JP7653695B2 - Composites - Google Patents

Description

This disclosure relates to composite materials made up of multiple wood materials.

Conventionally, composite materials that include a base material that serves as a core and a surface material that is placed on the surface of the base material have been used as plate-shaped members that utilize wood or wood-based materials. The following Patent Document 1 discloses laminated wood in which the fibers are arranged to cross each other.

JP 2008-126572 A

Wood and wood-based materials can warp due to changes in moisture content. In particular, when the base material and surface material have a laminated structure, the surface material is prone to warping and cracking. Conventional technology has not always been able to fully suppress the effects of warping.

The purpose of this disclosure is to propose a technology that can suppress warping of wooden materials.

One aspect of the present disclosure is a composite material comprising a substrate and a surface material. The surface material includes a plurality of veneers having a length in a predetermined direction, and is arranged on the surface of the substrate. Each of the plurality of veneers warps in a cross direction that crosses the predetermined direction depending on the degree of drying of the veneer, and has a first surface having a relatively large shrinkage rate depending on the degree of drying, and a second surface having a relatively small shrinkage rate depending on the degree of drying. The end surface in the cross direction of each of the plurality of veneers is an inclined surface that is inclined so that the side of the first surface is located closer to the center of the cross direction in the thickness direction. The plurality of veneers are arranged side by side with the inclined surfaces of the veneers aligned so that the orientations of the first and second surfaces of adjacent veneers are different.

Another aspect of the present disclosure is a composite material comprising a base material and a surface material. The surface material includes multiple veneers having a length along the grain of the wood, and is arranged on the surface of the base material. Each of the multiple veneers has an end face in the intersecting direction, which is a direction that intersects with the grain of the wood, that is an inclined surface that is inclined so that the end face is located closer to the center of the intersecting direction as it approaches the front side of the wood. The multiple veneers are arranged side by side with the inclined surfaces of the veneers aligned so that the front and back sides of adjacent veneers are oriented differently.

With such a configuration, warping due to drying is suppressed, and the occurrence of peeling and cracking of the surface material due to the warping can be suppressed. In the following, warping and peeling and cracking due to warping are described as warping, etc. The reasons for the above effects are presumed to be as follows. (A) Since the first surface (e.g., the front surface of the wood) and the second surface (e.g., the back surface of the wood) of multiple veneers are arranged in an alternating order so that the orientations of the first surface (e.g., the front surface of the wood) and the second surface (e.g., the back surface of the wood) are arranged in an alternating order, the parts that shrink due to drying or expand to a greater extent due to moisture absorption are distributed on the front and back surfaces, which functions to counteract the warping that occurs. (B) Since the joint surfaces between the veneers are inclined surfaces, the area of the joint surfaces is larger than when the joint surfaces are parallel to the thickness direction of the veneers, improving the adhesive strength. (C) If there is a process of applying adhesive between the base material and the surface material and applying pressure, the joint surfaces are inclined surfaces, so that the pressure force is also applied to the joint surfaces, improving the adhesive strength.

In the composite material, the substrate may be wood or a wood-based material having wood grain. The substrate and the plurality of veneers may be arranged so that the grain directions of the veneers are aligned with each other.
With this configuration, the surface material can warp in response to warping of the base material, so cracking or peeling of the surface material due to warping of the base material can be suppressed.

In the above composite material, the multiple veneers may be compressed materials with a compression ratio of 30% to 50%. With this configuration, the veneers themselves are less likely to warp. This makes it possible to highly suppress the occurrence of warping and other problems in the entire surface material. In addition, the hardness of the veneers increases, making it possible to use the composite material in applications that require a high hardness on the surface.

In the composite material, the surface material may be disposed on both main surfaces of the substrate, which can suppress warping of the composite material as a whole.
The composite material may be used for a desk top, which can prevent warping from occurring in the surface material of the desk top.

In addition, in the above composite material, a resin coating layer may be disposed on the surface side of the surface material. With this configuration, it is possible to change the surface characteristics of the composite material.

