JP5965670B2 - Process for producing heat-treated wood - Google Patents
Process for producing heat-treated wood Download PDFInfo
- Publication number
- JP5965670B2 JP5965670B2 JP2012044979A JP2012044979A JP5965670B2 JP 5965670 B2 JP5965670 B2 JP 5965670B2 JP 2012044979 A JP2012044979 A JP 2012044979A JP 2012044979 A JP2012044979 A JP 2012044979A JP 5965670 B2 JP5965670 B2 JP 5965670B2
- Authority
- JP
- Japan
- Prior art keywords
- wood
- pressure
- heat
- specimen
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K5/00—Treating of wood not provided for in groups B27K1/00, B27K3/00
- B27K5/0085—Thermal treatments, i.e. involving chemical modification of wood at temperatures well over 100°C
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K5/00—Treating of wood not provided for in groups B27K1/00, B27K3/00
- B27K5/007—Treating of wood not provided for in groups B27K1/00, B27K3/00 using pressure
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Forests & Forestry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
Description
本発明は、高い寸法安定性と耐朽性を有する熱処理木材の製造方法に関するものである。さらに詳しくは、超臨界二酸化炭素中で木材を加熱することを特徴とする熱処理木材の製造方法に関するものである。 The present invention relates to a method for producing heat-treated wood having high dimensional stability and decay resistance. More specifically, the present invention relates to a method for producing heat-treated wood characterized by heating wood in supercritical carbon dioxide.
木材を利用する際には、水や湿気による寸法安定性や、木材腐朽菌による腐朽、シロアリによる食害を防ぐために、通常何等かの保存・改質処理が施される。その一方で、地球環境や利用者の健康に対するユーザーの関心も年々高まっており、薬剤や有機溶媒を使用しない木材保存・改質処理を望む声は大きくなっている。 When using wood, in order to prevent dimensional stability caused by water or moisture, decay caused by wood-rotting fungi, or damage caused by termites, some kind of storage / modification treatment is usually applied. On the other hand, user interest in the global environment and user health is increasing year by year, and there is a growing demand for wood preservation / modification without using chemicals or organic solvents.
近年、フィンランドを始めとするヨーロッパ諸国において、寸法安定性や耐朽性に優れた材料として熱処理木材(thermally modified wood, heat treated wood)が開発された。 In recent years, thermally modified wood (thermally modified wood, heat treated wood) has been developed as a material having excellent dimensional stability and decay resistance in European countries including Finland.
熱処理木材とは、窒素雰囲気下(乾式)や水蒸気中(湿式)で、150〜240℃の高温処理を数十時間行ったノンケミカル処理木材のことである。その性能発現機構は十分には明らかになっていないが、木材の主要成分であるヘミセルロースの分解とセルロース結晶化度の増加、リグニンの解重合と再結合といった熱処理時の変性等によって木材の平衡含水率が低下し、寸法安定性や耐朽性が向上するといわれている。 The heat-treated wood is non-chemically treated wood that has been subjected to high-temperature treatment at 150 to 240 ° C. for several tens of hours in a nitrogen atmosphere (dry) or in water vapor (wet). Although the mechanism of its performance has not been fully clarified, the equilibrium water content of wood has been improved due to degradation during heat treatment such as decomposition of hemicellulose, the main component of wood, increase in crystallinity of cellulose, depolymerization and recombination of lignin. It is said that the rate will decrease and the dimensional stability and decay resistance will improve.
乾式の熱処理方法としては特許文献1が、湿式の熱処理方法としては特許文献2、特許文献3などが知られている。
しかしながら、木材を加熱して処理する従来の方法は、高湿・長時間処理するため木材の強度が低下したり、また多量の投入エネルギーを要するなど、改善すべき問題点を多く抱えている。 However, the conventional method of heating and treating wood has many problems to be improved, such as reduction in strength of wood due to high humidity and long time treatment, and a large amount of input energy.
本発明が完成しようとする課題は、強度低下と、投入エネルギーが少なく、高い寸法安定性と耐朽性を持った熱処理木材の製造方法を提供することである。 The problem to be completed by the present invention is to provide a method for producing heat-treated wood with reduced strength, less input energy, and high dimensional stability and decay resistance.
本発明者らが鋭意研究を重ねたところ、拡散浸透性に優れ、高い密度を持つ超臨界二酸化炭素中で木材を熱処理することで、上記課題が解決できることを見出し、本発明を完成するに至った。 As a result of extensive research by the present inventors, it was found that the above problems can be solved by heat treating wood in supercritical carbon dioxide having excellent diffusion permeability and high density, and the present invention has been completed. It was.
