine (hard pine, soft pine, radiata pine, etc.), birch, rubber (rubber tree), etc., but are limited to these tree species. However, various tree species can be used. Various tree species include spruce, spruce, spruce, sawara, cypress, kaya, 栂, maki, various pine, paulownia, maple, birch (white birch), shii, beech, oak, oak, oak, 楢, zelkova, zelkova. Domestic lumber such as rice cypress, rice hiba, rice cedar, rice fir, spruce, rice pine, redwood and other North American wood, Agatis, Terminaria, Rawan, Melanchi, Junkon, Camerele, Karampayan, Amberoi, Melina, Teak, Apiton , South Sea lumber such as Sengonlaut, other external lumber such as Barça, Sedro, Mahogany, Lignum baita, Acacia mangume, Mediterranean pine, bamboo, Kouryan, Camerele, etc., and any material can be used.

Regarding the physical properties of the first woody flakes 1, the density is preferably 250 kg / m ³ or more, more preferably 300 kg / m ³ or more, and preferably 800 kg / m ³ or less, more preferably 500 kg / m ³ or less. More preferably, it is 400 kg / m ³ or less. When the density is less than 250 kg / m ³ , the thickness of the mat required to form the wood laminated board A having the same density and strength becomes large, and the press pressure related to the hot pressure pressing process in the press forming process is increased. Need to be increased.

The density of the first wood flakes 1 may exceed 800 kg / m ³ , but it is difficult to easily obtain such first wood flakes. 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 first woody flakes 1 exceeding 800 kg / m ³ can be easily obtained.

The water content of the first woody flakes 1 is preferably about 2 to 20%, more preferably 2 to 8%. When the water content is less than 2%, it takes a long time to soften in the hot pressure pressing process in the press forming process, the pressing time becomes long, and the strength may decrease.

Further, if the water content of the first wood flakes 1 exceeds 20%, it takes time to heat and compress in the same hot pressure pressing process, and further, the curing of the adhesive may be hindered and the strength may decrease. There is.

In the first wood material layer B, a large number of first wood small flakes 1, 1, ... Are oriented in the fiber direction (length direction) along the fibers 1a, 1a, ... In the reference direction. However, the orientation in the fiber direction is not essential, and the fiber direction may be randomly oriented. The fact that the fiber direction (length direction) is oriented in the reference direction means that the fibers 1a, 1a, ... Of all the first wood thin sections 1, 1, ... In the first wood material layer B are accurate. It does not limit that the fibers are oriented in the same direction, in other words, the fiber directions of the oriented first wood flakes 1, 1, ... Are parallel to each other. As some of the first woody flakes 1,1, ..., the first woody flakes 1,1, ... In which the fiber direction is inclined to some extent (for example, about 20 °) with respect to the reference direction may be included. ..

(2nd wood layer)
In the second wood material layer C, as shown in an enlarged manner in FIG. 2, a large number of second wood small flakes 2, 2, ... A large number of second wood flakes 2, 2, ... Have one thickness.

The second woody flakes 2 are flakes smaller in size than the first woody flakes 1. Explaining the second wood small slice 2 in detail, as shown in an enlarged manner in FIG. 4, the thickness t of the second wood small slice 2 is 0.05 to 0.35 mm, preferably 0.10 to 0. It is .30 mm, more preferably 0.15 to 0.25 mm, still more preferably 0.15 to 0.25 mm. That is, the thickness t of the second woody flakes 2 is equal to or smaller than the thickness t of the first woody flakes 1. Thereby, the characteristics of the second wood material layer C, that is, the characteristics of the wood laminated board A are determined by the second wood small flakes 2, 2, ... Of the thin thickness t. The thickness t of the second woody flakes 2 is an average value.

