JPH0342164B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to plywood in which laminated veneer veneers (hereinafter referred to as veneer veneers) are shifted by a predetermined dimension and then laminated and bonded.

In Japanese Patent Application Laid-Open No. 58-98202, the applicant has
Alternatively, a plywood made by laminating and bonding a plurality of veneers shifted by a predetermined dimension in the direction of their fibers, or in JP-A-58-151201, all or a plurality of veneers are shifted by a predetermined dimension in the direction perpendicular to the fibers of the plywood. We proposed plywood that is made by laminating and gluing the sheets in a staggered manner.

However, with any of the above plywoods, most of the veneers have their fibers aligned in the same direction, so it is not possible to obtain sufficient strength in the direction perpendicular to the fibers, and the strength deteriorates over time. It had a tendency to warp easily.

The purpose of the present invention is to improve the plywood previously proposed and filed by the applicant, and to provide a plywood that improves the strength in a well-balanced manner in the direction perpendicular to the fibers and prevents warping. .

The present invention will be described below with reference to Examples.

Fig. 1 is a perspective view showing examples of veneers constituting each layer of plywood according to the present invention, Fig. 2 is a perspective view showing plywood 3, and 1 in the figure uses at least three veneers 2a to 2c. The respective fiber directions are orthogonal to each other, and the width in the fiber direction of the plywood boards 2a and 2c located at both ends is longer than a predetermined dimension l1 described later, preferably at least 5 times the thickness of the veneer, and more preferably about 15 to 150 times. This is a bonded veneer as a group of veneers made by lengthening the veneer and bonding the fibers in the same direction.

A scarf cut having an appropriate scarf cut surface length is formed at the ends 1a and 1b of the bonded veneer 1, if necessary.

The plywood 3 is made by arbitrarily laminating the above-described bonded veneers 1, with single veneers located at both ends so that the end 1a exposed on one surface and the end 1b exposed on the other surface are positioned substantially opposite each other. The plates 2a and 2c are shifted by a predetermined distance _l1 in the direction of the fibers of the plates 2a and 2c, and are extended parallel to the respective surfaces, bent in the thickness direction of the plywood 3 by the predetermined distance l1, and laminated and bonded. The figure shows an example of the 5-ply plywood.

The above-mentioned predetermined dimension l1 is approximately
l1=L/N is set.

The plywood 3 shown in FIG. 3 is made by laminating and bonding each of the bonded veneers 1 in the same manner as described above, without scarf cutting the ends of the bonded veneers 1.
Compared to the plywood 3 shown in the figure, there are some recesses on both sides, but the flatness is generally good and aesthetics can be sought for there, so there is no practical problem, and if necessary, the recesses It is also possible to easily seal the surface or form grooves of arbitrary shapes.

The plywood 3 illustrated in FIG. 4 is similar to that shown in FIGS.
Compared to the plywood 3 shown in the figure, this is a 5-ply plywood in which the ends 1a and 1b of each bonded veneer 1 exposed on each surface are laminated and bonded in an overlapping relationship, and configured to have small convex portions on both sides. .

If necessary, the above-mentioned small protrusions can be left as they are to create an aesthetic appearance, or they can be processed into a protrusion of a desired shape, or even sanded as shown by the two-dot chain line in the figure. It can also be easily removed by cutting or other processing, and it is possible to obtain excellent flatness like the plywood shown in FIG. 2.

Furthermore, when the small protrusions are removed, the ends of the veneers 2a and 2c that make up the bonded veneer 1 are exposed on each side, but even in the case of the plywood 3 shown in FIG. It can be obtained by inverting it and laminating and bonding the scarf cuts formed at the ends 1a and 1b facing outward.

Further, FIGS. 5 to 8 show various examples of the laminated state before being laminated and bonded to the plywood 3, and show the opposing relationship between the end portions 1a and 1b of the bonded veneer 1, and the relationship between the end portions 1a and 1b of the bonded veneer 1.
Examples of processing modes a and 1b are shown, and in either case, the plywood 3 according to the present invention can be constructed.

FIG. 9 illustrates the basic manufacturing method of the plywood 3 according to the present invention. The ends 1b of the veneers 1 are overlapped as shown in the figure, and the adhesive is applied by the spreader 4.