FIG. 2 is a perspective view showing a substrate and a surface material constituting a composite material of an embodiment. FIG. 2 is a schematic front view illustrating a layered structure of a composite material according to an embodiment. FIG. 3A is a schematic front view of a veneer of the embodiment, and FIG. 3B is a schematic perspective view of the veneer of the embodiment. 11A and 11B are diagrams illustrating a pressure force applied to an inclined surface of a veneer. FIG. 13 is a diagram illustrating the state of contraction depending on the position. FIG. 13 is a schematic front view illustrating a composite material according to a modified example.

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.
1. Embodiment
[1-1. Overall configuration]
1 and 2 , the composite material 1 includes a substrate 11 and a pair of surface materials 12 disposed on the surfaces of the substrate 11. The surface materials 12 are disposed on both main surfaces of the substrate 11.

<Substrate>
The substrate 11 may be a plate-like member having wood grain. The wood grain here can also be referred to as the fiber direction. In this embodiment, the substrate 11 is a laminated wood. The specific material and configuration of the substrate 11 are not particularly limited. The wood grain direction of the substrate 11 is the direction along the wood grain direction shown in FIG. 1.

<Surface material>
The surface material 12 is a plate-like member having a wood grain. In this embodiment, the surface material 12 is configured to be thinner than the base material 11. The surface material 12 includes a plurality of veneers 21 having a length along the wood grain. The plurality of veneers 21 are compressed materials with a compression rate of 50% and have a thickness of 3 mm. When compressed materials are used for the veneers 21, compressed materials with a compression rate of 30% to 50% may be used, for example. The thickness of the veneers 21 is not particularly limited, and a plate material in the range of 3 mm to 10 mm may be used, for example.

As shown diagrammatically in Figures 3A-3B, the multiple veneers 21 are long, trapezoidal cross-sections of boards. Comparing the front side 21A, which is the surface on the front side of the veneer 21, with the back side 21B, which is the surface on the back side of the wood, the width of the front side 21A is smaller. The width here refers to the length in the direction that intersects with the grain direction. This direction that intersects with the grain direction will be referred to as the intersecting direction below. The intersecting direction is the direction that intersects with the grain direction and the thickness direction of the veneer 21. To be clear, the front side is the surface of the board that is farther from the core and closer to the bark when the tree is standing.

The end faces of the multiple veneers 21 in the cross direction are inclined faces 21C. The inclined faces 21C are inclined so that they are closer to the center of the cross direction of the veneer 21 as they approach the front side of the wood. In other words, the inclined faces 21C on both sides of the veneer 21 are at an angle that approaches each other toward the front side 21A. As shown in FIG. 3A, the inclined faces 21C on both sides of the veneer 21 have an angle θ with respect to the cross direction. In this embodiment, the angle θ is 80°.

As shown in FIG. 2, the multiple veneers 21 are arranged with the inclined surfaces 21C of the veneers 21 aligned so that the orientations of the front and back of adjacent veneers 21 are different. In other words, the multiple veneers 21 are arranged in a cross direction in order so that the orientations of the front and back of the veneers 21 are alternately different. Here, "aligning the inclined surfaces 21C" means that the inclined surfaces 21C are lined up facing each other, and is not necessarily limited to a configuration in which the inclined surfaces 21C are in contact with each other strictly. For example, a sheet-like member may be arranged between the inclined surfaces 21C.

<Relationship between base material and surface material>
1, the base material 11 and the multiple veneers 21 may be arranged so that the grain directions are aligned. The laminated wood constituting the base material 11 and the veneers 21 may be made of the same material. The same material type here means, for example, wood or wood materials of the same species.

<Example of manufacturing method>
The composite material 1 can be manufactured, for example, by applying an adhesive between the materials and applying pressure. The pressing device may be a so-called hot press that is capable of applying pressure and heat. The adhesive may be selected according to the pressing device. For example, when a hot press is used, a thermosetting resin adhesive may be used.