Further, the second wood piece 2 has fibers 2a, 2a, ... Due to a conduit, a temporary conduit, etc., like the first wood piece 1, and has a fiber direction dimension (length) d1 along the fiber 2a. Is an elongated shape (strip shape) longer than the fiber orthogonal direction dimension (width) d2. The length d1 is preferably 10 mm or less, more preferably 8 mm or less, still more preferably 5 mm or less, and its lower limit is a length exceeding the width d2. The width d2 is preferably 2 mm or less, more preferably 1 mm or less, still more preferably 0.8 mm or less, and the lower limit thereof is not particularly limited, but is, for example, 0.02 mm or more. That is, the second woody flakes 2, 2, ... According to the present invention are flakes having at least one dimension smaller than the first woody flakes 1 having a length d1 and a width d2. The length d1 and the width d2 of the second woody flakes 2 are both average values.

The tree species used for the second woody flakes 2, 2, ... Are not particularly limited, and the same tree species as those used for the first woody flakes 1, 1, ... May be used, or other tree species may be used. You may use it. Further, the tree species of the second woody flakes 2, 2, ... may be the same as or different from the tree species of the first woody flakes 1, 1, .... From the viewpoint of easily producing the second wood small slices 2, 2, ... using the first wood small slices 1, 1, ..., the tree species of the second wood small slices 2, 2, ... are the first wood small slices 2, 2, .... It is preferable that the tree species are the same as those of 1, 1, ....

Regarding the physical properties of the second woody flakes 2, the density is preferably 250 kg / m ³ or more, more preferably 300 kg / m ³ or more, and preferably 800 kg / m ³ or less, more preferably 500 kg / m ³ or less. More preferably, it is 400 kg / m ³ or less. When the density is less than 250 kg / m ³ , the thickness of the mat required to form the wood laminated board A having the same density and strength becomes large, and the press pressure related to the hot pressure pressing process in the press forming process is increased. Need to be increased.

The density of the second woody flakes 2 may exceed 800 kg / m ³ , but it is difficult to easily obtain such second woody flakes 2. 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 second woody flakes 2 exceeding 800 kg / m ³ can be easily obtained.

The water content of the second woody flakes 2 is preferably about 2 to 20%, more preferably 2 to 8%.

In the second wood material layer C, a large number of second wood small flakes 2, 2, ... Are oriented in the fiber direction (length direction) along the fibers 2a, 2a, ... In the reference direction. However, the orientation in the fiber direction is not essential, and the fiber direction may be randomly oriented. As some of the second wood flakes 2, 2, ..., the second wood flakes 2, 2, ... In which the fiber direction is tilted to some extent (for example, about 20 °) with respect to the reference direction may be included. ..

<Manufacturing method of wood laminated board>
Next, it is a figure about the manufacturing method of the 1st wood small flakes 1, 1, ... And the 2nd wood small flakes 2, 2, ..., and the method of manufacturing the wood laminated board A from these wood small flakes 1, 2, ... 5 will be described. The method for producing the first wood flakes 1, 1, ... Has a wood flakes manufacturing step P1 and a first wood flakes manufacturing process P2. The method for producing the second woody flakes 2, 2, ... Further comprises the subsequent second woody flakes manufacturing step P3. The method for manufacturing the wood laminated board A further includes an adhesive application step P4, a mat forming step P5, and a thermal pressure step P6.

(Wooden flakes manufacturing process P1)
If necessary, cut logs such as logs and thinned wood as materials to remove the bark, and then adjust the water content in some cases to make an outer-blade type or inner-blade type cutting device (strander). To form a large number of wood flakes (post-cut wood flakes) that are thinner and smaller than the cut pieces normally used as constituents of OSB. It can also be formed from scraps, waste materials, and waste pallet materials generated at construction sites. A general cutting device is used. The thickness of the wood flakes is adjusted by the speed at which the raw wood is sent to the cutting device. The wood flakes formed by this cutting (post-cut wood flakes) are different from the first wood flakes 1 and the second wood flakes 2 constituting the wood laminated board A of the embodiment, and are in the direction orthogonal to the fibers. It is a large one.

At this time, the fibers are cut so as to appear linearly on the front and back surfaces of each wood thin piece, and the cutting thickness is cut so as to be the thickness t of the first wood piece 1 and the second wood piece 2. In the subsequent steps, the thickness t of the first wood flakes 1 and the second wood flakes 2 is basically the same as the thickness of the post-cut wood flakes, and the thickness of the post-cut wood flakes remains the same as the first wood flakes. This is because the thickness t of the small flakes 1 and the second woody flakes 2 is obtained.

