JP2698792B2 - Wood treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications] Used to increase the efficiency and efficiency of all types of wood processing, including wood used in construction, crafts such as sculptures, and furniture, as well as to reduce the number of replacements of cutting tools used in wood processing. Can be

[0002] Regarding this technology, in the world wood drying method, in any of the world wood drying methods, natural water contained in wood is merely an obstacle,
Since there is no literature on a method for drying wood that uses a natural water content to prevent uneven reduction in water content, wood processing can only be started after completion of drying, which is said to have a uniform water content. and are only part of the processing steps in the pressure vessel, it is only present those patents and patent-pending owns the present applicant. Even in this regard, we have never explained the technology using academic papers because the applicant has not published any papers. For this reason, academic papers cannot exist worldwide. Even more, the present invention is a technology that does not cause defects in wood-processed products after drying is completed, even if the time for performing wood processing is performed at a time when drying is not completed. I can say that there is no scholarly literature at all.

[0003]

2. Description of the Related Art In a conventional wood drying method, in a process of drying treated wood, a water gradient occurs in a thickness direction, and a moisture content is uneven in a length direction. There is uneven distribution in the water content, and it was not possible to reduce the water content uniformly throughout the treated wood, so as a matter of course, in the drying process, uneven shrinkage occurred, so shrinkage unevenness disappeared Until the drying range has been completed, when processing of the wood is started, the wood is supposed to be deformed in the process of drying. Therefore, it was unimaginable that even if wood processing was performed in the process of decreasing the moisture content, the processed wood would not be deformed.

[0004]

In the process of lowering the water content of wood, if the water content is more than 23%, scorching occurs and finishing is difficult. 20-21 moisture content
When the percentage is reached, no scorching occurs and processing becomes easier. As the moisture content falls below 19%, the shrinkage of the wood increases and the wood becomes harder. Therefore, if you can process wood at about 20%,
It can be said that processing is easy.

[0005] However, if there is uneven distribution of the water content at this time, the shrinkage rate differs for each part of the processed wood, and when the wood processing is started at such a time, various processed wood products are produced. Deformation occurs and cannot be processed during the drying process.

For this reason, if the processing is started with wood having a water content of 20%, which is easy to process, the wood whose water content is uniformly reduced before and after the processing is started,
Unless the shrinkage rate can be made to be exactly the same wood, such a process cannot be performed very much.

[0007]

Means for Solving the Problems In describing the invention of the present application using embodiments, explanations of past patent rights owned by the applicant of the present application are also included so as to be easily understood by general industry persons. The embodiment will be described while explaining related technologies.

The lumber products are piled and stacked, and the thickness of the first lumber products is made the same, and the error of the total thickness (the width is not related) is within 10 to 20%. Close the door, inject saturated steam from the boiler into the pressure vessel, release the air in the vessel and fill the vessel with the saturated steam, then open only the valve that releases condensed water and close the other valves. When the temperature in the pressure vessel reaches 100 degrees, the opening of the valve for discharging condensed water is reduced.

[0009] There is a certain range of error in the thickness of the wood put in the pressure vessel. When the thin wood is processed in accordance with the processing time, the internal temperature of the thick wood is not uniform. Treatment with timed thick wood, thin wood becomes too long time steamed, failure deformation or discoloration timber occurs. Even if the deformed wood is dried, various deformation obstacles occur in the processed wood, so that there is a limit to the thickness that can be processed simultaneously and naturally.

[0010] The pressure in the pressure vessel is 0.2 to 0.7 kg
/ G range. If you increase the pressure from the beginning,
Low-temperature water contained in the wood from the beginning is pushed into the center of the wood, causing a low-temperature water mass in the center of the wood,
Care must be taken because the specific heat is an obstacle to heating the wood. When high temperature saturated steam hits low temperature wood,
Hot condensed water is generated on the surface of wood. If the pressure in the pressure vessel is varied by blowing or stopping it to fluctuate the pressure in the pressure vessel within a predetermined pressure range, the high-temperature condensate generated on the surface of the wood during the process of increasing the pressure Pushed into the wood. As the pressure drops, the reaction causes the cold water contained in the wood to move toward the surface of the wood.

[0011] By repeating this process, high-temperature condensed water and low-temperature contained water are mixed, and at the same time, the thickness of the thick wood in the pressure vessel is expressed in mm. In the treatment for about half the time converted to the above, the internal temperature of the wood exceeds 100 degrees, but does not reach the same temperature until.

Immediately after the completion of the step 0011, the pressurized pressure in the pressure vessel by the injection of saturated steam is set to 0.4 to 1.
The pressure is raised to a fluctuating pressure of 2 Kg / G to mix the hot condensed water generated on the wood surface with the water contained in the wood at a relatively low temperature, as in step 0011. The internal temperature of the wood becomes the same in a time obtained by multiplying the number expressed in mm of the thickness of the wood by minutes by about 1 to 1.3.

The reason for the range of the time difference is that the heat transfer time varies depending on the species of the tree, depending on whether the cell cavity is aggregated or not.