Specifically, first, a substrate, which is a laminated lumber, is prepared. Then, adhesive is applied to the surface of the substrate 11 and one or both of the faces of the veneers 21 facing the substrate 11, and to the inclined surfaces 21C, so that the adhesive is applied between the substrate 11 and the surface material 12 and between each veneer 21. After the adhesive is applied, the veneers 21 are arranged in a row on the main surface of the substrate 11. Then, as shown in FIG. 4, pressure and heat are applied from the side of the surface material 12 to bond the substrate 11 and the surface material 12 together.

<Application examples>
The composite material 1 can be used, for example, as a tabletop. When used as a tabletop, a joining mechanism may be provided so that it can be joined to the legs of the desk. For example, a countersunk nut may be embedded in the tabletop so that it can be fastened to a bolt attached to the leg. Of course, the composite material 1 may be used for purposes other than tabletops.

[1-2. Effects]
According to the embodiment described above in detail, the following effects can be obtained.
(1a) In the composite material 1, multiple veneers 21 are arranged so that the orientation of the front and back of adjacent veneers 21 is different. Therefore, as shown by the arrows in Fig. 5, for example, the front, which shrinks a lot due to drying, and the back, which shrinks a little due to drying, are distributed and arranged on both sides of the surface material 12. Therefore, the difference in the amount of shrinkage on both sides of the surface material 12 is small, and warping is suppressed. As a result, peeling and cracking of the surface material 12 can be reduced.

(1b) In the composite material 1, the inclined surfaces 21C become the joint surfaces between the veneers 21. Therefore, compared to conventional joint surfaces that are parallel to the thickness direction of the veneers, the area of the joint surfaces is larger, and the adhesive strength between the joint surfaces (i.e., between the inclined surfaces 21C) is improved. In addition, in the pressurizing process, as shown by the arrows in the surface material 12 in Figure 4, the pressurizing force is also applied to the inclined surfaces 21C, which are the joint surfaces. Therefore, the adhesive strength after pressing is increased. In this way, by increasing the adhesive strength between the end surfaces of the veneers 21, even if the veneers 21 shrink or expand, warping can be suppressed, and peeling and cracking of the veneers 21 can be reduced.

(1c) In the composite material 1, the grain direction of the base material 11 and the surface material 12 are the same. Therefore, when warping occurs in the base material 11, the surface material 12 can easily follow the deformation of the base material. This reduces the load applied to the surface material 12 due to warping of the base material 11, and prevents peeling and cracking.

(1d) In the composite material 1, the veneer 21 is a compressed material. This is advantageous because the veneer 21 is less likely to warp. In addition, the veneer 21 has high hardness, so it can be used for a wide range of purposes. For example, it can be used as a desk top for writing.

2. Other embodiments
Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is in no way limited to the above-described embodiments, and can take various forms as long as it falls within the technical scope of the present disclosure.

(2a) In the above embodiment, a laminated wood having a grain was used as the base material 11, but the material and configuration of the base material 11 are not particularly limited. Examples of materials having a grain include wood and wood materials having grain in a certain direction. In addition to laminated wood, examples of such wood materials include parallel plywood. The base material may be wood materials that do not have a grain. The base material may be, for example, plywood, particle board, medium density fiberboard, etc. Note that when a wood material having a grain is used as the base material, the effect of (1c) above can be obtained by matching the grain of the surface material. Of course, the grain direction of the base material and the surface material does not have to be matched.

(2b) In the above embodiment, compressed material is exemplified as the veneer 21 of the surface material 12. However, the specific form of the multiple veneers constituting the surface material 12 is not particularly limited as long as the material satisfies the following conditions (a) to (c). (a) It has a length in a predetermined direction. (b) Depending on the degree of dryness of the veneer, warping occurs in a direction intersecting the predetermined direction. (c) It has a first surface with a relatively large shrinkage rate according to the degree of dryness, and a second surface with a relatively small shrinkage rate according to the degree of dryness. The degree of dryness can be rephrased as moisture content.

