JPH07132505A - Timber reforming method - Google Patents

Abstract

PURPOSE:To obtain a timber which is reformed so as to have desired properties such as decay resisting property, insecticidal property, fire protecting property, and dimensional stability up to the depth of the timber. CONSTITUTION:A timber 3 is compressed laterally at a compressibility of 10-50% at least 5 times by a press device in a hot water 1 of 70-160 deg.C above a softening temperature of lignin of the timber component so as to enlarge a penetrating cavity in the timber by breaking a periphery of wall pores and a wall pore membrane of a cell membrane without breaking the cell membrane of the timber in a state that a restoring force which is proper to the timber is maintained. Thereafter, the timber is dried in a reduced pressure so as to obtain a treated timber. Then, a large quantity of desired treating liquids such as a decay resisting agent, an insecticide, and a synthetic resin agent are impregnated up to the depth of the treated timber through the penetrating cavity in the timber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for modifying wood, which improves the drying property and the injectability of chemicals without impairing the original strength of the wood.

[0002]

2. Description of the Related Art Wood, especially cedar, cypress and other softwood materials,
Due to its excellent strength and straightness, it is used as various structural materials. On the other hand, wood has dimensional stability, antiseptic and ant-proof properties,
There are problems in discoloration, abrasion resistance, process liquid injectability, etc., and various modification treatment methods have been developed conventionally in view of such problems. For example, a boiling method, a chemical injection method, a synthetic resin injection method, etc. are adopted as a method of imparting dimensional stability and antiseptic / preventive properties, and also prevent discoloration and fading due to ac component and resin content in wood. As a method, a method of pressing wood in a treatment liquid at a low temperature by pressing is adopted.

[0003]

However, according to the former boiling method, chemical injection method, and synthetic resin injection method, wood such as thick plates and large-diameter squares, especially when the wood is softwood. In the above, there is a problem that the inside of the surface layer cannot be sufficiently modified regardless of the resin content in the wood and the closing of the wall holes in the core material. On the other hand, the latter method has been conventionally adopted as a discoloration prevention treatment for hardwood materials such as paulownia wood used for furniture, but when this treatment method is used for softwood materials, softwood is constructed. Lignin and hemicellulose do not soften, and even if it is possible to remove the ac component and the resin component, the wall pore membrane etc. are not destroyed, so there is a problem that the drying property and the injectability of drugs etc. cannot be improved. It was An object of the present invention is to provide a method for modifying wood which can completely solve such problems and improve the drying property and the injectability of a treatment liquid such as a chemical to the inside without impairing the original strength of the wood. It is what

[0004]

Means for Solving the Problems In order to achieve the above object, a method for modifying wood according to the present invention is to immerse wood in hot water at 70 to 160 ° C. to soften it, and then in the hot water. Compressibility of wood 10
It is characterized in that a lateral compression treatment of up to 50% and a gradual pressure after compression are repeated at least 5 times or more, and thereafter, the product is dried in a reduced pressure state. As hot water,
As described in claim 2, those containing a dye or other coloring agent or bleaching agent may be used.

Further, the invention according to claim 3 of the present invention is characterized in that the treatment liquid is injected into the wood obtained by the above method and then dried, and the treatment liquid is the treatment liquid according to claim 4. As described above, any one or more of preservatives, insect repellents and fire retardants can be used,
Further, as described in claim 5, a synthetic resin liquid diluted with a solvent can be used.

[0006]

When the wood is immersed in hot water, the softening temperature of the wood components, such as hemicellulose and lignin, lowers as the water content increases, and it is easily softened by hot water at 70 to 160 ° C. In this case, if the hot water contains a dye or other coloring material or a bleaching agent, it is possible to color the wood or perform the bleaching treatment. Furthermore, the compressibility of the wood in hot water
When the lateral compression treatment of 10 to 50% is repeated 5 times or more, the cell membrane of the wood is compressed with almost no destruction within the range of the compression rate, and the compressive stress is concentrated on the wall pores of the cell membrane. It destroys the peripheries of the pore walls and the closed wall membrane.