本発明は、以下のとおりである。
(1) 超臨界二酸化炭素中で木材を加圧加熱することを特徴とする熱処理木材の製造方法。
(2) 前記加圧圧力が7.4〜30MPaであることを特徴とする(1)に記載の熱処理木材の製造方法。
(3) 前記加熱温度が150〜250℃であることを特徴とする(1)または(2)記載の熱処理木材の製造方法。
(4) 木材を収容する耐圧容器と、耐圧容器に備えられた大気圧解放用バルブと、二酸化炭素を充填した充填容器と、該充填容器から耐圧容器に流体を加圧注入する加圧ポンプと、耐圧容器内を加熱する加熱器を備えたことを特徴とする熱処理木材の製造装置。
The present invention is as follows.
(1) A method for producing heat-treated wood, characterized in that wood is heated under pressure in supercritical carbon dioxide.
(2) The method for producing heat-treated wood according to (1), wherein the pressure is 7.4 to 30 MPa.
(3) The method for producing heat-treated wood according to (1) or (2), wherein the heating temperature is 150 to 250 ° C.
(4) a pressure-resistant container that contains wood, an atmospheric pressure release valve provided in the pressure-resistant container, a filling container filled with carbon dioxide, and a pressure pump that pressurizes and injects fluid from the filling container to the pressure-resistant container; An apparatus for producing heat-treated wood, comprising a heater for heating the inside of the pressure vessel.
本発明の熱処理木材の製造方法は、強度低下と、投入エネルギーが少なく、高い寸法安定性を持った熱処理木材を製造することができる。また、従来法による熱処理では木材の耐朽性が向上することが報告されており、本発明によって製造された熱処理木材にも高い耐朽性が付与されると期待される。 The method for producing a heat-treated wood of the present invention can produce a heat-treated wood having high dimensional stability, reduced strength, little input energy. In addition, it has been reported that the heat resistance by the conventional method improves the decay resistance of the wood, and it is expected that the heat-treated wood produced by the present invention will also have high decay resistance.
本発明において加熱媒体として用いられる超臨界二酸化炭素とは、臨界点(31℃、7.4MPa)以上の二酸化炭素のことであり、液体のように高密度でありながら、気体のように拡散浸透性に優れた、気体でも液体でもない、特別な性質を持った流体である。 The supercritical carbon dioxide used as a heating medium in the present invention is carbon dioxide having a critical point (31 ° C., 7.4 MPa) or more, and is diffusive and penetrating like a gas while having a high density like a liquid. It is a fluid with special properties that is excellent in properties and is neither gas nor liquid.
熱処理木材を製造するには、まず木材を耐圧容器に入れて密封する。本発明に用いられる耐圧容器は、加熱処理しようとする木材を収容でき、超臨界二酸化炭素を保持できる容器であれば特に限定されないが、円筒形の方が超臨界の高圧状態にも耐えやすくなるためより望ましい。また、材質は耐食性に優れたステンレス鋼、例えばSUS316などが望ましい。 In order to manufacture heat-treated wood, first, the wood is placed in a pressure vessel and sealed. The pressure vessel used in the present invention is not particularly limited as long as it can accommodate wood to be heat-treated and can hold supercritical carbon dioxide, but a cylindrical shape can easily withstand a supercritical high pressure state. Because it is more desirable. The material is preferably stainless steel having excellent corrosion resistance, such as SUS316.
このとき、処理対象となる木材の樹種や形状などは特に限定されない。木材の含水率(木材実質に対する水分の質量百分率)も特に限定されないが、30%以下であることが望ましい。また、少量の水を添加させることでヘミセルロースの分解が促進されるので、耐圧容器の容量1リットルに対して10g以下の水をあらかじめ注入しておく場合もある。 At this time, the tree species and shape of the wood to be processed are not particularly limited. The moisture content of wood (mass percentage of moisture relative to the wood substance) is not particularly limited, but is preferably 30% or less. Moreover, since decomposition | disassembly of hemicellulose is accelerated | stimulated by adding a small amount of water, the water of 10 g or less may be poured beforehand with respect to 1 liter of capacity | capacitance of a pressure vessel.
