JPH0535261U - Laminate - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a laminate that can be used as a substitute for plywood. To obtain a laminated board having a strength not inferior to that of plywood by using a low quality raw wood which cannot be used as plywood as a constituent element of the laminated board. [Structure] A surface wood fiber layer 1 of a laminated plate in which a surface wood fiber layer 1, a middle wood veneer layer 3, a middle wood fiber layer 2 and a back wood veneer layer 4 are laminated in this order from the front side. Is thicker than the middle-layer wood fiber layer 2, and the middle-layer wood veneer layer 3 is thicker than the back-layer wood veneer layer 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 TECHNICAL FIELD The present invention relates to a laminated plate used for structural materials, as well as for building exterior, interior and furniture.

[0002]

[Prior art]

 Laminated plates are known such as plywood in which veneers are laminated and bonded with their fiber directions orthogonal to each other, and parallel plywood (LVL) in which the fiber directions of veneers 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 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. This problem is expected to 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 in order from the surface side, a surface wood fiber layer 1, a middle wood veneer layer 3, a middle wood fiber layer 2, and a back wood veneer layer 4 in this order. It is a laminated board that is integrally laminated, and the thickness of the surface wood fiber layer 1 is thicker than that of the middle wood fiber layer 2 and the thickness of the middle wood veneer layer 3 is thicker than that of the back wood veneer layer 4. It has been done.

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, shrinkage and expansion due to absorption and release of moisture in the single plate have an influence on dimensional stabilization 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, the wood veneer has a contraction and expansion in the direction perpendicular to the fiber direction which is 5 to 20 times larger 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 parallel direction and the vertical direction is significantly 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 effect of mutually suppressing the movements of the laminated plates is generated, the contraction and expansion of the laminated plate in the length direction and the width direction are made uniform, and the laminated plate has excellent dimensional stability.

Further, in the present invention, the middle-layer wood veneer layer 3 is formed thicker than the back-layer wood veneer layer 4. This is because the back wood veneer layer 4 is farther from the center of the laminated wood than the middle wood veneer layer 3, so the back wood veneer layer 4 contracts and expands due to moisture absorption and release of the back wood veneer layer 4. The movement due to the tension greatly affects the warpage of the laminated plate.

Therefore, by making the thickness of the back wood veneer layer 4 thinner than the thickness of the middle wood veneer layer 3, the movement of contraction and expansion of the back wood veneer layer is weakened, and conversely By increasing the thickness of the veneer layer, the movement of the middle-layer wood veneer layer due to contraction and expansion is strengthened, so that the laminated plate is balanced in the thickness direction and warpage is prevented.

Further, since the middle-layer wood veneer layer 3 is thickly formed at the substantially central portion in the thickness direction, the laminated wood sheet has a very excellent wood screw holding force.

Furthermore, by arranging the fiber veneer of the back layer wood veneer layer 4 so as to be parallel to the length direction of the laminated board, the wood veneer has a direction parallel to the fiber direction in terms of mechanical strength. Since it has a high bending strength and a high tensile strength, the durability against the tensile load generated on the back side when a bending load is applied in the length direction of the present invention is improved, and the length direction as a laminated plate is improved. It has excellent bending strength.

Therefore, it is a plate material that is very suitable for use as a substrate that is required to have bending strength in the length direction, such as a floor material that is generally constructed so as to support the end portions in the length direction by the underlying structural material. .

Further, as the wood veneer used for the middle-layer wood veneer layer 3 and the back wood veneer layer 4, a phenol resin treatment, an acetylation treatment, an esterification treatment, a formalization treatment, a PEG (polyethylene glycol) treatment or By using a material that has been subjected to a treatment such as WPC treatment (resin impregnation) 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 as a wood veneer, a veneer that has been treated with a flame retardant agent such as ammonium phosphate, a phosphorus nitrogen compound, a halogen compound, sulfamic acid, boric acid, etc. Is obtained. These treatments are carried out by immersing the veneer in a fireproofing agent, applying 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, soot dust, and chip dust produced during the production of the wood fiber board can be mixed and used in the wood fiber layer.

These wood fiber layers have excellent stability such that the dimensional change rate per 1% of water content is uniform in the length direction and the width direction and is 0.03 to 0.04%. The stability of the wood fiber layer is added to the function 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. By doing so, it becomes a laminated plate with further excellent dimensional stability, and the dimensional change rate due to moisture absorption and desorption as a laminated plate is 0.02-0.03% per 1% moisture content. It is comparable to the performance of plywood with properties.

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 drop test of an iron ball on the surface or local load such as high heels and casters is locally applied, it is difficult to dent. In addition, by forming the surface wood fiber layer 1 to be thicker than the middle wood fiber layer 2, the durability of the surface portion against dents due to the local load becomes further excellent.

Further, when the laminated plate of the present invention is subjected to a bending load, the surface wood fiber layer 1 is thick and exhibits excellent compression resistance against the addition of compression generated on the surface side. It has excellent characteristics in bending strength in the transverse direction and the width direction.

Further, since the wood fiber layer having excellent smoothness and processability is disposed on the surface, an excellent finish can be obtained even if a decorative sheet is attached or a coating treatment is applied, and it is optional. The cutting in the direction can be performed easily and deeply.

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 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 with even more excellent bending strength and dimensional stability.