By passing the post-cut wood flakes obtained in this step P1 through a sieve (for example, a mesh of Φ5 mm or more) and sorting (classifying) the size of the post-cut wood flakes (classification step), the following first step is performed. Wood flakes of a size comparable to the first wood flakes 1, 1, ... (included in the size range of the first wood flakes 1, 1, ...) obtained after passing through the wood flakes manufacturing process P2. It may be obtained. In that case, the wood flakes can be used as the first wood flakes 1, 1, ... In the adhesive application step P4 without being subjected to the first wood flakes manufacturing step P2.

(1st woody small flakes manufacturing process P2)
Next, after the above-mentioned cutting, the classified wood pieces (wood pieces after cutting) are crushed using a crusher that does not use a knife such as a hammer mill, a pin mill, or a jet mill, or a knife such as a knife flaker or a cutter mill. The first wood piece 1,1 constituting the first wood layer (core layer) B of the wood laminated board A by crushing it with a machine and making it smaller than the size of the wood piece immediately after cutting in the fiber orthogonal direction. , ... are formed. At this time, by crushing the wood flakes after cutting in the width direction so as to crack along the fiber direction (length direction), the elongated first wood flakes 1, 1, ... Can be produced. That is, when a force (impact) is applied to the wood flakes after cutting along the fiber orthogonal direction orthogonal to the fiber direction, it is difficult to crack, but when a force is applied along the fiber direction, it easily cracks. Even if the wood flakes are curled after cutting, they are divided into flat surfaces by crushing them. The direction of the force applied to the wood flakes after cutting is not limited to the direction parallel to the fiber direction. When a force is applied to the post-cut wood flakes in random directions, the post-cut wood flakes usually crack from the weaker part (easily cracked in the weaker force direction). The force that connects the fibers of the wood flakes after cutting (force in the direction orthogonal to the fibers) is overwhelmingly weaker than the force in the fiber direction, so if the wood flakes after cutting are crushed in random directions with the above general crusher After cutting (when a force is applied), the wood shards are cracked along the fiber direction and shortened in the fiber orthogonal direction, and the elongated first wood shards 1, 1, ... Are obtained.

Further, even if the wood flakes have knots after cutting, the knots are more brittle than other parts, so that the knots become powdery by crushing and are removed in a later classification step.

In the case of a crusher using a blade, there is a risk that the wood flakes will be unintentionally crushed in the direction orthogonal to the fibers after cutting, but in the case of a crusher that does not use a blade, such a risk is reduced. It is preferable to crush the wood flakes after cutting using a crusher that does not use a blade.

By passing through a two-step process by adding a crushing step after that, instead of just one step of cutting in this way, the wood flakes that are thinner and smaller than the cutting piece can be knotted to the required size. High-strength first wood flakes 1, 1, ... Without portions can be easily produced.

Even if a classification step is included in which the first wood flakes 1, 1, ... Obtained in the above crushing step are passed through a sieve or the like to sort (classify) the sizes of the first wood flakes 1, 1, ... good. As a result, a large number of first wood flakes 1, 1, ... Are fine and have a more uniform size and shape. As described above, the first woody thin section 1 is manufactured.

(2nd woody small flakes manufacturing process P3)
In the manufacturing process P2 of the first woody small slices 1, 1, ..., the woody material removed in the classification step of the first woody small thin sections 1, 1, ... And the first woody small thin sections 1, 1, ... From the small flakes 3, 3, ... (not shown), the second wood flakes 2, 2, ... Which are smaller in size than the first wood flakes 1, 1, ... Can be obtained. The wood flakes 3 removed in the classification step refer to wood flakes other than the first wood flakes 1 formed in the manufacturing step P2, and are the size (thickness) of the first wood flakes 1. t, a small piece of wood whose dimension (at least one of the length d1 and the width d2) is out of range.