次に超臨界二酸化炭素を耐圧容器内に充填し、所定の温度・圧力まで昇温昇圧させる。あるいは二酸化炭素の加圧充填が終わってから耐圧容器を加熱して二酸化炭素を超臨界状態としてもよい。 Next, supercritical carbon dioxide is filled in the pressure vessel, and the temperature is raised to a predetermined temperature and pressure. Alternatively, the carbon dioxide may be brought into a supercritical state by heating the pressure vessel after the pressure filling of carbon dioxide is completed.
本発明における超臨界二酸化炭素の温度・圧力条件は、温度が150〜250℃、好ましくは、180〜240℃、圧力が7.4〜30MPa、好ましくは、10〜20MPaの範囲である。昇温昇圧後はしばらくその状態を保持し、木材の内部まで十分に加熱させる。加熱時間は30分〜24時間、好ましくは1〜8時間の範囲である。そして熱処理終了後、耐圧容器内の圧力を開放し、熱処理した木材を取り出す。 The temperature and pressure conditions of supercritical carbon dioxide in the present invention are a temperature of 150 to 250 ° C., preferably 180 to 240 ° C., and a pressure of 7.4 to 30 MPa, preferably 10 to 20 MPa. After raising the temperature and pressure, the state is maintained for a while, and the wood is fully heated. The heating time is in the range of 30 minutes to 24 hours, preferably 1 to 8 hours. After the heat treatment is completed, the pressure in the pressure vessel is released and the heat-treated wood is taken out.
例えば、寸法が50mm(L)×20mm(R)×20mm(T)のスギ心材(含水率:約10.7%)を220℃/10MPaの超臨界二酸化炭素中で1時間熱処理したところ、木材の寸法安定性を示す抗膨潤能(以下ASEと略す)は63.9%となった。さらに、含水率が約16.7%のスギ心材を220℃/10MPaの超臨界二酸化炭素中で1時間熱処理した場合のASEは69.5%であった。これは水分に対する寸法変化が未処理材の1/3未満に抑制されたことを意味している。本発明の反応機構については現在検討中であるが、超臨界二酸化炭素の持つ高い密度と拡散浸透力によって熱が素早く伝わり、木材内部まで短時間で昇温されたことによるものと推測される。また、含水率の高い木材を熱処理した方がより高いASEを示したのは、少量の水分の存在がヘミセルロース等の木材成分の分解を促進したことや、熱伝導率の高い水分の存在によって木材内部まで昇温される時間がより短くなったことなどが考えられる。本発明によって処理時間の短縮や処理温度の低下が可能になれば、エネルギー投入量を大幅に削減できると予想される。また、高温・長時間の熱処理では木材の強度低下が懸念されるが、処理時間が短縮されることで、強度低下も最低限に抑えられることが期待される。 For example, when a cedar heartwood (water content: about 10.7%) having dimensions of 50 mm (L) × 20 mm (R) × 20 mm (T) was heat-treated in supercritical carbon dioxide at 220 ° C./10 MPa for 1 hour, The anti-swelling ability (hereinafter abbreviated as ASE) showing the dimensional stability was 63.9%. Furthermore, the ASE when a cedar core material having a water content of about 16.7% was heat-treated in supercritical carbon dioxide at 220 ° C./10 MPa for 1 hour was 69.5%. This means that the dimensional change with respect to moisture was suppressed to less than 1/3 that of the untreated material. Although the reaction mechanism of the present invention is currently under investigation, it is presumed that heat is transferred quickly due to the high density and diffusion penetration power of supercritical carbon dioxide, and the temperature inside the wood is raised in a short time. In addition, heat treatment of wood with a high moisture content showed a higher ASE because the presence of a small amount of moisture promoted the decomposition of wood components such as hemicellulose and the presence of moisture with high thermal conductivity. It is conceivable that the time for raising the temperature to the inside has become shorter. If the present invention makes it possible to reduce the processing time and the processing temperature, it is expected that the amount of energy input can be greatly reduced. Moreover, although there is a concern that the strength of the wood may be reduced by high-temperature and long-time heat treatment, it is expected that the strength reduction can be suppressed to a minimum by shortening the treatment time.
図1に本発明の熱処理木材の製造装置の一実施形態を図示する。 FIG. 1 illustrates an embodiment of a heat-treated wood production apparatus of the present invention.
