Orthogonal laminated board for furniture and fixtures and method for manufacturing the same

Abstract

To provide an orthogonal integration plate for a furniture-fitting capable of weight saving while securing an advantage of hardness of a broad leaf tree.SOLUTION: An inside ply 20 is constituted by laminating-adhering between two outside plies 10 by making a fiber direction mutually orthogonal, and the outside ply is constituted by juxtaposing or adhering a lamina or a small square bar of a broad leaf tree mutually in parallel in its fiber direction, and an inside ply is constituted of Japanese cedar or cypress, and a plate thickness of the inside ply is a dimension within a range of 12 mm-14 mm, and a plate thickness of the outside ply is a dimension within a range of 2.4 mm-2.6 mm or a dimension within a range of 3.9 mm-4.1 mm or the plate thickness of the inside ply is a dimension within a range of 15 mm-17 mm, and the plate thickness of the outside ply is a dimension within a range of 3.4 mm-4.6 mm.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an orthogonally laminated board for furniture and fixtures and a method for manufacturing the same, and more particularly to a laminated board and a method for manufacturing the same that can achieve weight reduction while ensuring the advantages of the hardness of broad-leaved trees.

Background Art

[0002] For example, among the privately-owned forests in Hyogo Prefecture, approximately 40% are broad-leaved forests, and there is a statistic that approximately 40% of those broad-leaved forests are Konara or Kunugi. Among broad-leaved trees, Kuri, Tamo, Keyaki, Mizunara, etc. are widely used as raw materials for wood, but since they require a long time to grow and it is necessary to use old trees, they cannot be said to be abundant resources in Japan and have relied solely on imports. On the other hand, among broad-leaved trees, Konara and Kunugi grow quickly and are abundant as resources, and can be used in large quantities like cedar and hinoki. Also, regarding Kuri, it is abundant only for small-diameter trees.

[0003] In addition, a technique has been proposed to perform low-temperature drying of wood at a temperature in the range of 30°C to 50°C without causing warping, distortion, or discoloration (Patent Document 1). However, even when Konara or Kunugi is dried by this low-temperature drying technique, warping or twisting occurs, making it difficult to use for the purpose of a board material, and it has only been used as firewood or a log for shiitake mushrooms (Patent Document 2).

[0004] Recently, the demand for firewood and logs has decreased, and the satoyama has been left unmaintained. Even when producing logs, large trees with a tree age of 60 to 80 years are cut and their branches are used as logs. The development of uses for broad-leaved trees, such as Konara, Kunugi, and Kuri, has been demanded.

[0005] The applicant of this application proposed a manufacturing method in which rough lumber is sawn from oaks such as Konara or Kunugi, then dried at a low temperature until the moisture content is within the range of 15% to 20% at a temperature within the range of 35°C to 60°C, cured by covering with a light-shielding and moisture-proof sheet, and then re-dried at a low temperature until the moisture content is 10% or less at a temperature within the range of 35°C to 60°C, and the low-temperature re-dried raw board is finished into a flooring material with a finished width and thickness (Patent Document 3).

[0006] By the way, it has been proposed to use CLT (Cross Laminated Timber), which has high strength, for floor materials and wall materials of building structures (Patent Document 4).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Disclosure of the Invention

Problems to be Solved by the Invention

[0008] If broad-leaved trees, such as Konara, Kunugi, or Kuri boards, can be used for furniture and fixtures, the applications of broad-leaved trees will expand. However, compared with cedar and cypress, Konara, Kunugi, and Kuri have a harder and heavier board quality, making them difficult to use for furniture and fixtures. Recently, DIY (Do-It-Yourself) has become popular, where non-experts process and work on materials by themselves to make furniture and fixtures. However, due to the hardness and weight of broad-leaved trees, they are difficult for non-experts to handle.

[0009] In view of this point, an object of the present invention is to provide a cross-laminated board for furniture and fixtures that can achieve weight reduction while ensuring the advantages of the hardness of broad-leaved trees.

