JPH0612008U - Laminate - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a laminate having mechanical strength not inferior to conventional plywood by replacing a part of the conventional plywood veneer with a wood fiber layer. [Structure] A middle-layer wood fiber layer 2 of a laminated plate obtained by laminating a surface-layer wood fiber layer 1, a middle-layer wood veneer layer 3, a middle-layer wood fiber layer 2, and a back-layer wood veneer layer 4 in this order from the front side. The laminated board is formed to be thicker than the surface wood fiber layer.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a laminated board used for structural materials, as well as for building exteriors, interiors and furniture.

[0002]

[Prior art]

 Laminated boards are known such as plywood in which single fibers are laminated and bonded with their fiber directions orthogonal to each other, and parallel plywood (L.V.L.) in which the fiber directions of single plates are laminated and bonded in the same direction. It is an indispensable part of today's building materials because it can stably supply large quantities of large-sized boards that cannot be obtained from sawn timber and has excellent dimensional stability.

[0003]

[Problems to be solved by the device]

 However, since this plywood is manufactured by laminating and bonding veneers from which thin pieces of natural wood have been peeled off, the problem of depletion of natural resources has been widely taken up worldwide, making it difficult to cut down the raw material raw wood. At the same time, the quality of the raw wood deteriorates, making it difficult to obtain a large amount of good quality veneer used for veneer, and to supply a large amount of good quality plywood to the market. It is predicted that this problem will become more serious in the future, and there is a strong desire to provide an alternative to plywood.

[0004]

[Means for Solving the Problems]

 The present invention has been completed as a result of earnest efforts for the purpose of providing a novel laminated plate that can be used as a substitute for plywood.

That is, the present invention has a structure as shown in FIG. 1, and the surface wood fiber layer 1, the middle wood veneer layer 3, the middle wood fiber layer 2, and the back wood veneer layer 4 are arranged in this order from the surface side. It is a laminated plate that is integrally laminated.

The wood veneer used for the middle-layer wood veneer layer 3 and the back-layer wood veneer layer 4 of the laminated plate is obtained by cutting a coniferous or hardwood log using a cutting device such as a rotary racer or a slicer. Softwood veneers and hardwood veneers used can be used. As the softwood veneer and the hardwood veneer, those having a plate thickness of 0.2 mm or more, preferably 0.5 to 5.5 mm are used.

When the plate thickness is 0.2 mm or less, the mechanical strength of the laminated plate is not improved. If it is 0.5 mm or more, it is given for improvement. Further, when the thickness is 5.5 mm or more, the shrinkage and expansion of the veneer due to the absorption and release of moisture affects the dimensional stability of the laminated plate.

The fiber directions of the middle-layer wood veneer layer and the back layer wood veneer layer can be arranged so as to be parallel or orthogonal to each other. However, in general, wood veneer shrinks and expands in the direction perpendicular to the fiber direction by 5 to 20 times greater than the contraction and expansion in the direction parallel to the fiber direction of the veneer by absorbing and releasing moisture. The rate of change between the vertical and vertical directions is very different.

Therefore, by arranging the middle-layer wood veneer layer 3 and the back-layer wood veneer layer 4 so that the fiber directions thereof are orthogonal to each other, shrinkage and expansion in the direction perpendicular to the fiber direction of the veneer due to moisture absorption and desorption. The effects of mutually suppressing the movements of the laminated plates are produced, the contraction and expansion of the laminated plate in the length direction and the width direction are made uniform, and the dimensional stability of the laminated plate is excellent. Further, the middle-layer wood veneer layer and the back layer wood veneer layer may be composed of veneers having the same plate thickness or different plate thicknesses.

Furthermore, by arranging the fiber layer of the backing layer veneer veneer layer 4 so as to be parallel to the length direction of the laminated plate, in terms of mechanical strength, the wood veneer can be oriented in any direction. Since it has the property of high bending strength and tensile strength in the parallel direction, when a bending load is applied in the length direction of the present invention, the durability against tensile addition that occurs on the back surface side is improved, and the strength as a laminated plate is improved. It has excellent properties in bending strength in the depth direction. Therefore, it is a plate material that is very suitable for use as a substrate that requires bending strength in the length direction, such as a floor material that is generally constructed so as to support the end in the length direction by a base structure material.

As the wood veneers used for the middle-layer wood veneer layer 3 and the back wood veneer layer 4, phenol resin treatment, acetylation treatment, esterification treatment, formalization treatment, PEG (polyethylene glycol) treatment or By using a material that has been subjected to a WPC treatment (resin impregnation) or the like to improve the dimensional stability and mechanical properties, a laminate having even more excellent bending strength and dimensional stability can be obtained. Furthermore, by using a wood veneer that has been treated with a flame-retardant chemical such as ammonium phosphate, a phosphorus-nitrogen compound, a halogen compound, sulfamic acid, or boric acid, a laminated board that also has a fire protection function can be obtained. To be These treatments are carried out by immersing the veneer in a fireproofing agent, coating the agent, or injecting the agent under pressure or reduced pressure.

