JP5756909B2 - Processed wood production method and woody plate-shaped building material using the treated wood - Google Patents

Description

  The present invention relates to a treated wood manufacturing method in which wood to be treated is heat-treated in a steam pot, and a wooden plate-shaped building material using the treated wood.

In order to improve the wood texture, design, etc. of wood, conventionally, wood is thermally colored by supplying high-pressure and high-temperature steam to the wood housed in the steam kettle and heat-treating it. .
For example, in Patent Document 1 below, wood is placed in an autoclave and sealed, high pressure steam is supplied into the autoclave, the wood is heated and colored, and further pressed in an autoclave to perform consolidation and other processing. A method has been proposed in which a veneer obtained by slicing the wood after application is laminated and bonded to a plate-like substrate to produce a woody decorative material. According to such a manufacturing method, it is described that it is colored from light brown to black-brown as compared with an untreated one, the surface hardness is remarkably improved, and a high-grade veneer is further filled with wood.

Japanese Patent Application Laid-Open No. 7-329018

By the way, when high-pressure high-temperature steam is supplied into an autoclave (steam kettle) and the wood to be treated is heat-treated as in Patent Document 1, when the water vapor contacts the surface of the wood to be treated, the thermal energy of the water vapor Is taken away by the wood to be treated, and condensation occurs on the surface of the wood to be treated due to a temperature difference between the surface and water vapor.
If high-pressure and high-temperature steam is continuously supplied in such a state, a pool of water is gradually formed on the surface of the wood to be treated due to the condensed moisture, and this prevents the penetration of water vapor into the wood to be treated.
As a result, the interior of the wood to be treated is not sufficiently heat-treated, and homogenization of the wood to be treated is hindered, resulting in problems such as insufficient coloring and insufficient light resistance in the treated wood after the heat treatment.

  This invention is made | formed in view of the said situation, and it aims at providing the processed-wood manufacturing method which can manufacture a homogeneous processed wood, and the woody board-shaped building material using this processed wood.

In order to achieve the above object, a method for producing treated wood according to the present invention is a method for producing treated wood by heat-treating treated wood in a steam kettle, wherein high-pressure high-temperature steam is produced in the steam kettle. A step of repeatedly raising the pressure in the steam kettle by intermittently supplying the wood to be treated is heated with high-pressure and high-temperature steam, and in the heat treatment step, Is reduced by a predetermined value or more than a preset target set pressure value, the high-pressure and high-temperature steam is supplied and the inside of the steam kettle is rapidly increased to a predetermined value or more, while the high-pressure and high-temperature steam is reduced. After the supply, if a predetermined time elapses without a pressure value in the steam pot lowering by a predetermined value or more than a preset target set pressure value, the steam pot is forcibly depressurized. High pressure high temperature steam Supplying a predetermined value or more steam in the kettle, characterized in that to abruptly boost.

In the present invention configured as described above, high-pressure high-temperature steam is intermittently supplied to cause a state in which the inside of the steam kettle is rapidly boosted, so that moisture condensed on the surface of the wood to be treated is removed from the surface of the wood to be treated. While being able to permeate inside, the wood to be treated can be heated by the supply of the new water vapor. As a result of this being repeated, the wood to be treated is sufficiently heat-treated to the inside thereof, so that a homogeneous treated wood can be produced.
According to the present invention as described above, the treated wood after the heat treatment is sufficiently thermally colored up to the inside, and light resistance is imparted. The thermal coloring and light resistance imparted by the heat treatment of the high-pressure and high-temperature steam are achieved by selectively thermally decomposing and changing the quality of hemicellulose among cellulose, hemicellulose and lignin, which are the main components of the wood composition. That is, due to the thermal degradation of this hemicellulose, a highly light-resistant polymerizable colored product is uniformly produced throughout the wood fiber cell tissue, and the wood grain is emphasized due to the density of the cell tissue and is thermally colored. , Light resistance is imparted. At this time, there may be a case where an oxidized colored product with low light resistance in which the phenol-like low molecular weight resin slightly contained in lignin is altered is by-produced and deposited on the surface of the treated wood after the heat treatment. In such a case, surface precipitates may be removed.

In this invention, you may make it perform the said heat processing in the state which made the thickness of the said to-be-processed wood 180 mm or less, and laminated | stacked the crosspiece member in the thickness direction.
With such a configuration, in combination with the thickness of the wood to be treated being 180 mm or less, the water supply path between the wood to be treated and the surroundings of the wood to be treated by the crosspiece member Since a drainage path for accumulated condensed water is formed, the permeability of water vapor to the wood to be treated can be improved more efficiently, and the heat treatment can be performed more efficiently.

In the present invention, the high-pressure / high-temperature steam may be intermittently supplied by intermittently opening a high-pressure / high-temperature steam supply on / off valve.
With such a configuration, the manufacturing apparatus (steam kettle) can be reduced in cost, and the manufacturing method can be executed by simple control.

In order to achieve the above object, the wood plate-shaped building material according to the present invention is a slice veneer produced by slicing the treated wood produced by any of the treated wood production methods according to the present invention, It is characterized by being laminated on the surface of a substrate.
With such a configuration, as described above, the treated wood is sufficiently heat-colored to the inside, so that the sliced single plate produced by slicing does not cause color unevenness due to insufficient coloring. It is a woody building material with good appearance and excellent light resistance.

  According to the method for producing treated wood according to the present invention, a homogeneous treated wood can be produced by adopting the above-described configuration.