Means for Solving the Problem

[0010] Therefore, the cross-laminated timber for furniture and fixtures according to the present invention is configured by laminating and adhering inner plies between two outer plies with their fiber directions orthogonal to each other. The two outer plies are formed by arranging or adhering hardwood veneers or small square timbers with their fiber directions parallel to each other, while the inner plies are made of cedar or cypress. The thickness of the outer plies and the inner plies is such that the inner plies have dimensions within the range of 12 mm to 14 mm, and the outer plies have dimensions within the range of 2.4 mm to 2.6 mm or within the range of 3.9 mm to 4.1 mm, or the inner plies have dimensions within the range of 15 mm to 17 mm, and the outer plies have dimensions within the range of 3.4 mm to 4.6 mm.

[0011] One of the features of the present invention is that two outer plies and an inner ply are orthogonally arranged in their fiber directions to form a CLT, and hardwood veneers or small square timbers are used for the two outer plies, and cedar or cypress is used for the inner ply.

[0012] Thus, the quality of the wood material can be reduced by the characteristics of cedar or cypress, while the hardness and strength of the CLT can be ensured by the hardwood. When the CLT of this case is applied to a door, the weight can be reduced, resulting in less burden on the hinge, and nailing can be facilitated compared to the case where the interior is hollow. Furthermore, since the pattern of hardwood appears on the surface, a more natural look can be obtained compared to plywood, etc., and it is aesthetically beautiful and has a high-quality texture.

[0013] When the thickness of the cross-laminated timber (hereinafter sometimes simply referred to as CLT) is 18 mm, the inner plies have dimensions within the range of 12 mm to 14 mm, and the outer plies have dimensions within the range of 2.4 mm to 2.6 mm. If the thickness of the outer plies exceeds 2.6 mm, the CLT becomes heavy and hard, making it complicated to process for DIY, etc. On the other hand, if it is less than 2.4 mm, the desired hardness cannot be obtained.

[0014] When the thickness of the CLT is 21 mm, the inner ply shall have dimensions within the range of 12 mm to 14 mm, and the outer ply shall have dimensions within the range of 3.9 mm to 4.1 mm. However, if the thickness of the outer ply exceeds 4.1 mm, the CLT will become heavy and hard, making it complicated to process with DIY etc. On the other hand, if it is less than 3.9 mm, the desired hardness cannot be obtained.

[0015] When the thickness of the CLT is 24 mm, the inner ply shall have dimensions within the range of 15 mm to 17 mm, and the outer ply shall have dimensions within the range of 3.4 mm to 4.6 mm. However, if the thickness of the outer ply exceeds 4.6 mm, the CLT will become heavy and hard, making it complicated to process with DIY etc. On the other hand, if it is less than 3.4 mm, the desired hardness cannot be obtained.

[0016] Also, the reason for specifying the dimensions of the outer ply and the inner ply within the above-mentioned ranges is that if they are outside the range, the CLT may warp or twist.

[0017] Cedar or cypress may be a single board, but cedar or cypress can be composed by arranging or bonding sawn boards or small square timbers parallel to each other in their fiber directions.

[0018] Sawn boards and small square timbers of hardwoods can be produced as follows. Cut straight timbers from the trunks of hardwoods, saw rough boards larger than the finished width and finished thickness from the straight timbers, air-dry the rough boards at a temperature within the range of 35°C or higher and 60°C or lower until the moisture content is within the range of more than 10% and 20% or lower, roughly finish the air-dried rough boards into raw boards larger than the finished width and finished thickness, cure the roughly finished raw boards covered with a light-shielding and moisture-proof sheet, re-air-dry the cured raw boards at a temperature within the range of 35°C or higher and 60°C or lower until the moisture content is 10% or lower, and finally finish the re-air-dried raw boards into sawn boards or small square timbers of the finished width and finished thickness.

[0019] By performing low-temperature drying at a temperature within the range of 35°C to 60°C until the moisture content reaches within the range of 10% to 20%, a rough board with less warping and twisting can be obtained. By curing this rough board, the moisture content of the rough board becomes uniform throughout the rough board. Subsequently, by performing low-temperature re-drying until the moisture content becomes 10% or less, a raw board material without warping and twisting can be obtained. By finishing this into sawn boards or small square timbers of a predetermined size, a board material with a higher density and higher abrasion resistance than beech or teak can be obtained, and a CLT optimal for furniture and joinery can be obtained.

