JP2616895B2 - Manufacturing method of plywood for floorboard - 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 plywood as a base material of a floorboard laid on a floor substrate of a building.

[0002]

2. Description of the Related Art Conventionally, as this kind of plywood for floorboards, a large plywood obtained by laminating and bonding several core materials or core materials and front and back veneers has been used. After bonding, the floorboard substrate is divided into appropriately sized floorboard substrates, and the floorboards are formed by applying actual processing, painting, and the like to the floorboard substrates.When the decorative raw veneer is bonded to the plywood, Since the raw veneer has a high moisture content, a concave warp occurs in the plywood due to shrinkage of the raw veneer during drying.

[0003] If the warpage is large, when the divided floorboard base material is actually processed, the warp of the base material prevents the fruit from being formed directly, and both ends of the floorboard material are lifted up from the floor base material at the time of floorboard construction. Not only is it difficult to fit, but also a part that is not adhered to the floor base material is generated and the workability is significantly reduced, and unevenness in grinding and painting on the floor plate is caused, and the appearance and wear resistance are reduced. Will be.

For this reason, conventionally, a convex warp is provided on a plywood in advance, and this convex warp is offset by the contraction force of a veneer veneer for makeup so that a concave warp is generated in a plywood for a floorboard. Prevention measures have been adopted. For example, when obtaining a plywood for flooring by laminating the front and back veneers to the core material and the core material, the front veneer is made thicker, the back veneer is made thinner, the difference in the expansion coefficient between the two veneers A method of generating convex warpage in plywood, or using a veneer with high moisture content as the back veneer to increase the shrinkage rate on the back side compared to the front side during hot pressing, causing convex warpage on the plywood Method, or when bonding a raw veneer for makeup to the surface of a plywood, a backer or a veneer is bonded to the back surface of the plywood, and the shrinkage force during drying of the raw veneer for makeup is applied by a backer or the like. A suppression method and the like are employed.

[0005]

However, according to the method described in the first aspect, since the front and back veneers having different thicknesses must be used, there is a problem that the veneer manufacturing process becomes complicated. According to the second method, it is difficult to adjust the moisture content of the back veneer to generate a warp in a convex shape.
There is a risk that puncture will occur due to steam generated during heat pressure. In addition, the third method has a problem in that a bonding step of a backer, a veneer, or the like is required and the cost is high in terms of material, and any method requires a special processing step. is there. An object of the present invention is to provide a method for manufacturing a plywood for floorboards, which can completely solve such a problem.

[0006]

In order to achieve the above object, a method for manufacturing a plywood for floorboards according to the present invention has a water content of 15% or less.
Front and back veneer dried to the bottom, moisture content below 15%
With a core that is dried until
The height of the center is 1.5% of the length of the veneer in the longitudinal direction.
Centered on a mountain-shaped molded part formed to a height of less than a cent
The front and back veneers will be in a laminated state on the front and back of the board respectively
To form a laminated plate, and cool the laminated plate along the surface of the molded member to form a single-sided
Plate is formed in a convex plywood central portion is increased made by bonding with an adhesive, then, is characterized in that the plywood facing surface hot-pressing by inserting a flat heat plates .

[0007]

[Function] Adheses back veneer on mountain-shaped molded member and front and back
The core plate coated with the agent and the front veneer are successively overlapped to form a laminated plate, and then the laminated plate is pressed toward the molding member to form the laminated plate. After the veneer is bonded integrally to the front and back surfaces of the heart plate through an adhesive with convexly curved along the surface (upper surface) of the member, accordingly, solving the pressure, the front and back surfaces of the heart plate Center part where veneer is adhered to
A plywood of convex shape having a higher value is obtained. The above laminate multiple sets, if at contrived on the forming member in the overlapping state, a number of central portion with respect to both end portions is occurring convex warp of the same height by a single pressing A set of plywood can be obtained at the same time.

Next, when the plywood is inserted between hot plates having a flat opposed surface and heated under a constant temperature condition for a predetermined time, the plywood is deformed into a flat plate shape . Then, when you decompress,
It is restored by a restoring force inherent to a height lower than the original warpage, and a gently convexly curved flooring plywood is obtained.

[0009] When a decorative veneer is adhered to the surface of the plywood thus obtained, the surface of the plywood for a floor is pulled in the longitudinal direction by a shrinkage force generated by drying of the veneer, and a convex shape is obtained. The warp is corrected so that it disappears, and the front and back surfaces become a flat plywood having a flat plate shape.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, an embodiment of the present invention will be described. FIG. 1 shows a plywood F for a floorboard comprising a three-layer plywood in which front and back veneers 2, 3 are bonded and integrated on both sides of a core board 1. , FIG. 2
Denotes a plywood F for a floorboard made of a five-layer plywood in which the coreboards 4, 4 and the veneer veneers 2, 3 are sequentially laminated and bonded on both the front and back surfaces of the core board 1, and the center in the length direction has both ends. After the veneer veneer 5 is adhered to the veneer veneer F on the front veneer 2 of the plywood F for floorboards as described later, When the raw veneer for makeup 5 is dried, the warp disappears due to the contraction force of the veneer for decorative veneer 5.