Further, by repeating the lateral compression treatment and the pressure reduction treatment after compression five times or more, the hot water permeation passage in the wood cells is expanded and the cell membrane is hardly destroyed, so that the wood restoration property is improved. It is not compromised so that hot water easily penetrates deep into the wood. And
Drying under reduced pressure after the lateral compression treatment allows drying in a shorter time than that after boiling treatment, and enables efficient modification without discoloration due to heat. Further, when the obtained modified wood is depressurized in a depressurized atmosphere, the pressure drop in the material is carried out in a short time, and the subsequent synthetic resin injection treatment or the like can be surely performed inside.

When the desired treatment liquid such as the above-mentioned preservative, insect repellent, synthetic resin liquid or the like is injected into the thus treated wood, the permeation passage in the wood cells is expanded, so that the treatment liquid is treated. The wood easily penetrates into the interior, and it is possible to obtain wood whose properties have been modified according to the purpose. The method of injecting the treatment liquid includes a depressurizing method, a pressurizing method, a depressurizing and pressurizing method, and the like.
A generally known method is adopted.

[0009]

EXAMPLE Next, an example of the present invention will be described in detail. FIG. 1 shows a press apparatus for carrying out the method of the present invention, which is installed in hot water 1 in an autoclave and is made of wood. The lower surface of the wood 3 and the press board 4 is composed of a compression jig 2 for housing the wood 3, a press board 4 for compressing the wood 3 in the compression jig 2, and an operation press cylinder 5 of the press board 4. A distance bar 6 for changing the compression ratio depending on the difference in thickness is interposed between the and.

In the compression jig 2 of this press machine, cedar,
Thick plate or prismatic wood such as cypress or hemlock 3
Set, and after heating and softening in hot water 1 at 70 to 160 ° C. for an appropriate period of time, the press cylinder 5 is operated and the compression ratio of the wood 3 is set within the range of 10 to 50% through the distance bar 6. Thus, the horizontal compression processing was performed. By this lateral compression treatment, the wood 3 is compressed with almost no destruction of its cell membrane, and the compressive stress concentrates on the wall pores of the cell membrane to selectively destroy the periphery of the pore wall and the closed pore membrane. To be done.

When the compression rate is 50% or more, the wood 3
This is not preferable because destruction of the cell membrane of (3) reduces the original restoring property of wood, and when cellulose is destroyed, the strength also decreases. Further, when the temperature of the hot water is 70 ° C. or lower, the softening temperature of the lignin is not reached even if the water content of the wood 3 is high, so that the pressing effect cannot be exhibited. On the other hand, when the temperature of the hot water exceeds 160 ° C, the softening temperature of the cellulose of the wood component is about 220 ° C, so there is not much problem with the restorability, but discoloration of the material easily occurs, so the temperature range above The set hot water 1 is used.

After the lateral compression processing, when the pressure applied by the press board 4 is gradually reduced, the wood 3 expands and expands in response to the slow pressure, and the hot water 1 permeates into the wood 3 when the wood 3 is restored. To do. This penetrability varies depending on the number of lateral compression treatments by the press machine, and it is not enough if the number of times is 1 or 2 times. Even if the compression treatment is applied, the permeation amount does not increase rapidly. If hot water contains a dye or other coloring agent or a bleaching agent, the wood can be colored or bleached.

Thus, after the wood 3 is subjected to the lateral compression treatment and the pressure reduction treatment after the compression in the hot water 1 by the pressing device 5 times or more, the wood 3 is taken out from the autoclave and then placed on the hot platen installed in the decompression tank. The wood 3 was placed on and dried under reduced pressure. Although the number of drying days varies depending on the temperature of the heating plate and the depressurizing condition, the wood 3 is impregnated by the lateral compression treatment because the peripheries of the cell membrane pores and the closed pore membranes are destroyed. Moisture evaporates smoothly to the outside and dries to the inside in a short time.

Then, the wood treated in this manner is provided with decay resistance, insect resistance, fire resistance, dimensional stability, mechanical properties and the like according to the purpose of use. That is, antiseptic, insect-proof,
When it is desired to impart antifungal property, fireproof property, etc., one or more of preservatives, insect repellents, antifungal agents, fireproofing agents and the like are selected and the treatment solution is applied to the treated wood. After injection, dry.

