JPS646253Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvement of laminated flooring.

For example, a flooring material in which laminated wood veneers are adhered to both sides of a core material made of laminated wood or plywood has high utility value because of its extremely high strength.

In this type of flooring, the surface is usually painted, but the back side is only coated with a moisture-proofing agent, and it is not economically viable to apply the same coating as the front side. As a result, there is a significant difference in the dry and wet conditions between the front and back veneers due to the breathing of the wood fibers, and the resulting difference in the degree of expansion and contraction creates the problem of unavoidable bending or warping of the flooring.

The purpose of the present invention is to provide a laminated flooring material that is free from bending and warping by balancing the degrees of shrinkage and expansion of the front and back veneers.

In order to achieve the above object, the laminated flooring material of the present invention is one in which the surface of the front veneer is painted, and the front veneer is made of coniferous or deciduous wood, and the back veneer is made of coniferous or deciduous wood. The thickness of the back veneer is made from coniferous wood, and the thickness of the back veneer is determined by the contraction/expansion coefficient α ₁ of the wood species of the front veneer and the contraction/expansion coefficient α ₂ of the wood species of the back veneer with respect to the thickness of the front veneer. It is characterized by having a thickness equal to the product of 1/2 of the ratio α ₁ /α ₂ to balance the degree of contraction and expansion in the front and back veneers.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Reference numeral 1 denotes a core material, and the core material 1 is made up of a large number of pieces 1α, 1α, . . . assembled in the width and length directions. A front veneer 2 and a back veneer 3 are integrally bonded to the front and back surfaces of the core material 1 with an adhesive, respectively.

The front veneer 2 and the back veneer 3 are formed by slicing or sawing the same laminated wood as the core material 1 to a predetermined thickness, and the materials constituting the front veneer 2 include, for example. Coniferous trees such as cypress and cedar, or oak leaves such as mizume and zelkova are used, and the back veneer 3
Coniferous trees are used.

Therefore, on the surface of the above-mentioned flooring material, a finishing coating treatment is applied to the surface of the front veneer 2, and on the back side of the flooring material, a moisture-proofing agent is applied to the back veneer 3 as necessary. be done. Therefore, in the front veneer 2, the adhesive layer 4 and the coating layer 5 bond the front and back surfaces 2a, 2.
The breathing of the wood fibers through b is suppressed, and only a slight amount of breathing occurs freely through the side surfaces 2c.On the other hand, in the back veneer 3, the adhesive layer 6 binds the core material 1 Although breathing through the adhesive surface 3a is suppressed, the opposite surface 3b
Breathing through the side surfaces 3c is allowed to occur freely to some extent, and therefore, there is a difference in dryness and humidity between the front veneer 2 and the back veneer 3 due to breathing, and the difference in the degree of expansion and contraction caused by this causes the difference in the degree of expansion and contraction. There is a risk that the flooring material will bend or warp.

Therefore, in the present invention, by setting the thicknesses of both veneers 2 and 3 in a specific relationship according to the contraction and expansion rates of the wood species, their contraction and expansion rates are balanced, and thereby the flooring material It is constructed to prevent bending and warping. That is, when the contraction/expansion coefficient of the wood species used as the front veneer is α ₁ and the contraction/expansion coefficient of the wood species used as the back veneer is α ₂ ,
The thickness t ₂ of the back veneer 3 is determined by multiplying the thickness t ₁ of the front veneer 2 by 1/2 of the ratio α ₁ /α ₂ of both contraction and expansion coefficients.

Generally, it is known that cypress wood exhibits a shrinkage/expansion rate that is about twice that of coniferous trees. Therefore, if the back veneer 3 is made of the same tree species as the front veneer 2, for example, a coniferous tree such as Japanese cypress, For example, the thickness of the back veneer 3 is the thickness of the front veneer 2.
Formed to about 1/2 of
When the back veneer 3 is made of coniferous wood, the thickness of the back veneer 3 is approximately the same as that of the front veneer 2.

The relationship between the thicknesses of both veneers 2 and 3 above was obtained based on various experimental results, and when both veneers are formed with such a thickness relationship, their degree of contraction and expansion is approximately The balance is achieved by the mutual relationship between the inherent contraction/expansion rate, volume, breathing area, etc. of both veneers. In other words, if the back veneer 3 is the same wood species as the front veneer 2, their inherent shrinkage and expansion rates are the same, but the breathing area of the front veneer 2 is reduced due to the surface coating. The degree of contraction and expansion is small, so by reducing the thickness of the back veneer 3 to suppress the contraction and expansion force, the degree of contraction and expansion of both veneers 2 and 3 can be balanced, and the front veneer 3 In the case of coniferous wood, its inherent shrinkage and expansion rate is large, so the degree of contraction and expansion is also large. Therefore, by making the thickness of the back veneer made of coniferous wood about the same as that, the degree of contraction and expansion can be balanced. can be achieved.

In addition, from a series of experiments, the thickness of the back veneer 3 was
Even if the thickness is not equal to the thickness of the back veneer 2 multiplied by 1/2 of the ratio α ₁ / α ₂ of the shrinkage/expansion coefficient of both veneers 2 and 3, the thickness is approximately ±30% based on the thickness of the back veneer 2. It has also been confirmed that equivalent effects can be obtained within this range.

Note that the core material 1 is not limited to the illustrated laminated wood, but plywood can also be used.

According to the laminated flooring of the present invention having the above configuration,
Since the front veneer and back veneer were glued to both sides of the core material,
These veneers can significantly increase the strength of the flooring material, and by setting the thickness of the back veneer appropriately according to the tree species, the degree of contraction and expansion of both veneers can be balanced. This makes it possible to reliably prevent the flooring from bending or warping due to drying and wetting of both veneers.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of a laminated flooring material according to the present invention. 1... Core material, 2... Front veneer, 3... Back veneer, 2
a...Surface.

Claims (1)

[Scope of utility model registration request] A front veneer and a back veneer made of laminated wood are glued to the front and back sides of a core material made of laminated wood or plywood, and the surface of the front veneer is painted, and the front veneer is made of softwood or wood. A leaf veneer is formed as a material, and a back veneer is formed as a coniferous material _. The shrinkage and expansion coefficients of the front and back veneers are balanced by forming the veneer to a thickness equal to the ratio of α ₁ /α ₂ multiplied by 1/2 of the contraction and expansion coefficient α ₂ of the wood species of the back veneer. Laminated flooring material.