(A) is a schematic flowchart for demonstrating one Embodiment of the process wood manufacturing method which concerns on this invention, (b) shows typically an example of the pressure fluctuation at the time of the temperature increase pressurization process of the manufacturing method. A graph and (c) are graphs which show typically an example of pressure fluctuation at the time of maintenance process execution of the manufacturing method. (A) is a schematic side view schematically showing an example of a system configuration of a heat treatment apparatus used in the manufacturing method, and (b) shows a state in which woods to be treated to be heat treated by the heat treatment apparatus are stacked. The schematic perspective view shown typically and (c) are the schematic front views which show typically the state which accommodated the to-be-processed wood in the heat processing apparatus. (A) is the table | surface which shows an example and the comparative example of the example of the process wood manufactured by the manufacturing method with the result of an evaluation test, (b) is the process wood manufactured by the manufacturing method typically The schematic perspective view to show, (c) is a general | schematic expanded longitudinal cross-sectional view which shows typically the wooden board-shaped building material using the processing timber manufactured by the manufacturing method.

Embodiments of the present invention will be described below with reference to the drawings.
In the present embodiment, the wood to be treated as a heat treatment target is a flitch material 1 processed into a prismatic shape as shown in FIG. 2 (b), and this is the heat treatment apparatus shown in FIG. 2 (a). It is accommodated in a high-pressure and high-temperature steam kettle (hereinafter abbreviated as a steam kettle) 20 and subjected to heat treatment.
First, a schematic configuration of an example of a heat treatment apparatus used in the treated wood manufacturing method according to the present embodiment will be described with reference to FIG.

As shown in FIG. 2 (a), the steam pot 20 is configured by closing the opening of a horizontally long cylindrical container body 21 with an opening / closing lid 22, and this opening / closing lid 22 includes a ferrule joint, a clamp joint, and a bolt / nut mechanism. The container main body 21 is hermetically sealed by a fastening means 29 such as, and is detachable or openable with respect to the container main body 21. FIG. 2C shows a state in which the opening / closing lid 22 is removed.
The container main body 21 and the opening / closing lid 22 are metal materials that are less pollutant such as stainless steel and have a pressure resistance from the viewpoint of preventing metal contamination of the flitch material 1 (see FIG. 2C) as the wood to be treated. It is good also as what was manufactured by.

As shown in FIG. 2 (c), a plurality of roller members 21a rotatably supported on both sides of the container body 21 are provided in the container body 21 from the opening side toward the back side. It has been. The roller member 21a is provided with a placement plate 8 on which an object to be processed is placed, and the flitch material 1 can be easily taken in and out.
A steam supply pipe 23 that supplies high-pressure and high-temperature steam from the high-pressure and high-temperature steam supply source 3 into the steam kettle 20 and a pressurized water supply that supplies pressurized water from the pressurized water supply source 4 to the steam kettle 20 are provided below the container body 21. A pipe 24, a drain pipe 27 that discharges liquefied water vapor and the like from the steam kettle 20, and a drain pipe 28 are connected.

Further, a pressurized air pipe 25 that supplies pressurized air from the pressurized air supply source 5 into the steam kettle 20 and an exhaust that discharges steam or gas from the steam kettle 20 are disposed above the container body 21. A tube 26 is connected.
As the high pressure / high temperature steam supply source 3, a high pressure boiler or the like may be employed.
As the pressurized water supply source 4, a high-pressure water tank, a high-pressure pump, or the like may be employed.
An air compressor or the like may be employed as the pressurized air supply source 5.
The above-described pipes 23, 24, 25, 26, 27, and 28 are provided with opening / closing valves 23a, 24a, 25a, 26a, 27a, and 28a in the middle of the respective pipes.
Among these, the steam supply valve 23a provided in the steam supply pipe 23 is an on-off valve (ON / OFF valve) in the present embodiment.
Further, the drain pipe 27 is provided with a filter, a steam trap or the like at an appropriate place in the middle of the pipe line.

Further, the container body 21 is provided with a temperature sensor 31 as temperature detecting means for detecting the temperature in the steam pot 20 and a pressure sensor 32 as pressure detecting means for detecting the pressure in the steam pot 20. . The pressure sensor 32 may be provided not on the container main body 21 but on the downstream side of the water vapor supply valve 23a of the water vapor supply pipe 23 (on the container main body 21 side).
The above open / close valves 23a, 24a, 25a, 26a, 27a, 28a and the sensors 31, 32 are connected to the control panel 30 via signal lines or the like.
The control panel 30 is connected to a CPU (Central Processing Unit) as a control unit for controlling the above-described devices of the steam kettle 20, and is connected to the CPU via a signal line to set various settings. Display operation section for displaying, setting conditions set by operation of the display operation section, various programs such as a control program for executing an example of a treated wood manufacturing method to be described later, various preset operating conditions Etc. are stored.
The specific configuration of the steam kettle 20 is not limited to that shown in the drawings, and any configuration may be used as long as the wood to be treated can be heat-treated with high-pressure and high-temperature steam.

Next, an example of the processed wood manufacturing method according to the present embodiment will be described with reference to FIGS. 1 and 2.
<Wood placement process>
First, as shown in FIG. 2 (b), a plurality of (12 in the example) flitch materials 1, 1... As the wood to be treated are arranged in the horizontal direction and in the height direction (thickness direction). 2) are stacked on the mounting plate 8 with the crosspieces 6 interposed therebetween, and are placed in the steam pot 20 as shown in FIG. 2 (c).

The wood to be treated as the heat treatment target (in this example, the flitch material 1) is not subjected to a drying treatment, and contains high moisture such as raw materials, boiled or cooked wood, etc. From the viewpoint of penetrability into the inside, the raw material may have a moisture content of about 30% (dry base) or more.
In addition, examples of the tree species include beech, oak, cedar, merkaba, beach, oak, teak, hard maple, cherry, walnut, white ash, mahogany, and other various tree species. Diffuse material such as beech wood is a tree species that is more difficult to emphasize the grain than ring material such as oak wood. In this way, it is colored by heat and can emphasize the grain.