As the wood fibers used for the surface wood fiber layer 1 and the middle wood fiber layer 2 of the laminated board, there are softwood materials such as pine, cedar and cypress, and hardwood materials such as lauan, capoule, chestnut and poplar. A wood fiber layer obtained by pressing and molding wood fibers obtained by defibrating wood chips obtained by cutting raw wood or scrap wood by a conventional method, and having a specific gravity of 0.4 or more, preferably 0.5 or more. It is known as MDF or the like. In addition, scrap materials such as sander dust, saw dust, and chip dust produced during the production of wood fiber boards can be mixed and used in the wood fiber layer.

These wood fiber layers have excellent dimensional change rate per unit water content of 1% in the length direction and the width direction of 0.03 to 0.04%, which is excellent stability. The stability of the wood fiber layer is added to the effect of suppressing the contraction and expansion of the wood veneer layers by arranging the middle-layer wood veneer layer 3 and the back layer wood veneer layer so that their fiber directions are orthogonal to each other. As a result, a laminated board having a property of further excellent dimensional stability is obtained. In particular, by forming the thickness of the middle-layer wood fiber layer 2 disposed between the middle-layer wood veneer layer 3 and the back-layer wood veneer layer 4 to be thicker than that of the front-layer wood fiber layer 1, the front and back of the middle-layer wood fiber layer 2 can be formed. The function of restraining the movement of shrinkage and expansion due to moisture absorption and desorption of each wood veneer layer located in the area becomes stronger, and the improvement of dimensional stability becomes excellent. This is comparable to the performance of plywood having excellent dimensional stability of 0.02 to 0.03% per 1%.

Further, in terms of mechanical strength, the wood fiber layer has a higher specific gravity than the wood veneer and is excellent in compression and shear strength. For this reason, even if a load is locally applied to the surface by a ball drop test, high heels, casters, etc., it is difficult to dent. Further, by forming the middle-layer wood fiber layer 2 to be thicker than the surface-layer wood fiber layer 1 and arranging the middle-layer wood fiber layer 2 at the center in the thickness direction, a bending load is applied to the laminated plate of the present invention. In this case, the surface wood fiber layer 1 exhibits excellent compression resistance against the addition of compression occurring on the surface side and the addition of shearing occurring at the center portion in the thickness direction. Since the layer 2 exhibits excellent shear resistance, the laminated plate has excellent properties in bending strength in the length direction and the width direction. Furthermore, since the wood fiber layer, which has excellent smoothness and processability, is placed on the surface layer, an excellent finish can be obtained even if a decorative sheet is attached or a coating treatment is applied, and cutting in any direction is possible. It can be easily processed.

As the wood fiber layers used for the surface wood fiber layer 1 and the middle wood fiber layer 2, phenol resin treatment, acetylation treatment, esterification treatment, formalization treatment, PEG (polyethylene glycol) treatment, or WPC treatment is performed. By using a material that has been subjected to a treatment (resin impregnation) or the like to have improved dimensional stability and mechanical properties, it is possible to obtain a laminated board having even more excellent bending strength and dimensional stability. These treatments include, for example, pine, cedar, cypress, and other softwood materials, or rawan, capoule, chestnut, poplar, and other hardwood materials into chips, which are then defibrated according to the usual method and dried at any stage. The above treatment is carried out by a conventional method, and a wood fiber layer is produced using the obtained wood fiber.

[0016] Furthermore, by using a wood fiber treated with a flame retardant agent such as ammonium phosphate, a phosphorus nitrogen compound, a halogen compound, sulfamic acid and boric acid as a wood fiber layer, a laminate having a fireproof function as well. A board is obtained. These treatments are performed in the same manner as the treatments for improving the dimensional stability and mechanical properties.

The laminated board of the present invention uses, for example, a pre-manufactured wood fiber board and wood veneer, and a surface wood fiber layer, a middle wood veneer layer, a middle wood fiber layer, and a back wood veneer layer from the surface side. It is obtained by laminating via the adhesive in this order and pressing in accordance with a conventional method. In addition, in the manufacturing process of wood fiberboard, a wood fiber mat obtained by cutting and temporarily pressing the dried wood fibers applied with a forming device on a screen belt and cutting them to a certain size is used. , Put the wood fiber mat on the wood veneer with the adhesive applied to the front side, and then put the wood veneer with the adhesive applied on the front and back, and finally put the wood fiber mat on it. A laminated board can be manufactured by hot pressing.

