JPH08132402A - Manufacture of floor covering ply wood - Google Patents

Abstract

PURPOSE: To obtain a simple and efficient manufacturing method for ply wood serving as the base material of floor board by a method wherein veneers and core plates, on which adhesive is applied, are laid under laminated state on a conical forming member so as to form protruding ply woods whose center part is high by cold pressing in order to insert the ply wood between hot plates for hot pressing. CONSTITUTION: In order to obtain three-layered ply wood structure at the manufacture of floor covering ply wood, face and back veneers 2 and 3 are placed upon both the surface, on which adhesive 6 is applied, of a core plate 1 so as to obtain a laminated sheet A. Next, the laminated sheets A are placed on a conical forming member B, which becomes gradually thicker from both the ends towards the center. On the laminates sheets A, cover plate member C is placed. After that, the laminated sheets A are cold-pressed so as to be formed into ply woods A1, which are curved projectingly along the top surface of the forming member B. Next, the ply wood A1 is inserted one by one in a hot press for heat treatment so as to correct a curved shape by pressing the convex part in order to be formed into a flat plate. Finally, decorative green veneer is pasted to the surface of the obtained floor covering ply wood F.

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 type of floorboard plywood, large-sized plywood in which several cores or cores and front and back veneers are laminated and bonded has been used. After adhering, it is cut into a floorboard base material of an appropriate size, and the floorboard is formed by subjecting the floorboard base material to actual processing, painting, etc., but when a makeup veneer is bonded to the plywood, Since the raw veneer has a high water 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.

Therefore, conventionally, a convex warp is provided on the plywood in advance, and the convex warp is offset by the contracting force of the raw veneer for makeup to cause a concave warp in the plywood for floorboard. Preventive measures have been adopted. For example, when plywood for flooring is obtained by laminating and bonding single-sided veneer to core material or core material, a mechanism is used to thicken the front and back veneers and thin the back veneer. A method of generating a convex warp on the plywood, or using a single veneer with a high water content for the back veneer to increase the shrinkage rate on the back side rather than the front side during hot pressing causes a convex warp on the plywood. Method, or when bonding the raw veneer for makeup to the surface of the plywood, a backer or veneer or the like is adhered to the back surface of the plywood, and the shrinkage force during drying of the raw veneer for makeup is backed by the backer or the like. A suppression method or the like is adopted.

[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. It is an object of the present invention to provide a method for manufacturing a floorboard plywood that can completely eliminate such problems.

[0006]

In order to achieve the above object, a method for manufacturing a plywood for floorboards according to the present invention comprises: a single veneer dried to a certain water content or less and a core plate coated with an adhesive in the longitudinal direction. The central portion has a mountain-shaped forming member having a predetermined height and is laminated, and the laminated plate is cold-pressed along the surface of the forming member to form a convex plywood plate having a raised central portion, and then It is characterized in that the plywood is inserted between hot plates having opposite flat surfaces to apply heat and pressure. In the above method, as described in claim 2, it is desirable that the height of the central portion of the molded member is within 1.5% of the dimension in the longitudinal direction.

[0007]

[Operation] A laminated plate is formed by assembling one or several core plates coated with an adhesive on a mountain-shaped molded member and front and back single plates, and then the laminated plate is pressed toward the molded member. Then,
The laminated plate is curved in a convex shape along the surface (upper surface) of the molded member, and the core plate and the front and back single plates are integrally bonded via an adhesive, and then, if the pressure is released, the convex shape is formed. A plywood with warpage is obtained. In addition, if a large number of laminated plates are stacked and assembled on a molding member, a plywood in which the central portion has a convex warp with respect to both ends by one-time pressure molding You can get it at the same time.

Next, when this plywood is inserted into a hot platen whose opposing surfaces are flat and heat-pressed for a predetermined time under a constant temperature condition, the plywood elastically deforms into a flat plate shape and is restored to a convex shape. Force (internal stress) decreases. Then, when the pressure is released, a plywood for floorboard, which is restored to a height lower than the original warp by an internal elastic restoring force and is curved in a gentle convex shape, 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
Indicates a plywood F for a floorboard, which is a five-layered plywood in which centering plates 4 and 4 and front and back single plates 2 and 3 are sequentially laminated on both front and back surfaces of a core plate 1, and the center portion in the longitudinal direction is at both ends. It has a structure which is formed higher than that and has a convex warp, and the height of the warp is obtained by bonding the makeup veneer 5 on the front veneer 2 of the plywood F for floor boards as described later, It is formed to such an extent that when the raw cosmetic veneer 5 is dried, the warp disappears due to the shrinking force of the raw veneer 5 for cosmetics.

To manufacture such a plywood F for floorboard,
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 shapes of the molded member B and the plate member C do not have to be flat inclined surfaces from the central portion to both ends, but are gently convex arcuate inclined surfaces from the central portion 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 the thickness of one set of convex plywood A1 is thin, 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 platen, when the convex plywood A1 is hot pressed by the hot press D, the convex parts are pressed to correct the curved shape and deform into a flat plate shape.

The hot pressing condition of the hot press D is such that when the hot pressing is released, the flat plywood is restored by its elastic restoring force up to 1/2 to 1/3 of the height of the warp at the convex plywood A1. Is set to do. In this case, the height of the central portion of the molding member B during the cold pressure treatment is too high and the convex plywood A1
If the warp height is higher than necessary, even if a floorboard plywood having a warpage height of 1/2 to 1/3 of the warp height is obtained by heat and pressure treatment, the warp height of the floorboard plywood is increased. Therefore, it is not possible to adhere the veneer veneer to this surface and eliminate the warp due to the contracting action during drying. Therefore, the height of the forming member B is formed within 1.5% of the length of the obtained floorboard plywood. And
The height of the forming member B depends on the thickness of the obtained plywood for floorboard, the thickness of the decorative veneer attached to the surface of the plywood for floorboard, and the water content of the decorative veneer. Is set appropriately.

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 shown.

EXAMPLE A 3 mm thick core plate (width 930 mm) dried to a water 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 the 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. Similar to the example in this plywood,
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. The average warp at this time 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-based paint was applied to this floor board to obtain a finished product, the average warp 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 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 state of hot pressing by a hot press,

FIG. 6 is a side view of a plywood for a floor plate with a laminated decorative veneer.

[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 (2)

[Claims] 1. A mechanism in which a veneer dried to a certain water content or less and a core plate coated with an adhesive are laminated on a mountain-shaped forming member having a predetermined height at the center in the longitudinal direction. The plate is cold-pressed along the surface of the forming member to form a convex plywood plate having a raised central portion, and then the plywood plate is inserted between hot plates having opposite flat faces to be hot-pressed. Method for manufacturing plywood for floorboard. 2. The method for producing a floorboard plywood according to claim 1, wherein the height of the central portion of the molded member is within 1.5% of the dimension in the longitudinal direction.