JP3486885B2 - Method of manufacturing wooden veneer - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to furniture, housing equipment,
It is an invention relating to a decorative board used for a building interior material and the like.

[0002]

2. Description of the Related Art A large amount of decorative boards made of wood boards such as plywood and fiber boards are used for furniture, housing equipment, building interior materials and the like. The decorative board is usually made of wood board such as plywood or fiber board, on the surface of which is a wooden decorative veneer (hereinafter simply referred to as decorative veneer), a sheet of vinyl chloride or other film printed with wood grain, or melamine. A veneer is attached. Among them, the one with natural veneered veneer on the surface has been evaluated as the highest quality product in the market. Since the natural veneer veneer is expensive, a thin veneer with a thickness of 0.3 mm or less is usually used except for the easily scratched part.

However, it is known that when a thin decorative veneer is pasted on a wood board such as plywood, a small crack is generated on the surface of the decorative veneer due to repeated absorption and desorption of the wood board, which lowers the commercial value. There is. As a method for preventing this cracking, first, a veneer whose fiber direction is orthogonal to the fiber direction of the surface-coated veneer is attached to the surface of the wooden board, and then the surface-coated veneer is attached thereon, or as shown in FIG. A method of interposing a thin paper between a wood board and a surface-coated veneer is known. In the method of interposing the thin paper, first, an adhesive is applied to the surface of the wooden board, the thin paper is placed on the adhesive, and hot pressing is performed to bond the thin paper.

Next, an adhesive is applied to the wooden board on which the thin paper is pasted, and the surface decorative veneer is stuck in the same manner as the thin paper.
With this method, the hot pressing process must be repeated twice. In order to complete the hot pressing process only once, the following method can be considered.

That is, first, an adhesive is applied to the surface of a wooden board with a roll-type spreader, and thin paper is placed thereon. Next, while the thin paper is placed, the surface of the thin paper is pressed by a pressing roll, and while the wrinkles of the thin paper are extended, the thin paper is temporarily bonded onto the plywood. Next, an adhesive is again applied to the surface of the thin paper with a roll-type spreader, the surface decorative veneer is placed thereon, and the thin paper and the surface decorative veneer are hot-pressed at the same time with a hot press to bond them.

[0006]

However, when the work of temporary adhesion by the above method is repeated, a small amount of adhesive exuded from the thin paper adheres to and accumulates on the press roll, and the accumulated adhesive forms a thin paper. It gets caught in the pressure roll. Also, by chance, when the wood board, which is thinner than the usual one, is passed through the roll, the thin paper cannot be sufficiently pressed by the roll, so that temporary adhesion is not sufficiently performed, and as a result, the thin paper is used in the next step, that is, the thin paper. In the process of applying the adhesive to the surface of the, it gets caught in the roll of the roll spreader.

[0007]

The inventor of the present application has tried various methods for solving the above problems, and as a result, has solved the following problems. That is, first, an adhesive is applied to the surface of the wooden board, and the thin paper is placed thereon. Up to this step, it is the same as the conventional method described above.

Next, before applying the adhesive to the surface of the thin paper, water is applied to the surface of the thin paper with a roll spreader (or roll coater). With this roll-type spreader (or roll coater), water is applied to the surface of the thin paper and the thin paper is temporarily adhered to the wood board. Therefore, the spreader coating roll serves both as a water coating and a pressing roll. Then, before the applied water is absorbed into the thin paper or does not evaporate from the surface of the thin paper, the adhesive is applied to the surface of the thin paper in the same manner as the conventional method, and the surface-coated veneer is placed on the thin paper by hot pressing. Simultaneously heat press the surface decorative veneer to bond it to the wood board.

The structure of the pressing roll for applying water on the surface of the thin paper and the roll for applying the adhesive on the thin paper are as shown in the right and left figures of FIG. 1, respectively. R1 in the figure
And R2 are coating rolls, and D1 and D2 are doctor rolls, which have the same structure as a known roll spreader or roll coater. W is water, which is always stored between the doctor roll D1 and the coating roll R1. A minute gap is provided between the coating roll R1 and the doctor roll D1, and a thin film of water W is always formed on the surface of the roll R1 by the gap, so that the wooden board B on which the thin paper P is placed. Water is applied to the surface of the thin paper P as it passes under the roll.

Since the surface of the roll R1 is constantly washed with the water W stored between the roll R1 and the doctor roll D1, even if the adhesive g exuded from the thin paper P adheres to the roll surface, It is not accumulated, and a thin film of water is always formed on the surface of the roll R1,
The thin film intervenes between the thin film P and the adhesive g exuding on the surface of the thin paper P and has a kind of peeling effect, so that the roll R1 does not wind up the thin paper P.

The thin film water of water formed on the surface of the roll R1 is transferred to the surface of the thin paper P when the wooden board passes through the roll R1. Then, the water intervenes between the thin paper P and the adhesive G applied to the surface of the thin paper P next,
The thin paper P does not wind around the roll R2 even in the next step because it has a kind of peeling effect.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the wood board used is a broad-leaved plywood of South Sea timber or plywood of coniferous wood, which is usually used for furniture, housing equipment, building interior materials, etc., or a tree typified by particle boats. It is a wood board such as a wood fiber board typified by a slab and a medium fiber board (MDF).
The surface veneer used is also a wood veneer that is commonly used for surface makeup of furniture, housing equipment, building interior materials and the like.

