JP2006192817A - Composite plate and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite plate of a new structure which suppresses the occurrence of warpage after its production. <P>SOLUTION: In the composite plate 10 produced by arranging a fiberboard 12 on the surface of plywood 11 comprising at least four veneers 11a-11d and laminating/bonding/integrating them, the fiber directions of the veneers 11a and 11d positioned on the surface and back sides of the plywood are made to coincide approximately with the longitudinal direction of the plywood, and the fiber directions of the veneers 11b and 11c positioned between the veneers 11a and 11d are made to coincide approximately with the direction crossing the longitudinal direction at right angles. The surface side veneer is made to be thicker than the back side veneer, and the sum of the thicknesses of the fiberboard and the surface side veneer is made below 50% of the total thickness. By satisfying these conditions, in its cross and vertical sections, the upper and lower veneers and the fiberboard bordered by the center line X give antagonistic influences on the upward warpage and downward warpage of the composite plate. As a result, in both longitudinal and short-hand directions, the warpage of the composite plate is prevented substantially. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a composite plate mainly used as a material for a house building member, furniture, joinery, and the like, and a method for manufacturing the same.

As a conventional composite plate, for example, the one described in Patent Document 1 below is known. This composite board heat-presses the whole after placing a wood fiber board having a thickness of about 8 to 17% and a thickness of 2 mm or less with respect to the whole thickness through an adhesive on the surface of the softwood base material. It is manufactured by.
Japanese Patent No. 2530952

  When the wood fiberboard is laminated on the base material with an adhesive and stuck by hot pressure, the surface of the wood fiberboard is heated and moisture on the surface side is dissipated, so the moisture content on the surface side of the wood fiberboard Decreases. Since the wood fiber board is substantially isotropic, when the moisture content on the front surface side is lowered, a warp-like warpage or deformation with the back surface side convex is caused. In 1, the thickness of the wood fiberboard is made small, but on the other hand, it is susceptible to damage such as surface scratches and dents, and has disadvantageous disadvantages such as flatness being easily impaired. There is a risk that the constraints will increase.

  Therefore, the problem to be solved by the present invention is to provide a composite plate having a novel structure that hardly warps after manufacture, and a method for manufacturing the same.

  To achieve the above object, the present invention according to claim 1 is a composite plate in which at least four veneers are sequentially laminated and bonded, and a fiber plate is arranged on the surface and laminated and integrated. The fiber direction of the single plate located on the front surface side and the outermost surface side substantially coincides with the longitudinal direction of the composite plate, and the fiber direction of the plural single plates located between the single plates on the outermost surface side and the outermost surface side is any Is substantially coincident with the direction orthogonal to the longitudinal direction of the composite plate, and the outermost surface-side single plate is thicker than the outermost surface-side single plate, and the total thickness of the fiber plate and the outermost surface-side single plate is 50. It is characterized by being less than%.

  According to the second aspect of the present invention, a plurality of second single plates whose fiber directions substantially coincide with the direction perpendicular to the longitudinal direction are bonded on the first single plates whose fiber directions substantially coincide with the longitudinal direction. And a third single plate whose fiber direction substantially coincides with the longitudinal direction and is thicker than the first single plate is laminated through an adhesive. Further, after the fiber board is further laminated via an adhesive, the obtained laminated body is integrated by heat pressure.

  The composite board of the present invention is mainly used as a material for housing building members, furniture, joinery and the like.

  In the composite plate of the present invention, at least four single plates are sequentially laminated and bonded, but the single plate on the outermost surface side and the outermost surface side (the first single plate and the third single plate) are composite. It has a fiber direction substantially coinciding with the longitudinal direction of the plate, and a plurality of single plates (second single plate) located between the single plates on the outermost surface side and the outermost surface side are orthogonal to the longitudinal direction of the composite plate. It is assumed that the fiber direction substantially coincides with (that is, the short direction or the width direction). By using a plurality of second single plates, the defects of each single plate are dispersed, and the local lack of strength can be solved. Each veneer may be a softwood veneer or a hardwood veneer, or any combination thereof.

