JP2006137147A - Manufacturing method of wooden board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a more improved wooden board capable of conducting a dimensional stabilization treatment of the wooden board using polyethylene glycol in high efficiency without an additional apparatus such as a heater. <P>SOLUTION: A raw material 10 of the wooden board is sprinkled on a forming base 2 to be of a mat-like shape 11, and the formed mat 11 is heat-compressed by a hot press 3. The polyethylene glycol or polyethylene glycol mono-methacrylate 5 is applied on the wooden board 12 which still keeps the heat of the hot-pressing immediately after the heat pressing, and the coated wooden board 12a is cooled to the ambient temperature by natural radiation of heat. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a wooden board, and more particularly to a method for manufacturing a wooden board having excellent dimensional stability.

  As processed wood material, particle board in which wood chips or crushed pieces are hot-pressed and integrated with an adhesive, and wood fiber in which plant fibers that have been pulverized into pulp are also hot-pressed together with an adhesive A board (fiber board) and the like are known, and these are collectively called a wooden board. Wood fiber boards are roughly classified into soft fiber boards, medium fiber boards (MDF), and hard fiber boards (hard boards) according to their density. As the adhesive, thermosetting resins such as phenol resin, urea resin, isocyanate resin, and epoxy resin are used. Such a wooden board is used in a wide field as a wooden decorative board in which a decorative surface layer such as a veneer or a decorative paper is laminated on the surface with an adhesive.

  However, conventional wooden boards have poor dimensional stability when moisture is absorbed, and when wooden boards are used as the base material for flooring, problems such as blistering, gaps due to expansion and contraction, and lifting may occur. There is. In order to improve the dimensional stability of the wood board, the wood board has been conventionally chemically treated, and PEG treatment is known as one of them. PEG treatment replaces the moisture in the wooden board with PEG (polyethylene glycol), which is a typical dimensional stabilizer, and attempts to suppress the expansion and contraction of the wooden board by the filled molecules. Cite.

  One example is shown in Patent Document 1, and after thermoforming resin is sprayed and formed on a piece of wood, it is hot pressed into a plate shape, subsequently cooled, and then cut to the required dimensions. Particles that have been dimensionally stabilized by spraying and impregnating a liquid non-humidifier (such as polyethylene glycol or polyethylene glycol methacrylic acid) that functions as a dimension stabilizer using a spray nozzle from the mouth, followed by curing. I am trying to manufacture a board.

JP-A-08-300320

  By the way, there is polyethylene glycol monomethacrylate as a modified substance of polyethylene glycol. This has a property that leaching due to moisture is eliminated by polymerization, and the usable life of the resin is limited. Use time can be adjusted by using a hardener, the use of a strong hardener will accelerate the curing of the resin, increase the processing efficiency when osmotically impregnated into a wooden board to stabilize dimensions Can do. However, the pot life of the resin is shortened, and the working efficiency in the case of spraying with a spray nozzle as in the method described in Patent Document 1 is deteriorated.

  By reducing the curing agent or using a weak curing agent, it is possible to suppress a decrease in work efficiency, but the processing efficiency for dimensional stabilization decreases. The treatment efficiency can be improved by heating the particle board after impregnating and impregnating the polyethylene glycol monomethacrylate, but after cooling the mat (particle board) formed as in the method described in Patent Document 1, In the case of the method of impregnating and impregnating polyethylene glycol monomethacrylate, a heating device for this is separately required.

  The present invention has been made in view of the circumstances as described above, and in the manufacturing process of a wooden board, for example, a heating device that performs a dimensional stabilization process of a wooden board using a dimensional stabilizer such as polyethylene glycol monomethacrylate. It is an object of the present invention to provide a more improved method for producing a wood board that can be performed with high work efficiency without using an additional device such as the above.

  The method for producing a wooden board according to the present invention includes a step of spreading a raw material of a wooden board on a forming base to form a mat, and a step of heat-pressing the formed mat with a hot press to form a wooden board A process for applying a dimensional stabilizer to a wooden board that has been subjected to hot-pressing and in which heat remains during hot pressing, and a wooden board after application. And a step of cooling to room temperature by natural heat dissipation.

  In the present invention, the term “wood board” is used to include both particle board and wood fiber board as described above. Therefore, “wood board raw material” is also a specific object of particle board. It is selected depending on whether it is wood fiberboard or not. The same applies to the “forming base”. In any case, the process of spreading the raw material of the wooden board on the forming base and making it into a mat shape, and the process of hot pressing the formed mat with a hot press to form a wooden board are the conventional wooden It may be the same as in the board manufacturing process.

  In the present invention, the dimensional stabilizer is not particularly limited, and those conventionally used can be appropriately used. For example, an amino resin such as urea resin or melamine resin, glyoxal resin, MDI (diphenylmethane diisocyanate) or polyethylene glycol monomethacrylate is impregnated into a wooden board together with a curing agent and polymerized to polymerize it. It may function as a stabilizer, and it functions as a wood stabilizer by impregnating the wood board without using a curing agent such as urea, glyoxal, and polyethylene glycol. It may be possible. Among these, polyethylene glycol and polyethylene glycol monomethacrylate are particularly preferable since high dimensional stability can be obtained.

