JPH0452102A - Production of conifer ligneous based material - Google Patents

Abstract

PURPOSE:To obtain the above ligneous based material which has the smooth surface and is free from a warpage and deterioration of strength by mixing an adhesive with the ligneous material such as wood flour and ligneous fiber to obtain a raw material of a board and laminating this raw material for the board at least on one side of the ligneous base material such as a plywood, a veneer and laminated wood. CONSTITUTION:Ligneous base material is manufactured by orthogonally crossing five sheets of Oregon pine rotary veneer having 2.5mm thickness with each other in the direction of fiber thereof and applying them with a melamine resin adhesive and performing cold press. On the other hand, Oregon pine is pulverized and the melamine resin adhesive is atomized at 12% and mixed with the pulverized powder to obtain a raw material of MDF (fiber board having intermediate sp. gr.) this raw material of DMF is placed on an iron plate in 15mm thickness and the previously cold-pressed veneer is placed thereon. Furthermore, the raw material of the board is placed thereon in 15mm thickness. When the obtained laminate is intruded into a hot press and thermocompression is performed at 130 deg.C at 12kg/m<2> for 10 minutes, the ligneous material is obtained which has the board layers having 1mm thickness on the surface and the rear and is smooth in the surface and has 14.5mm thickness. Decorative plywood having extremely flat finishing on the surface is obtained by sticking Oregon pin decorative veneer having 0.6mm thickness on the surface of this ligneous material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a coniferous material having a smooth surface, and to a coniferous material having a smooth surface.

[Prior Art] When manufacturing plywood, LVL (laminated veneer lumber), etc. from softwood materials, it is difficult to obtain wood materials with smooth surfaces. this is,
Normally, when coniferous wood is made into a veneer, knots, cracks, etc. often appear on the surface, and there are few defect-free materials like South Sea wood. Although there are some high-quality coniferous logs with no knots, their quantity is small and the price of the logs is high.

Further, even if the softwood material is defect-free, the spring wood portion and the summer wood portion of the softwood material are soft and hard, so the surface often becomes uneven due to the pressure after pressing.

Therefore, as a solution to these drawbacks, there are patching methods in which holes are made in the joints of the surface veneer and buried in wood, and MFD (
A method has been considered in which a smooth surface material such as medium-density fiberboard (medium-density fiberboard) is attached to the front and back surfaces, but with the patching method, traces of the embedded wood become visible and the appearance deteriorates. Even when the boards are attached a second time, there is an inconvenience that traces of the embedded wood appear on the surface of the decorative veneer, etc.

In addition, in the method of pasting MDF, normally MDF cannot be produced with a thickness of 3 m/m or less because thinner MDF causes a waving phenomenon due to a decrease in strength, so even if the thinnest MDF of 3 m/m thickness is pasted, Since MDF occupies a thickness of 6 m/m on both sides, there is a problem in that when it is made into plywood, the strength decreases compared to the thickness. Furthermore, there were many disadvantages such as warpage in single-sided MFD bonding.

[Problem to be solved by the invention]

The present invention aims to provide a coniferous material using coniferous wood as a wood base material, which has a smooth surface and does not warp or decrease in strength, and a method for producing the same.

[Means for Solving the Problems] The method for producing coniferous wood materials of the present invention is to produce board materials such as plywood, LV
It is characterized in that it is laminated on at least one surface of a wood base material such as L.

The method of laminating board raw materials on the surface of the wood base material is as follows:
This is carried out by placing the board raw material on at least one surface of the wood base material and hot-pressing it. As for the hot press method,
A flat plate hot press method or a roll hot press method may be used. The heating method may be by heating and compressing with a heated pressure flat plate or roll, or by blowing heated steam onto the board material, or by supplying pre-heated board material to the wood base material and pressurizing it. You can also do this.

In the present invention, the board raw material made by mixing adhesive with wood materials such as wood flour and wood fibers may be prepared specifically for repair, but raw materials for particle board and fiberboard may also be used as they are for 7M. . Therefore, as the wood material, in addition to wood flour, wood chips crushed into small pieces, small particle boards, pressed pieces of these pieces, fiber pieces, etc. can be used. The particle size and size of these materials are determined depending on the desired smoothness, and they are appropriately selected and used.

Medium-density fiberboard (MDF) has recently been attracting attention as having properties similar to plywood, and it is preferable to use this raw material because its wood fibers are fine and smoothness can be achieved accordingly.

As the adhesive to be mixed with the wood material, since the board raw materials are laminated by hot pressure pressing, a thermal adhesive is used, and phenol resin, melamine resin, etc. are used. Choosing a melamine resin adhesive will also improve the water resistance of the laminated board layers.

During lamination, by increasing or decreasing the amount of this board raw material as necessary, defects such as knot holes on the surface of the wooden base material can be plugged and a smooth surface can be formed over the entire surface of the base material.

The board layer should be formed as thin as possible as long as it can compensate for the defects of the base material and make the entire surface smooth (for normal plywood, it is preferably about 1 to 2 m/m).

