JPH0699410A - Coloring method and device for woody material - Google Patents

Abstract

PURPOSE:To remove excessive wood stain. CONSTITUTION:A vacuum pump 4 and a device 6 for recovering excessive wood stain are disposed in vacuum chamber 2 in which a woody material M for coloring is passed. A clear grain pattern, therefore, can be formed on a building material plywood or the like, and the generation of a defective product because of the uneven coloring of wood stain can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for coloring the surface of a wood base material when a transparent paint is applied to wood materials such as furniture, Buddhist altars, and plywood for building materials.

[0002]

2. Description of the Related Art As is well known, wood stain is applied to a surface of a base material of wood as a pre-coating step of applying clear paint such as clear or color clear to the surface of the base material. It is necessary to remove the excess wood stain except the part. This is to obtain a clear wood grain pattern because it is necessary to emphasize the conduit portion by coloring the conduit portion with wood stain in a dark color and the other portion with a light color. The surface of the wood material colored in this way is subsequently coated with a sealing paint or a sanding sealer several times in accordance with normal coating specifications, and after polishing, a clear or color clear is applied as an overcoat.

By the way, conventionally, the method of removing the excess wood stain other than the conduit portion has been by brushing, spraying, or applying wood stain adjusted to an appropriate color tone and viscosity.
A common method is to coat the surface of the base material evenly with a roll coater or the like, and then wipe off excess wood stain with a paper waste cloth or a cloth.

Further, in recent years, such a coloring process has been automated to spread wood stains on the surface of a wood material with a sponge roll coater and scrape with a continuously installed reverse roll coater or natural roll coater. A method of removing excess wood stain is also adopted.

[0005]

However, in order to remove the wood stain other than the conduit portion in this way, a paper cloth,
With a method of wiping with a cloth or a method of scraping with a roll coater, if there are irregularities such as depressions or swells on the surface of the wood material, the surface of the depressions will be dark and the raised surface will be colored lightly. It causes unevenness. Especially, plywood used for building materials and furniture is 2
Since ~ 7 thin veneers are laminated by adhering them so that the fiber directions are orthogonal to each other, dents and bulges are formed on the surface due to defects such as cracks, swelling, and partial thickness differences of individual veneers. Is occurring. On plywood like this,
When the wood stain is removed by the conventional method, the recessed portion becomes dark color and the raised portion becomes light color due to the excess wood stain which is not removed, and uneven coloring occurs. Therefore, in the conventional method, the surface of the wood material may not have a uniform and clear wood grain pattern. By the way, in the painting of building materials and plywood for furniture, such wood stain coloring unevenness accounts for a considerable portion (about 20%) of the defective product occurrence rate. After studying such problems, after spreading wood stain on the material surface with depressions and swells, in the conventional wiping and scraping method, the material surface comes into contact with some pressure, It has been found that even with skill, it is not possible to avoid uneven coloring caused by the effect of gentle unevenness on the surface.

[0006] Therefore, an object of the present invention is to obtain a clear wood grain pattern without uneven coloring even if there are dents or bulges other than the conduit portion on the surface of the wood material.
It is an object of the present invention to provide a method and apparatus for coloring a wood material that removes excess wood stain other than the conduit portion.

[0007]

A feature of the present invention is to remove excess wood stain without contacting the surface of the wood material, and one means therefor is to remove wood on the surface of the wood material. After applying the stain, a high-pressure, high-speed air is blown onto the surface of the base material to blow away the wood stain other than the conduit portion.Another means is to apply the wood stain on the surface of the base material of wood material. By decompressing this wood material, the extra wood stain is forcibly absorbed.

[0008]

According to the present invention, since the wood stain other than the conduit portion is removed without coming into contact with the surface of the material, the excess wood stain can be removed without being affected by the unevenness of the surface, so that only the wood grain portion can be colored. .

[0009]

EXAMPLES The present invention will be specifically described below with reference to examples.

As the wood stain used in the present invention, any commercially available wood stain can be used, and examples thereof include water-based stain, alcohol-soluble stain, and alcohol-insoluble stain based on nitrocellulose or alkyd resin.