Specifically, the first wood flakes 1, 1, ... And / or the wood flakes 3, 3, ... are further pulverized using the same method as in the manufacturing step P2. As a result, the first wood flakes 1, 1, ... And / or the wood flakes 3, 3, ... Are crushed in the width direction so as to be split along the fiber direction (length direction), and the elongated shape first. Compared with 1 wood small flakes 1, 1, ..., it is possible to make second wood small flakes 2, 2, ... With a more elongated shape. That is, the second woody thin section 2 becomes a thin piece having a width d2 smaller than that of the first woody small thin section 1. Further, in the further crushing step in the manufacturing step P3, the first wood flakes 1, 1, ... And / or the wood flakes 3, 3, ... Are also crushed in the length direction. As a result, the second woody thin section 2 becomes a thin piece having a length d1 as well as a width d2 smaller than that of the first woody small thin section 1.

Further, as another method, the above-mentioned woody flakes 3, 3, ... may be sorted by, for example, a mesh of Φ2, and those that have passed through the mesh may be referred to as the second woody flakes 2, 2, ....

In this way, using the first wood flakes 1, 1, ... Formed in the manufacturing process P2 and the removed wood flakes 3, 3, ..., these wood flakes 1, 3, ... By further passing through a step of crushing or a step of classifying, the second wood flakes 2, 2, ... Which are smaller in length d1 and / or width d2 than the first wood flakes 1, 1, ... can do.

The second wood flakes 2, 2, ... obtained in the above further crushing step are passed through a sieve or the like (for example, a mesh of Φ2) to sort (classify) the second wood flakes 2, 2, ... You may. As a result, a large number of second wood flakes 2, 2, ... Are fine and uniformly uniform in size and shape. As a result, the second woody flakes 2, 2, ... Are manufactured.

(Adhesive application step P4)
In the manufacturing process P2 of the first wood flakes 1, 1, ... And the manufacturing process P3 of the second wood flakes 2, 2, ..., a large number of first wood flakes whose size and shape are uniformly uniformized by sorting. Once the flakes 1, 1, ... And the second wood flakes 2, 2, ... are obtained, the adhesive application step P4 is performed, and the first wood flakes 1, 1, ... And the second wood flakes 2 are performed. , 2, ... Are carried into the adhesive application device and the adhesive is applied. 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 adhesive may be used. Further, a commonly used water repellent may be used in combination with the adhesive.

(Mat forming process P5)
Next, as shown on the left side of FIG. 6, first, a large number of second wood flakes 2, 2, ... By stacking (stacking) to a predetermined thickness (height) in the state of being made to form a mat C1 (second aggregate) composed of only the second woody flakes 2, 2, ... Subsequently, on the formed mat C1, a large number of the first woody flakes 1, 1, ... To which the adhesive was applied were assembled in the thickness direction with or without being oriented in the fiber direction. By laminating to a predetermined thickness in this state, a mat B1 (first aggregate) composed of only the first woody flakes 1, 1, ... Is formed. Finally, on the formed mat B1, a mat C1 composed of only the second woody flakes 2, 2, ... Is formed in the same manner as described above. In this way, the mat C1, the mat B1, and the mat C1 are laminated in this order to form the laminated mat A1 having a three-layer structure.

At this time, the thicknesses of the mat B1 and the mat C1 are adjusted so that the ratio of the thickness of the first wood material layer B and each second wood material layer C to the entire wood laminated board A is a desired ratio. For example, the ratio of the thickness of each second wood layer C to the entire wood laminated board A is 15% (second wood layer C: first wood layer B: second wood layer C = 15: 70 :. 15) In the case of forming the wood laminated board A having a thickness of 4 mm, first, the thickness t is 0.2 mm so that the thickness (height) of the mat C1 is about 5 mm. Stack the second small pieces of wood 2, 2 ... Subsequently, first wood flakes 1, 1, ... With a thickness t of 0.2 mm are stacked on the mat C1 so that the thickness of the mat B1 is about 24 mm. Finally, the second wood flakes 2, 2 ... Are stacked on the mat B1 so that the thickness of the mat C1 is about 5 mm. In this way, the thickness (height) of the laminated mat A1 having a three-layer structure composed of mats C1, B1 and C1 is about 34 mm.