  As the adhesive interposed between the single plates or between the single plate and the fiberboard, it is preferable to use a thermosetting adhesive with less formaldehyde emission, urea resin, phenol resin, melamine resin, urethane resin or their modification. It is preferable to use one or more types arbitrarily selected from resin adhesives, isocyanate-based adhesives, synthetic rubber-based adhesives, and the like.

  The fiberboard can be selected from medium density fiberboard (hereinafter referred to as MDF) or hard fiberboard depending on the use of the composite board, and the thickness is preferably in the range of 1.0 to 4.0 mm. It can be used. When using coniferous wood as a veneer, a fiberboard having a relatively large (thick) thickness, for example, a thickness exceeding 2.5 mm can be used. If the use of the composite board is other than flooring and the load on the surface is relatively small, a hardwood veneer can be used to laminate a relatively thin fiberboard on the surface, for example A fiberboard having a thickness of about 1.5 mm can also be used.

  Regarding the thickness of each single plate and fiber plate constituting the composite plate of the present invention, the outermost surface side single plate is thicker than the outermost back surface side single plate, and the total thickness of the fiber plate and the outermost surface side single plate is It is an essential requirement to be less than 50% of the total thickness of the composite plate. The total thickness of the plurality of single plates (second single plate) disposed between the outermost surface side single plate and the outermost surface side single plate is in the range of 30 to 45% of the total thickness of the composite plate. Is preferred. These reasons will be described in detail in the test examples.

  In the case of forming a fruit, it is formed so as to extend at least along the longitudinal direction of the composite plate. Furthermore, you may form together the fruit extended along the transversal direction of a composite board. The surface on the fiberboard side of the fruit (male, female) formed so as to extend along the longitudinal direction of the composite board is composed of a single board (that is, a third single board) adjacent to the fiber board. It is preferable that As described above, the fiber direction of the third single plate substantially coincides with the longitudinal direction of the composite plate.

The hot pressing is performed by, for example, hot pressing with the laminated body sandwiched between two upper and lower hot pressing plates having a flat surface. The hot pressure conditions are, for example, hot pressure pressure: 8 to 20 kgf / cm ² , hot platen temperature: 110 to 150 ° C., hot pressure time: 1 to 10 minutes, and more preferably hot pressure pressure: 10 kgf / cm ^2. , Hot platen temperature: 125 ° C., hot pressing time: about 5 minutes. Since the surface of the fiberboard that has been hot-pressed has unnecessary irregularities and scratches, the surface layer may be smoothed by grinding with a sander or a planar.

  According to the first aspect of the present invention, each single plate is used in combination with a laminated body of single plates and a fiber plate, and each single plate is arranged in a predetermined fiber direction in the longitudinal direction or the short direction. The single plate exerts an action of mutually restraining and canceling the movement of the single plate contracting and expanding in a direction orthogonal to the fiber direction, and the outermost surface side single plate is thicker than the outermost surface side single plate, and the fiber plate Since the total thickness of the outermost surface single plate is less than 50% of the total thickness, a composite plate is obtained in which warpage is unlikely to occur before manufacturing and construction. In addition, it is excellent in bending strength against the load to be bent in both the longitudinal direction and the short direction, and since the fiberboard is arranged on the surface, it is excellent in surface smoothness, color uniformity, hardness, etc. A board is obtained.

  More specifically, the composite board of the present invention has a laminated structure in which a fiber board is arranged on the surface of a laminate of at least four single boards and bonded and integrated, and the fiber direction of the single board is determined. The fiber directions of the single plates located on the outermost surface side and the rearmost surface side substantially coincide with the longitudinal direction of the composite plate, and the fiber directions of the plurality of single plates located between these single plates are perpendicular to the longitudinal direction. Since it is made to substantially coincide with the (short direction), as will be described later, when the pressure is released after hot pressing, the upper and lower veneers and fiberboards with the center line as the boundary in both the transverse and longitudinal sections Exerts an antagonistic effect on the upper and lower warpage of the composite plate, and as a result, substantially acts to prevent the composite plate from warping.

