JP2013023909A - Method for producing woody floor plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a woody floor plate in which an assortment step of each product according to the moisture content of woody fiber plates is established and the occurrence of warping is reduced so as to eliminate the need for a screening step of defective products.SOLUTION: A method for producing a woody floor plate in which after a woody fiber plate and a base plate are bonded to be formed into a composite material, a surface decorative member is bonded to the surface of the woody fiber plate side in the composite material comprises a step 2 of measuring the moisture content of the woody fiber plate, steps 3-5 of bonding the woody fiber plate to the surface of the base plate with a specific gravity corresponding to the measured moisture content of the woody fiber plate through an adhesive agent to form a composite material, and steps 6-8 of bonding a surface decorative member corresponding to the measured moisture content of the woody fiber plate to the surface of the woody fiber plate side of the composite material through the adhesive agent.

Description

  The present invention relates to a method for producing a wooden floor board.

  Usually, the wood-based floorboard has a structure in which a surface decorative material is bonded and integrated on the surface of the wood fiberboard side of the composite material obtained by bonding and combining the substrate and the wood fiberboard.

  In general, a plywood, a particle board, an OSB (Oriented Strand Board) or the like is used as a substrate, and a MDF (Medium Density Fiberboard) or the like is used as a wood fiber board bonded and composited on the surface.

  Moreover, a veneer and a resin sheet are used as the surface decorative material bonded to the surface of the wood fiber board.

  A composite material composed of a wood fiber board and a substrate is manufactured by applying an adhesive to the wood fiber board or the substrate, then laminating and cold pressing, but the dimensional change rate per moisture content of the wood fiber board and the substrate is low. Due to the difference, there is a problem that a predetermined warpage standard is not satisfied unless a certain moisture content difference is given.

  In current production, the warp is measured after the wooden floorboard is selected and sorted by product, and the non-standard one is disposed of as a defective product, or it is forced to flatten and repair using a warp straightener. Things have been done.

  However, according to such a method, since it is necessary to measure warpage individually, there is a problem that it takes a lot of time and labor and cost to dispose of a defective product.

  Further, the forcible flattening process using the warp straightening machine has a problem that it is a batch type and the process steps increase.

  In response to this situation, a plurality of wet veneers, dry veneers, and MDFs are laminated, pre-hydrated and humidity-adjusted to give convex warpage, and as a result, substantially flat by heating and pressurizing treatment. A method has been proposed (see, for example, Patent Document 1).

JP-A-9-85715

  However, even with such a proposal, there are problems such as difficulty in stable production of the product because the condition of the convex warpage to be given in advance differs depending on the size and thickness of the target product and the production environment. .

  The present invention has been made in view of the circumstances as described above, and establishes a constituent material selection process according to the moisture content of the wood fiber board, reduces the occurrence of warping, and stably manufactures the product. It is an object of the present invention to provide a method for manufacturing a wooden floor board that can be used.

The present invention is characterized by the following in order to solve the above problems.
That is, the method for producing a wood floor board according to the present invention is a method for producing a wood floor board in which a wood fiber board and a substrate are bonded to form a composite material, and then a surface decorative material is adhered to the surface of the composite wood fiber board side. In this case, the step of measuring the moisture content of the wood fiber board and the surface of the substrate having a specific gravity according to the measured moisture content of the wood fiber board are bonded to the wood fiber board via an adhesive to form a composite material. It has the process and the process which adhere | attaches the surface decoration material according to the moisture content of the measured wood fiber board on the surface of the composite material wood fiber board side via an adhesive agent.

  In this method for producing a wooden floorboard, a high specific gravity substrate is used when the moisture content of the wood fiber board is low, and a low specific gravity is used when the moisture content of the wood fiber board is medium moisture content or high moisture content. It is preferable to use the substrate.

In addition, in this method for producing a wooden floorboard, when the moisture content of the wood fiber board is medium moisture content or low moisture content, a veneer is used for the surface decorative material, and the moisture content of the wood fiber board is high moisture content. It is preferable to use a resin sheet for the surface decorative material.

  According to the method for manufacturing a wooden floorboard of the present invention, the substrate and the surface decorative material constituting the wooden floorboard are selected and manufactured according to the moisture content of the wooden fiberboard measured during the manufacturing process of the wooden floorboard. Therefore, the occurrence of warpage can be reduced, and it is not necessary to select defective products, and products can be stably manufactured.