Water contained in cell cavities and water contained in extremely thin capillaries does not move even when the pressure is changed, but unlike heating from the wood surface, containing water that has become hot in nearby conduits or thick capillaries Due to the heat transfer from the water, their contained water also has the same temperature. The small number of cell cavity clumps produces the time difference described in 0012. During this time, the temperature of the entire wood is about 120 degrees, which is proportional to the pressure of 1 kg / G of saturated steam.

At the time of the last step of 0014,
When the pressure inside the pressure vessel is reduced toward the atmospheric pressure while discharging the condensed water stored in the pressure vessel, the internal temperature of the wood becomes a uniform temperature of about 120 degrees. The high-temperature water, which is a mixture of the high-temperature condensed water and the originally contained water, and the water contained in the cell cavity also boil at the same time. In the boiling state, since the temperature inside the wood is uniform, the boiling state cannot be different for each part of the wood.

Since the contained water boils and turns into a gas, the contained water in the cell cavity, which was difficult to diffuse, can also diffuse through the adjacent cell cavity. A cavity with divergent water content results.

In the case of wood having the same cavities in which the same contained water diverges in the whole cell cavity, even if the wood is naturally dried after being taken out from the pressure vessel, the residual water contained in the whole cell cavity is contained in the adjacent cell cavity. Can be moved to the divergent cavity, so that the water contained in all cell cavities, which has been considered difficult to diverge, can be moved simultaneously. For this reason, it is possible to reduce the moisture content of the wood without causing uneven distribution in the moisture content, and to reduce the moisture content of the wood regardless of the thickness of the wood so that the shrinkage does not differ in the process of decreasing the moisture content. It has become possible.

Since the shrinkage rate of the whole wood is the same, it is possible to produce wood which does not undergo any cracking or distortion in the wood which has been subjected to this treatment.

[0019] Depending on the type of wood, there is a tree in which the movement of the contained water is hindered by the resin. Even in this tree species, when the water content boils, the resin that had hindered the release of the water contained was chemically decomposed into turpentine and colophonium by steam distillation by boiling, and the turpentine diverged as gas. , Colophony is foamed and extruded to the surface of the wood and removed, eliminating the cause of the divergence of water contained by the resin.Therefore, cracking and distortion due to imbalance in shrinkage in the process of reducing the water content depending on the tree species There is no more worry about the occurrence of

Some wood species have extremely thin capillaries and very small pits. Due to this condition, when the contained water boils, there is a difference in the boiling pressure before and after the portion that is a hindrance to the divergence of the contained water.
If a large difference occurs in the boiling pressure, a steam explosion can be caused only in this portion by using the difference in the pressure. Due to this steam explosion, very fine capillaries and fine cracks were generated in the portions of the crests, and the water contained therein was more easily diverged.

At this time, care must be taken. When the pressure is reduced toward the atmospheric pressure, the temperature of the wood is higher than the temperature proportional to the pressure of the saturated steam remaining in the pressure vessel, so the pressure increases too rapidly toward the atmospheric pressure. When lowered, a steam explosion occurs throughout the interior of the wood,
The wood structure inside the wood can be so severely destroyed that no wood is available for all the wood in the pressure vessel.

When the pressure in the pressure vessel reaches atmospheric pressure, the pressure vessel is closed, and the pressure is reduced by using a vacuum pump. The time for reducing the pressure is about 30 minutes, and the amount of heat for boiling the contained water disappears. It should be noted that the display numbers of the combined gauge and the thermometer attached to the pressure vessel are indications of the pressure and temperature of the air in the pressure vessel, and are different from the indication indicating the temperature of the wood.

[0023] By performing the decompression time more, Ri Do to the child absorb water evaporated from the surface of the wood, the moisture gradient is increased, since the shrinkage of the surface only is increased, extreme moisture content Moisture gradients occur, shrinkage rates differ, and wood will crack and strain in large quantities.

When the time for reducing the pressure is over, the inside of the pressure vessel is returned to the atmospheric pressure, and the wood is taken out of the pressure vessel.

[0025] The past in the past. and. It is not necessary to repeat pressurization and depressurization as many times as in the vacuum method. This past method was intended to dry wood by a method that uses a combination of multiple heating and depressurization of saturated steam with a fixed pressure. The present application is different from the purpose of this past method in that the purpose is to make the water contained in the wood evenly irrespective of the thickness of the wood, so that the application by the saturated steam at the fluctuating pressure is performed. The pressure heating and decompression are performed only once, and the object of the present invention can be achieved.

The wood which has been subjected to the above processing is naturally dried while being piled in a region having good weather. In the area where snow falls, after two or three days, the water content is lowered by placing it in a dehumidifying and drying chamber that can control the humidity and temperature at which the water content reaches an equilibrium water content of 20%. Alternatively, a hot air drying method is performed at a temperature of 30 ° C. or less with a weak wind speed.