  Furthermore, since at least four single plates are laminated in the composite plate of the present invention, even if any single plate has a defect such as a node, a knot, or a grain dent, it is adjacent to this. It is almost impossible to overlap with defects on a single plate, and the defects are dispersed and the local lack of strength is resolved.

  In addition, it is difficult to construct a single plate (second single plate) disposed between the outermost surface side single plate and the outermost surface side single plate with a large thickness at the present when the depletion of raw wood advances. Even if a single plate having such a thickness can be obtained, it has disadvantages such as nodes and cracks, so that the strength effect on the composite plate is increased. In the present invention, a plurality of second single plates are provided. Since it is composed of a single plate, such a drawback is not exposed.

  Further, since the total thickness of the fiberboard and the outermost surface side single plate is less than 50% of the total thickness, the single plate (second single plate) located between the outermost surface side and the outermost surface side single plate ) Can be increased relative to the total composite plate, and can be set to 30% or more, for example. Since the second single plate is provided so that the fiber direction thereof substantially coincides with the direction orthogonal to the longitudinal direction of the composite plate, the second single plate functions to restrain the movement to warp in the short direction in the composite plate. By setting the total thickness of the second single plate that fulfills such an action to be, for example, 30% or more of the total thickness of the composite plate, the balance of the layers that antagonize each other as the composite plate is maintained. Occurrence of warpage in the width direction, which sometimes becomes a problem, can be suppressed over a long period of time.

  According to the second aspect of the present invention, it is possible to efficiently manufacture the composite plate in which the occurrence of warpage is suppressed as described above.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view (a cross-sectional view taken along a vertical plane perpendicular to the longitudinal direction) of a composite plate according to Embodiment 1 of the present invention. In FIG. 1, the layered portion between the male fruit 14 and the female fruit 15 is shown reduced in the lateral direction Y. This composite board 10 is used as a floor board for a residential building, and four hardwood veneers 11a to 11d and MDF 12 are sequentially laminated and integrated by an adhesive interposed between adjacent layers. Yes. Although not shown, a decorative sheet such as a veneer can be attached to the surface of the MDF 12. The size of the composite plate 10 is a product dimension, for example, width W = 303 mm, thickness T = 12 mm, and length L = 1818 mm. Since this dimension is a product dimension, it is manufactured in consideration of the compression allowance and the machining allowance due to heat pressure.

  Regarding the lamination of the single plates, the first single plate 11a, the two second single plates 11b and 11c, and the third single plate 11d are sequentially involved from the back side, and an adhesive is provided between the single plates. Thermocompression bonding. The fiber direction of the 1st single board 11a provided in the outermost surface side in the single board and the 3rd single board 11d provided in the outermost back side is the longitudinal direction (paper surface perpendicular direction in FIG. 1) of the composite board 10. It is almost coincident. The fiber direction of the two second single plates 11b and 11c located between the first single plate 11a and the third single plate 11d is a direction orthogonal to the longitudinal direction (the left-right direction in FIG. It substantially coincides with the short direction of the plate 10.

  Further, the composite plate 10 has a male fruit 14 and a female fruit 15 extending along the longitudinal direction thereof. The surfaces of the male fruit 14 and the female fruit 15 on the MDF 12 side are formed by a third single plate 11 d having a fiber direction substantially coinciding with the longitudinal direction of the composite plate 10. Although not clear from the drawing, the composite plate 10 may further have a fruit extending along the short direction in addition to the male fruit 14 and the female fruit 15 extending along the longitudinal direction. good.

  A method for manufacturing the composite plate 10 will be described.

  Hardwood veneers are prepared as the first to third veneers 11a to 11d. The first single plate 11a and the third single plate 11d have a fiber direction substantially coincident with the longitudinal direction Z, and the second single plate 11b and 11c have a direction (short direction) perpendicular to the longitudinal direction. The fiber direction substantially coincides with Y. In addition, an MDF made of softwood is prepared as the fiber board 12. About these single plates 11a-11d and MDF12, the thickness requirement mentioned later shall be satisfied.