The application of the adhesive is carried out by leaving an unapplied area on one side of the bonded veneer 1, and in the next lamination process B, the adhesive veneer 1 is sequentially applied with the unapplied area exposed. Stack them while shifting them as shown in the figure.

The laminated bonded veneers are transported to a temporary gluing process C which has an intermittent or continuous cold press (not shown) or a device that temporarily fixes the relative positions of the bonded veneers by appropriate means. Temporarily bonded, and then cut to a predetermined size in the next cutting step D.

Then, in a bonding process E using an adhesive curing device (not shown) such as a hot press, the bonded veneers are bent in stages in the thickness direction of the plywood and extended parallel to the front and back surfaces of the plywood. The bent parts are bonded together to produce plywood having the laminated form described above.

Regarding the adhesive application step A,
As in the process example described above, bonded veneer lamination process B
In the case where the adhesive applied to the bonded veneers is to be laminated while being shifted one after another without exposing the adhesive at all or almost, the adhesive application step A has an appropriate width. It is necessary to apply the adhesive while ensuring areas where the adhesive is not applied.

Incidentally, Fig. 10 shows a partially enlarged view of the laminated state of the bonded veneers 1 in the lamination process B, and in this way, the edge of the edge 1a of the top layer bonded veneer and the edge of the bottom layer bonded veneer 1 are shown in an enlarged view. In the lamination step B, in which the edges of the portion 1b are stacked in a facing relationship as shown in the figure (in this case, the facing dimension is referred to as 0), each bonded veneer 1 is stacked with a dimension of L/N from the edge. (L: the length of the bonded veneer, N: the number of laminated layers, which is 4 in the illustrated case). For other reasons, as shown by the two-dot chain line in the figure, the facing dimension S or S' (in the case of the plywood of the present invention, it is preferably about 15 times or less than the thickness of the bonded veneer used). When setting and facing each other, the exposed dimensions also increase or decrease accordingly, and it is necessary to secure an area where no adhesive is applied in order to avoid applying adhesive to these exposed surfaces.

Securing such adhesive-unapplied areas can also be achieved by controlling an adhesive application device such as a spreader, curtain coater, or film adhesive supply device (when using a film adhesive).
Practically speaking, it is extremely convenient to place the ends 1a and 1b of the bonded veneer 1 in an overlapping state as shown in FIG. 11, and then apply the adhesive using various types of ordinary adhesive applicators.

In this case, the overlapping length of the bonded veneers is set based on the exposed surface dimensions in the lamination process B described above,
I1 shown in the figure is the overlapping length when the above-mentioned L/N is exposed, and this l1 is approximately L/N, and if an arbitrary opposing dimension S and S' are set, a dashed double-dot line As shown in the figure, the overlapping length is also set to increase or decrease.

Of course, it is basic that the dimensions of the non-adhesive part and the dimensions of the exposed surface completely match, but in practice, the former should be slightly smaller or larger to reduce errors in each process or between the two processes. deal with.

In any case, the lamination work in the lamination process is the same, but the work of overlapping this type of bonded veneer is the 12th work.
If carried out automatically, semi-automatically, or manually on a conveyor with a positioning member, such as the conveyor belt 6 with the stopper 5 illustrated in FIGS. It can be implemented by

Furthermore, as illustrated in FIG. 14, a conveyor such as the one described above for the adhesive application process A is driven from the drive source 7, and furthermore, a conveyor such as the one described for the adhesive coating process A is driven from the same drive source 7 via the deceleration mechanism 8. If such a configuration is adopted to drive the conveyance body, each process will be extremely stably related to each other by the uniform setting of the deceleration mechanism 8, and the error between both processes will become a fixed value.

In this case, there is no particular problem even if the drive source 7 is turned ON and OFF and driven intermittently, so it is easy to provide an intermittent cold press in the temporary bonding process C in the process shown in FIG. .

In addition, if the adhesive applied to the bonded veneers is permitted to be exposed in the bonded veneer lamination step B, or if it is assumed that the adhesive is actively exposed, the adhesive application step is not particularly detailed. Adhesive is applied without properly securing the non-adhesive area.

For example, in the example shown in FIG. 9, an adhesive application process is configured in which the bonded veneers 1 are sequentially supplied to the spreader 4 without overlapping them and the adhesive is applied to the entire surface of one side.