In order to manufacture such a plywood F for floorboards,
As the core plate 1 and the core plate 4, a rectangular veneer having a constant width, a length, and a thickness that is dried to a moisture content of 15% or less is used. Like the core plate 1 and the core plate 4, the water content is dried to 15% or less, and the core plate 1 and the core plate 4 have the same width and the same length as the core plate 1 and the core plate 4. Use veneer. And first,
To obtain a three-layer plywood structure, the adhesive 6 is applied to both sides of the core board 1, and then the front and back veneers 2, 3 are superposed on both sides to form a laminated board A. To obtain a five-layer plywood structure, a two-layer plywood structure is obtained. After applying the adhesive 6 to both sides of the core plate 4 disposed on the first and fourth layers, the core plate 1 is disposed on the third layer, and the front and back veneers 2 and 3 are disposed on the first and fifth layers, respectively. It is assumed to be plate A. In addition, since the manufacturing method is the same in the case of three-layer plywood or five-layer plywood,
A method for manufacturing a three-layer plywood will be described.

First, the laminated plate A is assembled on a mountain-shaped forming member B which gradually increases in the longitudinal direction from both ends to the center. That is, on the molded member B, the back veneer 3 and the core plate 1 coated with the adhesive 6 on both sides and the front veneer 2 are sequentially laminated to form a set of laminated plates A. After stacking and laminating, as shown in FIG. 3, the shape of the forming member B is inverted on the front veneer 2 of the uppermost laminated board A, that is, the lower surface is depressed from both ends toward the center. The plate material C whose depression depth is equal to the height of the center of the molded member B is placed on the plate member C. As the adhesive 6, a normal phenol-based adhesive, a melamine-based adhesive, a urea-based adhesive, or the like is used, and no special adhesive is required.

As described above, several tens of sets of laminated plates A are formed on the forming member B, and the plate material C is placed thereon. After that, the laminated plates A are pressed and cooled. As a cold press means, a cold press is used, and when the plate material C is pressed with a predetermined pressing force by this cold press, as shown in FIG. While being pressed in the direction of bending toward the inclined surface side of the molding member B, both ends of the upper laminate A are pressed downward by both ends of the plate material C. The front and back veneers 2 and 3 are integrally adhered to the front and back surfaces of the core plate 1 with an adhesive 6. In this way, all the laminated boards A are formed into a plywood A1 that is convexly warped along the upper surface of the formed member B.

The pressing of the laminated board A by the cold press is a temporary pressing for facilitating the insertion and handling in the hot press for hot press in the next step. Therefore, the core plate 1 in each convex plywood A1 is pressed. Adhesive 6 between front and back veneers 2 and 3
Is temporarily bonded. As shown in the figure, the shape of the molded member B or the plate material C is not formed as a flat inclined surface from the center to both ends, but is a gentle convex arc-shaped inclined surface from the center to both ends. May be formed in advance.

Next, as shown in FIG. 5, the plywood A1 which is warped in a convex shape is inserted into a hot press D one by one and subjected to a heat and pressure treatment. When one set of convex plywood A1 has a small thickness, two sets of convex plywood A1, A1 may be overlapped and subjected to a heat and pressure treatment.
Since the hot press D is a flat hot plate, when the convex plywood A1 is hot-pressed by the hot press D, the convex portion is pressed, the curved shape is corrected, and the plate is deformed into a flat plate shape.

The hot press condition of the hot press D is such that when the heat pressure is released, the flat plywood is restored by its elastic restoring force to a warp of 1/2 to 1/3 of the warp height at the time of the convex plywood A1. Is set to In this case, if the height of the central portion of the molded member B during the cold pressure treatment is too high and the warp height of the convex plywood A1 is unnecessarily high, the warp height of the convex plywood A1 is reduced to 1 by the heat and pressure treatment. Even if a plywood for a floorboard having a warp height of ２〜 to を 得 is obtained, a veneer veneer is adhered to the surface of the plywood for a floorboard, and the shrinkage of the plywood during drying is obtained. Warpage cannot be eliminated by the action. Therefore, the height of the molded member B is formed within 1.5% of the length of the obtained plywood for floorboard. The height of the molded member B is determined by the thickness of the obtained plywood for floorboard, the thickness of the decorative veneer adhered to the surface of the plywood for floorboard, and the moisture content of the veneer. It is set appropriately within the numerical values.

When the decorative veneer 5 is attached to the surface of the plywood F for floorboard thus obtained as shown in FIG.
The surface of the plywood for floorboards is pulled in the length direction by the shrinkage force generated by drying, and the convex warpage is corrected so that it disappears, and the front and back surfaces with almost no warp are flat-plated veneer veneers. A plywood for floorboard can be obtained. Next, specific examples of the present invention will be described.

