JP3144648B2 - Method for producing film-coated wood board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a film-covered wood board in which a resin film is coated on the surface of a wood board.

[0002]

2. Description of the Related Art In general, wood boards such as plywood and particle board having a relatively smooth surface have been used for construction, especially as base materials for construction. In recent years, in order to improve the water resistance of wood boards, In addition, a film-coated wooden board having a surface coated with a resin film such as a polyolefin is used. Conventionally, such a method for producing a film-covered wood board is performed by covering one surface of a veneer with a resin film and applying a flat plate press to about 120 ° C.
Before and after, the resin film is heat-welded to the wooden board. And
In this way, the two plates having one surface covered with the resin film are overlapped with each other on the other surface not covered with the resin film to form a plywood.

[0003]

However, according to the conventional manufacturing method, only one surface of the plywood surface is coated with the film, so that the woody portion of the edge is exposed, and moisture is absorbed and dehumidified from that portion. There was a risk of causing dimensional changes. Such a wood board undergoes remarkable dimensional change due to moisture absorption and dehumidification.
It is known that the change in thickness (thickness swelling ratio) after absorbing water for 4 hours is 5% or more.

[0004] On the other hand, in the field of food packaging, there is known a technique in which a stretchable film is covered over the whole food, and heat is applied to the stretchable film at about 80 ° C to cause the packaging film to expand and contract, thereby packaging the entire surface of the food. ing. According to the covering with such an elastic film, it is possible to facilitate packaging in close contact with the entire surface of the food. Therefore, in the field of the film-covered wood board, it is conceivable to apply the same packaging as the food packaging technique. However, if this food packaging technique is simply used for coating a film on a wooden board, there is a disadvantage that the stretchable film and the wooden portion cannot be sufficiently adhered to each other. Also,
Vacuum packaging methods in which materials are vacuum-sealed after heat sealing are also known, but such vacuum packaging methods have the drawback that continuous steps are difficult and equipment costs are increased. Furthermore, in the case of vacuum packaging, there is a disadvantage that excess film resin remains on the surface of the wooden board as it is, and irregularities are generated on the surface of the wooden board, particularly on the wood opening.

Accordingly, an object of the present invention is to provide a method for producing a film-covered wood board having a smooth surface, which can continuously and easily cover the entire surface of the wood board with a resin film.

[0006]

According to the present invention, a heat-shrinkable film is coated on the entire surface of a wooden board (coating step), and then the heat-shrinkable film is heated and heat-shrinked to cover the entire surface of the wooden board. The heat-shrinkable film is brought into close contact with the heat-shrinkable film, and a heated heat roll is rolled over the surface of the heat-shrinkable film, and the heat-shrinkable film is heat-fused to the wooden board while the film surface is heat-fused. (Heat roll process )
A method for producing a wood-covered board, comprising:
Concave at least one of the end faces perpendicular to the front and back of the wood board
Place in the hot roll process.
By providing a method for producing a film-coated wood plate by melting the heat-shrinkable film characterized by the this <br/> be housed in the recess, it is obtained by achieving the above object.

[0007]

According to the present invention, since the heat-shrinkable film covers the entire surface of the wooden board, the dimensional change does not occur due to the absorption or dehumidification of moisture from the exposed portion. Also,
After coating the heat-shrinkable film on the wooden board, the heating roll is rolled to the film and the heat-shrinkable film is heat-welded to the wooden board, so that the heat-shrinkable film is securely adhered to the wooden board. The heat-shrinkable film surface can be smoothed by rolling the heat roll onto the film surface. In addition, heat shrinkable film
Before covering the wooden board, at least an end surface perpendicular to the front and back
A concave is formed in one of the
Transfer contact to the surface, the excess heat-shrinkable film (hereinafter, referred to as
(May be called resin film) in the above recess
As a result, irregularities on the end face can be suppressed.
You . Further, since there is no vacuum step or the like, a continuous step is possible.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 1 and 2. FIG. 1 is a process diagram showing each step of the method for producing a film-coated wood board of the present invention, and FIG. 2 is a partial cross-sectional view of the film-coated wood board manufactured by the method of the present invention.

In the method for producing a film-coated wood board of the present invention, the heat-shrinkable film 1 is coated on the entire surface of the wood board 2 (coating step), and then the heat-shrinkable film 1 is heated to form the heat-shrinkable wood board. The film 1 is brought into close contact with the entire surface of the wooden board 2 by heat shrinkage (heat shrinkage step), and then the heat rolls 4a and 4a are heated on the heat shrinkable heat shrinkable film 1 surface.
b, 4c, and 4d are roll-contacted and the heat-shrinkable film 1 is heat-fused to the wooden board 2 to smooth the film surface (heat roll process). Hereinafter, the present invention will be described according to the order of the manufacturing steps.