In this case, in the process B of laminating the bonded veneers, the adhesive will be exposed almost continuously on the bonded veneers exposed on one side, but this is not acceptable for the plywood to be manufactured. Alternatively, it is also possible to use the exposed adhesive to bond other veneers, for example, so-called original boards, decorative paper, boards, etc., in order to wipe away the unevenness on the surface of plywood.

Therefore, the adhesive application step A is carried out, and the desired exposure of such adhesive is carried out in the lamination step B, and other laminated materials are further laminated in the lamination step. It is also possible to proceed to the next step.

As described above, the actual configuration of the adhesive application process that embodies the plywood manufacturing method according to the present invention is determined based on the relationship with the next lamination process, and there are various examples other than the above-mentioned examples. It is constructed in the form of

In addition, the adhesive application process and the lamination process are on the same plane other than being connected as shown in FIG.
In some cases, the adhesive application process is provided at the upper part in the conveyance direction, and the lamination process is provided at the lower part, and the two processes are connected in a desired manner, if necessary.

Furthermore, in the example of FIG. 9, if instead of the temporary bonding process C, the bonding process E having a continuous hot press is connected to the laminating process B, the production of plywood according to the present invention can be carried out continuously, and the process can be carried out as desired. When the length is increased, cutting is performed in cutting step D.

As explained above, in the plywood of the present invention, the fibers of the veneer located on the inside of the plywood are arranged perpendicularly to those on the front and back surfaces, which improves the strength in both directions in a well-balanced manner and prevents warping. Plywood can prevent this from occurring.

In addition, the wood species, thickness, size of the veneer to be used,
Changes in general matters related to plywood, such as the positioning of cracks on the back of laminated veneers, the number of plies, the adhesive used, and the moisture content of veneers, should be made in accordance with common practice, but there are no particular restrictions. It's not something you do.

In addition, in the examples, the manufacturing process etc. of the veneers of each layer constituting the plywood has been described using the bonded veneer 1 as an example, but the manufacturing process is not limited to veneers that have been bonded in advance, and The veneers are arranged in a single row in a non-bonded state in a direction perpendicular to the thickness direction of the veneers, and the fiber direction of the veneers located at both ends of the veneers in the orthogonal direction in each layer is determined by forming a veneer group by oriented in a direction that coincides with the arrangement direction and arranging at least one veneer other than the two ends in a direction in which the fiber direction thereof is orthogonal to the fibers of the veneers located at both ends; It is also possible to manufacture plywood by laminating a plurality of groups of veneers. Of course, when arranging the individual veneers, a so-called tunnel may be formed.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a bonded veneer constituting the plywood according to the present invention, FIG. 2 is a perspective view showing the plywood, and FIG.
The figure is a perspective view showing a plywood according to a modified embodiment of the present invention, FIGS. 4 to 8 are explanatory views showing the state of lamination of bonded veneers, FIG. 9 is an explanatory view showing a method for manufacturing plywood, and FIG. 11 is an explanatory diagram showing a partially enlarged state of lamination of bonded veneers, FIG. 11 is an explanatory diagram showing a state of adhesive application, and FIGS. 12 and 13 are transportation for overlapping bonded veneers. FIG. 14 is a perspective view showing each belt, and is an explanatory diagram showing a state in which the adhesive application process and the lamination process are driven by the same drive source. In the figure, 1 indicates bonded veneers as a group of veneers, 1a, 1b
is an end of a joined veneer, 2a to 2c are veneers, and 3 is a plywood.

Claims (1)

[Scope of Claims] 1 Each layer constituting the plywood is formed by arranging three or more veneer veneers in a row in a direction perpendicular to the thickness direction of the veneer veneer, and in each layer, the thickness direction The fiber direction of the veneer veneers located at both ends of the veneer veneer is oriented in a direction that coincides with the arrangement direction of the veneer veneers, and at least one veneer veneer other than the two ends is oriented such that the fiber direction of the veneer veneer is located at both ends. The veneer veneer group of each layer is arranged in a direction perpendicular to the fibers of the veneer veneers, and the veneer veneer group of each layer is arranged in a predetermined direction in the direction of the fibers of the veneer veneers located at both ends with respect to the veneer veneer groups of other layers. The sheets are bent in the thickness direction of the plywood at intervals of the predetermined dimensions in the fiber direction, and are laminated and bonded so as to extend substantially parallel to both surfaces of the plywood and include the bent portions. Plywood characterized by being cut into any size.