The flitch material 1 is processed into a prismatic shape, and in this embodiment, as shown in FIG. 2C, the thickness T in the stacking direction is 180 mm or less.
As described above, the wood to be treated has at least one of vertical (thickness), horizontal (width), and length (in this embodiment, thickness T) having a thickness of 180 mm or less. In the heat treatment process and the cooling process described later, the temperature rise difference (temperature drop difference) between the surface of the wood and the core can be efficiently reduced, and the surface cracking and strength deterioration of the wood can be efficiently reduced. Efficient heat treatment and cooling can be performed.

In addition, when the pressurized water is supplied and submerged in the cooling step described later, appropriate lifting prevention means 7 is disposed so that each flitch material 1 disposed in the steam pot 20 does not float.
In the illustrated example, the lifting prevention means 7 is a weight 7 corresponding to the flitch material 1 disposed in the steam kettle 20, but the lifting prevention means 7 may be made of a metal net that is appropriately weighted. You may make it comprise. Alternatively, the uppermost flitch material 1 (or the crosspiece member 6 disposed above it) and the mounting plate 8 are fixedly held by winding a metal wire rope or the like to lift the flitch material 1. Any device can be used as long as it can prevent the above.

  The crosspiece member 6 interposed between the flitch materials 1 may be made of a metal material such as stainless steel similar to the steam pot 20 or made of a woody material. Such a crosspiece member 6 may not be provided according to the size of the wood (in this example, the flitch material 1) as a heat treatment target. The surface area of contact with water vapor is increased, high-pressure high-temperature water vapor can be permeated into the wood relatively quickly, and efficient heat treatment can be performed.

  Further, the thickness of the crosspiece member 6 is such that a gap is formed between the flitch materials 1 stacked in the thickness direction as a supply path for high-pressure and high-temperature steam and a discharge path for condensed water accumulated around the flitch material 1. As described above, the thickness is preferably about 3.0 mm or more. Further, the crosspiece member 6 is preferably a rod-like or plate-like member that does not form a closed loop contact portion on the contact surface with the flitch material 1. That is, the weir in which condensed water accumulates is not formed on the surface of the flitch material 1 as in the ring shape or mesh shape, and the width direction (or length direction) of the flitch material 1 as shown in the figure. It is preferable to have a shape that is arranged in a through shape in an oblique direction. Moreover, when it is set as such a rod-shaped or plate-shaped crosspiece member, it is preferable that the width dimension is 180 mm or less.

  While the crosspiece member 6 is configured as described above, and the thickness T of the flitch material 1 is 180 mm or less, a flitch of high-pressure and high-temperature steam that is intermittently supplied into the steam pot 20 as will be described later. The heat treatment action on the material 1 is performed more efficiently. In other words, the condensed water tends to accumulate around the flitch material 1 due to the supplied water vapor. However, this cross member 6 allows the condensed water to be discharged from between the flitch materials 1 and to the lower part of the steam pot 20. In addition, in combination with the thickness T of the flitch material 1 being 180 mm or less, the permeability of the high-pressure and high-temperature steam into the flitch material 1 can be improved more efficiently. As a result, it is possible to more efficiently heat the flitch material 1.

In the present embodiment, the bar member 6 is arranged so that the flitch material 1 disposed in the steam cooker 20 does not come into contact with the inner wall (the mounting plate 8 in the illustrated example) of the steam cooker 20. And between the mounting plate 8. Further, when the lifting prevention means 7 is a weight 7 as shown in the figure, a crosspiece member 6 is interposed between the weight 7 and the uppermost flitch material 1 so as not to contact with each other. You may make it make it.
In addition, when arranging the flitch materials 1 in the horizontal direction, a predetermined gap may be provided between the flitch materials 1. The predetermined gap may be about 3.0 mm or more so that a supply path of high-pressure and high-temperature steam and a discharge path of condensed water collected around the flitch material 1 are formed as described above.
The larger the size of the supply path and the discharge path formed between the flitch materials 1, the more effectively the supply of high-pressure and high-temperature steam and the discharge of condensed water are possible. In order to accommodate efficiently, it may be more than the above.

<Heat treatment process: temperature increase pressurization process>
As described above, after the flitch material 1 is disposed in the steam kettle 20, the steam kettle 20 is sealed by the open / close lid 22, and the steam supply valve 23a, the exhaust valve 26a, and the drain valve 27a among the above-described valves are provided. The other valves 24a, 25a, and 28a are closed, high-pressure high-temperature steam is supplied into the steam kettle 20, and the air in the steam kettle 20 is replaced with steam.

Next, the exhaust valve 26a is closed from the above state, and the temperature raising / pressurizing step is executed.
This temperature increase / pressurization step is performed based on a preset target set pressure value at the time of pressurization and an actually measured pressure value in the steam pot 20 (measurement signal (detected pressure value) of the pressure sensor 32). Accordingly, the CPU of the control panel 30 is controlled by opening and closing the water vapor supply valve 23a.
As the target set pressure value at the time of pressure increase, for example, a value corresponding to a temperature rise value of about 1 ° C./min to 5 ° C./min may be used, and the final target set pressure value depends on a predetermined processing temperature. It can be set to a value.