Regardless of which method is used, the wood which has been subjected to the above-mentioned treatment does not have a water gradient when the surface is removed by 3 mm, and the water content of the whole wood is reduced without causing uneven distribution. and you go, because there is no uneven distribution of water diversion rate even when any of the wood to dry in the course of lowering the water content, the fact that cracking or distortion in the wood is dry does not occur at all,
It has been confirmed in many experimental examples and follow-up tests of large-scale industrial production.

In any of the world's wood drying methods, the water content originally present in the wood is merely a hindrance, so that the water content of the wood decreases during natural drying and during the artificial drying process. There is no scholarly literature in the world that tracks the occurrence of water content distribution unevenness and the state of shrinkage.

In step 0026, if it can be confirmed that the water content has decreased to around 20%, it is sufficient to enter the timber as it is. If there is a danger of wood, the temperature and humidity of wood that is being dried naturally or wood that has been subjected to a hot-air drying method using low temperature and light breeze are adjusted so that the moisture content becomes an equilibrium moisture content of 20%. It is safer to put it in a dehumidifying dryer that can be used.

According to the above steps, the water content of the whole wood becomes
Wood that is approximately 20 to 21% is processed according to each purpose, and after finishing the processing, it is piled up again and brought into a room that has an equilibrium moisture content according to the place for the intended use. And a desiccant suitable for the intended moisture content. As described above, even after finishing the wood processing, the wood content does not decrease non-uniformly, so that it becomes a dried material suitable for the place of use without being deformed in the processed state.

In this step, the distribution of the water content of the processed wood product may be a distribution of ± 0 with respect to the water content according to the purpose of use.

If the above-mentioned series of treatments are not carried out and the wood having a water content of 20% is suddenly formed by a normal drying method and the wood processing is carried out, various processes are carried out until the water content reaches the intended use. Deformation occurs and cannot be used wood products.

In the above series of steps, after making a wood product having a water content for the purpose of use, the pile is dismantled to give a finished wood product such as super-finished canner or sandpaper. , A series of steps is completed.

If the water content of the wood is 23%, the processed product is crushed. When the water content reaches 22%, no sprinkling occurs.

When the water content is 20%, the processing is easy as in the processing of raw wood. If the water content is less than 19%, the wood becomes hard and difficult to process.

Although there are tens of thousands of cubic meters of wood processing experience so far, it is still unknown why such an extreme difference occurs with a difference of only 1% of water content.

[0037] Since the reason is not know, look at the safety, if you work in the moisture content of 20-21%, processing is easy, you can extend the replacement time of the blade to be processed, so many that work efficiency is good Has been proven by its industrial production. Based on this large number of production results, the present application has been filed as a method that does not cause damage to the finished product due to distortion or cracking even when processing is performed during the period when the moisture content is undried.

Even wood that has been dried using the commonly used hot-air type wood drying method, the ditch of the Kamoi gutter was formed, and if left for a while, the shape of the ditch of the Kamoi grew or narrowed. Deformation occurs in normal conditions.

[0039] Similarly, the wood after drying is complete is less likely to work hard, When you have finished processing, immediately and not Shimawa formed a working portion of the timber, distortion is generated in the processed wood,
It was said that building components could not be installed and furniture could not be installed.

[0040] Even such a general sense, by the present, no longer-class.

Further , even if the carved woodwork is crafted with a water content of 20 to 21%, which is easy to process, no deformation occurs.

[0042]

As explained in the above embodiments, according to the invention of the present application, the common sense of the timber-related traders who assume that the timber processing should be performed after the drying is completed is no longer established. In the entire process from when you start the drying of sawn timber to complete a dry, non-dried state at it can be a timber that does not generate even cracking or distortion performing wood processing, to the finished product
The common wisdom that processing had to be started after disappearing without deformation and becoming hard and difficult to process after the completion of drying has disappeared. Because it became possible to perform wood processing that cannot be judged by general common sense that wood processing should be performed when the moisture content is easy to process,
This has provided immense benefits to all wood processing industries that use lumber to process wood.

Claims (1)

(57) [Claims] 1. The sawn timber is made to have a uniform thickness.
Pile it into a pressure vessel and use saturated steam to
Pressurization of the sawn timber inside by two different variable pressurization pressures
And the addition of heat, after the first heating and pressurizing for a predetermined time at a pressure varying in the more low have pressure width atmospheric pressure, the second pressure that varies at high pressure width than the first is heated to approximately 2 times the pressure of the first time Te,
The saturated steam is released from the pressure vessel to the outside of the pressure vessel, the pressure is reduced to the atmospheric pressure from the above-mentioned pressurized pressure, and the pressure is reduced to a value lower than the atmospheric pressure. This series of steps is performed only once, the wood is taken out of the pressure vessel, and natural drying or artificial drying such as dehumidifying drying is performed to reduce the water content to about 20%, and this level of undried Wood processing is performed in the condition, and after the wood processing is completed, artificial drying such as dehumidification drying method or self-
Natural in the drying, after the dry material having a moisture content of interest, variations of the finished product, characterized in that the specifications <br/> up process in the row Migihitsuji
Wood processing can be performed in the undried state without forming
Wood treatment method .