  In the present invention, any of the above-described dimensional stabilizers is applied to a wooden board after hot pressing and in which heat at the time of hot pressing remains. If the dimension stabilizer is a type of dimension stabilizer that is desirably used together with a curing agent, such as the amino resin, glyoxal resin, MDI, and polyethylene glycol monomethacrylate described above, the dimension stability is applied and impregnated inside. Since the agent hardens quickly by the heat accumulated in the wood board, there is an advantage that a heating device for promoting hardening is not required separately. Moreover, the hardening agent to add can be decreased and the useful life of a dimension stabilizer can be lengthened. Furthermore, since the viscosity of a dimension stabilizer falls by apply | coating a dimension stabilizer in the state where the temperature of a wooden board is high, the osmosis | permeation to the inside of a wooden board also becomes easy.

  In addition, when the dimensional stabilizer is of a type that does not require a curing agent such as urea, glyoxal, and polyethylene glycol, the viscosity is high at room temperature and the wood board is not impregnated as it is, but the method of the present invention According to the above, the viscosity is lowered by being heated by the heat accumulated in the wood board, and the wood board can easily penetrate into the wood board. Therefore, there is an advantage that a heating device for lowering the viscosity is not necessary.

  In either case, the wooden board coated with the dimension stabilizer is cooled to room temperature by natural heat dissipation. The cooled wood board is sanded as necessary to obtain a product adjusted to a predetermined thickness.

  Hereinafter, the manufacturing method of the wooden board by this invention is demonstrated more concretely, referring drawings. FIG. 1 schematically illustrates a method of manufacturing a wood board (eg, MDF) according to the present invention.

  Using a thermosetting resin (urea resin, melamine resin, phenolic resin, water-soluble isocyanate resin, etc.) as an adhesive to what has been defibrated into pulp-like fiber from old materials by ordinary methods Prepare a raw material applied by spraying, etc., and form it into a mat 11 by spreading it from the hopper 1 onto a forming base 2 (shown as a belt conveyor in this example) to an appropriate thickness. (FIG. 1a). The formed mat 11 is sent to the hot press machine 3 and hot pressed to form a wood board 12 (FIG. 1b).

  Polyethylene, which is a dimensional stabilizer, is applied to the wood board 12 immediately after decompression, that is, on the surface of the wood board 12 in a hot state in which heat at the time of pressing still remains by means of a spray coating device 4 or the like. An aqueous solution of glycol monomethacrylate (with a slight amount of curing agent) 5 is applied (FIG. 1c). In the example shown in the figure, an aqueous solution is spray-coated on one surface and sucked by an appropriate pump P from the other surface to facilitate internal impregnation of the applied polyethylene glycol monomethacrylate, but suction is omitted. You can also Further, an aqueous solution 5 of polyethylene glycol monomethacrylate may be applied from both sides.

  The wood board 12a coated with polyethylene glycol monomethacrylate is deposited as it is and slowly cooled to room temperature by natural heat dissipation (for example, for several days). As a result, a wooden board with greatly improved dimensional stability is produced (FIG. 1d).

  According to the production method of the present invention, the viscosity of the applied polyethylene glycol monomethacrylate is reduced by the heat of the wooden board itself, so that it easily penetrates into the interior, and the penetrated polyethylene glycol monomethacrylate is still woody. Curing is accelerated by the heat of the board. Therefore, there is no need for a separate heating device for reducing the viscosity or a heating device for thermosetting, and the curing agent to be added can be cured with a very small amount (for example, about 0.05% by weight). Since it is obtained, it becomes possible to lengthen the pot life of polyethylene glycol monomethacrylate.

MDF was produced by a conventional method using a hot press. In a state where the MDF immediately after pressing was hot, an aqueous solution of polyethylene glycol monomethacrylate (Nippon Yushi Co., Ltd .: Bremer PE350G: active ingredient 60%) mixed with 0.05% by weight of the curing agent KPS was spray-coated at 35 g / scale ² . . The MDF coated with the drug was deposited as it was without passing through the cooling step, and was allowed to stand for several days and slowly cooled to room temperature, thereby curing the Bremer PE350G. When the cooled MDF was sanded and adjusted to a predetermined thickness to obtain a product, an MDF product having high dimensional stability could be obtained.

The figure which illustrates schematically the method to manufacture the wooden board (for example, MDF) by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Hopper, 2 ... Forming base, 3 ... Hot press apparatus, 4 ... Spray coating apparatus, 5 ... Aqueous solution of polyethylene glycol monomethacrylate which is a dimensional stabilizer, 11 ... Formed mat, 12 ... Wood board , 12a ... Wood board coated with polyethylene glycol monomethacrylate, P ... Pump

Claims (5)

  A method of manufacturing a wooden board comprising at least a step of spreading a raw material of a wooden board on a forming base to form a mat, and a step of heat-pressing the formed mat with a hot press to form a wooden board In addition, a process of applying a dimensional stabilizer to a wooden board after heat-pressing and heat remaining at the time of hot pressing, and a process of cooling the wooden board after application to room temperature by natural heat dissipation Furthermore, the manufacturing method of the wooden board characterized by the above-mentioned.   The method for producing a wooden board according to claim 1, wherein suction is performed from the other surface of the wooden board in the step of applying the dimension stabilizing agent to the wooden board.   The method for producing a wood board according to claim 1 or 2, wherein the wood board is a wood fiber board.   The method for producing a wooden board according to claim 1 or 2, wherein the wooden board is a particle board.   The method for producing a wooden board according to any one of claims 1 to 4, wherein the dimensional stabilizer is polyethylene glycol or polyethylene glycol monomethacrylate.

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