JP2014108577A - Method for producing fiber board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a fiber board, with which loss of resin is reduced and a predetermined amount of the resin is easily compounded with plant fiber, in producing the fiber board by using the plant fiber and the powder resin.SOLUTION: Powder resin is melted with heat and is fixed to plant fiber, the plant fiber with the resin fixed thereto is formed into a mat-shaped fiber mat, and the fiber mat is molded so as to produce a fiber board.

Description

  The present invention relates to a fiberboard manufacturing method.

  As shown in Patent Document 1, it is known to manufacture a fiberboard by a dry method. This method includes a mat forming step for forming a mat (fiber mat) made of a mixture of long fibers of vegetable fibers and a powder resin, a preheating step for heating the mat, and a press for pressing the preheated mat. A molding step.

JP 2002-192507 A

  Since the above-described method uses a powder resin as a binder component of the fiberboard, the manufacturing process can be simplified such that it is not necessary to dry the mat before press molding.

  However, since the powder resin is generally difficult to adhere to the long fiber, even if the long fiber and the powder resin are mixed in the mat forming process, the powder resin is dropped from the mat, and the loss of the powder resin is increased. was there. There is also a problem that it is difficult to blend a predetermined amount of resin.

  The present invention has been made in view of the circumstances as described above, and in manufacturing a fiberboard using vegetable fiber and powder resin, resin loss is reduced and a predetermined amount of resin is easily blended. It is an object of the present invention to provide a method for manufacturing a fiberboard that can be used.

  In order to solve the above-mentioned problems, the fiberboard manufacturing method of the present invention is a method in which a powder resin is melted by heat and fixed to vegetable fibers, and the plant fibers to which the resin is fixed are formed into a mat shape. A mat is formed, and the fiber mat is manufactured to produce a fiberboard.

  In this fiberboard manufacturing method, after heating the plant fiber, the powder resin is supplied to the plant fiber, and the powder resin is melted by the residual heat of the heated plant fiber to be fixed to the plant fiber. It is preferable to make it.

  Further, in this fiberboard manufacturing method, the powder resin is supplied to the vegetable fiber, and the powder resin is melted by applying heat before the powder resin contacts the vegetable fiber. It is preferable to fix by contacting with plant fibers.

  According to the present invention, in producing a fiberboard using plant fibers and powder resin, resin loss can be reduced and a predetermined amount of resin can be easily blended.

It is a manufacturing flow figure of a fiber board. It is explanatory drawing of 1 process of the manufacturing method of a fiber board.

  An embodiment of a fiberboard manufacturing method will be described with reference to FIG. 1 showing a fiberboard manufacturing flow diagram.

  First, vegetable fibers and powder resin as raw materials are prepared.

  Examples of plant fibers include various natural fibers. For example, fibers collected from the bast of hemp plants such as kenaf, flax, ramie, cannabis, jute, fibers collected from the stem or end of hemp plants such as Manila hemp and sisal hemp, conifers and broadleaf trees It is wood fiber etc. used as a raw material. Moreover, the fiber which uses as a raw material agricultural wastes, such as sugarcane, corn, bamboo, and rice, which can be squeezed after simmering sugar from sugarcane. These vegetable fibers can be used alone or in a mixture. When fibers composed mainly of hemp plants, for example, fibers of hemp plant fibers of 50% by mass or more are used in the total amount of plant fibers, the strength of fiber strength and good dimensional stability during moisture absorption are utilized. Even when the fiberboard contains moisture, the dimensional change of the fiberboard can be reduced. Therefore, when the humidity control board which consists of this fiber board is incorporated as a door or a backplate, curvature and distortion can be suppressed.

  The average fiber length of the vegetable fiber is preferably 5 to 200 mm. Moreover, the average fiber diameter of vegetable fiber is 500 micrometers or less suitably. By using vegetable fibers having an average fiber length and an average fiber diameter in such a range, a fiber board with good dimensional stability can be obtained. Of course, vegetable fibers having an average fiber length of less than 5 mm, vegetable fibers having an average fiber length exceeding 200 mm, and vegetable fibers having an average fiber diameter exceeding 500 μm can also be used. The average fiber length is measured using a fiber length distribution measuring machine or the like. The average fiber diameter is measured as an average value obtained by measuring fiber diameters at a plurality of locations from an image of an optical microscope or an electron microscope.