It is a block diagram for demonstrating the manufacturing process of the wood type floor board of this invention.

  The manufacturing method of the wooden floorboard of the present invention measures the moisture content of the wooden fiberboard, and selects and manufactures the substrate and the surface decorative material constituting the wooden floorboard according to the moisture content.

  The wood fiberboard used in the present invention can be used without particular limitation as long as it is a generally known wood fiberboard. Examples thereof include MDF such as conifers, HDF (High Density Fiberboard), and insulation. Examples include boards, kenaf fibers, jute fibers, and synthetic fibers that have been defibrated and pressed.

  In the method for producing a wood floor board of the present invention, first, the moisture content of the wood fiber board is measured, and the wood fiber board is sorted into a high moisture content, a medium moisture content, and a low moisture content according to the measured moisture content.

  In the present invention, for example, a high water content is a water content higher than 6.5%, a medium water content is a water content of 5 to 6.5%, and a low water content is a range of a water content lower than 5%. These thresholds are appropriately set depending on the thickness of the substrate and the wood fiber board used.

  The method for measuring the moisture content is not particularly limited as long as it is a method for measuring the moisture content of wood. For example, a measurement method using a non-contact type infrared moisture meter, an electric resistance moisture meter is used. Various measuring methods such as a measuring method used, a measuring method using a high-frequency moisture meter, and a measuring method using a microwave moisture meter can be employed.

  Next, the board | substrate according to the moisture content of a wood fiber board is selected. A high specific gravity substrate is used when the moisture content of the wood fiber board is low, and a low specific gravity substrate is used when the moisture content is medium or high.

  In the present invention, the high specific gravity of the substrate means a range of 0.6 or more and the low specific gravity means a range of 0.4 or less.

  The substrate that can be used in the present invention is not particularly limited as long as the specific gravity is in the above range. For example, solid wood, plywood, particle board, OSB (Oriented Strand Board), LVL (Laminated Veneer Lumber) ) And the like.

  Examples of the high specific gravity substrate tree include eucalyptus and capol, and eucalyptus can be particularly preferably used.

  Further, examples of the tree species of the low specific gravity substrate include Falkata and Japanese cedar, and Falkata can be particularly preferably used.

  In addition, adjustment of specific gravity can be performed by selecting suitably the wood seed | species which comprises a board | substrate. Moreover, it can also be set as the board | substrate of desired specific gravity by combining several kinds of wood.

  Hereinafter, the moisture content of the wood fiber board for reducing the occurrence of warpage and the mechanism for selecting the substrate according to the moisture content will be described in detail with estimation.

  In the present invention, the reason for using the high specific gravity substrate for the low moisture content wood fiber board is that the high specific gravity is relatively small for the low moisture content wood fiber board with relatively little dimensional change. This is because by using the substrate, a composite material in which the dimensional change is small and the occurrence of warpage is reduced as a whole.

  The reason for using a low specific gravity substrate for medium moisture content or high moisture content wood fiber board is that it is relatively dimensioned for high moisture content and medium moisture content wood fiber board with relatively large dimensional changes. This is because, by using a low specific gravity substrate capable of coordinating with changes, the composite material can flexibly cope with dimensional changes as a whole and the occurrence of warpage is reduced.

  Thus, in the present invention, it is important to grasp the dimensional change characteristic from the moisture content of the wood fiber board and select a substrate having a dimensional change characteristic corresponding to this.

  That is, the difference in dimensional change characteristics between the wood fiber board and the substrate is not forcibly suppressed in accordance with either, but the occurrence of warpage is reduced by combining the wood fiber board and the substrate having similar dimensional change characteristics. Is.

  After measuring the moisture content of the wood fiber board, the substrate and the wood fiber board are bonded almost continuously through an adhesive to form a composite material. As the adhesive used here, a non-aqueous adhesive such as a PUR (Poly Urethane Reactive) adhesive is used in order not to absorb the substrate and the wood fiber board.

  PUR is a reactive hot-melt resin, mainly composed of a polyurethane-based uncured resin (prepolymer), which reacts with water, for example, moisture in a wooden fiberboard, and is particularly suitably used. it can.

  Next, the surface decoration material according to the moisture content of a wood fiber board is selected. A veneer is used when the moisture content of the wood fiber board is low or medium, and a resin sheet is used when the moisture content is high.

