JPH1148213A - Method and apparatus for impregnation of green wood veneer with fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impregnate the whole of wood veneer internal tissue stably with a medical fluid of a specific concentration efficiently in a short time without forming a crack especial even for the wood veneer having little crack with a simple facility when the wood veneer is to be treated by impregnation with the medical fluid for antisepsis, insect proofing, etc. SOLUTION: In the method for impregnation of a green wood veneer with medical fluid, after dehydrating the green wood veneer by compressing in a veneer thickness direction with a dehydrator 3, the dehydrated green wood veneer 1a is conveyed in a fiber direction compressing in the veneer thickness direction with a pair of rolls 71, 72 provided in a liquid 5, and the dehydrated green wood veneer la is impregnated with the liquid 5 thereby. In this case, the green wood veneer 1a is compressed by a compressibility A% in the veneer thickness direction (wherein the compressibility A% is not more than a void ratio of the green wood veneer) and thereafter, is preferably conveyed in a fiber direction compressing the green wood veneer 1a by a compressibility B% in the veneer thickness direction (wherein, the compressibility B% is not more than the compressibility A%) with a pair of the rolls provided in the liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for impregnating a liquid inside the veneer veneer (hereinafter referred to as raw veneer) before drying obtained by cutting a log. Stated differently, the raw veneer is impregnated with a chemical solution for preservation and insect repellency, or impregnated with a dye solution for coloring, or a synthetic resin is used to improve hygroscopicity, dimensional stability, mechanical properties, and the like. The present invention relates to a method and an apparatus for impregnating a treatment liquid such as molecules.

[0002]

2. Description of the Related Art As a method for impregnating wood such as veneer with a chemical solution such as an insect repellent or an antiseptic, an adhesive mixing method, a veneer treatment method, a pressure treatment method and the like have hitherto been known. Hereinafter, each method will be described.

[Adhesive Mixing Method] The adhesive mixing method in which a chemical solution is mixed in an adhesive does not require special equipment, does not require a change in the manufacturing process, is inexpensive, and has low surface contamination. Because there is no such thing, it is the most simple and promising method technically and efficiently for existing factories. However, when the thickness of the veneer to be treated is large, the penetration of the chemical solution into the veneer is poor, so that effects such as antiseptic and insect repellency cannot be expected. Therefore, it was suitable for relatively thin single plates (1.5-3 mm or less). In addition, if the water content of the veneer is low, the penetration of the chemical solution is poor, so that a high water content was desired as long as the adhesive strength was not affected.

[Single veneer treatment method] This is a method in which a chemical solution or the like is adhered to the surface of a dried veneer or a raw veneer by a method such as coating, spraying or dipping. When processing raw veneer, in order to make the solution containing the chemical permeate into the wood by diffusion phenomenon,
A thick solution such as a preservative was deposited on the surface of the green veneer, then deposited, covered with a sheet or the like, and impregnated while preventing diffusion of the solution. According to this method, the drug can be uniformly impregnated into almost the entire veneer, which is effective. However, for example, a raw veneer is dipped for about 10 seconds and then covered with a sheet or the like so as not to dry. , At least 2
It was necessary to leave it for about 4 hours to secure the diffusion time. On the other hand, when a dried veneer is processed, it must be dried again after the processing, so that the drying is performed twice for convenience, resulting in a loss in productivity and cost.

[Pressure treatment method] This is a treatment method in which a dry veneer is put in a pressure-resistant injection can, hermetically sealed, and a chemical solution is injected into the material by decompression and pressure operations. . According to this method, the chemical penetrates into the veneer, so there is little processing unevenness and a product with a high chemical effect can be produced. However, special equipment and a management system are required, and the product cannot be incorporated into a conventional production line. Or the processing time is long and the cost is high. In addition, after injection, there were problems such as fluffing of the plywood surface due to wetting and distortion of the product, and poor work efficiency due to the necessity of re-drying.

On the other hand, in order to solve the problems such as permeability and productivity of a chemical solution observed in the above-mentioned methods, the following methods have also been conventionally performed. For example, “Japanese Patent Laid-Open No. 59-1
No. 65611 discloses that "a plurality of roll coaters are arranged in parallel in a dyeing tank containing a dye solution, and the roll gap of the roll coater is set to be about 70% to 80% smaller than the thickness of the veneer. Thereafter, the veneers are sequentially passed to dye the veneer uniformly. "

[0007] JP-A-48-18403 discloses that
"After spraying a concentrated chemical solution with a surfactant added to the front and back surfaces of the veneer, it is pumped by a pair of feed rollers, and the suction action and the capillary action that occur when the veneer is released from the pressure of the roll are applied. A method in which the chemical solution is permeated into the raw veneer, and then left for a certain period of time to uniformly diffuse and infiltrate the chemical solution throughout the raw veneer to perform the chemical treatment. "

[0008] Japanese Patent Application Laid-Open No. 52-143208 discloses that while a strip-shaped veneer veneer is brought into contact with a chemical solution, it passes between a pair of rolls made of an elastic member having a large number of vertical grooves on the peripheral surface. A device that creates cracks and allows a chemical solution to penetrate inside the veneer ”has been disclosed.