  Then, on the first single plate 11a having the fiber direction substantially coincident with the longitudinal direction Z, the lower second single plate 11b and the upper second plate having the fiber direction substantially coincident with the short direction Y. The single plate 11c is laminated with an adhesive interposed between the single plates. In this case, if the adhesive is applied to both the front and back surfaces of the lower second single plate 11b with a roll coater or the like, the adhesive is applied to the first single plate 11a and the upper second single plate 11c. This is preferable because the adhesive application work can be simplified.

  Further, a third single plate 11d having a fiber direction substantially coincident with the longitudinal direction is laminated on the upper second single plate 11c with an adhesive. At this time, an adhesive is applied to both the front and back surfaces of the third single plate 11d by a roll coater or the like, and finally, the MDF 12 is laminated on the third single plate 11d.

  Thus, after obtaining the laminated body in which the single plates 11a to 11d and the MDF 12 are sequentially laminated through the adhesive, the laminated body is placed between the lower hot platen and the upper hot platen of the hot press. Hot-press with sandwiching.

  The adhesive interposed between the single plates 11a and 11b, between the single plates 11b and 11c, between the single plates 11c and 11d, and between the single plate 11d and the MDF 12, uses a thermosetting adhesive that emits less formaldehyde. For example, a urea-melamine resin adhesive is used.

The hot pressure condition is adjusted according to the types of the single plates 11a to 11d and the MDF 12, the type of adhesive to be used, and other conditions. For example, the pressure is 10 kgf / cm ² , the temperature is 125 ° C, and the time is 5 minutes. Since there are unnecessary irregularities and scratches on the surface of the MDF 12 of the composite plate 10 that has been hot-pressed, the surface layer is shaved with a sander or a planar.

  Thus, the real bodies 14 and 15 are formed along the longitudinal direction formed by hot pressing. At this time, the actual formation position in the thickness direction of the composite plate 10 is set so that the surfaces on the MDF 12 side of the actual materials 14 and 15 are formed by the third single plate 11d.

  Next, the operation of the composite plate 10 will be described with reference to FIG. 1 which is a cross-sectional view thereof. When the pressure is released after hot pressing, the fiber direction is approximately the same as the longitudinal direction Z (FIG. 2). The single plate 11a and the third single plate 11d tend to contract in the lateral direction Y. Further, the MDF 12 whose fiber direction is non-directional tends to contract in the longitudinal direction Z and the lateral direction Y. On the other hand, the upper and lower second single plates 11b and 11c have substantially the same shrinkage rate in the lateral direction Y because the fiber direction thereof substantially coincides with the lateral direction Y.

  That is, when the magnitude of the contraction rate after decompression is compared in the short direction Y, the contraction rate of the first single plate 11a and the third single plate 11d is the largest, and then the contraction rate of the MDF 12 is large, The contraction rate of the second single plates 11b and 11c is the smallest. Further, the influence of the contraction of each plate on the entire composite plate 10 becomes more significant as the distance from the center line X in the thickness direction of the composite plate 10 increases.

  Since the first single plate 11a is farthest from the center line X in the thickness direction of the composite plate 10 and the contraction rate in the short direction Y is the largest, the composite plate 10 is warped upward (warping that protrudes upward). Try to. On the other hand, the third single plate 11d also has a large contraction rate in the lateral direction Y, but is close to the center line X in the thickness direction of the composite plate 10 and warps the composite plate 10 downward (a warp that protrudes downward). However, the effect is small by the amount closer to the center line X. Like the first single plate 11a, the MDF 12 has a large distance from the center line X and tries to warp the composite plate 10. However, since the contraction rate in the lateral direction Y is relatively small, The impact is not so great. Since the second single plates 11b and 11c have the smallest shrinkage in the short direction among these five layers and are located within or close to the thickness range including the center line X, the warp of the composite plate 10 The effect on is small and can almost be ignored.

