JPS633721B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for dewatering a veneer veneer.

Conventionally, as a dewatering means for mechanically removing moisture contained in a veneer veneer (hereinafter simply referred to as veneer) by conveying it while compressing it in the thickness direction, for example, " A device for removing moisture contained in dried veneer has been proposed (Japanese Patent Application Laid-Open No. 148003/1983).

The above-mentioned device had the disadvantage that, as previously proposed, the veneer would break before sufficient dehydration was achieved by simply compressing the veneer in the thickness direction using, for example, a pair of conveyor rolls. A regulating body is provided at the rear of the conveyor body that conveys the veneer, and the veneer is conveyed in a direction perpendicular to the fibers while applying a braking force.
The idea is to achieve effective dewatering by compressing the veneer not only in the thickness direction but also in the direction perpendicular to the fibers.In principle, it is an improvement over the previous method, but it is different from the known method. Due to the presence of conduits, veneer has the property that water tends to move in the direction parallel to the fibers and is difficult to move in the direction perpendicular to the fibers. If the water is compressed and transported in that direction, it is difficult for the water that should be removed with the compression to move in the transport direction, resulting in insufficient water removal, and the force required for the compression increases accordingly. Therefore, depending on the configuration of the device, it has not always been possible to achieve a satisfactory effect.

The present invention compresses the veneer in the thickness direction while conveying it in the direction parallel to the fibers, where moisture can easily move, and then compresses the veneer in the direction perpendicular to the fibers using an extremely rational configuration. The present invention was developed to further improve the efficiency of dewatering and to provide a dewatered veneer suitable for forming plywood. That's right.

In the veneer dehydration method according to the present invention, in a pair of rolls whose outer circumferential surfaces are arranged with an interval smaller than the thickness of the veneer veneer, the outer circumferential surface of at least one of the rolls is coated in a direction parallel to the axis of the roll. The projections have a substantially mountain-shaped cross section, a height from the outer circumferential surface is smaller than the interval, and are continuously continuous at an arbitrary length in substantially the same direction as the rotational direction of the roll, in the axial direction. are arranged in parallel at arbitrary intervals, and furthermore, at least one of the rolls is rotationally driven, and a veneer veneer is inserted between these pair of rolls in the direction of the fibers, thereby making the veneer into fibers. The compressor is also compressed in the orthogonal direction to perform dehydration.

That is, as illustrated in FIGS. 1 and 2, the cross section in the direction parallel to the axis is approximately mountain-shaped, the height from the outer circumferential surface 4 is lower than the thickness of the veneer 6 to be processed, and the direction of rotation is Projections 3 that continuously extend around the same direction
The projecting rolls 1 are arranged in parallel at arbitrary intervals in the axial direction of the outer circumferential surface 4, and the veneer 6 has a substantially mountain-shaped cross section in the direction parallel to the axis and has a height from the outer circumferential surface 5. A protrusion roll 2 in which protrusions 3 that are lower than the thickness of , and continuously extend around the circumference in substantially the same direction as the rotation direction are arranged in parallel at arbitrary intervals in the axial direction of the outer circumferential surface 5.
are arranged oppositely, and the distance between the outer peripheral surfaces 4 and 5 of both is set to a single plate 6.
At the same time, at least one of them is driven to rotate in the direction of the arrow shown in the figure via shafts 8 and 9, and the veneer 6 is inserted between the projection rolls 1 and 2 in the fiber direction. It does dehydration.

According to such a method, the veneer 6 has protruding rolls 1,
2 is compressed in the thickness direction by the outer peripheral surfaces 4 and 5 of the projection 3, and as the projection 3 is press-fitted, a compressive force is applied from the slope 7 of the projection 3 in the direction of the arrow shown in the figure. As a result, the fibers are also compressed in the direction perpendicular to the fibers, so it is possible to perform effective compression within a range that does not cause breakage. Furthermore, due to the compression, water can freely move between the protrusions in the axial direction toward the input side in the fiber direction, and is effectively removed, making dewatering more efficient overall. obtain.

In addition, in the above embodiment device, the thickness is 3 to 4 mm.
A veneer with an initial moisture content of around 120% has a moisture content of 80 after dehydration.
It went back and forth.

Furthermore, as shown in FIG. 3, a veneer dehydrated by the method described above has a large number of grooves B continuously extending parallel to the fibers on both the front and back surfaces. Multiple grooves B in plate 6'
The presence of the veneer facilitates the release of steam generated as the moisture contained in the adhesive or the veneer evaporates to the outside during hot-press molding of plywood as illustrated in FIG. 4, for example. Therefore, it is possible to effectively prevent adhesion defects (punctures) which normally occur when using veneers, and the dehydrated veneer 6' becomes extremely suitable for forming plywood as an intermediate board.