[0009] Japanese Patent Application Laid-Open No. 49-86503 discloses that
"A method in which a veneer veneer with a large number of cracks and back cracks is immersed in a chemical solution, and the chemical solution is penetrated and diffused into the veneer veneer by alternately and continuously repeating pressing and immersion with a roller press. Apparatus "is disclosed.

[0010]

However, the following problems have been encountered in the above-mentioned method which has been performed to solve the problems such as the permeability and the productivity of the chemical solution. First, in JP-A-59-165611, equipment is complicated because a plurality of roll coaters are required. In addition, since the impregnation is not sufficiently performed unless the inhalation-discharge is repeated a plurality of times, the efficiency is poor, and the impregnation amount of the chemical solution is also unstable.

Next, "Japanese Patent Laid-Open No. 48-18403"
Has adopted a configuration in which the chemical liquid is sprayed on the front and back surfaces by the injection nozzle, so there is no guarantee that the chemical liquid enough to match the suction action after the pressure is released by the pressure feed roller can be reliably supplied. Was bad. For this reason, it was difficult to control the impregnation amount of the chemical solution to a constant value, and the effect of the chemical solution was unstable. In addition, since the treatment is performed using the dilution phenomenon due to the moisture content of the raw veneer, after impregnating with a highly concentrated solution, the diffusion and infiltration time of 1 to 2 days is secured and the whole is made uniform. It had to be spread to achieve the desired proper concentration of impregnation. Therefore, the productivity is poor and it is difficult to control the concentration to an appropriate concentration when the water content varies. Furthermore, since a high-concentration solution is used, there is a problem in the safety when handling a chemical solution and the safety of a chemical solution scattered in the air at the time of spraying to a human body.

Next, in Japanese Patent Application Laid-Open No. 52-143208, the veneer veneer is passed between rolls composed of a pair of elastic members, and the veneer is actively stretched in the transport direction to obtain a fiber. A large number of cracks are generated in the direction, and the chemical solution is made to penetrate from these many cracks.
Actually, it was necessary to secure the diffusion penetration time.

Next, "JP-A-49-86503"
In the above, it is assumed that veneers with a large number of cracks and back cracks are processed in advance, so the veneer with many cracks has rough skin and poor thickness. Could not make a good quality product. In addition, since the chemical liquid is forcibly penetrated by alternately repeating the squeezing and immersion, when the squeezing is performed, the moisture of the veneer is discharged from the cracked portion to the outside, so that the chemical is easily contaminated, and the chemical is diluted by the moisture. As a result, it was difficult to supply a chemical solution having a stable concentration, and it was difficult to control the amount of chemical solution impregnated in a veneer at a constant level.

Accordingly, an object of the present invention is to provide a simple apparatus for impregnating a veneer with a chemical solution for preservatives and insect repellents, etc., by using simple equipment without causing cracks even in a veneer having a small number of cracks. It is another object of the present invention to provide a chemical treatment technique for stably impregnating the entire internal tissue of a veneer with a constant concentration of a chemical in a short time.

[0015]

Therefore, according to the invention of claim 1, after the green veneer is compressed in the thickness direction and subjected to a dehydration treatment, the green veneer is rolled by a pair of rolls provided in a liquid. A method for impregnating a green veneer with a liquid is characterized in that the green veneer is conveyed in the fiber direction while being compressed in the thickness direction.

In the invention of claim 2, the green veneer is compressed in the thickness direction at a compression ratio of A% (however, the compression ratio A% is equal to or less than the porosity of the green veneer) and subjected to a dehydration treatment. The raw veneer is compressed in a thickness direction by a pair of rolls provided in the liquid in a compressibility B% (however,
The method of impregnating a green veneer with a liquid is characterized in that the raw veneer is conveyed in the fiber direction while compressing at a compression ratio of B% or less.

In the invention of claim 3, the liquid is a chemical for preservation or insect repellency.

According to a fourth aspect of the present invention, as a device for impregnating a green veneer with a liquid, the green veneer is compressed at a compression ratio A in the thickness direction.
% (However, the compression ratio A% is equal to or less than the porosity of the green veneer) to perform a dehydration treatment by compressing the raw veneer, a liquid tank containing the liquid, and a liquid tank provided in the liquid tank. And a pair of pressurized transport rolls for transporting the veneer in the fiber direction while compressing the veneer in the liquid at a compressibility of B% (where the compressibility is not more than A%) in the thickness direction. A characteristic liquid impregnation device was used.

According to a fifth aspect of the present invention, a pair of pressure-conveying rolls provided in the liquid tank according to the fourth aspect of the present invention are provided with a plurality of spiral convex portions on at least one of the rolls. Roll.

According to a sixth aspect of the present invention, the pair of pressure transport rolls provided in the liquid tank according to the fourth aspect of the invention is a roll having a plurality of protrusions on the surface of at least one roll. .

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments of the present invention. In the following drawings, only the main parts of the apparatus are described, and illustration or description of well-known structures or functions other than those necessary for the description of the present invention is omitted or simplified.

First, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a dehydrating apparatus 3 (hereinafter, referred to as a dehydrating apparatus) for conveying a raw veneer 1 while compressing it in the thickness direction and performing a dehydrating process, and a raw veneer 1a (hereinafter, referred to as a dehydrating apparatus) after the dehydrating process. FIG. 2 is a schematic side view of an impregnation processing device 7 (hereinafter, referred to as an impregnation device) for impregnating a liquid 5 into a dehydrated veneer veneer.

First, the dehydrator 3 will be described. The dewatering device 3 includes a pair of compression and pressure rolls (hereinafter, referred to as dewatering rolls) including an upper roll 31 and a lower roll 32. The rotation axis of each roll is parallel to each other,
At least one of the rolls is rotationally driven by receiving a driving force from an electric motor (not shown). The upper roll 31 and the lower roll 32 in the present embodiment have a central portion made of steel, and the periphery thereof is covered with a synthetic rubber having a hardness of 80 degrees or more.

Next, the dewatering rolls are arranged at intervals smaller than the thickness of the raw veneer 1 to be carried in, that is, so as to compress the raw veneer 1 in the thickness direction at an arbitrary compression ratio. Is configured to be arbitrarily set. However, the compression ratio (hereinafter referred to as dehydration compression ratio) is set to a value equal to or less than the porosity of the green veneer. This will be described later.

The total thickness of the synthetic rubber coated on the dewatering roll is set to be at least 10 times the value obtained by subtracting the interval between the dewatering rolls from the thickness of the green veneer 1. . The reason for this will be described later.

The raw veneer 1 is inserted between the dewatering rolls while being transported at a speed of about 80 m / min in the fiber direction of the raw veneer by the rotationally driven transport rolls 33a and pressure rolls 34a. Is done. When the green veneer 1 is carried in between the dewatering rolls in this way, the green veneer 1 is compressed and deformed by synthetic rubber, so that an amount of water corresponding to an arbitrarily set dewatering / compression ratio is obtained. It will be removed from the raw veneer 1.

Here, the dewatering compression ratio of the green veneer is shown in FIG.
This will be described with reference to FIG. FIG. 2 is a partial side view showing a state in which the dewatering roll is conveying the raw veneer 1 while compressing it in the thickness direction. FIG. 3 is a partial side view in which a main part of the dewatering roll is further enlarged in order to explain the dewatering compression ratio. Here, a specific description will be given of a case in which a raw veneer of radiator pine having a thickness of 4 mm is subjected to a dehydration treatment at a dehydration compression ratio of 50%.

First, the upper roll 31 and the lower roll 32
The synthetic rubbers 31a and 32a are coated around the steel bases 31b and 32b forming the central part. As synthetic rubber, urethane rubber having a rubber hardness of 98 degrees is 20
It is coated with a thickness of mm.

As is clear from FIG. 3, when the gap between the dewatering rolls is set to 2 mm, when the raw veneer 1 having a thickness of 4 mm passes through the dewatering rolls, It will be compressed by half 2mm. That is, it is compressed by 50% of the original thickness. The dewatering compression ratio at this time is referred to as “set dewatering compression ratio”. Therefore, when the gap between the dewatering rolls is 3 mm, the green veneer 1 is compressed by 1 mm, and the set dewatering compression ratio at this time is 25%. Similarly, when the gap is 1 mm, the green veneer 1 is compressed by 3 mm, so that the set dewatering compression ratio is 75%. Note that, when the dewatering roll actually compresses the raw veneer 1, the urethane rubber is deformed. Therefore, strictly speaking, the actual dehydration compression ratio and the set dehydration compression ratio are different. The dewatering compression rate is regarded as the actual dewatering compression rate, and is hereinafter simply referred to as the dewatering compression rate.

Next, the thickness of the coated urethane rubber is 2
Since it is 0 mm, the total thickness of the urethane rubber of the dewatering roll is 40 mm. This value is 10 times or more the value obtained by subtracting the interval between the dewatering rolls from the thickness of the raw veneer 1. Here, the reason why the total thickness of the synthetic rubber is set to 10 times or more a value obtained by subtracting the interval between the dewatering rolls from the thickness of the raw veneer 1 will be described.

First, the reason why the dewatering roll is coated with the synthetic rubber will be described. For example, when a raw veneer containing many knots such as radiata pine is carried between the dehydrating rolls,
Most of the green veneer, except for the knots, can be easily compressed and deformed in the thickness direction by the dewatering rolls. Therefore, it is difficult to compress and deform in the thickness direction. Therefore, if the dewatering roll is coated with synthetic rubber,
Instead of compressing and deforming the knot portion, the green veneer can be passed through in a state where the urethane rubber portion corresponding to the knot portion is compressed and deformed. As described above, since the urethane rubber side is deformed almost without deforming the knot portion, an excessively large force is not applied to the knot portion, so that the destruction of the knot portion is suppressed as much as possible. Moisture can be easily removed by sufficiently compressing and deforming portions other than the nodes.