  Eventually, the action of the first single plate 11a to warp the composite plate 10 upward (convex), the third single plate 11d and the MDF 12 resist the composite plate 10 downward (concave). Since it acts to warp, these actions are antagonized, and the composite plate 10 as a whole has almost no warpage (see the upper table of FIG. 4).

  FIG. 2 is a longitudinal sectional view of the composite plate 10 (a sectional view taken along a vertical plane along the longitudinal direction Z). When the contraction rate after decompression is compared in the longitudinal direction Z, the contraction rate of the second single plates 11b and 11c is the largest, then the contraction rate of the MDF 12 is large, and the first single plate 11a and the third single plate The contraction rate of the single plate 11d is the smallest. As described above, the influence of the contraction of each plate on the entire composite plate 10 increases as the distance from the center line X in the thickness direction of the composite plate 10 increases.

  Therefore, considering the contraction after decompression in the longitudinal section of the composite plate 10, the second single plates 11b and 11c have a large contraction rate in the longitudinal direction Z, but are located within or close to the thickness range including the center line X. Therefore, the action of trying to warp the composite plate 10 is suppressed to be relatively small. Although the first single plate 11a is located far from the center line X, the contraction rate in the longitudinal direction Z is the smallest, and the action of causing the composite plate 10 to warp is extremely small. Since the third single plate 11d is close to the center line X and the contraction rate in the longitudinal direction Z is also minimum, the influence on the downward bending of the composite plate 10 is almost negligible. The MDF 12 has a large distance from the center line X like the first single plate 11a, and tries to warp the composite plate 10 by its contraction. However, since the contraction rate in the longitudinal direction Z is relatively small, The effect on warpage is not so great.

  Eventually, the second single plate 11b, 11c acts to warp the composite plate 10 upward (convex), and the MDF 12 acts against this to cause the composite plate 10 to warp downward (concave). Therefore, these actions antagonize and there is almost no warping of the composite plate 10 as a whole (see the lower table of FIG. 4).

  Therefore, in the composite plate 10, when the pressure is released after hot pressing, the upper and lower single plates and the upper and lower single plates with the center line X as the boundary in both the transverse section (short direction Y) and the longitudinal section (longitudinal direction Z) The fiber board exerts an antagonistic influence on the upper warp and the lower warp of the composite board 10, and as a result, the warpage of the composite board 10 is substantially prevented.

  Further, since the third single plate 11d, which is the outermost single plate of the plywood 11, is thicker than the first single plate 11a, which is the outermost single plate, warping due to post-manufacturing decompression occurs. Can be prevented.

  Furthermore, as a requirement regarding the thickness of each layer (plate) in the composite plate 10, the total thickness of the MDF 12 and the third single plate 11d arranged on the surface side is less than 50% of the total thickness of the composite plate 10, and The third single plate 11d is required to be thicker than the first single plate 11a. By satisfying these thickness requirements, in combination with the above-described laminated structure and the warp prevention effect obtained by specifying the fiber direction of each single plate, the warpage in both the long and short directions is substantially completely suppressed. Composite plate. This point will be described in detail below with reference to FIG.

Test example

20 specimens (30 × 30 cm) of composite plates according to the inventive examples and comparative examples 1 and 2 were produced. The test specimens according to the examples use a hardwood veneer having a thickness of 2.1 mm as the veneers 11a to 11c, a hardwood veneer having a thickness of 3.1 mm as the veneer 11d, and a conifer MDF having a thickness of 2.3 mm as the MDF12. After laminating the fiber directions of the single plate 11a and the single plate 11d and the fiber directions of the single plates 11b and 11c through an adhesive, and laminating the MDF 12 through the adhesive, 10 kgf / cm ² , manufactured by hot pressing under conditions of 125 ° C. and 5 minutes. Each thickness in the obtained test body was 2.0 mm for the single plates 11a to 11c, 3.0 mm for the single plate 11d, and 2.2 mm for the MDF 12, and the total thickness was 11.2 mm. That is, in this example test body, the total thickness of the MDF 12 and the third single plate 11d was 5.2 mm, and occupied 46.4% of the total thickness. The total thickness of the second single plates 11b and 11c was 4.0 mm, accounting for 35.7% of the total thickness.