Furthermore, the end face in the cross direction of each of the multiple veneers that satisfy the above conditions is an inclined surface that is inclined so that the closer to the first surface in the thickness direction the closer it is to the center in the cross direction. Also, the surface material is constructed by arranging the veneers side by side with the inclined surfaces aligned so that the orientations of the first and second surfaces of adjacent veneers are different.

If the veneer has the above configuration, it can be treated the same as the veneer 21 of the above embodiment. For example, a board material other than a cross grain board, such as a straight grain board, may be used as the veneer. Also, if the veneer has the above configuration, it does not necessarily have to have wood grain. The veneer 21 may be wood other than compressed material. Also, the base material 11 and the surface material 12 do not have to be the same type of material. Note that in the veneer 21 of the embodiment, the direction of the wood grain is the above-mentioned specified direction, the front side 21A, which is the wood surface, is the first side, and the back side 21B, which is the wood back, is the second side.

The specific shape of the veneer is not particularly limited, as long as it has an inclined surface on both ends in the cross direction, and the inclined surface is inclined toward the center of the cross direction of the veneer as it approaches the surface of the wood.

(2c) In the above embodiment, a configuration in which the surface material 12 is disposed on both main surfaces of the base material 11 is exemplified, but the surface material 12 may be disposed on only one of the main surfaces of the base material 11.

(2d) In the above embodiment, the angle θ of the inclined surface 21C is 80°, but this angle is not particularly limited. The angle θ can be set in the range of 65° to 85°, for example. In particular, if the angle θ is 75° or more, adjacent veneers can be prevented from sliding on the inclined surface, causing one veneer to ride up onto the other veneer, resulting in misalignment in the thickness direction. Furthermore, if the angle θ is 82° or less, the above-mentioned effect of pressurizing the joint surface during the manufacturing process can be effectively achieved.

(2e) The composite material 1 may have other features in addition to the configuration described in the embodiment. For example, as shown in FIG. 6, a resin coating layer 31 may be disposed on the front side of the surface material 12. The resin constituting the resin coating layer 31 is not particularly limited, but for example, an ultraviolet-curable resin may be used. The resin coating layer 31 coats the entire surface of the surface material 12. With this configuration, the physical properties of the surface of the composite material 1 can be adjusted by the resin. For example, by using an ultraviolet-curable resin, the strength of the surface of the surface material 12 can be increased.

(2f) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

(2g) In addition to the composite material 1 described above, the present disclosure can also be realized in various forms, such as furniture that includes the composite material 1 as a component, and a method for manufacturing the composite material 1.

1...composite material, 11...substrate, 12...surface material, 21...single plate, 21A...front side, 21B...rear side, 21C...inclined surface, 31...resin coating layer

Claims (8)