Furthermore, as mentioned above, the existence of the grooves facilitates the dissipation of steam to the outside and prevents the occurrence of poor adhesion, which means that the tolerance range of the final drying rate of the dehydrated veneer itself is improved compared to the conventional method. Since this leads to the possibility of expansion, it is expected that the moisture content of the dehydrated veneer can be easily controlled during the drying process, or that a decrease in the veneer yield due to shrinkage caused by overdrying can be avoided.

On the other hand, in the embodiment illustrated in FIG. 6, a protrusion roll 10 having protrusions 13 arranged side by side on the outer circumferential surface and a roll 11 having a cylindrical outer circumference are disposed opposite each other, and one of them is driven to rotate. The veneer 12 is inserted between the protrusion roll 10 and the roll 11 in the fiber direction, and even with such a configuration, the seventh
As is clear from the figure, the veneer 12 is also compressed in the direction perpendicular to the fibers as the protrusions 13 are press-fitted, so dewatering is more efficient and effective than in the past. If the dehydrated veneer is used with the side where the grooves are formed facing toward the middle plate, it is possible to promote the dissipation of steam to the outside, and it is also suitable for forming plywood as a base plate without damaging the external appearance. In the present invention, it is preferable that one of the pair of rolls has protrusions arranged side by side on the outer peripheral surface.

It should be noted that the protrusions of the roll are not limited to the form in which they are continuous in a ring shape in the same direction as the rotation direction as illustrated in the above embodiments. A continuous spiral shape is convenient because it is easy to form.Furthermore, as shown in FIG. A separable protrusion A having an appropriate cross-sectional shape with a substantially mountain-shaped cross section and a height from the outer circumferential surface that is lower than the thickness of the veneer to be processed is removably fitted into a groove formed on the outer circumferential surface of the roll. In this way, it is convenient to take measures against wear of the protrusions.

In addition, in the above embodiment, the protrusions are provided in a continuous manner around the rotation direction, but if it is accepted that the dehydration effect is slightly reduced, the protrusions are provided in a continuous manner with a constant length in the rotation direction. The bodies may be provided intermittently at intervals in the direction of rotation.

Furthermore, if the protruding roll is heated to an appropriate temperature using steam or the like, moisture on the surface of the veneer can be expected to evaporate. For example, if heated to 120°C or higher, the surface side of the veneer will evaporate as it is compressed. Part of the removed moisture instantly evaporates and is blown away.

As is clear from the above, according to the veneer dehydration method according to the present invention, the veneer is compressed in the thickness direction and also in the direction orthogonal to the fibers, thereby increasing the compression effect, and moreover, moisture is removed in the axial direction. Since the protrusions can freely move toward the input side in the fiber direction, the dewatering of the veneer can be made more efficient than in the past, and the effect of implementing the present invention is extremely high. It's a huge amount.

[Brief explanation of the drawing]

The drawings are for explaining the present invention, and FIG. 1 is a schematic side view for explaining an embodiment of the veneer dewatering method according to the present invention, and FIG. 2 is a dashed-dotted line in FIG. 1. Partial cross-sectional enlarged explanatory diagram in X-Y, 3rd
The figure is a perspective view of a dehydrated veneer, Figure 4 is a side view of plywood formed using the dehydrated veneer, Figure 5 is an enlarged partial cross-sectional view of another embodiment of the roll, and Figure 6 is a book. FIG. 7 is a schematic partial front explanatory view for explaining another embodiment of the veneer dewatering method according to the invention, and FIG. 7 is an enlarged partial cross-sectional explanatory view of the main part of FIG. 6. 1, 2, 10...roll, 3,13...protrusion,
4, 5... Outer peripheral surface of roll, 6, 12... Single plate, 6'
... Dehydrated veneer, 7... Slope of protrusion, 8, 9... Axis of roll, 11... Roll with cylindrical outer periphery, A... Separable protrusion, B... Groove formed in dehydrated veneer.

Claims (1)

[Claims] 1. In a pair of rolls arranged such that the interval between the outer peripheral surfaces is smaller than the thickness of the veneer veneer, at least one of the rolls has a cross section parallel to the axis of the roll that is substantially mountain-shaped, and the outer periphery Protrusions whose height from the surface is smaller than the interval and which are continuous at an arbitrary length in substantially the same direction as the rotational direction of the roll are arranged in parallel at arbitrary intervals in the axial direction, and A method for dewatering a veneer veneer, characterized in that at least one of the rolls is rotationally driven, and the veneer veneer is inserted between the pair of rolls in the fiber direction.