The predetermined treatment temperature (atmosphere temperature in the steam kettle 20) as the heat treatment condition is 105 ° C. or more and 160 ° C. or less (0.2 kgf / cm ² G (about 0.02 MPaG) or more in the pressure range). It may be about 3 kgf / cm ² G (about 0.52 MPaG) or less, preferably about 150 ° C. (3.9 kgf / cm ² G (about 0.37 MPaG)) or less.
If this predetermined treatment temperature is less than the above lower limit temperature, the hemicellulose of the wood composition component is not sufficiently thermally decomposed, and the homogenization of the wood to be treated and the imparting of heat coloring and light resistance to the wood to be treated are sufficient. On the other hand, if the above upper limit temperature is exceeded, depending on the size of the wood to be treated and the treatment time, the thermal decomposition of hemicellulose tends to be excessive and the wood fiber cell tissue tends to deteriorate, and the strength of the wood to be treated decreases. Tend to.
This treatment temperature greatly contributes to the degree of coloration of the wood to be treated (in this example, the flitch material 1). By appropriately setting this treatment temperature within the above range, the degree of coloration of the wood to be treated can be easily controlled. can do.

As shown in FIGS. 1A and 1B, the opening / closing control of the steam supply valve 23a is performed when the actually measured pressure value in the steam pot 20 is smaller than the predetermined value P1 by a predetermined value P1 or more (step). 100), the steam supply valve 23a is opened, high-pressure and high-temperature steam is supplied, the inside of the steam kettle 20 is rapidly boosted by a predetermined value P1 or more, and the steam supply valve 23a is closed (rapid boosting process, see step 101). ).
The predetermined value P1 may be about 0.005 MPa to 0.02 MPa, although it depends on the final target set pressure value and the size of each flitch material 1.
Moreover, it is preferable that the pressure fluctuation in the steam kettle 20 due to the supply of the high-pressure and high-temperature steam is instantaneously made by rapidly supplying the high-pressure and high-temperature steam. For example, it is preferable that the atmospheric pressure in the steam kettle 20 before supply is rapidly increased to the predetermined value P1 or more within 10 seconds, more preferably within 5 seconds. .

  As described above, new high-pressure and high-temperature steam is supplied into the steam kettle 20, and the steam kettle 20 is rapidly boosted so that moisture condensed on the surface of the flitch material 1 has a porous structure due to instantaneous pressure fluctuations. The flitch material 1 is permeated so as to be sucked into the flitch material 1 to form a passage for water vapor, and the flitch material 1 is heated by the supplied high-pressure high-temperature water vapor. Further, the thermal energy of the newly supplied high-pressure and high-temperature steam is deprived by the flitch material 1 and dew condensation occurs on the surface of the flitch material 1 until the next supply of high-pressure and high-temperature steam is performed. The actually measured pressure value gradually decreases as shown in FIG. In particular, at the time of temperature increase and pressure increase, the temperature of the flitch material 1 (particularly, the temperature of the surface layer portion) is in the middle of temperature increase, and therefore decreases relatively rapidly at the initial stage.

If the actually measured pressure value in the steam cooker 20 decreases by a predetermined value P1 or more than the target set pressure value at the time of pressurization (see step 100), the rapid pressure increase process similar to the above, that is, the steam supply valve 23a is opened and the high pressure High-temperature steam is supplied, the inside of the steam pot 20 is rapidly increased to a predetermined value P1 or more, and the steam supply valve 23a is closed (see step 101).
Thus, at the time of executing the temperature raising / pressurizing step, the high-pressure / high-temperature steam is supplied every time the actually measured pressure value in the steam kettle 20 decreases by a predetermined value P1 or more than the target set pressure value at the time of pressurization. The state in which the pressure is intermittently supplied and the inside of the steam pot 20 is rapidly boosted by a predetermined value P1 or more is repeatedly generated.
Thereby, the flitch material 1 is heated by penetrating the moisture condensed on the surface of the flitch material 1 so as to be sucked toward the inside of the flitch material 1, and while repeating the state of causing condensation on the surface, The temperature is gradually raised. Further, along with this, the actually measured pressure value in the steam pot 20 is gradually increased while repeating the rapid increase and decrease by the supply of new high-pressure and high-temperature steam (see FIG. 1B).

<Heat treatment process: holding process>
As described above, when the actually measured pressure value in the steam cooker 20 gradually increases and approaches the final target set pressure value, and the actually measured temperature in the steam cooker 20 reaches the predetermined processing temperature, the CPU of the control panel 30 The timer built in is started, and the holding process is executed until a predetermined processing time elapses (see step 102). In addition, instead of the mode of shifting to the holding process and ending the holding process by such automatic control, the measured pressure value and the measured temperature in the steam pot 20 are confirmed by the display operation unit or the like, and the operator side It is good also as an aspect which inputs processing time. Alternatively, the entire processing time including the processing time of the temperature raising / pressurizing step after the start-up of the apparatus is set in advance as a predetermined processing time without determining the transition to the holding step in this way. It may be.

  The predetermined treatment time includes a temperature difference between the surface temperature of the wood to be treated (in this example, the flitch material 1) (substantially the same as the ambient temperature in the kettle) and the temperature of the wood core to be treated. You may make it set so that it may become within 10 degreeC. Preferably, a holding time of about 10 minutes or more may be provided after the temperature difference is within 10 ° C. More preferably, the temperature of the wood core to be treated is about the same as the above-mentioned treatment temperature (105 ° C. or more, 160 ° C. or less, preferably 150 ° C. or less), or about 10 minutes or more after becoming the same level. You may make it provide holding time.

By setting such a treatment time, color unevenness inside the treated wood can be reduced more efficiently, homogenization of the treated wood can be further improved, and yield and productivity can be improved. it can.
The processing time after reaching the predetermined processing temperature depends on the wood species, size, temperature in the pot, etc., but in the case of beech, oak, etc. with the flitch material 1 having the above thickness. May be about 1 to 4 hours.
In addition, it may replace with the aspect which sets the said processing temperature, and you may make it control the coloring degree of wood by setting this processing time suitably.