(Heat pressure step P6)
As this laminated mat A1 is performed on a normal wood board, the laminated mat A1 is first pressed and compacted a little, and then carried into a hot pressure press device and set between hot plates. The laminated mat A1 is hot-pressed at a predetermined pressure and temperature by a hot-pressure pressing device to be compressed, and is integrally molded by curing the adhesive. As a result, the wood laminated board A shown in FIG. 1 is formed.

At this time, as shown in FIG. 6, the laminated mat A1 having a thickness of about 40 mm illustrated above is compressed into, for example, a 4 mm wood laminated board A, and the thickness is compressed to 1/10. The press temperature related to the hot pressure press process is not particularly limited, but is, for example, 100 to 180 ° C. The press pressure related to the hot pressure 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 wood laminated board A, and may be completed in less than 1 minute or may take 2 minutes or more. Further, the preliminary heat treatment by the heating device may be performed before the hot pressure pressing treatment by the hot pressure pressing device.

In addition, the first wood flakes 1, 1, ... And the second wood flakes 2, 2, ..., which are smaller in size, have the knots removed, and the size is within a fine range without variation. The mats B1 and C1 become homogeneous, respectively, because they are kept in the same condition. That is, the entire laminated mat A1 becomes homogeneous, and this eliminates variations in the strength of the wood laminated board A. That is, in a strand board using a large strand (cut piece), for example, a non-uniform mat including a knot portion causes a partially (spot-like) thin and low-strength portion, and the strength varies, but it disappears. Moreover, the thinner the first thin wood pieces 1, 1, ..., the higher the homogeneity of the mat B1, and the stronger the wood laminated board A becomes. In general, a strand board using a large strand (cut piece) can increase the strength, but in the present invention, the first wood piece 1 which is thinner and smaller than the cut piece and is made smaller by crushing the wood piece 1 Therefore, the wood laminated board A has both homogeneity and strength.

Further, the first wood flakes 1, 1, ... Are small and have a uniform size, and in the mat B1, gaps are uniformly formed between the first wood flakes 1, 1, .... Similarly, the second wood flakes 2, 2, ... Are smaller and more uniform in size than the first wood flakes 1, 1, ..., and in the mat C1, the second wood flakes 2, 2, ... A gap is uniformly formed between ... Therefore, even if the first wood flakes 1, 1, ... Of the mat B1 and the second wood flakes 2, 2, ... of the mat C1 are hot-pressed with a relatively large amount of water contained, the heat is applied. The steam generated by the evaporation of water smoothly escapes from the mat B1 and the mat C1. That is, as shown on the left side of FIG. 6, in the mat B1, a large number of minute voids exist between the first woody flakes 1, 1, ... Adjacent to each other. Similarly, in the mat C1, a large number of minute voids are present between the second woody flakes 2, 2, ... Adjacent to each other. These voids communicate not only in the fiber direction and the fiber orthogonal direction of the first wood small slices 1, 1, ... And the second wood small slices 2, 2, ..., but also in the thickness direction. Further, these voids are not only continuous in the mat B1 and the mat C1, but also continuous between the mat B1 and the mat C1, and are three-dimensionally continuous in the entire laminated mat A1. Therefore, puncture is less likely to occur when the pressurization on the wood laminated board A is stopped.

Through such a process, the density of each of the first wood layer B and each second wood layer C (the density of the entire wood laminated board A) is 500 to 800 kg / m ³ , and the bending young is 3.5 to. A 5.0 GPa wood laminated board A is formed.

The density of the first wood material layer B and the density of each second wood material layer C may be the same or different. The densities of the wood layer B and C are preferably different from the viewpoint of preventing a puncture during molding. When the densities of the first wood material layer B and each second wood material layer C are different, the difference in density between the two layers B and C is, for example, 400 kg / m ³ or more. Further, the magnitude relationship between the densities of the first wood material layer B and each second wood material layer C is not particularly limited, and even if the density of the first wood material layer B is higher than the density of each second wood material layer C. It may be good or low. From the viewpoint of improving the smoothness, color tone, and color homogeneity of the surface of the wood laminated board A, each second wood layer C is a high-density wood layer having a higher density than the first wood layer B. preferable.