As preservatives and fungicides, water-soluble ones such as fluoride (NaF), arsenic compounds (NaHAsO ₄ ), chromium compounds
(K ₂ Cr ₂ O ₇ ), phenols, etc., oil-soluble ones such as pentachlorophenol, trichlorophenol, nitrophenol, etc.Also, in addition to the above insect repellents, there are aldolin, terdrin, tofusafene, etc. is there. Further, phosphorus compounds, phosphorus nitrogen compounds, halogen compounds and the like are used as fireproofing agents, and acetylating agents, formalizing agents and polyethylene glycols are suitable as dimensional stabilizers. On the other hand, as the treatment liquid injected to impart mechanical properties to the treated wood, there are synthetic resin agents such as phenol resin, vinyl chloride resin, MMA resin and polyester resin.

In such a treating liquid, antiseptics, insect repellents, fireproofing agents and the like may be added to the treated wood and then the solvent may be removed. However, heating and drying may reduce the efficacy or discolor the material. Since some are generated, it is preferable to perform treatment by drying at a low temperature such as vacuum drying. On the other hand, in a synthetic resin liquid that is injected to impart mechanical properties to wood, a treatment liquid diluted with a solvent such as phenol is subjected to heat treatment after removing the solvent. This is to improve the permeability of the synthetic resin liquid into the material by diluting it with a solvent. Most of the synthetic resin liquid is adopted for this treatment method, but it has good permeability and low viscosity. In the case of a synthetic resin liquid, it may be heat-treated after being injected into wood.

Upon injecting the treatment liquid, as described above, the wood was immersed in hot water at 70 to 160 ° C. and subjected to lateral compression at a compression ratio of 10 to 50% at least 5 times. After that, by drying under reduced pressure, the peripheries of the pores of the cell membrane and the closed pore membranes are destroyed and the permeation passage in the cells is expanded, so the treatment liquid can easily penetrate into the interior. It can be done.

Next, concrete test examples and comparative examples in which the wood itself is modified as described above so that the treatment liquid can be injected into the inside will be described. First, as a test example of the present invention
4.5 cm x 10.5 cm in a press installed in hot water at 120 ° C
Set a 90 cm thick plate-shaped Batsuga as a sample,
After heating and softening in this hot water for 60 minutes, 10% lateral compression was performed using the press bar for controlling the press thickness, and then the pressure was gradually reduced. Similarly, after subjecting the specimens of the same shape and the same material in the above hot water to lateral compression of 30% and 50%, respectively,
The pressure was gradually reduced.

2 to 4 show the results of the permeation test by the natural longitudinal permeation measuring method. FIG. 2 shows 10% lateral compression treatment, FIG. 3 shows 30% lateral compression treatment, and FIG. 4 shows 50% transverse compression treatment. In the result of compression treatment, C on the horizontal axis indicates an untreated material before being treated in hot water, and the number of presses O is a boiling material when treated in hot water under the same conditions ( All have the same shape and the same material). As is clear from the results of this test, the amount of water permeated during boiling was slightly improved in the boiling treatment as compared with the untreated material, but the amount was extremely small.
On the other hand, in the case of using the hot water treatment and the press treatment in combination as compared with the boiling treatment, the effect of improving the permeability can be seen, but when the number of presses is small, there is a difference in the amount of permeation due to the lateral compression rate. When the number of presses is 5 or more, the difference due to the compression rate becomes small and a sufficient penetration amount can be obtained.

FIG. 5 shows the test results of the above-mentioned untreated material, boiling material, and press-treated material which were dried under reduced pressure on a hot plate. In the figure, the solid line shows the untreated material, the two-dot chain line shows the boiling material, the dotted line shows the treated material with a lateral compression rate of 30%, and the one-dot chain line shows the treated material with a lateral compression rate of 50%. From this figure, it can be seen that the treated material subjected to the press treatment in hot water has an improvement in the drying speed which cannot be obtained only by the boiling treatment.

FIG. 6 shows the depressurization process in the material when a decompression sensor was set at the center of the dried material and the material was decompressed in a decompression chamber. In the figure,
Circles are untreated materials, triangles are boiling materials, squares are lateral compression ratio 30
%, The black square indicates the material with a lateral compression rate of 50%.
From this figure, the depressurization rate in the material is considerably improved in the boiling material as well, but the pressure-treated material subjected to the press treatment is further accelerated in its depressurization rate and reaches 1/100% of that of the boiling material. 3. It can be performed in 1/6 or less time of the untreated material.