  At the time of this holding process, since the surface layer portion on the outer periphery of the flitch material 1 has been heated to some extent by the execution of the temperature raising / pressurizing process, as shown in FIG. The value gradually decreases from the time of the temperature raising / pressurizing step until the next supply of high-pressure high-temperature steam is performed. As shown in FIGS. 1A and 1C, when the actually measured pressure value in the steam pot 20 is lower than the final target set pressure value by a predetermined value P1 or more (see step 100), the same as above. The rapid pressure increasing process is executed (see step 101). That is, the steam supply valve 23a is opened, high-pressure and high-temperature steam is supplied, the inside of the steam pot 20 is rapidly increased to a predetermined value P1 or more, and the steam supply valve 23a is closed.

Further, in the present embodiment, as shown in FIGS. 1A and 1C, when this holding process is executed, the actually measured pressure value in the steam kettle 20 is a predetermined value P1 or more than the final target set pressure value, If the predetermined time T1 or more has elapsed since the previous supply of the high-pressure and high-temperature steam without decreasing (see Steps 100 and 103), the exhaust valve 26a is opened and the inside of the steam pot 20 is forcibly set to the predetermined value P1 or more. The forced pressure-lowering process of lowering the pressure and closing the exhaust valve 26a is executed (step 104).
This predetermined time T1 may be about 30 seconds to 10 minutes, preferably about 5 minutes or less, although it depends on the amount and size of the wood to be treated accommodated in the steam kettle 20.
After forcibly lowering the pressure in the steam pot 20 in this way, the same rapid pressure increase processing as described above is executed (see step 101).

In other words, in the present embodiment, as shown in FIG. 1A, if the actually measured pressure value in the steam pot 20 decreases by a predetermined value P1 or more than a preset target set pressure value (step 100), The rapid boosting process is executed (step 101), and this is repeated until a predetermined processing time elapses (steps 102, 100, 101).
Further, the elapsed time after the supply of the high-pressure high-temperature steam is counted by a timer or the like built in the CPU of the control panel 30, and the actually measured pressure value in the steam kettle 20 is a predetermined value rather than the final target set pressure value. If the predetermined time T1 has elapsed since the previous supply of the high-pressure and high-temperature steam (step 103) without decreasing (step 100), the forced pressure-lowering process is executed (step 104). The boosting process is executed (step 101).

In this way, by repeatedly generating a state in which the pressure is rapidly increased even when the holding step is performed, the flitch material 1 accommodated in the steam pot 20 is heated up to the inside efficiently and reliably. And sufficient heat treatment is performed. As a result, the flitch material 1 is homogenized and sufficiently thermally colored up to the inside, and light resistance is imparted.
In particular, in the present embodiment, when the actually measured pressure value in the steam cooker 20 does not decrease by a predetermined value P1 or more from the final target set pressure value, the predetermined time T1 is maintained. When the time elapses, the forced pressure reduction process is executed, and further, the rapid pressure increase process is executed, so that the heat treatment to each flitch material 1 can be performed more efficiently and reliably. That is, when the holding process is executed, the flitch material 1 (particularly the surface layer portion) is heated to some extent, so that the actually measured pressure value in the steam pot 20 decreases relatively slowly, and if this state continues for a long time, There is a tendency that the temperature inside the flitch material is not rapidly increased. On the other hand, according to the present embodiment, every time at least the predetermined time T1 elapses, a new high-pressure high-temperature steam is supplied into the steam kettle 20 and the steam kettle 20 is rapidly boosted. As a result, more efficient and reliable heat treatment can be performed.
Through the above heat treatment process, a processed flitch material 1A (see FIG. 3B) that has been heat-treated with high-pressure and high-temperature steam is manufactured.

<Wood cooling, pot pressure reduction process>
After performing the heat treatment process as described above, the treated wood (treated flitch material 1A (see FIG. 3B)) may be cooled and the pressure in the steam kettle 20 may be reduced as follows.
It is preferable that the pressure reduction process of the steam pot 20 is performed after the core of the treated wood is cooled to a predetermined temperature or less from the viewpoint of preventing dry cracking of the treated wood.
This predetermined temperature may be about 100 ° C. or lower, preferably about 90 ° C. or lower.
In order to improve the efficiency of the cooling process and prevent dry cracking of the treated wood more efficiently, the treated wood is submerged and cooled in a state in which the inside of the steam kettle 20 is maintained at a predetermined high pressure state before performing the pressure reduction treatment. You may make it do.

  For example, after performing the heat treatment step, the water vapor supply valve 23a is closed and the pressurized water supply valve 24a and the pressurized air supply valve 25a are opened, while maintaining a high pressure state so that the pressure in the steam kettle 20 does not decrease. Then, the treated wood in the steam pot 20 is submerged and cooled. Preferably, the cooling may be performed while maintaining a high pressure state so that the pressure in the steam pot 20 is equal to or higher than the pressure during the heat treatment. Or, depending on the pressure at the time of heat treatment, a high pressure state that is slightly lower than the pressure at the time of heat treatment to such an extent that sudden pressure fluctuations occur and dry cracks do not occur on the surface of the wood after heat treatment. You may make it cool by submerging, keeping.