When coloring with wood stain, it is spread on the surface of the material by a usual coating method. For this coating method,
A brush coating, a spray coating, a roll coater coating, a curtain flow coater coating or the like is appropriately selected and used. In the case of roll coater coating, a sponge roll coater or a reverse roll coater is most suitable.

As means for blowing high-pressure and high-speed air, there is air blowing means having a constant pressure and a constant wind speed, and by jetting a jet stream from the blowing means to the colored wood material moving on the table, Excessive wood stains are scattered and removed.

It is desirable that the blowing means be provided with an appropriate number of partition plates so that the wind velocity is uniform in the direction orthogonal to the fiber direction of the wood material, that is, in the width direction.

The wind velocity at the outlet of the blowing means is preferably 50 to 120 meters per second, and if it is less than 50 meters, the effect of removing wood stain is low,
When it is 120 meters or more, the wood stain is excessively removed, and sufficient coloring cannot be obtained. Furthermore, the spraying distance from the blowing means to the colored wood material is 2 to 30.
Centimeters, preferably 5-12 centimeters. If it is less than 2 cm, the tip of the blowing means may collide when the wood material is warped, and if it is 30 cm or more, the effect of removing wood stain is insufficient.

As described above, the wood material colored according to the present invention is successively coated with a sealing paint or a sanding sealer several times in accordance with the usual coating specifications, and after polishing, a clear or color clear is applied as a top coat. be able to.

In contrast to the above example, the air blowing means may be moved above the colored wood material M.

If a device for recovering the removed wood stain is added, the wood stain can be reused, which contributes to resource saving and cost saving.

Next, a device for forcibly sucking excess wood stain will be described with reference to FIG.

A decompression chamber 2 is installed on the mounting table 1. The coloring wood material M moving on the mounting table is passed through to absorb and remove excess wood stain.

The decompression chamber 2 is designed to have an appropriate size according to the size of the wood material M to be colored with wood stain, and the height and width thereof are both 50 to 150 from the size of the wood material M.
It is desirable that it is about mm. If the decompression chamber 4 is unnecessarily large, the decompression efficiency will be reduced, and if it is small, the suction of the wood stain will be non-uniform, and uneven coloring is likely to occur. The decompression chamber 2 is provided with a passage hole 21 for allowing the wood material M to pass therethrough, and the height and width thereof are set to be 2 to 5 mm larger than the size of the wood material so that the wood material M can pass smoothly. A vacuum pump 4 is connected to the top plate of the decompression chamber 2 via a suction pipe 3, and a recovery device 6 is provided to the decompression chamber via a suction pipe 5. A pressure gauge 7 is installed in the decompression chamber 2.

When decompressing the inside of the decompression chamber 2, a wood material M having the same size as the wood stain to be colored is previously inserted into the chamber and the clearance of the passage hole 21 is made as small as possible. The pressure can be reduced efficiently and in a short time. The pressure when the pressure inside the chamber 2 is reduced is preferably −80 to −120 mbar. If it is -80 mbar or more, the effect of absorbing and removing excess wood stain is insufficient, and if it is less than -120 mbar, it is excessively removed, and the coloring effect is insufficient.

The wood material M colored according to the present invention is subsequently coated with a sealing paint or a sanding sealer in accordance with ordinary coating specifications, and after being polished to have a smooth surface, a clear or color clear is applied as an overcoat. be able to.

Contrary to the above example, the decompression chamber 2
May move above the colored wood material M.

Further, since the wood stain can be reused by attaching the recovery device 5 for the removed wood stain, it is possible to contribute to resource saving and cost saving.

Next, the method according to the present invention will be specifically described with reference to experimental examples and comparative examples.

Experimental Example 1 A brown wood stain based on nitrocellulose was diluted by adding the same amount of lacquer thinner in a weight ratio, and for a floor board having a thickness of 12 mm, it was applied to a veneer plywood per square measure. It was brush-coated so that the amount was 20 to 30 g.
Immediately, high-speed air with a wind speed of 80 / sec was blown in a curtain shape and moved at a speed of 5 m / min to scatter excess wood stain. At this time, the distance from the outlet of the slit to the surface of the plywood was 5 cm. Before brushing the wood stain, the surface of the plywood of the veneer veneer was partially polished with abrasive paper to make several recesses with a depth of 0.2 to 0.5 mm, but the wood stain was dry. After that, a uniform and clear wood grain pattern without coloring unevenness was obtained in the depressions, and the surface was colored well.