  The powder resin is a binder component that bonds vegetable fibers to each other in the fiberboard. In the present embodiment, a resin that is solid at room temperature (5 to 35 ° C.) but melts when predetermined heat is applied is used as the powder resin. Here, “melting” includes the meaning of softening. Examples of the resin type of the powder resin include thermosetting resins such as urea resin, phenol resin, melamine resin, epoxy resin, urethane resin, and unsaturated polyester resin. Moreover, thermoplastic resins, such as a polypropylene resin, a polyethylene resin, a polyethylene terephthalate (PET), a vinyl chloride (PVC) resin, can also be mentioned.

  As the particle size of the powder resin, for example, the average particle size is preferably 200 μm or less, and more preferably 100 μm or less. The powder resin having an average particle size within such a range is more easily melted and has better adhesion to the surface of the vegetable fiber. As a result, vegetable fibers can be more effectively bonded to each other, and a fiber board having good strength, dimensional stability, and moisture permeability can be manufactured. The lower limit of the particle diameter of the powder resin is not particularly limited, but in practice, the average particle diameter is 10 μm. The average particle diameter can be obtained as a median diameter (d50, volume basis) by cumulative distribution from a measured value of particle size distribution by a laser diffraction / scattering method using a commercially available laser diffraction / scattering particle size distribution measuring apparatus. it can.

  Next, the powder resin is melted by heat to be fixed to the vegetable fiber, and the vegetable fiber to which the resin is fixed is obtained.

  When the resin type of the powder resin is a thermosetting resin, it can be brought into a molten state by applying heat to such an extent that the curing reaction is not completely completed. When the resin type of the powder resin is a thermoplastic resin, it can be brought into a molten state by applying heat at a temperature equal to or higher than the melting point of the resin.

  While the resin in the molten state easily adheres to the surface of the vegetable fiber, it does not easily penetrate into the vegetable fiber. Since the resin in the molten state easily adheres to the surface of the vegetable fiber, the loss of the resin due to dropping off can be suppressed. In addition, since the molten resin hardly penetrates into the vegetable fiber, most of the resin adhering to the surface of the vegetable fiber is fixed while remaining on the fiber surface. Since the amount of the resin penetrating into the fiber is small, the tenacity of the fiber itself can be utilized without making the fiber brittle. As a result, the action of strength and dimensional stabilization by the plant fiber works effectively, and it is possible to provide a fiberboard that is further excellent in strength and dimensional stability and has good moisture permeability.

  The fixing of the resin to the vegetable fiber is performed as follows, for example. First, a sheet on which a predetermined amount of vegetable fiber is stacked is heated. Next, the powdered resin is supplied to the heated vegetable fiber, and the powdered resin is melted and adhered by the residual heat of the vegetable fiber, and then solidified by cooling, standing, etc., and fixed to the vegetable fiber. Specifically, as shown in FIG. 2A, the assembly 3 of plant fibers 1 is heated by a heater 4 such as a heater or a hot air blower arranged below the assembly 3 of plant fibers 1. . Next, the powder resin 2 is supplied to the heated assembly 3 of vegetable fibers 1 from above by a method such as spraying. The powder resin 2 near the aggregate 3 and the powder resin 2 reaching the aggregate 3 are in a molten state due to the residual heat of the vegetable fiber 1. Thus, since the powder resin 2 is in a molten state, the resin can be fixed to the vegetable fiber 1 by solidifying the resin adhering to the vegetable fiber 1.

  As another method, the powder resin can be supplied to the vegetable fiber, and the powder resin can be melted by applying heat before the powder resin contacts the vegetable fiber. Specifically, as shown in FIG. 2B, when the powder resin 2 is supplied to the aggregate 3 by dropping from the powder resin supply source 5 above the aggregate 3 of the vegetable fibers 1, the aggregate 3 and The area A between the powder resin supply source 5 is heated by the heater 4 to a temperature at which the powder resin 2 can be melted. By doing so, the powder resin 2 is heated during dropping, and is in a molten state before reaching the aggregate 3 of the vegetable fibers 1. Since the powder resin 2 is in a molten state when the powder resin 2 reaches the aggregate 3 of the plant fibers 1, the resin adhering to the plant fibers 1 is solidified to fix the resin to the plant fibers 1. Can be made.

  Any of the methods can more efficiently melt the powder resin and efficiently fix it to the vegetable fiber. Moreover, since a general-purpose heater can be used, manufacturing cost can be suppressed.