Next, the results of an experiment in which a dewatering roll is coated with urethane rubber and subjected to a dewatering treatment will be described. The dewatering roll is coated with a urethane rubber having a rubber hardness of 98 degrees in a thickness of 20 mm, and the dewatering compression ratio is 65% with respect to the raw single plate of radiator pine having a thickness of 4 mm, that is, the gap between the dewatering rolls is 1.4 mm. After treatment, the average water content was about 1 on average.
43% raw veneer has an average moisture content of about 7 after dehydration.
9%.

Next, the hardness of the urethane rubber is set to 90 degrees to 11 degrees.
As a result of experiments in the range of 0 degrees, the lower the rubber hardness, the less the breakage of the nodes, but the removal of water was not sufficient, and the higher the rubber hardness, the better the water removal, but the breakage of the nodes was not. Increased. When the rubber hardness was 95 to 98 degrees, good results were obtained with respect to removal of water and breakage of the nodes.

In comparison with the case of a urethane rubber having a hardness of 98 degrees and a thickness of the urethane rubber of 20 mm and a case of 40 mm, the removal of water is better at 20 mm, but the breakage of the node is better at 40 mm. There were few.

As described above, the experiment was performed while changing the thickness of the raw veneer to be dewatered, the thickness of the urethane rubber, and the compression dewatering rate. As a result, the total thickness of the urethane rubber was calculated from the thickness of the veneer. If the value is at least 10 times the value obtained by subtracting the interval between the dewatering rolls, the result that the breakage of the knot is small and the water can be removed well can be obtained.

In the above-mentioned dewatering roll, both rolls constituting the dewatering roll adopt a configuration in which synthetic rubber is coated around the two rolls. However, the present invention is not limited to this. For example, when processing a raw veneer containing almost no knots, one of the rolls may be a steel roll.

Next, the porosity of wood will be described. As described above, when the dewatering compression ratio is set, it is set so as to be equal to or less than the porosity of the green veneer 1. The reason is that the porosity is the volume ratio of the voids contained in the wood, and if the compression is performed beyond this porosity, the wood of the raw veneer 1 is destroyed. The porosity can be determined from the true specific gravity ρ of wood and the total dry specific gravity r by the following formula. In other words, “porosity C
(%) = (1−r / ρ) × 100 ”.

Accordingly, since the true specific gravity ρ of wood is about 1.5 regardless of the tree type, if the total dry specific gravity of the raw veneer to be dehydrated is known, the porosity can be easily obtained by the above formula. Can be. Note that the specific gravity of the total dry weight is calculated by
The weight obtained by drying at 0 to 105 ° C. and containing no water can be easily obtained by dividing the weight by the wood volume at the time of the weight measurement. Further, the total dry specific gravity r has a specific value depending on the tree species. For example, when the total dry specific gravity is “0.
In the case of “1”, “0.5”, and “1.0”, the porosity corresponding to the specific gravity is obtained from the above formula, and is “9”.
4% "," 67% ", and" 34% ".

Next, some specific examples of the total dry specific gravity and the porosity according to the difference in tree species will be given. The total dry specific gravity of cedar is about 0.40.
Therefore, the porosity is 74%, the total dry specific gravity of paulownia is about 0.26, the porosity is 83%, and the total dry specific gravity of balsa is about 0.10, so the porosity is 94%. Also, for example, the total dry specific gravity of radiata pine is about 0.43, and the porosity is calculated to be about 71%. Therefore, when dehydrating a radiator pine raw veneer, the dehydration compression ratio is set to be about 71% or less.

Next, the impregnating device 7 will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 4 is a partial side view of the impregnating device 7 for impregnating the liquid 5 stored in the liquid tank 4 (not shown) into the dehydrated veneer veneer 1a. The impregnating device 7
A pair of compression and pressure rolls (hereinafter, referred to as impregnation rolls) including an upper roll 71 and a lower roll 72 is provided. The impregnating roll is made of steel, and has a cylindrical shape having a smooth outer peripheral surface (hereinafter, referred to as a cylindrical impregnating roll). The rotation axes of the respective rolls are parallel to each other, and at least one of the rolls is driven to rotate by receiving a driving force from an electric motor (not shown).

Next, similarly to the dewatering roll, the column-shaped impregnated rolls have an interval smaller than the thickness of the conveyed dehydrated veneer veneer 1a, that is, an arbitrary length of the dehydrated veneer veneer 1a in the plate thickness direction. The dewatering roll interval can be set arbitrarily so as to enable compression at a compression ratio (hereinafter referred to as impregnation compression ratio). In the present embodiment, the impregnation compression ratio is set to a value equal to or less than the dehydration compression ratio at the time of performing the dehydration treatment. This will be described later.

As shown in FIG. 1, the dewatered raw veneer 1a subjected to the dewatering treatment by the dewatering device 3 is transferred to the impregnating device 7 by a transport roll 33b and a pressure roll 34b which are driven to rotate. It is carried in. The transport speed at this time is the speed at which the raw veneer 1 is transported to the dewatering device 3, that is, 80 m /
The transport is performed by synchronizing with the speed of about a minute or slightly increasing the speed. Therefore, the dehydrated veneer veneer 1a inserted between the cylindrical impregnating rolls is conveyed while being compressed in the thickness direction by the cylindrical impregnating rolls at a rate corresponding to a preset impregnation compression ratio. .