This method is an industrially advantageous method such that the conventional production line of wood fiber board can be used as it is and the laminated board can be formed by thermal compression once (one shot).

Further, it is also possible to obtain a very excellent adhesive force between the wood fiber layer of the obtained laminated board and the wood veneer. In addition, the wood veneer is placed on the screen belt and inserted into the forming device, the wood fibers are deposited on the wood veneer, the wood veneer is placed on the wood fiber, and then the wood fiber is further formed by the forming device. After being deposited, they are cut at regular intervals and temporarily pressed and hot-pressed, or they are temporarily pressed without cutting and then laminated by continuous hot-pressing and cutting, or a forming device. After depositing the wood fibers on the screen belt by the above, the wood veneers were placed on the wood fibers, and then the wood fibers were deposited on the wood veneers by the forming device, and the wood veneers were further placed on the wood fibers. After that, the laminate is cut by a constant radiation and temporarily pressed and hot-pressed, or temporarily pressed without cutting and continuously pressed and then cut to obtain a laminated plate.

If necessary, a decorative sheet is attached to the surface of the laminate of the present invention. As the decorative sheet to be adhered, for example, a natural veneer obtained by cutting natural wood having a thickness of about 0.2 to 3 mm, an artificial veneer, and a veneer sheet lined with a nonwoven fabric, paper, or a synthetic resin sheet, or 20-40 g / m ² decorative paper, 32-500 g / m ² non-woven fabric, 50 g / m ² parchment paper, etc. with pattern pattern printing or monochrome coating, or after adhering to the decorative sheet, A top coat process can also be provided.

For the adhesion of these decorative sheets, a thermoplastic adhesive such as vinyl acetate resin mixed with a thermosetting resin or urea powder for improving water resistance can be used. Further, in the laminated board of the present invention, even when the veneer veneer is stuck, the veneer veneer does not crack because the shrinkage and expansion of the surface wood fiber layer 1 on the surface of the laminated board due to moisture absorption and desorption is small.

[0022]

[Effect of device]

 In the laminated board according to the present invention, a part of a conventional plywood veneer is replaced with a wood fiber layer, and these wood fiber layers are obtained by crushing or defibrating raw wood having a defect that cannot be used as a veneer. Because it is obtained, it can be used effectively for resources and can help prevent the destruction of nature.

Further, by arranging the middle-layer wood veneer layer and the back layer wood veneer layer so that the fiber directions are orthogonal to each other, the dimensional stability in the width direction and the length direction is excellent, and the mechanical strength is also in the length direction. The bending strength is excellent both in the width direction and the dimensional stability is further improved by arranging the wood fiber layers between the veneer layers and on the front and back surfaces.

Further, by making the fiber direction of the wood veneer layer of the back layer parallel to the length direction of the laminated plate, the bending strength particularly in the length direction becomes excellent. Furthermore, by forming the middle-layer wood fiber layer to be thicker than the surface wood fiber layer, the effect of suppressing the contraction and expansion of the veneer layer is further improved, and the dimensional stability is further improved. In addition, by forming the middle-layer wood fiber layer and the surface wood fiber layer thicker than any other layer, and by arranging the middle-layer wood fiber layer having a higher specific gravity than the veneer layer at the center in the thickness direction, the middle-layer wood fiber layer is excellent. By exhibiting shear resistance, more excellent bending strength is exhibited. In addition, since the surface of the laminated plate is composed of a wood fiber layer, it has high compressive strength and excellent smoothness and workability. Since the contraction and expansion due to moisture absorption and desorption is small, a veneer sheet is placed on the surface. It has excellent properties such that cracks do not easily occur even when it is attached and cutting can be performed in any direction.

[Brief description of drawings]

FIG. 1 is a sectional view of the laminated plate of the present invention,

[Explanation of symbols]

1: Surface wood fiber layer, 2: Middle wood fiber layer, 3: Middle wood veneer layer, 4: Back wood veneer layer.

Claims (3)

[Scope of utility model registration request] 1. The thickness of the middle-layered wood fiber layer of the laminated plate obtained by laminating the surface-layer wood fiber layer, the middle-layer wood veneer layer, the middle-layer wood fiber layer, and the back-layer wood veneer layer in this order from the surface side. Is a laminated board formed by being thicker than the surface wood fiber layer. 2. The laminated board according to claim 1, wherein the middle-layer wood veneer layer and the back layer wood veneer layer are arranged so that the fiber directions thereof are orthogonal to each other. 3. The laminated plate according to claim 2, wherein the fiber direction of the back layer single-ply veneer layer is arranged parallel to the longitudinal direction of the laminated plate.