[0010] 1. Coating Step In the method for producing a film-coated wood board of the present invention, first, as shown in FIGS. 1A and 1B, the heat-shrinkable film 1 is coated on the entire surface of the wood board 2. Examples of the heat shrinkable film used in the production method of the present invention include polyolefin, polyester, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, and rubber hydrochloride, and a polyolefin film is preferable. Specific examples of the polyolefin film include polypropylene (PP) and polyethylene (PE). As the heat-shrinkable film, a single-layer or two-layer film is used. In the case of a single-layer film, the thickness is 20 μm to 200 μm.
Is preferred. In the case of two layers, a strong corona discharge treatment (for example, a voltage of 100 to 200 V,
When the current is 5 to 30 A and the feeding speed is 1 to 30 mm / min), peeling becomes difficult.

In the case of a two-layer film, a polyolefin film having a thickness of 10 μm to 200 μm, fluorine, silicone, vinyl chloride, nylon or the like is used as a surface film, and an ethylene acetate copolymer (EVA) or the like having a thickness of 10 μm or more is used as an inner layer film. Use a chemically modified film or the like. As the wooden board 2, ordinary wood, plywood, particle board, or the like having a relatively smooth surface is used. The thickness of the wooden board 2 is not particularly limited, but is preferably 12 to 20 mm. It is preferable that recesses 2a for accommodating an extra resin film are formed in advance on both sides of the wooden edge of the wooden board 2 on the wooden edge surface (front and rear surfaces in the transport direction). The recess 2a preferably has a width of 5 to 10 mm and a depth of 2 to 10 mm, although it varies depending on the thickness of the resin film to be coated.

2. Heat shrinking step Next, after cutting an excess film in the coating step, FIG.
As shown in FIG. 3 (c), the coated film 1 is passed through a heating furnace 3 so as to shrink the coated film 1 and adhere to the wooden board 2. In the heating furnace 3, preferably, the temperature in the furnace is 90 to 250 ° C. and the transport speed is 10 to 50 m / min, and the film 1 is substantially heated to a film shrinkage temperature, for example, polyethylene 80 to 150.
C., 150-230.degree. C. of polypropylene and 60-150.degree. C. of polyvinyl chloride. The heating in the heating furnace 3 causes the heat-shrinkable film 1 to shrink and adhere to the entire surface of the wooden board 2.

3. Heat Roll Process The film 1 adhered to the wooden board 2 by heat shrinkage is shown in FIG.
(D), heated rolls 4a, 4b,
4c and 4d. Hot rolls 4a, 4b, 4c,
4 d is preferably heated to 100 ° C. to 300 ° C., and heat rolls 4 a and 4 b are arranged on the upper and lower surfaces of the wooden board 2, and hot rolls 4 c and 4 d are provided on both sides of the wooden board 2 in the transport direction.
, That is, four of the six surfaces of the wooden board 2 are rolled and contacted with the heat rolls 4a, 4b, 4c, and 4d.
Therefore, the heat roll is not disposed on the front and rear edges of the front and rear sides in the transport direction. In this way, by leaving the open end surface free, by the rolling contact of the heat rolls 4a and 4b,
The extruded resin film is allowed to protrude to the wood edge side, and the rolling contact surface can be flattened.

Further, by leaving the film 1 on the open end free, the heat rolls 4a, 4b, 4
When the board is heated by the rolling contact of c and 4d to generate steam, this can be escaped. Heat roll 4
As a, 4b, 4c, and 4d, those having high releasability are used so that they can be easily separated even when they are in contact with the resin film 2. Incidentally, in the hot roll step, in order to impart absorption dehydration to the board, it is possible to cope with the purpose, such as spraying a powder of thermoplastic polyethylene oxide. This makes it possible to adhere the film to the wooden board and simultaneously fuse the powder to the film. Finally, in the heat roll process, as shown in FIG. 1E, the heat rolls 4e and 4f are rolled and contacted to the cut edge surface to smooth the cut edge surface. In the step of smoothing the edge of the wood, as shown in FIG.
a, and its surface can be smoothed, and the dimensional accuracy of the board can be improved.

