JP6021071B2 - Manufacturing method of wood fiberboard - Google Patents

Description

  The present invention relates to a method for manufacturing a wood fiber board.

  Conventionally, a wood fiber board having moisture permeability has been used as a wall material in a room such as a house.

  As a method for producing a wood fiber board, for example, a powder resin is supplied to wood fibers on a conveyor, and a fiber mat is obtained by defibrating with a rotating defibrating cylinder (roll with a needle). A method for producing a wood fiber board by pressure molding is known (Patent Documents 1 and 2).

JP-A-5-51466 Japanese Patent Laid-Open No. 5-220878

  However, in the case of the conventional methods such as Patent Documents 1 and 2, since the powder resin scatters at the time of defibration with the defibrating cylinder, the powder resin contained in the fiber mat may be partially lost and become non-uniform. is there. And the wood fiber board manufactured by hot-press-molding such a fiber mat has the problem that physical properties, such as water resistance, are inadequate.

  The present invention has been made in view of the circumstances as described above, and it is possible to uniformly mix the wood fibers and the powder resin contained in the fiber mat, and reliably ensure the water resistance of the wood fiber board. It is an object of the present invention to provide a method for producing a wooden fiberboard that can be used.

  In order to solve the above-described problems, a method for producing a wood fiber board of the present invention includes the following steps, a laminate step of supplying a powder resin from a resin supply unit on a wood fiber to form a laminate, and the laminate A method for producing a wood fiber board, comprising a defibrating step of defibrating a body with a defibrating cylinder to obtain a fiber mat, and a molding step of producing a wood fiber board by hot pressing the fiber mat, The amount of the powder resin supplied in the laminating step is excessive as compared with the content of the powder resin to be contained in the fiber mat, and the excess powder resin is scattered by defibration in the defibrating step and the fibers It is characterized by obtaining a mat.

  In this wood fiber board manufacturing method, it is preferable to collect the powder resin scattered by the defibration in the defibrating step and re-inject the powder resin into the resin supply unit.

  In this wood fiber board manufacturing method, it is more preferable to supply dehumidified air in the defibrating step.

  In this wood fiber board manufacturing method, it is more preferable that the wood fiber layer in the laminating step contains a liquid material.

  According to the method for producing a wood fiber board of the present invention, the wood fiber contained in the fiber mat and the powder resin can be mixed uniformly, and the water resistance of the wood fiber board can be reliably ensured.

It is the schematic which illustrated one Embodiment of the manufacturing method of the wood fiber board of this invention.

  FIG. 1 is a schematic view illustrating an embodiment of a method for producing a wood fiber board of the present invention. Hereinafter, one embodiment of the method for producing a wood fiber board of the present invention will be described with reference to FIG.

The manufacturing method of the wood fiber board of this invention includes the following processes.
(1) A lamination process in which a powder resin is supplied from a resin supply unit on a wood fiber to form a laminate.
(2) A defibrating step of defibrating the laminate with a defibrating cylinder to obtain a fiber mat.
(3) A molding step of manufacturing a wood fiber board by hot-pressing a fiber mat.

  In the laminating step, the powder resin 2 is supplied from the resin supply unit D2 on the wood fiber 1, and the laminate 3 in which the powder resin 2 is laminated on the wood fiber 1 is formed.

  Specifically, the wood fiber 1 is supplied onto the conveyor C from the upstream fiber supply unit D1. The supplied wood fiber 1 may be oriented so that the fiber bundle is in the same direction as the transport direction.

  Examples of the wood fiber 1 supplied from the fiber supply unit D1 include hemp bast fibers such as kenaf and jute. Among these, hemp bast fibers are preferable because they contain a large amount of crystalline and high strength cellulose and have high strength as fibers. Hemp bast fibers can obtain long fibers from a hemp plant by, for example, a soaking process called letting and a physical defibrating process.

  The wood fiber 1 is preferably, for example, a long fiber having a length of 10 to 200 mm and a diameter of 100 μm or less. By using the long fiber, the shape retention of the fiber mat 4 can be improved by entwining the long fibers well. Can be increased. Moreover, the wood fiber 1 may be subjected to a pretreatment that is immersed in water to remove the adhesive component.

  Subsequently, the powder resin 2 is uniformly supplied and laminated on the wood fiber 1 from the resin supply part D2 disposed downstream of the fiber supply part D1, and the laminate 3 is formed.

  The powder resin 2 has thermosetting properties, and examples thereof include a powdered vinyl acetate resin, acrylic resin, epoxy resin, urethane resin, urea resin, melamine resin, phenol resin, and the like.

  And the quantity of the powder resin 2 supplied in a lamination process is the powder resin content set as the quantity which should be contained in the fiber mat 4 (powder resin content set from the resin content of the wood fiber board to be manufactured) Is excessive. The amount of the powder resin 2 to be contained in the fiber mat 4 can be set in consideration of the strength, thickness, density, etc. of the wood fiber board, and based on this amount, the amount of the powder resin 2 supplied in the laminating process Can be set. Specifically, for example, the amount of the powder resin 2 supplied in the laminating step is set to about 1.1 to 2.0 times the content of the powder resin 2 set as the amount to be contained in the fiber mat 4. It is considered.

  Moreover, it is preferable that liquid materials, such as water and alcohol, are contained in the wood fiber 1 in a lamination process. In this case, a liquid material can be mixed with the wood fiber 1 in advance, and the wood fiber 1 containing the liquid material can be supplied. Moreover, after supplying the wood fiber 1, the liquid material can be contained in the wood fiber 1 by spraying the liquid material from above.