Adhesives are also urea-based, melamine-based, which are commonly used for bonding wood materials to each other or wood materials to paper.
Adhesives such as vinyl acetate-based, vinyl urethane-based, and latex-based adhesives. Tissue paper is suitable those ^{25g / m 2 ~30g / m 2} . If the grammage is less than this, not only the effect of preventing cracks on the surface-coated veneer is small, but also the sticking work is time-consuming and the work efficiency is reduced. When the grammage is larger than this, not only the cost becomes high, but also the adhesive does not sufficiently penetrate into the inside, so that peeling between papers easily occurs.

The pulp fibers of the thin paper are oriented in the direction in which the pulp fibers flow in the papermaking machine in the manufacturing process, that is, in the longitudinal direction of the product, and the longitudinal direction has a tensile strength about twice that of the width direction. There is. Therefore, when the thin paper is attached so that the longitudinal direction of the thin paper and the fiber direction of the surface decorative veneer are orthogonal to each other, the effect of preventing the surface decorative veneer from cracking is greater.

The amount of adhesive applied, the hot pressing conditions of the hot press, etc. may be determined according to conventional methods. That is, the adhesive is approximately 70 g / m ² to the wood board when the thin paper is applied.
80 g / m ^2, about 65g / m ² ~75g / m ² is applied to the surface of the tissue paper when pasting surface decorative veneer. However, the hot pressing conditions of the hot press may be the same as the conventional method such as the pressing pressure and the pressing temperature, but the pressing time is set longer than the case of using the thin paper and the decorative veneer at the same time. Is natural.

The amount of water applied onto the thin paper may be the minimum necessary. If the amount is too large, the adhesive may be diluted with water and the adhesive strength may be reduced, or the adhesive may exude onto the surface of the surface-coated veneer. In the case of a thin paper having a basis weight of 25 g / m ² , the standard for applying or spraying water is about 3 g / m ² .
When the grammage is larger or smaller than the above, the amount of water may be appropriately adjusted according to the grammage.

However, if there is a considerable difference in water absorption depending on the type of thin paper, and if the time from the application or spraying of water to the application of the adhesive is long, the amount of water absorbed inside the thin paper The amount of water to be applied to the surface of the thin paper should be appropriately adjusted in consideration of the absorbability of the thin paper, the time until the adhesive is applied to the thin paper, etc. It is desirable to determine the minimum required amount by conducting preliminary experiments.

Since the amount of water to be applied is extremely small, the roll R1 is preferably a smooth-faced roll having no groove. It is difficult to squeeze the coating amount with a roll having grooves.

[0019]

EXAMPLES In roll spreader plywood surface thickness 12 mm, modified styrene - butadiene latex adhesive 80 g / m ² was applied, place the tissue paper of 25 g / m ² basis weight, lightly pressing the surface by hand Immediately after that, 3 g / m ² of water was applied to the surface of the thin paper with a pressing roll shown in the right diagram of FIG. 1. Two seconds after the water was applied, the same adhesive as that used for adhering the thin paper was applied on the surface of the thin paper with a roll type spreader at 70 g / m ² to give a thickness of 0.3 m.
If it is in a wet state of m, put a single plate and hot press
If it was thin paper, a veneer was attached to the plywood at the same time to obtain a decorative plywood. The adhesive force between the plywood and the thin paper and the adhesive force between the thin paper and the decorative veneer in the decorative plywood were subjected to a Type II dipping and peeling test by the JAS dipping and peeling test method of the special plywood, and as a result, all passed. Further, 1000 plywoods were continuously passed through the decorative plywood manufacturing process, but none of the thin papers was wound around the roll of the roll spreader.

[0020]

Since the water applied to the surface of the thin paper has a kind of peeling effect, the thin paper P is not caught in the roll R2. Further, by using a roll-type spreader (or roll coater) for applying water, the roll R1 is
Not only does it play a role of applying water to the surface of the thin paper P, but since it is constantly washed with water, the adhesive that has exuded on the surface of the thin paper does not accumulate on the surface of the roll R1. Further, the thin paper P can be prevented from being wound around the roll R1 due to the peeling effect of the water thin film formed on the surface of the roll R1.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of a spreader roll.

FIG. 2 is a perspective view showing a cross section of a decorative plate.

[Explanation of symbols]

D1 doctor roll D2 doctor roll R1 coating roll R2 coating roll B wood board F wood makeup veneer G adhesive g Adhesive P thin paper W water

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-60-67153 (JP, A) JP-A-59-62146 (JP, A) JP-A-59-55741 (JP, A) JP-A-59- 123608 (JP, A) JP 53-118501 (JP, A) JP 53-29903 (JP, A) JP 50-42013 (JP, A) JP 7-96596 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (2)

(57) [Claims] 1. 1. Applying an adhesive to the surface of the wooden board and placing the thin paper on it. 2. a step of applying wrinkles to the surface of the thin paper with a pressing roll having a thin film of water formed on the surface thereof to extend wrinkles of the thin paper and temporarily adhering; 3. The process of applying an adhesive agent with a roll and placing a wooden decorative veneer on it. The process of adhering thin paper and wood decorative veneer to a wood board by hot pressing with a hot press. A method for manufacturing a wooden decorative board comprising the above-mentioned four steps. 2. The pressing roll comprises a coating roll and a doctor roll, water is stored between the both rolls, and the surface of the coating roll is constantly cleaned as the two rolls rotate. A method for producing the wood board decorative board described.