The dehydrated veneer 1a compressed and deformed by the cylindrical impregnating roll in this way, when it is released from the compressed state by passing through the cylindrical impregnating roll, attempts to return to the original state at once. . The liquid 5 is forcibly sucked into the dehydrated veneer 1a from the conduit or the temporary conduit of the dehydrated veneer 1a by the restoring action of returning to the original state. Therefore, since the liquid 5 is impregnated by utilizing such a restoring action, the dewatered veneer 1a can be uniformly impregnated with the liquid in an amount corresponding to the set impregnation compressibility. Hereinafter, the dehydrated veneer veneer 1a impregnated with the liquid 5 is referred to as an impregnated veneer veneer 1b.

As described above, the dehydrated veneer veneer 1a
Is already dewatered by the dewatering device 3, and the impregnation compression rate is set to a value equal to or less than the dehydration compression rate at the time of the dehydration processing. No water leaks from the dehydrated veneer 1a. Therefore, since there is no possibility that the concentration of the liquid 5 is reduced by the leaked water, it is possible to always impregnate the liquid 5 with a constant concentration.

Next, the liquid 5 to be impregnated into the dehydrated green veneer 1a
The types are described. An object of the present invention is to provide a chemical treatment technique for stably impregnating a chemical solution such as an antiseptic and insect repellent over the entire internal tissue of a veneer. Chemical solutions such as preservatives, insect repellents, and fungicides are used. However, the chemical solution is not limited to this, and it is impregnated with a dye solution to color the veneer, or a chemical solution such as a synthetic polymer to improve fire resistance, moisture absorption, dimensional stability and mechanical properties. The processing can also be performed using. Of course, two or more of the above-mentioned chemical solutions may be used in combination.

Examples of the preservative and antifungal agent include preservatives and antifungal agents which are usually used for treating wood, and examples thereof include nitrile antibacterial agents, pyridine antibacterial agents, haloalkylthio antibacterial agents, and organic antifungal agents. An antibacterial composition containing, as an active ingredient, one or more antibacterial agents selected from the group consisting of iodine antibacterial agents and thiazole antibacterial agents. Further, the antibacterial composition may further contain a benzimidazole antibacterial agent, if desired.

Next, examples of insect repellents include phoxime, fenitrothion, dichlorofenphos, chlorpyrifos and the like.

Examples of the fire retardant include boron-based flame retardants and phosphorus-nitrogen-based flame retardants.

On the other hand, agents for improving dimensional stability and mechanical strength of wood include vinyl polymerizable monomers,
Phenol resin, polyethylene glycol (PEG) resin and the like can be mentioned. Further, these resins may be used in combination with the above-mentioned chemicals such as preservatives, insect repellents, fungicides, and dyeing solutions for coloring veneers.

Next, the outer peripheral surface shape of the impregnation roll will be described in detail with reference to FIGS. As described above, the impregnated roll shown in FIG. 4 is a cylindrical impregnated roll, but the shape of the outer peripheral surface of the impregnated roll is not limited to this shape. That is, FIG. 6 is a schematic view showing a state in which a liquid (not shown) is impregnated into the dehydrated veneer veneer 1a by an impregnating roll having another outer peripheral surface shape. Impregnated rolls having a plurality of spiral convex portions (hereinafter referred to as spiral impregnated rolls).

In FIG. 6, the surface (upper surface) and the back surface (lower surface) of the dehydrated veneer 1a after the liquid impregnation treatment shown on the lower side in the transport direction (indicated by an arrow in the figure) are shown. The pattern shows, for the sake of convenience, a compression mark generated when the dewatered veneer veneer 1a is compressed by the spiral impregnated roll. A indicated by a thin solid line represents a compression mark by the upper roll 73, and a broken line. B shown by the symbol represents a compression mark by the lower roll 74. In addition, these compression marks, after the liquid impregnation process,
Since it is restored with the passage of time, there is no particular hindrance when it becomes a product.

Next, the liquid impregnation action of the dewatered veneer veneer 1a by the spiral impregnation roll will be described with reference to FIGS. 5, 7 and 8. The spiral impregnated roll is made of steel, and the spiral impregnated roll is provided with a plurality of spiral convex portions (hereinafter referred to as spiral convex portions) on the outer peripheral surface. 7 and 8 are plan views for explaining how the dewatered veneer veneer 1a is compressed by the spiral projection and how the liquid 5 is impregnated. 1a is displayed.
In addition, A and B in the figure show, for the sake of convenience, compression marks generated when the dewatered veneer veneer 1a is compressed by the spiral projections, as already described with reference to FIG. In the figure,
The compression trace A rising to the left shown by the solid line represents the compression trace formed by the upper roll 73 on the surface of the dehydrated veneer 1a, and the compression trace B rising to the right shown by the broken line is the lower roll 74 formed on the back surface.
Represents a compression mark due to

Now, regarding the shape of the spiral projection,
Originally, it should be described using the drawing of the impregnating roll. However, since the spiral protrusion compresses the dehydrated veneer veneer 1a, it corresponds to the spiral protrusion generated in the dewatered veneer veneer 1a. The size of the compression mark will be used instead.