[0020] In addition, as characteristics of konara and kunugi, there are patterns such as tiger stripes, which have a high-class texture comparable to oak and chestnut and are excellent in design, have a high nail holding power, and are excellent in workability.

[0021] Solid wood is sawn into rough boards using a band saw carriage and a table saw.

[0022] The rough board and the raw board material are dried at a low temperature using a low-temperature dryer at a temperature within the range of 35°C to 60°C. The reason for setting it at 35°C or higher is that at a temperature below 35°C, it takes a long time to dry the rough board to a moisture content within the range of 10% to 20% or the raw board material to a moisture content of 10% or less, and if it exceeds 60°C, there is a risk that warping and twisting will increase due to drying.

[0023] Since the inner and outer plies of the sawn board and the small square timber are adhered to each other, they may be arranged in the width direction. For example, if they are joined in the width direction using a wood router and used for CLT, high strength can be obtained.

[0024] In addition, the manufacturing method of the orthogonal laminated board for furniture and fixtures according to the present invention includes a step of cutting out straight materials from the trunk of a broad-leaved tree, a step of sawing a rough board larger than the finished width and thickness from the straight materials, a step of low-temperature drying the rough board until the moisture content is within the range of more than 10% and not more than 20% at a temperature within the range of 35°C or higher and 60°C or lower, a step of roughly finishing the low-temperature dried rough board into a raw board material larger than the finished width and thickness, a step of curing the roughly finished raw board material by covering it with a light-shielding and moisture-proof sheet, a step of low-temperature re-drying the cured raw board material until the moisture content is 10% or less at a temperature within the range of 35°C or higher and 60°C or lower, a step of finishing the low-temperature re-dried raw board material into a drawn board or small square timber of the finished width and thickness, a step of manufacturing an outer ply by arranging or bonding drawn boards or small square timbers with their fiber directions parallel to each other, and a step of bonding with an inner ply of cedar or cypress sandwiched between two outer plies. It is characterized by comprising these steps.

Brief Description of Drawings

[0025]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0026] Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. FIGS. 1 and 2 show preferred embodiments of the orthogonal laminated board for furniture and fixtures according to the present invention. In the figures, the CLT30 of this example is configured by laminating and bonding two outer plies 10 and an inner ply 20 with their fiber directions orthogonal to each other.

[0027] The two outer plies 10 are manufactured by arranging and bonding drawn boards 11 or small square timbers 12 of a broad-leaved tree, for example, konara or oak, with their fiber directions parallel to each other, and the inner ply 20 is manufactured by arranging and bonding drawn boards 21 or small square timbers 22 of cedar or cypress with their fiber directions parallel to each other.

[0028] The thicknesses of the outer ply 10 and the inner ply 20 are such that the inner ply 20 has a dimension b within the range of 12 mm to 14 mm, for example 13 mm, and the outer ply 10 has a dimension a within the range of 2.4 mm to 2.6 mm, for example 2.5 mm or within the range of 3.9 mm to 4.1 mm, for example 4.0 mm, or the inner ply 20 has a dimension b within the range of 15 mm to 17 mm, for example 16 mm, and the outer ply 10 has a dimension a within the range of 3.4 mm to 4.6 mm, for example 4.0 mm.

[0029] When manufacturing CLT30, conifers or oaks are logged. The trunks with a top diameter of 28 cm or more are cut at the bent part to obtain straight timbers, and the timbers are sawn into lengths of 2 m to 4 m.

[0030] Next, rough board sawing is carried out. Using a band saw carriage and a table saw, the rough boards are sawn to be +20 mm wider and +5 mm thicker than the finished width and thickness. The sapwood, and those with mold, stains or insect damage are chipped. After sawing, they are immediately "piled flat" to prevent mold from entering. Also, avoid direct sunlight and exposure to wind and rain so that there is no warping or twisting.