  Examples of the veneer used in the present invention include a thin sheet veneer formed by slicing natural precious wood thinly. From the viewpoint of aesthetics, texture, etc., for example, beech, oak, oak, walnut, A wood veneer such as walnut, beach or birch can be suitably used.

  The resin sheet used in the present invention can be used without particular limitation as long as it is a resin sheet that has no moisture permeability or is extremely low in moisture permeability, which is usually used as a surface decorative material for wooden floorboards.

  These include, for example, polyolefin resin sheets such as polyethylene resin sheets and polypropylene resin sheets, polystyrene resin sheets, vinyl chloride resin sheets, polyethylene terephthalate resin sheets, polyester resin sheets such as polybutylene terephthalate resin sheets, and various resins. A sheet can be mentioned. Various patterns may be printed on the surface of these resin sheets.

  Below, the moisture content of the wood fiber board for reducing the occurrence of warpage and the mechanism of selection of the surface decorative material according to the moisture content will be described in detail with estimation.

  In the present invention, the reason for using a veneer as a surface decorative material for a low-moisture content or medium-water content wood fiberboard is that a relatively air-permeable veneer is used as the surface of the low-moisture content or medium-water content wood fiberboard This is because the low moisture content or the medium moisture content of the wood fiber board is stabilized so as not to be biased to the high moisture content, thereby reducing the dimensional change.

  On the other hand, when a resin sheet is used as a surface decorative material for a wood fiber board having a low water content or a medium water content, moisture on the surface layer of the wood fiber board is not released through the resin sheet. There is a possibility that the surface is expanded and convex warpage occurs due to high water content.

  The reason for using a resin sheet as a surface decorative material for a high moisture content wood fiberboard is that the surface of the wood fiberboard having a high moisture content is a resin sheet that has no moisture permeability or a very low moisture permeability. This is because the moisture content of the wood fiber board can be stably maintained in a high moisture content state by bonding to the glass fiber to reduce the dimensional change.

  On the other hand, for example, when a veneer is used as a surface decorative material for a wood fiber board with a high water content, the moisture on the surface layer of the wood fiber board is released through the veneer, so that only the surface has a low water content. May shrink and cause concave warping.

  As an adhesive for adhering the wood fiber board and the surface decorative material, any adhesive can be used without particular limitation as long as the wood fiber board and the surface decorative material can be firmly bonded to each other. Aqueous adhesives such as resin adhesives, aqueous vinyl acetate resin adhesives, and aqueous isocyanate resin adhesives can be suitably used.

  Hereinafter, a preferred embodiment of a method for producing a wooden floor board of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram for explaining a manufacturing process of a wood floor board according to the present invention.

  In the embodiment shown in FIG. 1, MDF is used as the wood fiber board. First, MDF is thrown into the production line in step 1 (MDF throwing step).

  Next, in step 2 (moisture content measurement step), the moisture content of the MDF is measured to obtain a high moisture content line A having a moisture content of more than 6.5%, and a medium moisture content line B, 5 to 5 to 6.5%. It is divided into each production line of a low moisture content line C of less than%.

  Next, in step 3 (PUR application step), PUR as an adhesive is applied on the wood fiber board. The application method of the adhesive in this step 3 (PUR application step) is not particularly limited, and various application methods such as roll coater, spray application, and hand application can be employed.

  Next, in step 4 (substrate mounting step), the specific substrate corresponding to each moisture content is bonded to the wood fiber board for each production line of high moisture content line A, medium moisture content line B, and low moisture content line C. Place it on the coating surface.

  In the present embodiment, in the high moisture content line A and the medium moisture content line B, Falkata plywood is placed as a low specific gravity substrate, and in the low moisture content line C, eucalyptus plywood is placed as a high specific gravity substrate.

  Next, a board | substrate and a wood fiber board are adhere | attached by process 5 (roll press process), and it is set as a composite material. In this roll press step, a roll press by heating and pressurization may be used, but it is preferable to bond by a so-called cold press with only pressurization at normal temperature in consideration of fluctuations in moisture content.

  The composite material thus manufactured is applied with an adhesive on the surface of the composite material on the side of the wood fiber board in step 6 (adhesive application step) for adhering the surface decorative material. The method of applying the adhesive in step 6 (adhesive application step) is not particularly limited, and various application methods such as roll coater, spray coating, and hand coating can be employed.