Further, as shown on the right side of FIG. 6, the wood laminated board A has a large number of three-dimensionally continuous minute voids inside the first wood material layer B and each second wood material layer C (in addition, the wood laminated board A has a large number of three-dimensionally continuous minute voids. Remaining). Therefore, the wood laminated board A is also excellent in breathability.

(Other processes)
In the method for manufacturing the wood laminated board A, as another step, after the thermal pressure step P6, the wood laminated board A is cured to the equilibrium moisture content, and then the second wood material layer C as the front and back surfaces is ground by a sander. However, it may have a finishing step of adjusting the final thickness. As the sander, a commonly used one can be used, and examples thereof include # 150. By going through this finishing step, a wood laminated board A having even better surface properties can be obtained.

Therefore, the wood laminated board A of the above embodiment can exert the following effects.

The wood laminated board A is composed of two types of wood flakes 1, 2, ... Of the same thickness range but different sizes. Specifically, the wood laminated board A has an extremely thin thickness t, its average value is 0.05 to 0.35 mm, and the average value of the fiber direction dimension d1 (length) along the fiber direction is 40 mm or less. A large number of first wood small flakes 1, 1, ... The first wood material layer B and a large number of second wood small pieces 2, 2, ... Which are smaller in size than the first wood small pieces 1, 1, ... The second wood material layers C and C are included in the layers, and the second wood material layers C and C are arranged on both sides of the first wood material layer B, and the second wood material layers C and C are arranged into three layers by adhesive integration. There is.

That is, the first wood material layer B constituting the core layer of the wood laminated board A is composed of only one type of first wood small slices 1, 1, ... Since the average value of the thickness t is extremely thin and fits within a narrow range of 0.05 to 0.35 mm, a large number of first wood flakes 1, 1, ... Have a small variation in the thickness t and are uniform. It will be uniform in thickness t. Further, since the fiber direction dimension d1 (length) and the fiber orthogonal direction dimension d2 (width) of the first wood flakes 1, 1, ... Are also within a certain range, the size of the first wood material layer B is within a certain range. The first woody flakes 1, 1, ... Therefore, not only the strength of the first wood material layer B (that is, the wood laminated board A) is increased, but also warpage due to moisture absorption and desorption is unlikely to occur, and good dimensional stability comparable to that of South Sea plywood can be obtained. Further, the two second wood material layers C and C constituting the front and back layers of the wood laminated board A are larger than the first wood small slices 1, 1, ... (Specifically, the length d1 and the width d2). Since a large number of small second wood pieces 2, 2, ... However, the wood laminated board A is more excellent in surface properties, and has excellent surface properties similar to MDF. In addition, mat B1 and mat C1, which are aggregates of a large number of first wood flakes 1, 1, ... And second wood flakes 2, 2, ... Of uniform size, are combined with mat C1 and mat. Since B1 and mat C1 are laminated and integrated in this order, their production becomes easy.

In particular, the average value of the thickness t of the first wood small pieces 1, 1, ... In the first wood material layer B constituting the core layer of the wood laminated board A is 0.15 to 0.25 mm, and the fiber direction dimension d1. When the elongated shape has an average value of 20 mm or less and an average value of the fiber orthogonal direction dimension d2 of 5 mm or less, the dimensional stability of the first wood material layer B is improved, and as a result, the dimensional stability of the wood laminated board A is improved. improves. Further, since the smoothness of the surface of the first wood material layer B is improved, the surface of the second wood material layers C and C laminated on the first wood material layer B also has smoothness and color tone / color homogeneity. improves. As a result, a wood laminated board A having even better surface properties can be obtained.

Further, the average thickness of the second wood small pieces 2, 2, ... In each second wood material layer C constituting the front and back layers of the wood laminated board A is 0.15 to 0.25 mm, and the fiber direction dimension d1. When the elongated shape has an average value of 10 mm or less and an average value of the fiber orthogonal direction dimension d2 of 2 mm or less, the surface property of each second wood material layer C, that is, the wood laminated board A is further improved.

Further, when the ratio of the thickness of each second wood material layer C to the entire wood laminated board A is 5% or more and 40% or less, the strength and surface properties of the wood laminated board A can be compatible with each other.