First, FIG. 7 will be described. As shown in the figure, the spiral convex portion is inclined by 15 degrees with respect to the direction perpendicular to the transport direction of the dehydrated veneer veneer 1a, that is, the rotation axis direction of the spiral impregnated roll. The width is 3 mm, and the spiral projections are provided at intervals of 7 mm. Then, the spiral impregnated roll having this shape is temporarily referred to as “a type”. In the figure, the size of the compression mark is shown as the size of the spiral protrusion. However, since the raw veneer is an elastic material, the compression mark having a width larger than the size of the spiral protrusion is actually compressed. Will occur.

Next, the diamond-shaped portion C shown in FIG.
And the spiral projection 73a of the upper roll 73 shown in FIG.
And a spiral crossing portion 74a of the lower roll 74. Hereinafter, the rhombus-shaped portion is referred to as a spiral convex intersection C. Thus, the dehydrated raw veneer 1a
When is compressed by the spiral impregnated roll, it is compressed by the spiral convex intersection C.

By the way, when the spiral impregnated roll is compared with the cylindrical impregnated roll, when compressed by using the cylindrical impregnated roll, the dehydrated veneer veneer 1a is moved in a direction perpendicular to the conveying direction, that is, in a cylindrical shape. Although compression is performed with a certain compression width over the entire width of the impregnating roll in the rotation axis direction, when compression is performed using the spiral impregnating roll, the dehydrated veneer veneer 1a is mainly driven by the spiral convex portion intersection C. It will be compressed. As described above, when compressed by the spiral impregnated roll, the total area for compressing the dehydrated veneer 1a is smaller than when compressed by the cylindrical impregnated roll. As for the total compressive force to be applied, the use of the spiral impregnated roll requires less total compressive force as the total compressive area is smaller.

Next, FIG. 8 will be described. As shown in the figure, the spiral projections are inclined by 30 degrees with respect to the rotation axis direction of the spiral impregnated roll, the width of the spiral projections is 2 mm, and the spiral projections are spaced at a pitch of 14 mm. Provided. The spiral impregnated roll having this shape will be temporarily referred to as “b type”.

Now, the above "a type" and "b type"
As can be seen from the figure, the total area of the spiral convex intersection C can be changed by changing the inclination angle of the spiral convex, the width of the spiral convex, or the pitch of the spiral convex. Recognize. By changing the total area of the spiral convex intersections C in this manner, the amount and state of impregnation of the dehydrated veneer veneer 1a with the liquid 5 can be changed. As described above, the amount of the liquid 5 impregnated into the dehydrated veneer veneer 1a can be changed by changing the impregnation compression ratio. Therefore, when the impregnation compression ratio is kept constant, the larger the total compression area with respect to the dehydrated veneer veneer 1a, the more the liquid 5 can be impregnated. Furthermore, as is clear from the figure, the larger the total area of the spiral convex intersections C is, the larger the area that the liquid is impregnated becomes. .

As described above, even with the same spiral impregnated roll, the "a type" has a larger total compression area than the "b type", and accordingly, the dewatered veneer veneer 1a has a corresponding amount. On the other hand, the liquid 5 can be uniformly impregnated over a wide range. On the other hand, when the impregnation compression ratio is set to the same value, the spiral impregnation roll of “a type” is more compact than the “b type”. As the area is large, the total pressing force naturally increases, so a device equipped with the "a-type" spiral impregnating roll requires a pressing device that only generates the pressing force and a device that can withstand the pressing force. The device must have sufficient strength. That is, for example, if the compression area is increased three times, the same impregnation compression ratio will not be achieved unless the pressure is increased three times.

On the other hand, in the case of the “b type”, the impregnation amount of the liquid 5 into the dehydrated veneer 1a tends to be smaller because the total compression area is smaller. For this reason, the present invention can be adopted for impregnation for the purpose of preventing insects and the like in which the effect can be obtained even if the impregnation is relatively uneven, rather than preservatives or the like that require the liquid 5 to be uniformly impregnated. In particular, when the compression area is small as in the case of the “b type”, the pressing force can be reduced as compared with the cylindrical impregnating roll, so that the mechanical strength of the device itself does not need to be strong. It is possible to prevent the device from being enlarged.

As described above, the amount of impregnation into the dehydrated veneer veneer 1a is determined by the impregnation compression ratio and the compression area, and therefore depends on the purpose such as the material of the veneer to be impregnated and the use of the impregnated veneer. It is necessary to determine the shape of the spiral projection.
The method of changing the total compression area by the spiral convex portion is not limited to the above-mentioned “a type” and “b type” spiral convex shape, but the point is that the area of the spiral convex portion intersection C changes. In addition, the inclination angle, width, and pitch of the spiral projection may be changed arbitrarily.