  Next, in step 7 (surface cosmetic material placement step), a surface cosmetic material corresponding to each moisture content is prepared for each of the production lines of high moisture content line A, medium moisture content line B, and low moisture content line C. Place it on the adhesive coated surface on the wood fiberboard side.

  In the present embodiment, a polyolefin resin sheet is placed as a resin sheet in the high moisture content line A, and a beech projecting plate is placed as a projecting plate in the medium moisture content line B and the low moisture content line C.

  Next, the composite material and the surface decorative material are bonded in step 8 (roll press step) to obtain a wooden floorboard. In this roll press process, it is preferable to use a heat and pressure roll press. The conditions of the heat and pressure roll press depend on the type of substrate, wood fiber board, surface decorative material, thickness, type of adhesive, etc. For example, the conditions of 80 to 190 ° C. and 1 to 5 MPa are considered.

  In this way, products A, B, and C of wood-based floorboards that suppress the occurrence of warping based on the moisture content of the wood fiberboard can be manufactured. Although not shown in the present embodiment, a step of applying a polishing agent or the like to the surface of the surface decorative material may be introduced after step 8 (roll press step).

  In addition, each process of the present embodiment can be automatically measured and controlled by a computer or the like, and is a production line that consistently controls from the introduction of the wood fiber board to the completion of the wood floor board. You can also.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all.

  Various materials shown below were used as materials for the wooden floorboard. Note that wood fiber boards having different lot numbers are prepared, and the moisture content is measured using a non-contact infrared moisture meter (JTE Engineering Rial Co., Ltd., JE10). The moisture content is 6.5. More than 5% high moisture content wood fiberboard, 5 to 6.5% medium moisture content wood fiberboard, and less than 5% low moisture content wood fiberboard.

Wood fiber board: conifer MDF (manufactured by N & E Co., Ltd.) (thickness 2.7 mm, width 303 mm, length 1818 mm)
Low specific gravity substrate: Falkata plywood (specific gravity 0.35, thickness 9.5 mm, width 303 mm, length 1818 mm

High specific gravity substrate: Eucalyptus plywood (specific gravity 0.77, thickness 9.5 mm, width 303 mm, length 1818 mm)
Adhesive (for composite material): Reactive hot melt adhesive PUR (manufactured by DIC Corporation, MK200Y)

Surface decorative material (resin sheet): Printed sheet (0.2 mm thick) made of polyolefin resin sheet
Surface decorative material (veneer): Beech material (0.2mm thick)
Adhesive (for surface cosmetics): Aqueous vinyl acetate resin adhesive

Example 1
<High moisture content wood fiberboard + low specific gravity substrate + surface decorative material (resin sheet)>
A high moisture content wood fiber board and a low specific gravity substrate were bonded with an adhesive (for composite material) by a roll press under a condition of a linear pressure of 3 kgf / mm to obtain a composite material.

  Next, the polyolefin resin sheet was heated and pressed under conditions of 110 ° C., 1 MPa, and 1 minute through an adhesive (for surface decorative material) on the wood fiberboard side of the composite material to obtain a wood-based floorboard.

  The prepared wooden floorboard was measured to have a width of 30 cm × length of 180 cm, and the amount of warpage in the width direction of the ten wooden floorboards was measured and found to be within a range of ± 0.7 mm.

(Comparative Example 1)
<High moisture content wood fiberboard + high specific gravity substrate + surface decorative material (resin sheet)>
A wooden floorboard was prepared under the same conditions as in Example 1 except that a high specific gravity substrate was combined with a high moisture content wood fiberboard.

  When the amount of warp in the width direction was measured in the same manner as in Example 1 for the prepared wood type floor board, there was a wood type floor board having a larger warp than -0.7 mm.

(Comparative Example 2)
<High moisture content wood fiberboard + low specific gravity substrate + surface decorative material (veneer)>
A wooden floorboard was prepared under the same conditions as in Example 1 except that a veneer was used as the surface decorative material.

  When the amount of warp in the width direction was measured in the same manner as in Example 1 for the prepared wood type floor board, there was a wood type floor board having a larger warp than -0.7 mm.