FIG. 7 illustrates the characteristics of the wood laminated board A according to the present invention in comparison with boards made of other materials. The wood laminated board A has a bending young and a length change rate during moisture absorption and desorption. It is as large as plywood and is superior to lauan plywood in anisotropy in dimensional stability, smoothness in surface properties, and color tone / color homogeneity. Further, the wood laminated board A has a uniform bending young in the vertical and horizontal directions as compared with the OSB, and has good anisotropy in dimensional stability, smoothness in surface properties, and color tone / color homogeneity. That is, the wood laminated board A has high strength and is excellent in dimensional stability and surface properties. Further, the wood laminated board A has only the above-mentioned characteristics as compared with the single-layer wood board (in other words, the first wood material layer B) composed of only the first wood flakes 1, 1, ... However, it can be said that it is a wood board that specializes in surface properties.

<Other embodiments>
In the above embodiment, the first wood material layer (core layer) B of the wood laminated board A is a first wood material in which the wood flakes (wood flakes after cutting) as cut from the raw wood are crushed and become smaller than the wood flakes. Although it is composed of small pieces 1, the present invention can also form a first wood material layer with wood pieces as they are cut from raw wood (wood pieces after cutting).

In the above embodiment, both the wood flake manufacturing step P1 and the first wood flake manufacturing step P2 have a classification step, but in the present invention, only one of the steps P1 and P2 includes the classification step. It may be included, and neither of the steps P1 and P2 may include the classification step. From the viewpoint of further improving not only the strength of the wood laminated board A but also the dimensional stability and the surface property, it is preferable that the step P1 or P2 has a classification step, and the step P2 has a classification step. It is more preferable that both steps P1 and P2 have a classification step.

The present invention is extremely possible because it is possible to easily manufacture a wood laminated board having high strength and good dimensional stability and surface properties comparable to those of South Sea plywood, which is composed of small pieces of wood having a uniform size. It is useful and has high industrial applicability.

A Wood laminated board A1 Laminated mat B 1st wood layer B1 mat C 2nd wood layer C1 mat P1 Wood flakes manufacturing process P2 1st wood flakes manufacturing process P3 2nd wood flakes manufacturing process P4 Adhesive application process P5 Matte forming process P6 Thermal pressure process 1 1st wood small flakes 1a Fiber 2 2nd wood small flakes 2a Fiber 3 Wood small flakes other than 1st wood flakes t Thickness d1 Fiber direction dimensions (length)
d2 Fiber orthogonal dimension (width)

Claims (6)

A wood laminated board in which a first wood layer and a second wood layer laminated on both sides of the first wood layer are integrated.
The first wood material layer is formed by laminating a large number of elongated first wood small pieces having front and back surfaces along the fiber direction in an aggregated state and adhering and integrating them.
The first woody flakes have a thickness of 0.05 mm or more and 0.35 mm or less between the front and back surfaces , a length of 40 mm or less along the fiber direction, and a width along the direction orthogonal to the fiber direction. 15 mm or less,
The second wood layer is formed by laminating a large number of elongated second wood flakes having front and back surfaces along the fiber direction in an aggregated state and adhering and integrating them.
The wood laminated board characterized in that the second wood flakes are smaller than the first wood flakes in the same thickness range as the first wood flakes. In the wood laminated board of claim 1,
The first woody thin section is a woody laminated board having an elongated shape having a thickness of 0.15 to 0.25 mm, a length of 20 mm or less, and a width of 5 mm or less. In the wood laminated board of claim 1 or 2.
The second woody thin section is a wood laminated board characterized in that at least one dimension of length and width is smaller than that of the first woody thin section. In the wood laminated board according to any one of claims 1 to 3,
The second woody flakes are characterized by having an elongated shape having a thickness of 0.15 to 0.25 mm, a length of 10 mm or less, and a width of 2 mm or less. In the wood laminated board according to any one of claims 1 to 4,
A wood laminated board characterized in that the ratio of the thickness to the entire wood laminated board of each of the second woody material layers is 5% or more and 40% or less. In the wood laminated board according to any one of claims 1 to 5,
A wood laminated board characterized in that the density of the first wood material layer and each of the second wood material layers is 250 to 800 kg / m ³ .

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