FIG. 7 shows the untreated material, the boiling material, and the treated material after drying under reduced pressure under a reduced pressure of 60 mmHg for 30 minutes under a pressure of 5 kg / cm ^2.
The results of the depressurization and pressure injection test in which fresh water was injected for 15 minutes and the respective weight increase rates were obtained are shown. C on the horizontal axis is an untreated material before being treated in hot water. ,
The number of presses O indicates the boiling material when treated in hot water under the same conditions. As is clear from this test result, the weight increase rate of the treated material is larger than that of the untreated material and the boiling material, and the injectability is improved depending on the number of presses rather than the press conditions. Like the air permeability, this improvement in the injectability is considered to be a result of the destruction of the wood pore film and the like that occur during the press treatment.

[0023]

As described above, according to the method for modifying wood of the present invention, the wood is dipped in hot water at 70 to 160 ° C. to be softened, and then the wood is compressed in the hot water at a compression ratio of 10 to 10. Repeat 50% lateral compression and pressure reduction after compression at least 5 times,
After that, the temperature is 70 to 160 because it is dried under reduced pressure.
Wood components such as hemicellulose and lignin can be easily softened by hot water at ℃, and the lateral compression treatment in hot water is repeated 5 times or more with a compressibility of 10 to 50%. It is possible to intensively destroy the periphery of the pore wall portion and the wall pore film without substantially destroying the pores.

Therefore, the original resilience of wood is hardly impaired, and the hot water permeation passage in the wood cells is expanded due to the destruction of the peripheries of the pore wall and the pore membrane, so that the permeability to the interior of the wood is improved. However, hot water can be smoothly and efficiently permeated by decompressing the wood during the lateral pressure reduction after the lateral compression treatment, and at the time of reduced pressure drying after the lateral compression treatment, water and the like can be diffused in a short time. It is possible to efficiently produce wood whose interior has been modified.

As described above, since it has good permeability to wood and can be easily depressurized in the material, a desired treatment liquid such as antiseptic, insect repellent, fire retardant, or synthetic resin liquid can be brought into the interior in a short time. It can be infiltrated, and its injection amount can be increased to 1.7 times or more that of untreated wood by expanding the infiltration passage, which makes it possible to efficiently produce excellent modified wood, and it Unlike the method of infiltrating the treatment liquid into the material by sizing or the like, since the surface of the wood is not damaged, a modified wood with a beautiful appearance can be obtained.

[Brief description of drawings]

FIG. 1 is a simplified vertical sectional view of a pressing device in hot water,

[Fig. 2] Permeation amount comparison diagram of treated material with compression rate of 10%, untreated material and boiling material,

[Fig. 3] Permeation amount comparison diagram of treated material with compression rate of 30%, untreated material, and boiling material,

[Fig. 4] Permeation amount comparison diagram of treated material with compression rate of 50%, untreated material, and boiling material,

FIG. 5 is a comparative diagram of the results of the reduced pressure drying test,

FIG. 6 is a comparison diagram of results of decompression progress test,

FIG. 7 is a comparison diagram of the results of decompression / pressure injection fulcrums.

[Explanation of symbols]

 1 Hot water 2 Compression jig 3 Wood 4 Press board 6 Distance bar

Claims (5)

[Claims] 1. Wood is dipped in hot water at 70 to 160 ° C. to be softened, and then lateral compression treatment at a compression ratio of 10 to 50% is applied to the wood in the hot water. A method for modifying wood, which is characterized in that the method is repeated more than once, and then dried under reduced pressure. 2. The method for modifying wood according to claim 1, wherein the hot water contains a dye or other coloring agent or a bleaching agent. 3. Wood is dipped in hot water at 70 to 160 ° C. to soften it, and then lateral compression treatment at a compression rate of 10 to 50% is applied to the wood in the hot water, and a gradual pressure after compression is at least 5. A method for modifying wood, characterized in that the method is repeated at least once, followed by drying under reduced pressure, then injecting a treatment liquid, and then drying. 4. The treatment liquid comprises at least one of a preservative, an insect repellent, and a fire retardant.
A method for modifying wood as described. 5. The method for modifying wood according to claim 3, wherein the treatment liquid is a synthetic resin liquid diluted with a solvent.