(Example 2)
<Low moisture content wood fiberboard + high specific gravity substrate + surface decorative material (veneer)>
A wood-based floorboard was prepared under the same conditions as in Example 1 except that a veneer surface decorative material was used for the composite material obtained by bonding a low moisture content wood fiberboard and a high specific gravity substrate.

  When the amount of warpage in the width direction was measured in the same manner as in Example 1 for the prepared wooden floorboard, it was within the range of ± 0.7 mm.

(Comparative Example 3)
<Low moisture content wood fiberboard + low specific gravity substrate + surface decorative material (veneer)>
A wooden floorboard was prepared under the same conditions as in Example 2 except that a low specific gravity substrate was combined with a low moisture content wood fiberboard.

  When the amount of warp in the width direction was measured in the same manner as in Example 1 for the prepared wood type floor board, there was a wood type floor board having a larger warp than +0.7 mm.

(Comparative Example 4)
<Low moisture content wood fiberboard + high specific gravity substrate + surface decorative material (resin sheet)>
A wooden floorboard was prepared under the same conditions as in Example 2 except that a resin sheet was used as the surface decorative material.

  When the amount of warp in the width direction was measured in the same manner as in Example 1 for the prepared wood type floor board, there was a wood type floor board having a larger warp than -0.7 mm.

(Example 3)
<Medium moisture content wood fiberboard + low specific gravity substrate + surface decorative material (veneer)>
A wood-based floorboard was prepared under the same conditions as in Example 1 except that a veneer surface decorative material was used as a composite material in which a medium moisture content wood fiberboard and a low specific gravity substrate were bonded.

  When the amount of warpage in the width direction was measured in the same manner as in Example 1 for the prepared wooden floorboard, it was within the range of ± 0.7 mm.

(Comparative Example 5)
<Medium moisture content wood fiberboard + High specific gravity substrate + Surface decorative material (Veneer)>
A wooden floorboard was prepared under the same conditions as in Example 3 except that a high specific gravity substrate was combined with a medium moisture content wood fiberboard.

  When the amount of warp in the width direction was measured in the same manner as in Example 1 for the prepared wood type floor board, there was a wood type floor board having a larger warp than +0.7 mm.

(Comparative Example 6)
<Medium moisture content wood fiberboard + low specific gravity substrate + surface decorative material (resin sheet)>
A wooden floorboard was prepared under the same conditions as in Example 3 except that a resin sheet was used as the surface decorative material.

  When the amount of warp in the width direction was measured in the same manner as in Example 1 for the prepared wood type floor board, there was a wood type floor board having a larger warp than +0.7 mm.

  From the above results, when the moisture content of wood fiberboard is high, use Falkata plywood and resin sheet decorative material, and when the moisture content of wood fiberboard is low, use eucalyptus plywood and veneer, and moisture content of wood fiberboard It was confirmed that a wooden floor board with small warpage can be obtained by using Falkata plywood and veneer in the middle.

  On the other hand, in the case of other combinations as in the comparative examples, it was confirmed that the warpage was increased.

DESCRIPTION OF SYMBOLS 1 MDF injection process 2 Moisture content measurement process A High moisture content line B Medium moisture content line C Low moisture content line 3 PUR application process 4 Substrate placement process 5 Roll press process 6 Adhesive application process 7 Surface cosmetic material placement process 8 Roll press process

Claims (3)

A method for producing a wooden floorboard in which a wood fiberboard and a substrate are bonded to form a composite material, and then a surface decorative material is bonded to the surface of the composite wood fiberboard side,
Measuring the moisture content of the wood fiberboard;
A step of adhering the wood fiber board to the surface of the substrate having a specific gravity according to the measured moisture content of the wood fiber board via an adhesive to form a composite material;
A method for producing a wooden floor board, comprising a step of adhering a surface decorative material according to the measured moisture content of a wood fiber board to the surface of the composite wood fiber board side through an adhesive.   A high specific gravity substrate is used when the moisture content of the wood fiber board is low, and a low specific gravity substrate is used when the moisture content of the wood fiber board is medium moisture content or high moisture content. The manufacturing method of the wood type floor board of Claim 1.   When the moisture content of the wooden fiberboard is low or medium moisture content, use a veneer for the surface decorative material, and when the moisture content of the wooden fiberboard is high, use a resin sheet for the surface decorative material. The manufacturing method of the wood type floor board of Claim 1 or 2 characterized by the above-mentioned.

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