  The specimen according to Comparative Example 1 was provided with a hardwood veneer having a thickness of 2.0 mm instead of a hardwood veneer having a thickness of 3.0 mm (the same applies after pressing) as the outermost veneer 11d. Except for this, it was manufactured in the same manner as in the examples. In the obtained test body of Comparative Example 1, the total thickness of the MDF 12 and the third single plate 11d was 4.2 mm, and occupied 41.2% of the total thickness. The total thickness of the second single plates 11b and 11c was 4.0 mm, accounting for 39.2% of the total thickness.

  The test body according to Comparative Example 2 was provided with a hardwood veneer having a thickness of 3.3 mm instead of a hardwood veneer having a thickness of 3.0 mm as the outermost veneer 11d, and a thickness 2 as MDF12. It was manufactured in the same manner as in the example except that a 3.3 mm thick one was provided instead of the 2 mm MDF. In the obtained test body of Comparative Example 1, the total thickness of the MDF 12 and the third single plate 11d was 6.6 mm, and occupied 52.4% of the total thickness. The total thickness of the second single plates 11b and 11c was 4.0 mm, accounting for 31.7% of the total thickness.

  About these test bodies, the amount of curvature was measured after leaving for 24 hours after a hot press. Each test body is square, but the straight direction ruler in each direction passes through the center point of the test body, with the fiber direction of the single plates 11a and 11d as the longitudinal direction and the fiber direction of the single plates 11b and 11c as the short direction. And the distance between the straight ruler at the center point and the specimen was measured as the amount of warpage. The measurement results (average values for each of the 20 bodies) are as shown in the table of FIG. 5. In the specimens according to the examples of the present invention, extremely small concave warpage (0.2 mm of warpage) was recognized in both the longitudinal and lateral directions. However, the specimens according to Comparative Example 1 and Comparative Example 2 have large warpage in both directions, and are not suitable for these applications. there were.

  The test body according to Comparative Example 1 satisfies the requirement of the present invention that the outermost surface side single plate 11d and the outermost surface side single plate 11a have the same thickness, and the outermost surface side single plate is thicker than the outermost surface side single plate. Absent. Separately from Comparative Example 1, a test specimen having the outermost back side single plate 11a thicker than the outermost side single plate 11d was manufactured in the same manner and the amount of warpage was measured. Occurred more prominently. The reason for this is not necessarily completely clarified, but in the short-side direction, the influence of the backmost single plate 11a is relatively large, resulting in a convex warp, and in the longitudinal direction, the influence of the MDF 12 is relatively large. Thus, it is presumed that the concave warpage has occurred (see FIG. 4 and the related description).

  In the test body according to Comparative Example 2, the total thickness of the MDF 12 and the outermost surface side single plate 11d occupies the majority of the total thickness, and the total thickness of the MDF (fiberboard) and the outermost surface side single plate is the composite plate. Does not satisfy the requirement of the present invention to be less than 50% of the total thickness. Separately from Comparative Example 2, a large number of test specimens in which the total thickness of the MDF 12 and the outermost surface side veneer 11d accounted for the majority of the total thickness were prepared and the amount of warpage was also measured. It was seen. The reason for this is not necessarily fully understood, but in the short-side direction, the influence of the convex warp by the outermost back side veneer 11a becomes insufficient with respect to the influence of the concave warpage by the MDF 12 and the outermost face side veneer 11d. As a result, it is presumed that the concave warp occurred as a result, and the influence of the MDF 12 was increased in the longitudinal direction, and the concave warp was slightly increased (see FIG. 4 and the related explanation).