  And the laminated body 3 formed at the lamination process is conveyed to the mixing part M in which the defibrating cylinder S was accommodated.

  In the defibrating process, the laminated body 3 formed in the laminating process is defibrated by the defibrating cylinder S to produce the fiber mat 4.

  A needle (protrusion) for defibrating the wood fiber 1 is formed on the surface of the defibrating cylinder S, and a pressing roll R is disposed in front of the defibrating cylinder S. The laminated body 3 transported by the transport conveyor C is separated by a defibrating cylinder S that is rotated at a high speed while being pressed by a pressing roll R and is defibrated and separated, and the separated wood fiber 1 and the powder resin 2 are mixed into a mixing unit. Splashes into M. And the fiber mat 4 can be obtained by stacking the aggregate | assembly of the wood fiber 1 and powder resin 2 which were mixed by this scattering, for example on the downstream conveyance conveyor C. FIG.

  In the laminated body 3 formed in the laminating process, the powder resin 2 is scattered around by centrifugal force during defibrating in the defibrating process. At this time, since the amount of the powder resin 2 in the laminate 3 is more than the content of the powder resin 2 to be contained in the fiber mat 4, the powder resin 2 contained in the fiber mat 4 is partially missing. Is suppressed, and the wood fiber 1 and the powder resin 2 can be mixed substantially uniformly without unevenness.

  Further, the excessive powder resin 2 scattered by the defibration in the defibrating process is sucked and collected by the fan F provided in the mixing unit M, and is reintroduced into the resin supply unit D2 through the resupply channel W. For this reason, the loss of the powder resin 2 is suppressed and the fiber mat 4 can be obtained efficiently.

  Further, in the defibrating step, it is preferable to defibrate the laminate 3 by supplying dehumidified air into the mixing unit M that houses the defibrating cylinder S. As a result, the aggregate of the defibrated wood fiber 1 and the powder resin 2 is dried to reduce the amount of water, so that the powder resin 2 scattered at the time of defibration is covered with the cover part M1 of the mixing part M and the surrounding wall M2. The adhesion of the powder resin 2 to the inside is suppressed. Therefore, since the scattered powder resin 2 is reliably sucked and collected by the fan F and re-introduced, loss of the powder resin 2 is suppressed, and the fiber mat 4 can be obtained more efficiently.

  Moreover, when the liquid material is contained in the wood fiber 1 formed in the lamination process, the scattering of the powder resin 2 at the time of the defibration of the laminate 3 in the defibration process can be adjusted appropriately.

  In the molding process, the fiber mat 4 manufactured in the defibrating process is hot-press molded to manufacture a plate-like wood fiberboard. As a method for pressing the fiber mat 4 in the molding step of the present invention, a batch type flat plate press, a continuous press, or the like can be adopted, but is not particularly limited. Moreover, the temperature, time, and pressure at the time of hot-press molding can be appropriately set depending on the type of powder resin, the thickness and density of the wood fiber board, and the like.

  In the molding step, the fiber mat 4 can be pre-pressed (pre-pressed) as necessary before the fiber mat 4 is hot-press molded. In addition, the moisture content of the fiber mat 4 can be adjusted by drying the fiber mat 4 with a drying furnace or the like before hot pressing the fiber mat 4.

  According to the method for producing a wood fiber board of the present invention, the amount of the powder resin 2 of the laminate 3 is excessive as compared with the content of the powder resin 2 to be contained in the fiber mat 4. Disperse in the defibration process. For this reason, the wood fiber 1 and the powder resin 2 contained in the fiber mat 4 can be mixed substantially uniformly, and the water resistance of the wood fiber board can be obtained by hot pressing the fiber mat 4 in the molding process. Can be ensured. Furthermore, when the excessive powder resin 2 scattered by the defibration in the defibration process is collected and re-introduced into the resin supply part D2, the powder resin 2 can be reused, and therefore the loss of the powder resin 2 Is reliably suppressed.

  The manufacturing method of the wood fiber board of this invention is not limited to the above embodiment. For example, the layered product in the layering step may contain humidity control materials such as diatomaceous earth, silica gel, activated carbon, zeolite, activated clay, and the like. Furthermore, the method for producing a wood fiber board of the present invention includes a step of attaching a decorative sheet or veneer having a desired coloring or pattern on the surface of the wood fiber board, if necessary, or a wood fiber board. A process of applying a desired paint on the surface of the film is also included.

DESCRIPTION OF SYMBOLS 1 Wood fiber 2 Powder resin 3 Laminated body 4 Fiber mat S Disentanglement cylinder D2 Resin supply part

Claims (4)

The following steps,
A laminating step of forming a laminate by supplying a powder resin from a resin supply unit on a wood fiber,
A method for producing a wood fiber board, comprising: a defibrating step of defibrating the laminate with a defibrating cylinder to obtain a fiber mat; and a forming step of producing a wood fiber board by hot pressing the fiber mat. ,
The amount of the powder resin supplied in the laminating step is excessive as compared with the content of the powder resin to be contained in the fiber mat, and the excess powder resin is scattered by defibrating in the defibrating step. A method for producing a wood fiber board, comprising obtaining a fiber mat.   2. The method for producing a wood fiber board according to claim 1, wherein powder resin dispersed by defibration in the defibrating step is collected, and the powder resin is reintroduced into the resin supply unit.   The method for producing a wood fiber board according to claim 1 or 2, wherein dehumidified air is supplied in the defibrating step.   4. The method for producing a wood fiber board according to claim 1, wherein the wood fiber layer in the laminating step contains a liquid material. 5.