JP2003211416A - Plywood for longitudinally jointing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a plywood for longitudinally jointing structure capable of decreasing waste of wood resources and the amount of a bonding agent to be used. <P>SOLUTION: A scarf joint is constituted by alternately providing a slope formed toward a rear plate form a surface of a front plate and a slope formed to the front plate from a surface of the rear plate by a reverse slope to the slope along an edge in a width direction of a plywood body in a longitudinally jointed plywood provided by jointing at least two sheets of plywood bodies wherein main fiber directions of the front plates are made the same one by scarfing joint. By the plywood for longitudinally jointed structure, not only the amount of the bonding agent to be used can be decreased by saving waste of resources, but also improvement of quality performance such as an increase of a strength and the like can be achieved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to plywood, and more particularly to plywood for a vertical joint structure used as a face material bearing wall, a field, an underfloor material, etc. of a framed construction house. is there.

[0002]

2. Description of the Related Art In recent years, shortage and depletion of wood resources have been sought, and plywood has been widely used as a woodworking material processed under such circumstances. This plywood usually peels wood thinly to form veneers and the fiber direction (grain direction) of each veneer.
Are bonded to each other at right angles to form an odd-numbered cross-band structure such as 3 ply, 5 ply, or 7 ply.
mm x 1820 mm), 48 plates (1210 mm x 242)
Various finished products such as 0 mm) are offered to consumers.

On the other hand, apart from this, for the purpose of streamlining construction, a house maker or the like, for example, as shown in FIG. 6, has a scarf joint having a slope S at the edge of the plywood body 1 constructed as described above. 3 is formed and the plywood bodies 1 and 1 are joined to each other, so that the length dimension is 182.
We have developed plywood for vertical joints set to lengths of 0 mm or more, and are used as face material bearing walls, fields and underfloor materials for framed construction houses, and floor materials, bearing walls, roofing substrates for framed construction houses. It is used for such purposes.

However, in the above-mentioned plywood for vertical joint structure, since the required joining strength is obtained by the adhesion area of the slope S in the scarf joint, the slope S is made a gentle gradient of 1/8 or more and the adhesion area is increased. And therefore not only wastes more material,
Various problems to be solved have been pointed out, such as the large amount of adhesive used.

[0005]

Therefore, according to the present invention,
In a plywood for a vertical joint structure, which is formed by joining at least two plywood bodies having the same main fiber direction of the front board with a scarf joint, a front board surface to a back board along a width direction edge of the plywood body. The slope slope is set larger than before by constructing a scarf joint by alternately providing slopes formed facing and slopes that are opposite to this slope and formed from the back plate surface toward the front plate. It is possible to save the material and improve the strength.

In this case, the slope gradient may be set to 1/8 or less, preferably 1/3 to 1/5.

Further, if the plane shape of the slope is set to be rectangular, the work for processing the scarf joint can be facilitated.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a plywood for vertical joint structure according to the present invention will be described below in detail with reference to the accompanying drawings. Referring to FIG. 1, a plywood 10 for a vertical joint structure according to the present invention includes two plywood bodies 12, 12.
Are basically configured by being joined via the scarf joint 14. That is, each plywood body 12
Is, for example, a veneer formed by thinly peeling lauan such as tanger, red lauan, white lauan, etc., and a front plate (face) 12a and a core plate ( A cross band) 12b, a core plate (core) 12c, a core plate (cross band) 12b, and a back plate (back) 12d are sequentially laminated, and an adhesive 16 such as a urea resin adhesive is added with flour or the like. It is configured as a 5-ply cross-band structure bonded together in (see FIG. 2). In this case, as the adhesive 16, a phenol resin adhesive, a resorcinol resin adhesive, a melamine urea co-condensed synthetic resin adhesive, a casein glue blood adhesive, a soybean glue, a viscose adhesive, etc., which are used for ordinary plywood, are used. Various adhesives can also be used as appropriate.

On the other hand, the scarf joint 14 is, as shown in FIGS. 3 and 4b, the plywood bodies 12, 12 facing each other.
Along the respective widthwise end edges, slopes 18 are formed at predetermined intervals from the surface of the front plate 12a toward the back plate 12d, and at the spacing portions of these slopes 18 from the surface of the back plate 12d toward the front plate 12a. The slopes 20 having the reverse slope are sequentially formed, and the slopes 18, 20 and the slopes 20, 1 are formed.
8 is engaged with and fixed by an adhesive 16. With this configuration, the slope 18 and the reverse slope 20 are different from the conventional plywood (FIG. 4a) in which the slope direction is one direction with respect to the tensile stress and the bending stress, respectively. The theory of opposing, so-called triangular inflexion, is applied, thus increasing the strength.