A composite material,
A substrate;
A surface material including a plurality of veneers having a length in a predetermined direction and disposed on a surface of the base material;
Each of the plurality of veneers has a warp occurring in a cross direction crossing the predetermined direction depending on a degree of drying of the veneer, and has a first surface having a relatively large shrinkage rate depending on the degree of drying, and a second surface having a relatively small shrinkage rate depending on the degree of drying,
an end surface in the intersecting direction of each of the plurality of single plates is an inclined surface that is inclined so as to be positioned toward a center in the intersecting direction toward the first surface side in the thickness direction,
The plurality of veneers are arranged with the inclined surfaces of the veneers aligned such that the orientations of the first surface and the second surface of adjacent veneers are different,
the first surface or the second surface of each of the plurality of veneers facing the base material is disposed so as to abut against a surface of the base material;
The surface material is configured to be thinner than the base material,
The plurality of veneers are compressed materials having a compression ratio of 30% to 50%,
The base material includes a plurality of rectangular plates having a length in the predetermined direction, and each of the plurality of rectangular plates has two side surfaces extending in the predetermined direction that are substantially parallel to each other;
The length of each of the plurality of veneers in the cross direction is constant in the predetermined direction,
A composite material , wherein the length of the first surface of each of the plurality of veneers in the cross direction is longer than the length of each of the plurality of rectangular plates in the cross direction . A composite material,
A substrate;
A surface material including a plurality of veneers having a length along the grain and disposed on a surface of the base material;
Each of the plurality of veneers has an end surface in a cross direction that crosses the grain direction, the end surface being inclined so that the end surface is located closer to the center of the cross direction as it approaches the surface of the wood,
The plurality of veneers are arranged with the inclined surfaces of the veneers aligned so that the orientations of the front and back surfaces of adjacent veneers are different,
The front surface or the back surface of each of the plurality of veneers facing the base material is arranged to abut against a surface of the base material,
The surface material is configured to be thinner than the base material,
The plurality of veneers are compressed materials having a compression ratio of 30% to 50%,
The base material includes a plurality of square boards having a length in the direction of the grain, and each of the plurality of square boards has two side surfaces extending in the direction of the grain that are substantially parallel to each other;
The length of each of the plurality of veneers in the cross direction is constant in the grain direction,
A composite material , wherein the length of the wood surface of each of the plurality of veneers in the cross direction is longer than the length of each of the plurality of square boards in the cross direction . The composite material according to claim 1 or 2,
The substrate is wood or a wood-based material having wood grain,
A composite material, wherein the base material and the plurality of veneers are arranged such that their grain directions match. A composite material,
A substrate;
A surface material including a plurality of veneers having a length in a predetermined direction and disposed on a surface of the base material;
Each of the plurality of veneers has a warp occurring in a cross direction crossing the predetermined direction depending on a degree of drying of the veneer, and has a first surface having a relatively large shrinkage rate depending on the degree of drying, and a second surface having a relatively small shrinkage rate depending on the degree of drying,
an end surface in the intersecting direction of each of the plurality of single plates is an inclined surface that is inclined so as to be positioned toward a center in the intersecting direction toward the first surface side in the thickness direction,
The plurality of veneers are arranged with the inclined surfaces of the veneers aligned such that the orientations of the first surface and the second surface of adjacent veneers are different,
The substrate is wood or a wood-based material having wood grain,
The base material and the plurality of veneers are arranged so that the grain directions of the veneers are aligned with each other,
The surface material is configured to be thinner than the base material,
The plurality of veneers are compressed materials having a compression ratio of 30% to 50%,
The base material includes a plurality of rectangular plates having a length in the predetermined direction, and each of the plurality of rectangular plates has two side surfaces extending in the predetermined direction that are substantially parallel to each other;
The length of each of the plurality of veneers in the cross direction is constant in the predetermined direction,
A composite material , wherein the length of the first surface of each of the plurality of veneers in the cross direction is longer than the length of each of the plurality of rectangular plates in the cross direction . A composite material,
A substrate;
A surface material including a plurality of veneers having a length along the grain and disposed on a surface of the base material;
Each of the plurality of veneers has an end surface in a cross direction that crosses the grain direction, the end surface being inclined so that the end surface is located closer to the center of the cross direction as it approaches the surface of the wood,
The plurality of veneers are arranged with the inclined surfaces of the veneers aligned so that the orientations of the front and back surfaces of adjacent veneers are different,
The substrate is wood or a wood-based material having wood grain,
The base material and the plurality of veneers are arranged so that the grain directions of the veneers are aligned with each other,
The surface material is configured to be thinner than the base material,
The plurality of veneers are compressed materials having a compression ratio of 30% to 50%,
The base material includes a plurality of square boards having a length in the direction of the grain, and each of the plurality of square boards has two side surfaces extending in the direction of the grain that are substantially parallel to each other;
The length of each of the plurality of veneers in the cross direction is constant in the grain direction,
A composite material , wherein the length of the wood surface of each of the plurality of veneers in the cross direction is longer than the length of each of the plurality of square boards in the cross direction . A composite material according to any one of claims 1 to 5,
A composite material, wherein the facing material is disposed on both major surfaces of the substrate. A composite material according to any one of claims 1 to 6,
The composite material in question is a composite material used for table tops. A composite material according to any one of claims 1 to 7,
A composite material, comprising a resin coating layer disposed on the front side of the surface material.

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