Next, the impregnation effect of the spirally impregnated roll on the dewatered green veneer 1a will be described with reference to FIG. In order to facilitate understanding, the explanation will be made in comparison with the impregnation action (FIG. 4) by the cylindrical impregnation roll. FIG. 5 is a partial side view of the impregnating device 7 for impregnating the liquid 5 into the dehydrated veneer veneer 1a using the spiral impregnating roll. The spiral impregnated roll is composed of an upper roll 73.
And a lower roll 74, and a pair of compression and pressing rolls.
3a, 74a and spiral grooves 73b, 74b are formed. These spiral projections are inclined at an arbitrary angle with respect to the rotation axis direction of the impregnating roll as described above.

First, the impregnation action of the cylindrical impregnation roll will be described with reference to FIG. When the dehydrated veneer 1a passes through a point where it is compressed and deformed by the cylindrical impregnated roll and undergoes maximum compression, the compression is released, and a restoring action to return to the original state works. When the dewatered veneer 1a is released from contact with the cylindrical impregnating roll and comes into contact with the liquid 5, the liquid 5 is forcibly removed from the dewatered veneer 1a by a conduit or a temporary conduit. It will be sucked inside the veneer 1a. Thus, in the case of a cylindrical impregnated roll, the dewatered raw veneer 1a
Is released from contact with the cylindrical impregnating roll,
It is believed that impregnation of liquid 5 begins. The impregnation compression rate at this time is set to be equal to or less than the dehydration compression rate by the dehydrator 3 so that moisture does not leak from the dehydrated veneer veneer 1a during compression by the cylindrical impregnation roll. .

On the other hand, in the case of the spiral impregnated roll, unlike the case of the cylindrical impregnated roll, a groove 7 is formed on the outer periphery of the roll.
3b and 74b are formed, so that the dehydrated raw veneer 1
When a passes through a point where the spiral convex portion receives the maximum compression, the liquid 5 existing in the groove portion around the spiral convex portion intersection C is immediately impregnated, so that the impregnation can be performed efficiently. It is. This is because, as can be seen from FIGS. 7 and 8, there is a groove around the spiral convex intersection C, and the liquid 5 is constantly present in the groove. Since the impregnation starts at a stage where the restoring force of the dewatered veneer veneer 1a is stronger than in the case of impregnation with the cylindrical impregnation roll, impregnation can be performed efficiently.

In terms of uniformity of impregnation of the liquid 5, the cylindrical impregnated roll is superior to the spiral impregnated roll, but even in the case of the spiral impregnated roll, Liquid 5 due to differences in plate material
By determining the shape of the spiral protrusion corresponding to various conditions such as the impregnation characteristics of the impregnated material, the use of the impregnated material, or the maximum impregnation compression ratio, it is possible to perform the impregnation treatment close to the cylindrical impregnation roll. The spiral impregnated roll is
At least one roll may be a spiral impregnated roll.

Next, another shape of the impregnation roll will be described. FIG. 9 shows an impregnating device 7 having impregnating rolls of other shapes.
Is simplified to show an impregnated roll 77 having a plurality of projections 77a on the surface of at least one of the rolls (hereinafter referred to as a projecting impregnated roll).
The projecting impregnated roll 77 has a configuration in which the spiral projection 73a of the spiral impregnated roll is formed as a discontinuous projection. This is because, in the compression by the spiral impregnated roll, since the portion where the veneer is actually compressed is mainly the spiral convex intersection C and its peripheral portion, the spiral convex other than the spiral convex intersection C is removed. It has a shape. When the impregnating roll provided with such projections 77a is used, particularly when used for compressing a thick single plate, the impregnation is performed with a smaller pressing force than the impregnation using the spiral impregnating roll. be able to. In other words, even if the impregnation compression ratio is the same, when a single plate having a large thickness is compressed, the area of the spiral convex portion intersection C becomes large. Further, the shape of the projection 77a is not particularly limited to the above-mentioned shape. In short, any shape that can compress the dehydrated raw veneer la is sufficient.

Next, the material of the impregnating roll will be described. As described above, the impregnating device 7 in FIG. 4 employs a steel cylindrical impregnating roll, and FIG. 6 also employs a spiral impregnating roll made of steel.
However, these impregnating rolls are not limited to steel,
For example, it may be performed by a synthetic rubber roll such as that used for the upper roll and the lower roll of the dewatering device 3. This is because if the veneer to be impregnated has many nodes such as radiata pine, it is desirable to use a synthetic rubber such as urethane rubber in order to prevent breakage of the nodes.

[0068]

Since the present invention is constructed as described above, it has the following effects. First, the green veneer is compressed in the thickness direction to perform dehydration treatment, and then conveyed in the fiber direction while compressing the green veneer in the thickness direction with a pair of rolls provided in the liquid. Since the liquid is impregnated into the veneer, the liquid is instantaneously and uniformly dispersed into the internal structure of the veneer without being affected by the moisture content, thickness, cracking, etc. Can be efficiently impregnated and fixed.