  Further, in addition to these examples and comparative examples 1 and 2, as a result of various thickness tests, a plurality of single units positioned between the outermost surface side single plate 11d and the outermost surface side single plate 11a were tested. When the total thickness of the plates (second single plates) 11b and 11c is in the range of 30 to 45% of the total thickness of the composite plate, the warpage is minimized in both the long and short directions, which is a preferred embodiment. found. If the total thickness of the second single plate is less than 30% of the total thickness of the composite plate, the function of the second single plate as a restraining material is not sufficiently exhibited, and the warp prevention effect is reduced. On the other hand, when the total thickness of the second single plate exceeds 45% of the total thickness of the composite plate, the antagonistic balance with the influence of the MDF 12 is lost particularly in the longitudinal direction, and the convex warpage is likely to occur (the bottom of FIG. 4). See table and related description).

  FIG. 3 is a cross-sectional view showing the composite plate 16 according to the second embodiment of the present invention. In FIG. 3, a laminated portion between a portion including the male fruit 14 and protruding in the short direction Y and a portion including the female fruit 15 and recessed in the short direction Y is reduced in the short direction Y. It is shown. In the composite plate 16, the same or corresponding elements or members as those in the composite plate 10 according to the first embodiment are denoted by the same reference numerals.

  The composite plate 16 includes a lower laminated body formed of a first single plate 11a and a lower second single plate 11b, an upper second single plate 11c, a third single plate 11d, and an MDF 12. And the upper laminated body formed by the above-described structure is shifted in the lateral direction Y. The size of the composite plate 16 is, for example, the thickness T = 12 mm, the width W = 303 mm, and the length L = 1818 mm, similarly to the composite plate 10 of the first embodiment. In order to manufacture the composite plate 16, as in the composite plate 10 of the first embodiment, the first single plate 11a, the upper and lower second single plates 11b and 11c, and the third single plate 11d are bonded via an adhesive. And the laminated body which laminated | stacked MDF12 sequentially is manufactured by hot-press-molding integration. Even in such a structure, there is almost no warpage and the surfaces 14 and 15 can be smoothly formed by the same action as described above for the composite plate 10 of the first embodiment.

  Since the other structure and operation of the composite plate 16 are the same as those of the composite plate 10 of the first embodiment, description thereof is omitted.

It is a cross-sectional view of the composite board by one Embodiment (Example 1) of this invention. It is a longitudinal cross-sectional view of this composite board. It is a cross-sectional view of the composite board by other embodiment (Example 2) of this invention. It is a table | surface explaining the mechanism in which the curvature of both long-side and short-side directions is prevented in the composite board of this invention. It is a table | surface which compares and shows the manufacturing conditions, the amount of curvature, etc. of the test body of the composite board by the Example of this invention, and a comparative example.

Explanation of symbols

10 Composite board 11a 1st single board (the back side single board)
11b (lower) second single plate 11c (upper) second single plate 11d third single plate (outermost surface side single plate)
12 MDF (fiberboard)
16 Composite plate X Composite plate thickness direction center line Y Composite plate short direction Z Composite plate longitudinal direction

Claims (2)

In a composite plate in which at least four single plates are sequentially laminated and bonded, and a fiber plate is arranged on the surface and laminated and integrated, the fiber directions of the single plates located on the outermost surface side and the outermost surface side are composite plates. The fiber directions of the plurality of single plates located between the single plate on the outermost surface side and the outermost surface side are substantially the same as the direction perpendicular to the longitudinal direction of the composite plate, The composite plate is characterized in that the outermost surface side single plate is thicker than the outermost surface side single plate, and the total thickness of the fiber plate and the outermost surface side single plate is less than 50% of the total thickness. On the first veneer whose fiber direction substantially coincides with the longitudinal direction, a plurality of second veneers whose fiber direction substantially coincides with the direction perpendicular to the longitudinal direction is laminated via an adhesive, and on that, A third veneer whose fiber direction substantially coincides with the longitudinal direction and is thicker than the first veneer via an adhesive, and a fiber plate is further bonded on the third veneer. After the lamination, the obtained laminate is integrated by hot pressure, and the composite board is produced.

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