EXAMPLE A 3 mm thick core (930 mm wide) dried to a moisture content of 15% or less
Melamine-based adhesive is applied to both sides of this core, and 1.5mm thick veneer veneer (water content, width and length are the same as the core) Length 1
m, width 2m, center height 12mm
A set of laminated plates was prepared, and 100 sets of the laminated plates were assembled on a molded member. At this time, a plate member having a shape obtained by inverting the formed member was arranged between the intermediate laminated plates and on the uppermost laminated plate. This was inserted into a cold press and pressed at a pressure of 9 kg / cm ² for 30 minutes. Then, after decompression, insert the laminates one by one into a hot press and apply them at 115 ° C and 8.5 kg / cm ^2.
For 3 minutes.

The plywood thus obtained had a thickness of 6 mm and a central portion curved to a convex shape with a warp height of 5 mm. A vinegar-biurea-based adhesive is applied to the surface of this plywood, and through this adhesive
0.25 mm thick veneer veneer veneers were superposed and bonded by hot pressing, and then divided into small pieces to obtain a perforated floorboard having an effective width of 75 mm and a length of 900 mm. The warpage of these 42 slabs is concave on average
0.4 mm, from 2 mm in the convex direction to 5 mm in the concave direction. An acrylic urethane paint was applied to the floorboard, and the finished product had an average value of 0.3 mm in the convex direction and a maximum value of 3 mm in the convex direction.

Comparative Example Under the same specifications and the same conditions as in the example, a plywood was manufactured by assembling on a flat plate at the time of temporary pressing. The obtained plywood had a thickness of 6 mm and almost no warping was observed. Like this example,
A 0.25 mm thick veneer veneer veneer was adhered and divided into small pieces to obtain a floorboard having the same shape as that of the example. At this time, the average warpage is 5.3 mm in the concave direction, the minimum value is 1 mm in the concave direction, and the maximum value is 13 mm in the concave direction.
Met. When an acrylic urethane paint was applied to this floorboard to obtain a finished product, the average warpage was 4.5 mm in the concave direction, the minimum value was 1 mm in the concave direction, and the maximum value was 12 mm in the concave direction.

In general, the warp without any trouble in construction is 90 cm long and is empirically determined to be about 4 mm in the concave direction and about 6 mm in the convex direction. In the case of the conventional example shown in the comparative example, some measure for warping is required. Can be easily understood. On the other hand, in the case of the method of the present invention, the warp is within the allowable range as seen in the embodiment, and a backer or a veneer is adhered to the back surface of the plywood for the floorboard as in the conventional case, and the veneer veneer is used. A complicated plywood for a veneered veneer can be formed with high accuracy by eliminating a complicated process of suppressing the shrinkage force of the veneer.

[0022]

As described above, according to the method for manufacturing a plywood for floorboards of the present invention, a veneer dried to a certain water content or less and a core plate coated with an adhesive have a predetermined height in the center in the longitudinal direction. A stacking structure is formed on a mountain-shaped molding member having a height, and this laminated plate is cold-pressed along the surface of the molding member to form a convex plywood having a raised central portion, and then the plywood is opposed to the plywood. Since it is inserted between hot plates with flat surfaces and heat-pressed, it does not require special treatment such as changing the thickness or moisture content of the veneer as in the past, and is simple and economical. Many plywood for floorboards can be manufactured.

Further, by changing the shape and height of the molded member, the state of the warp of the obtained plywood for floorboard can be easily adjusted, and the moisture content and the water content of the veneer veneer to be adhered to the surface thereof can be easily adjusted. This makes it possible to efficiently manufacture a plywood for a floorboard in accordance with the thickness, that is, a plywood for a floorboard having a degree of warpage that is offset by a shrinkage force during drying of a veneer veneer.

Accordingly, a complicated veneer or veneer is adhered to the back surface of a plywood for floorboard as in the prior art, thereby eliminating a complicated process of suppressing the contraction force of the veneer veneer and eliminating the need for a complicated veneer veneer. A plywood can be formed, and actual processing, painting, and the like can be accurately performed on a floorboard obtained by dividing the plywood for a decorative veneer pasted floorboard.

[Brief description of the drawings]

FIG. 1 is a side view of a plywood for a floorboard made of three-layer plywood,

FIG. 2 is a side view of a plywood for floorboards made of five-layer plywood,

FIG. 3 is a simplified side view of a state where the laminate is inserted into a cold press;

FIG. 4 is a simplified side view of a state in which a laminated plate is temporarily pressed;

FIG. 5 is a simplified side view showing a hot-press processing state by hot pressing;

FIG. 6 is a side view of a plywood for a decorative veneer pasted floorboard.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core board 2, 3 Front and back veneer 5 Raw veneer for makeup 6 Adhesive A Laminated board B Molded member C Applicable board material D Hot press F Plywood for floor board

Claims (1)

(57) [Claims] 1. A table dried to a water content of 15% or less.
Back veneer, dried to a moisture content of 15% or less and front and back
A center plate with an adhesive applied to the surface
Formed within 1.5% of the longitudinal dimension of the board
On the front and back of the core plate
Structured so that the front and back veneers are each laminated
A laminated plate is formed, and the laminated plate is cold-pressed along the surface of the molded member, and the front and back veneers are bonded on both sides of the core plate with an adhesive.
A method for manufacturing a plywood for floorboards, comprising forming a plywood having a raised central portion formed by bonding the plywood, and then inserting the plywood between hot plates having a flat facing surface and hot-pressing.