The slopes of the slopes 18 and 20 are
It is larger than the 1/8 slope (inclination ratio) specified in the conventional plywood for vertical joint structure, that is, preferably 1 /
Set in the range of 3 to 1/5. With such a configuration, not only cutting chips (waste chips) of the plywood body (material) are reduced, but also the amount of adhesive applied (used) can be saved.

In the present embodiment, the notch widths of the slopes 18 and 20 are set to be the same width in order to improve the efficiency of the machining work and to enhance the strength. However, as shown in FIG. It goes without saying that it is possible to adopt a configuration in which the notch width is appropriately changed according to the application. Further, by making the slopes 18 and 20 have a rectangular plane shape as in the present embodiment, the work by the slope cutting machine can be facilitated.

When the quality performance of the plywood for vertical joint structure according to the present invention constructed as described above was confirmed, the total adhesive area is smaller than that of the conventional plywood for vertical joint structure because the slope slope is large. Despite this, we were able to obtain more than double the conventional values in both the tensile strength and bending strength specified in the certification regulations. As a precaution, the strength of the vertical joint structure plywood according to the present invention, which is set to the same slope gradient (1/8) as that of the conventional vertical joint plywood, is also confirmed. It was confirmed that a value improved by several percent or more was obtained in the same manner as described above in comparison with the respective strengths. This is compared with the conventional vertical joint structure plywood in which the slope S is only one-direction inclination with respect to the tensile stress and bending stress applied to the vertical joint structure plywood. Since the slopes 18 and the slopes 20 are oppositely inclined in the plywood for work, these slopes oppose to the respective stresses applied to the plywood for the vertical joint structure.

[0013]

As described above, according to the plywood for vertical joint structure according to the present invention, the scarf joint is directed from the front plate surface to the back plate along the widthwise edges of each plywood body. Since the slopes formed by this method and the slopes that are opposite to this slope and formed from the back plate surface toward the front plate are alternately provided, the slope gradient is larger than that of the conventional vertical joint plywood. Even if it is set, not only can the strength more than the strength specified in the certification regulations be secured, but also valuable woodworking resources can be wasted and the amount of adhesive applied (used) can be reduced. . Further, since the shape of the slope is set to be rectangular, it has various advantages such as facilitating the cutting work of the scarf joint. The preferred embodiment of the vertical joint plywood according to the present invention has been described above, but the present invention is not limited to this embodiment, and is appropriately within a range not departing from the spirit of the present invention. Of course, design changes can be made.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a preferred embodiment of a plywood for vertical joint structure according to the present invention.

FIG. 2 is an exploded perspective view of a plywood body in the plywood for the vertical joint structure shown in FIG.

FIG. 3 is an exploded perspective view of a scarf joint provided on a plywood body of the plywood for the vertical joint structure shown in FIG.

FIG. 4 is a perspective view of a main part of a scarf joint in a plywood for vertical joint structure, where a is a conventional plywood for vertical joint structure and b is a plywood for vertical joint structure according to the present invention.

FIG. 5 is a schematic perspective view showing another embodiment of the plywood for vertical joint structure according to the present invention.

FIG. 6 is a schematic perspective view of a conventional plywood for vertical joint structure.

[Explanation of symbols]

10 ... Plywood for vertical joint structure, 12 ... Plywood body,
12a ... front plate (face), 12b ... core plate (cross band), 12c ... core plate (core),
12d ... Back plate (back): 14 ... Scarf joint, 16 ... Adhesive, 18 ... Slope,
20 ... slope,

Claims (3)

[Claims] 1. A warp plywood formed by joining at least two plywood bodies having the same main fiber direction of the front board with a scarf joint, and the front board along the widthwise end edge of the plywood body. A slope formed from the surface to the back plate,
A plywood for a vertical joint structure, characterized in that a scarf joint is formed by alternately providing slopes which are reversely inclined and slopes which are formed from the back plate surface toward the front plate. 2. The plywood for vertical joint structure according to claim 1, wherein the slope gradient is set to 1/8 or less. 3. The plywood for vertical joint structure according to claim 1 or 2, wherein the slope has a rectangular plane shape.