The predetermined high pressure state in the steam pot 20 during the cooling process is that the pressurized water supply valve 24a and the pressurized air supply valve 25a are opened and the measured values of the pressure sensor 32 and the like are obtained while supplying pressurized water and pressurized air. Based on this, the exhaust valve 26a may be adjusted by opening / closing control or opening control.
Further, the pressurized water is supplied so that the pressurized water supplied in the steam kettle 20 is not scattered in the steam kettle 20 in order to suppress pressure fluctuations in the steam kettle 20 and deterioration (metal fatigue) of the steam kettle 20 itself. It is preferable that the steam kettle 20 is gradually and gently supplied from below.
Further, in order to improve the cooling efficiency, when performing this cooling step, the pressurized water supply valve 24a and the drain valve 28a are controlled to open / close or the degree of opening is controlled so that the cooling water in the steam pot 20 is replaced. You may make it perform.

In the cooling step, instead of supplying the cooling water (pressurized water) directly into the steam pot 20, a container capable of storing the flitch material 1 and storing water is installed in the steam pot 20, You may make it supply pressurized water in this container. In this case, a water vapor supply pipe 23, a pressurized water supply pipe 24, a drain pipe 27, and a drain pipe 28 may be connected to the lower part of the container. In this case, the drain pipe 27 and the drain pipe 28 may be further connected to the lower portion of the steam pot 20. This container may be designed to be freely put into and out of the steam kettle 20.
In this way, by installing the container to which the pressurized water for cooling the flitch material 1 is supplied in the steam kettle 20, deterioration of the steam kettle 20 can be efficiently reduced. Further, in this case, the container may be made of stainless steel with little contamination as described above, and the steam kettle may be made of iron with pressure resistance. According to this, deterioration of the steam pot 20 can be reduced more efficiently.
Moreover, you may make it use the nitrogen gas from a viewpoint of the oxidation suppression of a process wood for the pressurized air introduce | transduced in the steam kettle 20 at the time of the said cooling process execution.

  Further, instead of the above-described embodiment in which cooling water is supplied and the treated wood is forcibly cooled, the steam supply valve 23a is closed after the heat treatment step, and the core of the treated wood is below the predetermined temperature. You may make it cool naturally until it becomes. Alternatively, the steam supply port 23a is closed, and the pressurized air supply valve 25a and the exhaust valve 26a are controlled to open / close or open in a state where the inside of the steam vessel 20 is maintained at a predetermined high pressure state. It is good also as an aspect which replaces the inside gas and cools.

After performing the cooling step, the pressurized water supply valve 24a and the pressurized air supply valve 25a are closed, the exhaust valve 26a and the drain valve 28a are opened, and the pressure in the steam kettle 20 is returned to the atmospheric pressure. The cooling water inside is discharged out of the steam pot 20 (in-pot pressure reducing step).
When returning the pressure in the steam pot 20 to the atmospheric pressure, the pressure may be gradually returned to the atmospheric pressure so that a sudden pressure fluctuation does not occur.
The pressure reduction in the steam pot 20 may be performed by opening the exhaust valve 26a before discharging the cooling water in the steam pot 20 to the outside of the steam pot 20, or the exhaust valve 26a and the drain valve. 28a may be opened to discharge the cooling water. Further, after the cooling water is discharged (substantially, the pressure in the steam kettle 20 is lowered to some extent by discharging the cooling water). Alternatively, the exhaust valve 26a may be opened.

Next, an example of the treated wood manufactured by the manufacturing method according to the present invention and a comparative example will be described with reference to the table of FIG.
In each example, nine flitch materials obtained by processing a raw beech material having a moisture content of about 45 to 65% (dry base) into a prismatic shape of a predetermined size are treated wood, and are arranged in three rows in the horizontal direction. Lamination was carried out so as to form three rows with cross members interposed in the direction.

In each example, the crosspiece member was a plate-like stainless steel crosspiece having a thickness of 4.0 mm, a width of 20.0 mm, and a length of 320.0 mm, and was arranged in a through shape as described above.
In addition, the size of each flitch material is 80 mm in thickness, 107 mm in width, and 450 mm in length in Example 1 and Comparative Example 1, and 180 mm in thickness, 107 mm in width, and length in Example 2. It was 450 mm.

The heat treatment conditions in each example were such that the treatment temperature was 135 ° C., the target pressure setting value during pressure increase was a value corresponding to a temperature rise value of 3 ° C./min, and the holding process execution time was 60 minutes. .
Further, in Examples 1 and 2, the above-described temperature rising / pressurizing step and holding step were performed with the predetermined value P1 being 0.01 MPa and the predetermined time T1 being 5 minutes.
On the other hand, in Comparative Example 1, the steam supply valve is a proportional control valve whose opening degree can be adjusted without causing a state of sudden pressure increase during the temperature raising and pressure increasing process and the holding process. Based on the actually measured pressure value, the amount of high-pressure and high-temperature steam supplied into the steam kettle is controlled finely by controlling each target set pressure value so as to prevent sudden pressure fluctuations.

  The treated wood according to each example manufactured by heat treatment as described above is sliced with a laterally sliced slicer to produce a plurality of sliced single plates each having a thickness of 0.25 mm, and after drying, the following An evaluation test was conducted.

<Evaluation Test 1 External Visual Observation>
The surface of each slice veneer produced from the treated wood according to each of Examples 1 and 2 and Comparative Example 1 was visually observed.
The results are as shown in the table of FIG. 3 (a). In Examples 1 and 2, color unevenness or the like was not observed on the plurality of sliced single plates made from each treated wood, and the results were good. It was.
On the other hand, in Comparative Example 1, the slice veneer produced from the surface layer portion of the treated wood did not show so much color unevenness, but the slice produced from the inner layer portion (near the core of the treated wood). A difference in color tone was observed between the center of the veneer and the outer periphery, and the lack of coloration in the center was conspicuous.