In addition, it is preferable in terms of balance to form the board layer with the same thickness on both sides of the wooden base material, but in the case of the present invention, it is possible to laminate the board layer extremely thinly compared to the thickness of the base material, so even if it is only on one side. It can be adjusted to the extent that it does not warp.

The wood base material is not particularly limited, but from the purpose of the present invention, it is preferably softwood plywood or softwood LVL, and softwood plywood coated with an adhesive and laminated or softwood LVL.
It is recommended to use a laminate for

The wood base material may be made of plywood, LVL laminated wood, etc., which is first hot-pressed into a single board, or it may be in the state of cold-pressing before hot-pressing, or it may be bonded before cold-pressing. The board material may be placed in a state in which the agent-coated veneers, lamina, etc. are laminated, and hot-press pressed.

[Function] As mentioned earlier, if MDF is formed only into a board, its strength will decrease and the deflection will increase, making it impossible to make a large board, and the waving phenomenon is likely to occur, so the thickness is usually up to 3 m/m. There is. Therefore, it is not possible to obtain a strong and thin wood material by laminating MDF together, but if the method of the present invention is used, a board layer is formed on the surface of the wood base material, so the board layer can be formed even if the thickness is 3 m/m or less. can. As a result, a wood material with a smooth surface and strength can be obtained.

Further, in the case of the present invention, since the board raw material can be placed extremely thinly on the wooden base material, there is an advantage that it can be adjusted to the extent that warping does not occur even when placed on one side.

[Examples] The present invention will be explained below using Examples, but the present invention is not limited to these.

Example 1 A melamine resin adhesive was applied to five 2.5 mm thick rotary veneers of Japanese pine with their fibers perpendicular to each other using the method used to make plywood, followed by cold pressing to create a wood base material. did.

At this time, there were 25 knot holes with a diameter of about 35 m/rn on a surface of 1,850 x 980 m/m in the veneer on the surface of the base material.

On the other hand, grind Japanese pine into fine powder and apply 12 ml of melamine resin adhesive.
% spray-mixed MDF raw material was placed on a steel plate to a thickness of 15 m/m, and the plywood that had been cold pressed was placed on it,
Furthermore, a board material was placed on top to a thickness of 15 m/m.

Push the stacked things into a hot press,
When the material was hot-pressed at 130 DEG C. and 12 kg/m2 for 10 minutes, a 14.5 m/m thick wood material with a smooth surface and a 1 m/m thick board layer on the front and back sides was obtained.

When a 0.6 m/m thick Japanese pine decorative veneer was adhered to the surface of this wood material, a decorative plywood with an extremely flat surface finish was obtained.

Example 2 In the same method as in Example 1, the board material was placed on only one side and pressed, resulting in a wood base with one side smooth.

The obtained wood material had a warp with a length of 1,850 m/m and a height of 1.5 m/m, with the smooth side being convex.

However, this degree of warping has been considered to pose no practical problem, and the product passed the test.

Comparative Example 1 In Example 1, the thickness of the rice pine rotary veneer was 2.5 m/
Create a base material by laminating in the same manner with m set to 1.7 m/m,
MDF with a thickness of 3 m/m was placed on both sides of this base material instead of the board raw material, and the same operation was performed to create a wood material with the same thickness as in Example 1.

The resulting wood material has low strength relative to its thickness, making it impractical. The results are shown in the table below.

Comparative Example 2 In Comparative Example 1, when MDF was pressed on only one side, a smooth surface was obtained, but the MDF side with an arrow height of 13 m/m in the length direction of 1.850 m/m was convex. This caused a warpage.

This product was so warped that it could not be put to practical use.

Comparative Example 3 In Example 1, the thickness of the rice pine rotary veneer was 2.5 m/
Decorative plywood having almost the same thickness as in Example 1 was made by setting m to 2.9 m/m and using plywood made only of softwood without using board raw materials.

The obtained decorative plywood had many knots, cracks, etc., and was rejected in terms of appearance.

The results of Examples and Comparative Examples are summarized in the table below.

[Effects of the Invention] As is clear from the results of the Examples, the method of the present invention is advantageous in that it is possible to produce wooden materials and decorative boards that not only have a smooth appearance but also have less strength and less warp. It is.

(2 idiots)

Claims (5)

[Claims] (1) A method for producing softwood material, which comprises laminating a board material made of a wood material such as wood flour or wood fiber mixed with an adhesive on at least one surface of a wood base material. (2) The coniferous wood material according to claim 1, characterized in that a board material made of a wood material such as wood flour or wood fibers mixed with an adhesive is placed on at least one surface of the wood base material and hot-press pressed. Method of manufacturing wood. (3) The method for producing a softwood material according to claim 1, wherein the wood base material is softwood plywood or softwood LVL. (4) The method for producing a softwood material according to claim 1, wherein the wood base material is a laminate for softwood plywood or softwood LVL, which is coated with an adhesive and laminated. (5) A coniferous wood material, characterized in that a board material made of a wood material such as wood flour or wood fiber mixed with an adhesive is laminated on at least one side of a wood base material.