Experimental Example 2 A brown wood stain based on nitrocellulose and an alkyd resin was diluted by adding the same amount of butyl acetate in a weight ratio, and diluted with a sponge roll coater. The coating amount was 20 to 30 g per square measure. Immediately, wind speed 100
It was passed under a slit that blows out high-speed air of m / sec in a curtain state at a speed of 15 m / min. At this time, the distance from the outlet of the slit to the surface of the plywood was 10 cm. In the same manner as in Experimental Example 1, the wood veneer plywood was dented with abrasive paper, but after the wood stain was dried,
A uniform and clear wood grain pattern with no uneven coloring was also obtained in the depressions, and the surface condition was good.

Experimental Example 3 A brown wood stain based on nitrocellulose was diluted by adding the same amount of lacquer thinner in a weight ratio to dilute it, and a veneer plywood for a floorboard having a width of 200 mm, a length of 900 mm and a thickness of 12 mm. The surface was coated with a brush so that the coating amount per square measure was 20 to 30 g. Immediately, 20m / min in the chamber depressurized to -80mbar
The excess wood stain was aspirated by passing it through at the speed of. At this time, the chamber has a height of 250 mm,
The width was 300 mm, the depth was 400 mm, and a passage hole having a height of 15 mm and a width of 206 mm was provided on the inlet side and the outlet side, so that the plywood coated with stain could pass smoothly.

Before brushing with wood stain, the surface of the veneer plywood was partially polished with polishing paper to form several recesses with a depth of 0.2 to 0.5 mm. After the stain was dried, a uniform and clear wood grain pattern was obtained without uneven coloring even in the depressions, and the surface was colored well.

Experimental Example 4 A brown wood stain based on nitrocellulose and an alkyd resin was diluted by adding the same amount of butyl acetate in a weight ratio and diluted with a sponge roll coater. The coating amount was 20 to 30 g per square measure. Immediately minus 1
The excess wood stain was sucked through the chamber, which was depressurized to 00 mbar, at a speed of 40 m / min. Before brushing with wood stain, the surface of the plywood plywood is partially polished with abrasive paper to a depth of 0.2 to 0.
Although several 5 mm dents were formed, after the wood stain was dried, a uniform and clear wood grain pattern was obtained without uneven coloring in the dents, and the surface was colored well.

Therefore, in order to clarify these Experimental Examples 1 and 2, Comparative Examples 1 and 2 will be shown next.

Comparative Example 1 Wood stain was spread in the same manner as in Experimental Example 1, and the surface thereof was immediately blown off with a paper waste. However, the periphery of the part where the dent was made with abrasive paper became dark and uneven coloring occurred. It was not possible to obtain a uniform and clear wood grain pattern.

Comparative Example 2 As in Experimental Example 2, wood stain was spread using a sponge roll coater and immediately scraped off with a reverse roll coater, but the entire area where the depressions were made with abrasive paper was colored dark. As a result, uneven coloring occurred, and a uniform and clear wood grain pattern could not be obtained.

[0034]

Industrial Applicability According to the present invention, since the excess wood stain on the surface of the wood material is removed in a non-contact manner, a clear wood grain pattern can be obtained. Therefore, defective products due to uneven coloring of the wood stain occur. Can be prevented, and improvement in production efficiency can be achieved. Further, it is particularly effective for plywood for building materials such as floorboards and wall materials, that is, those which are easily dented or raised due to defects in veneer.

[Brief description of drawings]

FIG. 1 is a perspective view.

[Explanation of symbols]

 1 Decompression chamber 4 Vacuum pump 6 Recovery device

Claims (3)

[Claims] 1. A method for coloring a wood material, which comprises applying wood stain to the surface of the wood material and then blowing high-pressure, high-speed air onto the surface of the wood. 2. A method for coloring a wood material, which comprises applying wood stain to the surface of the base material of the wood material and then depressurizing the wood material. 3. A wood stain removing device comprising a decompression chamber, a vacuum pump for decompressing the inside of the decompression chamber, and a wood stain recovery device communicating with the decompression chamber.