<Evaluation Test 2 Color Difference Measurement>
Out of the slice veneers produced from the treated wood according to each of the examples 1 and 2 and the comparative example 1, the outer periphery and the center of each slice veneer in the inner layer (near the core of each treated wood) Part is measured with a spectrocolorimeter (Konica Minolta CM-2500d), and the color difference ΔE (L ^* a ^* b ^* color system) between the outer periphery and the central part is determined to be 3.0 or less as an acceptance criterion. did.
The results are as shown in the table of FIG. 3A. In Example 1, the color difference ΔE = 1.25, and in Example 2, the color difference ΔE = 2.31.
On the other hand, in Comparative Example 1, the color difference ΔE = 4.65, and a difference in color tone was recognized between the outer periphery and the central portion.

  As described above, according to the treated wood manufacturing method according to the present invention, it was shown that the heat treatment with high-pressure and high-temperature steam was sufficiently applied to the inside of the wood to be treated, and homogeneous treated wood could be produced.

Next, an example of a method for manufacturing a wooden plate-shaped building material using the processed flitch material 1A manufactured as described above will be described with reference to FIGS. 3 (b) and 3 (c).
After performing the above-mentioned pressure reduction process in the pot, the processed flitch material 1A is taken out from the steam pot 20 and, if necessary, precise finishing is performed.
By such precise processing of the entire surface of the treated flitch material 1A, in the heat treatment step, the phenol-like low-molecular resin contained in the lignin, which is a composition component of wood, is altered and by-produced to produce the treated flitch material 1A. The oxidized coloring matter having low light resistance deposited on the surface is removed, and the entire surface of the treated flitch material 1A becomes smooth.

After each processing flitch material 1A is precisely processed as described above, as shown in FIG. 3 (b), the bonded surfaces are bonded so that the thickness surface of the processing flitch material 1A faces the adjacent processing flitch material 1A. A flitch assembly 2 is produced.
In the illustrated example, four processed flitch materials 1A are joined in the longitudinal direction, and are bonded together so that the lateral direction is in three rows. The processing flitch material 1A cut to an appropriate length is distributed and assembled and bonded so as to be shifted in a staggered manner.
As an adhesive used for the above-mentioned laminated adhesion, an adhesive capable of adhering the wet treated flitch material 1A may be used. For example, a moisture-curing urethane adhesive or the like may be adopted.

Next, the flitch assembly 2 produced as described above is introduced into a laterally slicer machine in a wet state, sliced to a predetermined thickness, and as shown in FIG. A plate 11 is produced.
Here, the wet state refers to a state in which the moisture content of the flitch assembly 2 as a slice processing target after the heat treatment step is not less than a predetermined level, and the moisture content of the flitch assembly 2 is 30%. It is preferable from the viewpoint of slicing workability to be about the above.
Since the wood subjected to the heat treatment with high-pressure and high-temperature steam as described above (in this example, the flitch assembly 2) is homogenized, the wood is sliced in a wet state to produce a slice veneer 11 By doing so, slicing workability improves and it is also possible to produce a relatively thick sliced single plate. For example, the thickness of the slice veneer 11 may be about 0.10 mm to 2.50 mm.

  Further, as in the present embodiment, the heat-treated wood is used as the treated flitch material 1A, and the sliced single plate 11 is produced by slicing the flitch assembly 2 in which the treated flitch materials 1A are assembled and bonded. Thus, it is possible to easily produce a wooden plate-shaped building material having a high design property. That is, the color tone differs by appropriately setting the heat treatment conditions (the treatment temperature, the treatment time, etc.) of each flitch material 1 and adjusting the coloring degree of each flitch material 1 during the heat treatment step described above. A treated flitch material 1A can be produced. The processed flitch materials 1A having different color tones are combined, bonded and sliced according to the taste, etc., and sliced single plates 11 of various pattern patterns (randomly stuck, parquet, checkered, etc.) can be easily obtained. Can be made.

  In the present embodiment, the treated wood is used as the treated flitch material 1A, and the sliced plate 11 is produced by slicing the flitch assembly 2 in which the treated flitch material 1A is assembled and bonded as described above. However, it is not limited to such an aspect. For example, the heat treatment target is a thick plate having a shape that matches the size of the desired wooden plate-shaped building material, and the above steps are executed on the plate as necessary, and then the plate is sliced. A slice veneer may be produced. In other words, one of the flitch materials is shaped according to the desired size of the wooden plate-shaped building material, and after performing each of the above steps as necessary, the slices can be sliced from the flitch material without assembling. You may make it produce a board.

As shown in FIG. 3C, the slice veneer 11 produced as described above is attached to a wooden base material 12 to produce a wooden board-shaped building material 10 having a laminated structure.
As the adhesive used for the lamination adhesion, various water-based adhesives, emulsion adhesives, and the like may be used. For example, rubber latex emulsion adhesives may be used.
Moreover, after laminating the wooden substrate 12 and the sliced veneer 11 via an adhesive, it may be appropriately introduced into a hot press machine (hot press machine) and heat-pressed to be dried and cured.
The wood substrate 12 and the slice veneer 11 are laminated and bonded with a paper material or the like in order to promote the release of water vapor from the adhesive or the slice veneer during hot pressing. Also good.
In addition, depending on the type of adhesive, instead of the heat-clamping mode, a cold press or natural drying may be used.