[0031] In the next step, artificial drying is carried out. In a low-temperature dryer, the battens with a thickness of 24 mm or more are placed at a pitch of 60 cm or less, and the rough boards are stacked on the battens with a gap of 1 cm or more in the width direction, and are dried at a low temperature within the range of 35°C to 60°C until the moisture content is within the range of more than 10% and less than or equal to 20%. The drying time varies depending on the moisture content of the rough boards. If the moisture content of the rough boards is high, a longer time is required.

[0032] Next, defects of the low-temperature dried rough boards are removed. First, rough planing is carried out so that it is +10 mm wider and +4 mm thicker than the finished width. Then, defects such as insect damage, cracks, mold, warping, and knots are removed with a cut-off saw to obtain plain lumber.

[0033] Finger processing is performed on the obtained raw board material. Finger processing uses a finger shaver to form fingers on the opposing end faces of the raw board material. After the finger processing is completed, the raw board materials are adhered longitudinally with an adhesive, for example, an aqueous vinyl chloride-based adhesive, and then trimmed to the required length. When adhering, press with a pressure adjusted so that pinholes do not occur.

[0034] Next, storage and curing are carried out. Lumber with a thickness of 24 mm or more is stacked at a pitch of 60 cm or less, covered with a light-shielding and moisture-proof sheet, for example, a plastic sheet, to prevent moisture absorption, and stored and cured. By this curing, the moisture content of the raw board material becomes uniform throughout the raw board material. The storage and curing time is until an order for the product is received, but for quality stability, long-term storage and curing are preferred.

[0035] When an order is received, re-drying is performed. Lumber with a thickness of 24 mm or more is placed in a low-temperature dryer at a pitch of 60 cm or less, the rough boards are stacked with a gap of 1 cm or more in the width direction, and low-temperature re-drying is performed at a temperature in the range of 35°C to 60°C until the moisture content becomes 10% or less. This results in raw board materials with stable quality and less warping and twisting.

[0036] After the low-temperature re-drying is completed, pre-processing is performed. That is, using a molder, splitting processing is carried out to manufacture split boards or small square timbers, wood carving processing is carried out using a molder, a ridge is formed on one side surface of the split board or small square timber, a groove is formed on the other side surface, end match processing is performed with a double-end tenoner, knots, cracks, etc. are repaired with putty and an adhesive, and finishing is done to a roughness of #240 with a wide sander.

[0037] After that, it is placed in a press, adhered with an adhesive, for example, an aqueous vinyl chloride-based adhesive, molded to the required dimensions, planed to be 0.5 mm larger than the finishing dimensions with a planer, finished to a roughness of #240 with a wide sander, and an assembled board is manufactured.

Explanation of Signs

[0038] 10 Outer ply 20 Inner ply

Claims

1. An inner ply (20) is laminated and adhered between two outer plies (10) with their fiber directions orthogonal to each other, wherein the two outer plies (10) are formed by arranging or adhering veneers or small-sized lumber of hardwood with a moisture content of 10% or less and less warping and twisting in parallel with each other in their fiber directions, the inner ply is made of cedar or cypress, the thickness of the cross-laminated board is 18 mm, the thickness of the inner ply is in the range of 2 mm to 14 mm, and the thickness of the outer ply is in the range of 2.4 mm to 2.6 mm; or the thickness of the cross-laminated board is 21 mm, the thickness of the inner ply is in the range of 12 mm to 14 mm, and the thickness of the outer ply is in the range of 3.9 mm to 4.1 mm; or the thickness of the cross-laminated board is 24 mm, the thickness of the inner ply is in the range of 15 mm to 17 mm, and the thickness of the outer ply is in the range of 3.4 mm to 4.6 mm. A cross-laminated board for furniture and fixtures, characterized by the above.

2. The cross-laminated board for furniture and fixtures according to Claim 1, wherein the inner ply (20) is formed by arranging or adhering cedar or cypress veneers or small-sized lumber in parallel with each other in their fiber directions.

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