[0015]

[Example 1 (Invention product 1)]

1. Coating process Heat shrinkable film: High pressure polyethylene film (thickness 5
0μm) Wood board: Particle board (15 × 300 × 300m)
m) With corona discharge: voltage 175 V, current 19.5 A, feed rate 3 mm / min. 2. Heat shrinking step Heating temperature: 80 ° C. in the heating furnace Heat roll process Heating temperature of the heat roll: 120 ° C

[Example 2 (Product 2 of the present invention)] Coating process Heat-shrinkable film: Two-layer film Surface layer Biaxially oriented polypropylene (OPP) film, thickness 30 μm Interior ethylene acetate copolymer (EVA) film, thickness 30 μm Wood board: Particle board (15 × 300 × 300) Corona discharge: None 2. 2. Heat shrinking step Heating temperature: 80 ° C. inside the heating furnace Heat roll process Heating temperature of the heat roll: 120 ° C

Example 3 (Product 3 of the Present Invention) Coating process Heat shrinkable film: High pressure polyethylene film (thickness 5
Wood board: particle board (15 × 300 × 300) Corona discharge conditions: voltage 175 V, current 19.5 A, feed rate 3 mm / min 2. 2. Heat shrinking step Heating temperature: 80 ° C. inside the heating furnace Heat roll process Heating temperature of the heat roll: 120 ° C. Powder of thermoplastic polyethylene oxide is added at 10% of the film weight.

[Comparative Example (Comparative Example Product)] A comparative product obtained by a conventional method in which a wooden board was coated with polyvinyl chloride by a flat plate press was used.

[Test] A water resistance test was performed on the manufactured products obtained in the above Examples. In the water resistance test, the manufactured product obtained in the example and the comparative product obtained in the conventional example were immersed in water for 24 hours to absorb water, and the swelling ratio of the thickness due to the water absorption and the water absorption were measured.

[0020]

[Table 1] As is clear from Table 1, the swelling ratio of the thickness of the film-coated wood board manufactured according to the present example was almost 0% and the water absorption was almost 0%, and the swelling ratio of the comparative example was 10% and the water absorption was 10%. It can be seen that the water resistance is remarkably superior to that of 15%. In addition, in Example 3, the reason why the water absorption was 0.1 was that polyethylene oxide powder having hygroscopicity was added. That is, by adding the polyethylene oxide powder, moisture absorption performance can be imparted to the film-covered wooden board. In addition, when the adhesiveness of the film subjected to the corona discharge treatment and that not subjected to the corona discharge treatment was tested in Example 1, the adhesive strength was 14.0 kg / cm ² in the case of the corona discharge treatment, and 1 in the case of no treatment.
It was 2.0 kg / cm ² .

The present invention is not limited to the embodiments described above,
Various modifications can be made without departing from the spirit of the present invention.
For example, the recess 2a is not limited to being formed on the wooden surface,
It may be formed on another surface of the wooden board, for example, on both sides (left and right in the transport direction). In addition, the heat roll, if it rolls the film-coated surface of the wooden board,
The shape is not limited to the cylinder shape, but may be a belt shape. Further, when the adhesiveness between the wooden board 2 and the film 1 is insufficient, an adhesive such as urethane or epoxy resin may be applied to the film side in advance by a spray gun or the like.

[0022]

According to the method for producing a film-coated wood board of the present invention, it is possible to manufacture a film-coated wood board having a smooth surface in which the entire surface of the wood board can be continuously and easily covered with the resin film. it can.

[Brief description of the drawings]

FIG. 1 is a process chart showing each step of a method for producing a film-coated wood board of the present invention.

FIG. 2 is a partial cross-sectional view of a film-coated wood board manufactured by the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat-shrinkable film 2 Wood board 2a recess 3 Heating furnace 4 Heat roll

Continuation of the front page (56) References JP-A-52-33321 (JP, A) JP-A-51-582 (JP, A) JP-A-48-99278 (JP, A) JP-A-1-77528 (JP) JP-A-61-22944 (JP, A) JP-A-59-165656 (JP, A) JP-A-50-4172 (JP, A) Japanese Utility Model Laid-Open No. 53-37767 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 E04C 2/00-2/54

Claims (1)

(57) [Claims] 1. A heat-shrinkable film is coated on the entire surface of a wooden board (coating step), and then the heat-shrinkable film is heated and adhered to the entire surface of the wooden board by heat shrinkage (heat shrinkage step). Subsequently, a heated heat roll is roll-contacted to the surface of the heat-shrinkable heat-shrinkable film, and the film surface is smoothened while the heat-shrinkable film is heat-fused to the wooden board (heat roll process). ), A method for producing a film-coated wood board.
, Prior to said coating step, perpendicular end face on the front and back surfaces of the wood board
A recess is formed in at least one of
Melts the excess heat shrinkable film
A method for producing a film-covered wooden board, wherein the wooden board is housed in the recess .