As the above-mentioned wood base material 12, wood laminate boards such as plywood and LVL (single board laminate), wood boards such as particle boards, or wood fiber boards such as insulation boards and MDF (medium density fiber boards) The thing which processed the woody material into the plate shape is mentioned. Alternatively, a wood powder / plastic composite material (WPC) containing a wood powder, an inorganic filler, a compatibilizing agent, a colorant and the like in a predetermined content ratio may be processed into a plate shape in a synthetic resin material. These may be appropriately combined and laminated to form the wooden substrate 12. For example, the wood substrate 12 may be configured by laminating MDF, WPC, or the like having a relatively high surface hardness on the surface of a plywood or particle board.
As described above, the woody plate-shaped building material 10 manufactured as described above has a good appearance and is light-resistant because the slice single plate 11 on the surface layer side is thermally colored by the heat treatment. It becomes an excellent woody plate-shaped building material.

In addition, a groove part or a chamfered part is appropriately formed on the surface of the wooden plate-shaped building material 10 manufactured as described above, or another wooden plate constructed adjacent to the four peripheral ends of the wooden plate-shaped building material 10. A real part or the like as a joint with the building material may be formed.
Moreover, you may make it give the thin coloring coating of the grade which does not inhibit the clear coating or the color tone of the said wooden plate-shaped building material to the surface of the wooden plate-shaped building material 10. In particular, in the present embodiment, the slice veneer 11 is thermally colored by the above heat treatment and light resistance is given, so that only clear coating may be applied as finish coating. According to such finish coating only by clear coating, the wooden texture of the surface of the wooden plate-like building material 10 after coating is not hindered, and the design can be improved.
Moreover, as a usage mode of a wooden plate-shaped building material, it is good also as interior materials, such as a flooring, a wall material, and a ceiling material. Or you may make it use it as another interior panel material, door material, various artificial members, furniture materials, etc.

  Note that, in the treated wood manufacturing method according to the above-described embodiment, a state in which high-pressure high-temperature steam is intermittently supplied and the inside of the steam kettle is rapidly boosted when the temperature raising and pressurizing step is performed and when the holding step is performed. However, the high pressure and high temperature steam is intermittently supplied only during execution of either one of the temperature raising / pressurizing step and the holding step to rapidly raise the pressure in the steam kettle. It is good also as an aspect which produces a state repeatedly. In this case, when executing the other, adjust the supply amount of high-pressure and high-temperature steam so that there is no sudden pressure fluctuation in the steam kettle, so that the measured pressure value in the steam kettle is always close to the target set pressure value. It is good also as a mode which performs various control.

In the present embodiment, the forced pressure reduction process is executed when a predetermined time or more has elapsed since the previous supply of the high-pressure and high-temperature steam, and further, the sudden pressure increase process is executed. Instead of executing the forced pressure reduction process, the rapid pressure increase process may be repeatedly executed based on the actually measured pressure value in the steam pot and the preset target set pressure value.
Furthermore, in the present embodiment, the steam supply valve is controlled to open and close based on the target set pressure value and the actually measured pressure value in the steam kettle, thereby supplying high-pressure and high-temperature steam intermittently, Although an example of repeatedly generating a state of sudden pressure increase is illustrated, high-pressure high-temperature steam is intermittently supplied by opening and closing the steam supply valve based on the target set temperature and the actually measured temperature in the steam kettle. Further, it is possible to repeat the state in which the pressure in the steam pot is rapidly increased.

Furthermore, in the above-described example, the treated wood manufactured by the treated wood manufacturing method according to the present embodiment is sliced to produce a sliced veneer, and the sliced veneer is laminated and bonded to the surface of the wooden substrate. Although the example which manufactured the wooden plate-shaped building material is shown, it is not restricted to such an aspect. For example, the processed wood may be made into a single plate by other processing methods to produce a single plate, and is not limited to a single plate, but is processed into an appropriate shape to produce an appropriately shaped wood product. It may be.
In the above example, the treated wood is colored by high-pressure and high-temperature steam to produce the treated wood. However, the treated wood manufacturing method according to the present invention improves the dimensional stability of the treated wood. It can be applied to various steam treatments such as high-pressure and high-temperature steam treatment for enhancing.

1 Flitch material (treated wood)
1A treated flitch material (treated wood)
6 Crosspieces 10 Woody plate-shaped building material 11 Slice veneer 12 Woody base material (base material)
20 Steam Pot 23a Steam Supply Valve (High Pressure High Temperature Steam Supply Open / Close Valve)
T Flitch material thickness

Claims (4)

A method for producing treated wood by heat-treating treated wood in a steam pot,
The steam pot is repeatedly supplied with high-pressure and high-temperature steam to cause a rapid pressure increase in the steam pot, and the wood to be treated is heated with high-pressure and high-temperature steam.
In the heat treatment step, when the pressure value in the steam kettle is lower than a preset target set pressure value by a predetermined value or more, the high-pressure high-temperature steam is supplied and the steam kettle is given a predetermined value or more. On the other hand, if the pressure value in the steam kettle is reduced by a predetermined value or more from a preset target set pressure value after the high pressure and high temperature steam is supplied, and the steam is passed, A method for producing treated wood , comprising forcibly lowering the pressure in the kettle and then supplying the high-pressure and high-temperature steam to rapidly raise the pressure in the steam kettle to a predetermined value or more . In claim 1 ,
A method for producing treated wood, wherein the heat treatment step is performed in a state where a plurality of treated woods having a thickness of 180 mm or less are stacked with a crosspiece interposed in a thickness direction. In claim 1 or 2 ,
A method for producing treated wood, characterized in that the high-pressure and high-temperature steam is intermittently supplied by intermittently opening a high-pressure and high-temperature steam supply on / off valve. A woody plate-shaped building material obtained by laminating a sliced veneer produced by slicing treated wood produced by the treated wood production method according to any one of claims 1 to 3 on a surface of a base material.

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