  Next, after mixing the vegetable fiber to which the resin is fixed to make the amount of the resin substantially uniform, the vegetable fiber is formed in a mat shape to obtain a fiber mat (matization treatment).

  The fiber mat can be obtained, for example, by using an apparatus called a mat former that continuously manufactures the fiber mat. Further, the fiber mat can be formed by a method such as spraying vegetable fibers on which a resin is fixed on a mold. If necessary, vegetable fibers may be entangled with each other by needle punching.

  In this embodiment, since the fiber mat is formed in a state where the resin is fixed as described above, the resin loss can be reduced as compared with the method of Patent Document 1. Moreover, since there is little loss of resin, it becomes easy to control the quantity of resin to mix | blend, and predetermined quantity resin can be mix | blended easily.

  The resin content in the fiber mat is preferably in the range of 5 to 40% by mass, and more preferably in the range of 15 to 25% by mass. By setting the resin content to 5% by weight or more, the fibers can be bonded more firmly. Thereby, a fiberboard having high strength characteristics and excellent dimensional stability can be obtained. By setting the resin content to 40% by weight or less, it is possible to suppress the occurrence of stains. Further, wasteful consumption of the resin can be suppressed, and the resin can be effectively cured, which is advantageous in terms of cost.

  Next, a fiber mat is formed into a predetermined shape to obtain a fiber board (press treatment).

  When the resin of the fiber mat is a thermosetting resin, for example, the fiber mat is sandwiched between a plurality of heated hot plates or a continuous press device that conveys the fiber mat while applying pressure to a gap between a pair of heated steel belts. A multi-stage press apparatus or the like that pressurizes with can be used. The molding temperature is appropriately set according to the temperature at which the resin is cured. Preferably it sets within the range of 120-200 degreeC. The molding pressure is preferably set in the range of 1 to 4 MPa because it affects the strength performance of the fiberboard obtained and the dimensional stability during moisture absorption. What is necessary is just to set shaping | molding time suitably according to the board | plate thickness and shaping | molding temperature of a fiber board.

  When the resin of the fiber mat is a thermoplastic resin, a fiber plate is obtained by performing cold pressing at a temperature at which the resin is cured in a molten state. The molding pressure is preferably set in the range of 1 to 4 MPa because it affects the strength performance of the fiberboard obtained and the dimensional stability during moisture absorption. What is necessary is just to set shaping | molding time suitably according to the board | plate thickness and shaping | molding temperature of a fiber board.

  As described above, the fiberboard manufacturing method according to the present embodiment melts the powder resin with heat and fixes it to the vegetable fiber, and the vegetable fiber to which the resin is fixed is formed into a mat shape to form a fiber mat. Resin loss can be reduced. Moreover, since there is little loss of resin, it becomes easy to control the quantity of resin to mix | blend, and predetermined quantity resin can be mix | blended easily.

  The fiberboard thus produced can be made into a cosmetic material by sticking a finishing material such as a decorative sheet or a single veneer on the surface. An olefin sheet etc. can be used as a decorative sheet. As the decorative veneer, a log or a product produced by thinly slicing a laminated material in which small-corner materials are assembled and bonded can be used.

  As a method for adhering the fiberboard and the finishing material, an adhesive is applied to the fiberboard or the finishing material, and the fiberboard and the finishing material are stacked with the adhesive-coated surface inside, and hot pressing is performed with a press machine. be able to.

  The manufactured fiberboard can be suitably used for a surface material of a flash panel used for interior fittings such as a door panel, a sliding door, and a partition, or a flooring material such as a flooring floor or a staircase.

1 Plant fiber 2 Powder resin

Claims (3)

  It is characterized in that the powder resin is melted by heat and fixed to vegetable fibers, the plant fibers to which the resin is fixed are formed into a mat shape to form a fiber mat, and the fiber mat is molded to produce a fiber board. A method for manufacturing a fiberboard.   The plant fiber is heated, and then a powder resin is supplied to the plant fiber, and the powder resin is melted and fixed to the plant fiber by the residual heat of the heated plant fiber. The manufacturing method of the fiber board as described in 2 .. Supplying powder resin to the vegetable fiber, heating the powder resin before the powder resin contacts the vegetable fiber, melting the resin, contacting the plant fiber and fixing the molten resin; The manufacturing method of the fiberboard of Claim 1 characterized by the above-mentioned.

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