These treatments are carried out, for example, by cutting softwood materials such as pine, cedar, and cypress or hardwood materials such as rawan, capoule, chestnut, and poplar into chips, and then defibrating them according to a conventional method and drying them. At the stage, the above treatment is carried out by a conventional method, and the obtained wood fiber is used to produce a wood fiber layer.

Furthermore, a laminate having a fireproof function by using wood fibers treated with a flame retardant agent such as ammonium phosphate, a phosphorus nitrogen compound, a halogen compound, sulfamic acid and boric acid as the wood fiber layer. 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 preliminarily manufactured wood fiber board and wood veneer, and the surface wood fiber layer, the middle wood veneer layer, the middle wood fiber layer, and the back wood veneer layer from the surface side. It is obtained by laminating in the order of, with an adhesive, and pressing according to a conventional method.

In addition, in the manufacturing process of the wood fiber board, a wood fiber mat obtained by applying an adhesive by a forming device and depositing dried wood fibers on a screen belt is cut into a certain size and temporarily pressed. Using the above, the wood fiber mat was placed on the wood veneer with the adhesive applied to the front side, and the wood veneer with the adhesive applied to the front and back was placed on it, and finally the wood fiber mat was placed. Then, a laminated board can be manufactured by hot pressing.

This method is an industrially advantageous method such that a conventional production line for wood fiber boards can be used as it is, and a hot pressing can be performed once (one shot) to form a laminated board.

Further, it is also possible to obtain an extremely excellent adhesive force between the wood fiber layer of the obtained laminate and the wood veneer. In addition, a wood veneer is placed on the screen belt and inserted into the forming device, wood fibers are deposited on the wood veneer, and then wood veneer is placed on the wood fiber. After the fibers are deposited, they are cut at regular intervals and temporarily pressed and hot-pressed, or they are temporarily pressed without cutting and continuously hot-pressed and then cut into laminated plates, or formed. After depositing the wood fiber on the screen belt by the device, put the wood veneer on the wood fiber, then deposit the wood fiber on the wood veneer by the forming device, and then put the wood veneer on the wood fiber. After that, it is cut into a certain width and temporarily pressed and hot-pressed, or it is temporarily pressed without cutting and continuously pressed and then cut to obtain a laminated plate.

In such a method using a wood fiber mat or a method in which wood fibers are deposited on a wood veneer and then collectively pressed, the laminated board of the present invention has a middle-layer wood veneer layer as a backing layer. Since it is thicker than the wood veneer layer and actually made up of veneers with a thickness of 2 mm or more, the middle-layer wood veneer layer does not change into a wavy shape when pressed.

If necessary, a decorative sheet is attached to the surface of the laminated plate of the present invention. Examples of the decorative sheet to be adhered include natural veneer obtained by cutting natural wood with a thickness of about 0.2-3 mm, artificial veneer, and veneer sheet lined with non-woven fabric, paper, synthetic resin sheet, or 20-40g / ^{m 2} of decorative paper, which 32-500g / ^{m 2} of non-woven fabric, the pattern pattern printing and monochromatic painting of parchment paper or the like of 50g / ^{m 2} has been subjected to, or, after the decorative sheet adhesive, A top coat process can also be provided.

For 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 plate of the present invention, even when the veneer veneer is stuck, the veneer veneer is cracked because the shrinkage and expansion of the surface wood fiber layer 1 on the surface of the laminated plate due to moisture absorption and desorption is small. There is no.

[0035]

[Effect of the 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. Since it is obtained, it can be used effectively for resources and can help prevent the destruction of nature.

By arranging the middle-layer wood veneer layer 3 and the back-layer wood veneer layer 4 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 long. The bending strength is excellent in both the width direction and 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 forming the middle-layer wood veneer layer 3 to be thicker than the back-layer wood veneer layer 4, warp of the laminate is prevented, and the laminate has excellent wood screw holding power.

Further, since the front and back surfaces of the middle-layer wood veneer layer 3 are covered with the wood fiber layer, a low-grade veneer can be used, which is also effective in reducing the cost of the laminated plate.

Further, by making the fiber direction of the back-layer wood veneer layer 4 parallel to the length direction of the laminated plate, the bending strength particularly in the length direction becomes excellent.

Furthermore, since the compressive strength in the plane direction on the surface side of the surface wood fiber layer 1 is particularly excellent, the bending strength is further improved.

Further, since the surface of the laminated plate is composed of a wood fiber layer, it has high compressive strength in the thickness direction and is excellent in smoothness. Also has an excellent finish, and can be easily cut in any direction.

These effects are further improved by forming the surface wood fiber layer to be thicker than the middle wood fiber layer. Further, since the surface wood fiber layer 1 has a small shrinkage and expansion due to moisture absorption and desorption, it has excellent properties such that cracks are less likely to occur even when a veneer sheet is attached to the surface.

[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. A surface-layer wood fiber of a laminated plate formed 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 surface side. A laminated board in which the layer 1 is thicker than the middle wood fiber layer 2 and the middle wood veneer layer 3 is thicker than the back wood veneer layer 4. 2. The laminated board according to claim 1, wherein the middle-layer wood veneer layer 3 and the back-layer wood veneer layer 4 are arranged so that the fiber directions thereof are orthogonal to each other. 3. The laminated board according to claim 1, wherein the fiber direction of the backing wood veneer layer 4 is arranged parallel to the longitudinal direction of the laminated board.