In particular, when the liquid is a chemical solution for preservation or insect repellency, the chemical solution can be uniformly penetrated and fixed to the whole internal tissue of the raw veneer. Alternatively, an insect repellent product can be provided. Therefore, after a chemical solution for preservation or insect repellency, which has been conventionally used, is penetrated into wood using a diffusion phenomenon, the chemical solution is allowed to stand for a certain period of time, and the chemical solution is uniformly diffused and penetrated throughout the whole raw veneer. Since there is no need to do this, productivity is dramatically improved.

Further, since there is no fear that the chemical solution is scattered into the air, the impregnation process can be performed safely.

Next, the green veneer is compressed in the thickness direction at a compressibility of A% (however, the compressibility A% is equal to or less than the porosity of the green veneer) and subjected to a dehydration treatment. The green veneer is conveyed in the fiber direction while being compressed with a pair of rolls at a compression ratio of B% in the thickness direction (however, the compression ratio is not more than A%), and the raw veneer is impregnated with the liquid. Therefore, the impregnation amount of the liquid into the green veneer can be easily controlled by changing the compression ratio A% and the compression ratio B%.

Therefore, for example, if the use of a high-concentration chemical solution poses a safety problem, the impregnation process is controlled more safely by impregnating the required amount of the low-concentration chemical solution. It can be performed.

Further, even if the green veneer is compressed in the liquid, the water contained in the green veneer does not leak into the liquid. The liquid having the specified concentration can be impregnated and fixed.

Next, by providing a plurality of spiral convex portions on the surface of at least one of the pair of pressurizing and transporting rolls provided in the liquid tank, the single unit by the pressurizing and transporting rolls is provided. Since the compression area of the plate can be reduced, the pressing force by the pressurizing and transporting rolls can be reduced accordingly, and it is not necessary to increase the mechanical strength of the impregnating device itself. Can be prevented.

In particular, when a plurality of projections are provided on the surface of at least one of a pair of pressurized conveyance rolls provided in the liquid tank, the thickness of the raw veneer is large. Also, the liquid can be impregnated and fixed by pressing with less pressing force.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a dehydrating device and an impregnating device.

FIG. 2 is a partial side view showing a compressed state of a green veneer by a dewatering roll.

FIG. 3 is a partial side view in which a compression state by a dewatering roll is further enlarged.

FIG. 4 is a partial side view of an impregnation roll in the impregnation device.

FIG. 5 is a partial side view of a spiral impregnation roll.

FIG. 6 is a perspective view for explaining an impregnation state by a spiral impregnation roll.

FIG. 7 is a plan view of a green veneer for explaining a compressed state by a spiral impregnated roll.

FIG. 8

FIG. 9 is a perspective view for explaining an impregnation state by an impregnation roll of another shape.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 ... Raw veneer 1a ... Dewatered raw veneer 1b ... Impregnated raw veneer 3 ... Dehydration device 4 ... Liquid tank 5 ... Liquid 7 ... Impregnation device 31 ... Upper roll 32 ... Lower roll 33a ... Transport roll 33b ... Transport roll 34a ... Pressure roll 34b Pressure roll 71 Upper roll 72 Lower roll 73a Spiral projection 73b Spiral recess 74 Lower roll 74a Spiral projection 74b Spiral recess A Compression mark B Compression mark C: Spiral convex intersection

Claims (6)

[Claims] 1. A method for compressing a green veneer in a thickness direction to perform dehydration treatment, and then conveying the green veneer in a fiber direction while compressing the green veneer in a thickness direction by a pair of rolls provided in a liquid. A method for impregnating a raw veneer with a liquid, characterized in that: 2. The raw veneer is compressed in the thickness direction with a compression ratio of A% (however,
After compressing at a compression ratio A% or less of the porosity of the green veneer and performing dehydration treatment, the green veneer is compressed in a thickness direction by a pair of rolls provided in a liquid with a compression ratio B% (however, A method for impregnating a green veneer with a liquid, wherein the raw veneer is conveyed in the fiber direction while being compressed at a compression ratio of B% or less. 3. The method for impregnating a raw veneer with a liquid according to claim 1, wherein the liquid is a chemical liquid for preservation or insect repellency. 4. An apparatus for impregnating a green veneer with a liquid, wherein the green veneer has a compression ratio of A% in the thickness direction (where the compression ratio A% is equal to or less than the porosity of the green veneer). A dewatering treatment apparatus for performing dehydration treatment by compressing the raw veneer, a liquid tank containing the liquid, and a compression ratio B% (provided that the green veneer is provided in the liquid in the liquid thickness direction in the liquid tank). A raw pressure veneer, comprising: a pair of pressurized conveying rolls for conveying in the fiber direction while compressing at a compression ratio of B% or less. 5. A pair of pressure transport rolls provided in the liquid tank are rolls having a plurality of spiral convex portions on at least one roll surface. A device for impregnating a raw veneer according to the above description. 6. The single unit according to claim 4, wherein said pair of pressurized transport rolls provided in said liquid tank are rolls having a plurality of projections on at least one roll surface. Liquid impregnation device for plate.