1は木材が密閉される耐圧容器であり、この耐圧容器1には内部圧力を大気圧まで減圧するための大気圧解放用バルブ2と減圧速度を調節するための背圧弁10が設けられている。さらに耐圧容器1には内部の圧力と温度を測定するための圧力計4と温度計5が備えられている。
二酸化炭素が充填された充填容器9からバルブ8、加圧ポンプ7及びバルブ6を介して流体が耐圧容器1に加圧充填される。加圧充填された二酸化炭素はヒーター3により加熱され、木材は超臨界二酸化炭素中で加熱される。一定時間超臨界状態を保持した後、バルブ2を解放して容器内の圧力を大気圧まで減圧する。
A fluid is pressurized and filled into the pressure
あらかじめ全乾質量と寸法を測定しておいたスギ心材試片(50mm(L)×20mm(R)×20mm(T))を用意した。そして、全乾状態のままの試片と、温度20℃・相対湿度64%の恒温恒湿室で3週間以上調湿した試片(平均含水率:10.7%)、温度20℃・相対湿度87%の恒温恒湿室で3週間以上調湿した試片(平均含水率:16.7%)、の3種類を用いた。調湿した試片は質量と寸法を測定して、以下の式により含水率を算出した。 A cedar core material specimen (50 mm (L) × 20 mm (R) × 20 mm (T)) whose total dry mass and dimensions were measured in advance was prepared. And a specimen that was completely dried, a specimen that was conditioned for 3 weeks or more in a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 64% (average moisture content: 10.7%), a temperature of 20 ° C./relative Three types of specimens (average moisture content: 16.7%) that were conditioned for 3 weeks or more in a constant temperature and humidity room with a humidity of 87% were used. The humidity-controlled specimen was measured for mass and dimensions, and the moisture content was calculated according to the following formula.
次に、容量0.9リットルの耐圧容器内に同じ条件で調湿した試片を4本入れて密閉した。そして、炭酸ガスボンベから二酸化炭素を容器内に充填させ、180,200,220℃/10MPaまで昇温昇圧させて超臨界二酸化炭素の状態にした。熱処理は1時間もしくは6時間行い、処理後は容器内の圧力を大気圧まで減圧して試片を取り出した。そして、60℃の乾燥器で48時間減圧乾燥し、質量と寸法を測定して、質量減少率(WL)を求めた。そして、処理試片を温度と相対湿度がそれぞれ20℃/33%、20℃/64%、20℃/87%の恒温恒湿室内でそれぞれ3週間以上調湿し、試片の質量および寸法を測定して、平衡含水率と、水分に対する寸法安定性を示す抗膨潤能(ASE)を算出した。ASEは以下の式により算出した。 Next, four specimens conditioned under the same conditions were put in a pressure-resistant container having a capacity of 0.9 liter and sealed. Then, carbon dioxide was filled into the container from a carbon dioxide gas cylinder, and the temperature was raised to 180, 200, 220 ° C./10 MPa to obtain supercritical carbon dioxide. The heat treatment was performed for 1 hour or 6 hours, and after the treatment, the pressure in the container was reduced to atmospheric pressure, and the specimen was taken out. And it dried under reduced pressure for 48 hours with a 60 degreeC drying machine, the mass and the dimension were measured, and mass reduction rate (WL) was calculated | required. The treated specimens were then conditioned for 3 weeks or more in a constant temperature and humidity chamber of 20 ° C / 33%, 20 ° C / 64%, and 20 ° C / 87%, respectively, and the mass and dimensions of the specimens were determined. Measurements were made to calculate the equilibrium moisture content and the anti-swelling ability (ASE) indicating dimensional stability against moisture. ASE was calculated by the following formula.
熱処理による試片の質量減少率を表1に示す。処理温度が高く、前もって高湿度で調湿した試片ほど質量減少率が大きくなる傾向が見られた。これは、温度が高く、試片内の水分量が多い試片ほど木材成分の分解反応が促進されているためと推測される。また、平衡含水率は、処理温度が高く、前もって高湿度で調湿した試片ほど低くなる傾向が見られた。例として、20℃/相対湿度64%調湿試片を熱処理した後に各相対湿度で調湿したときの平衡含水率を図2に示すが、処理温度の上昇に伴い平衡含水率が低下しているのがわかる。これは木材成分の分解による水分吸着点の減少に因るものと推測される。 Table 1 shows the mass reduction rate of the specimen by the heat treatment. A sample with a high treatment temperature and humidity controlled in advance had a tendency to increase the mass reduction rate. This is presumably because the decomposition reaction of the wood component is promoted as the temperature of the sample increases and the amount of water in the sample increases. In addition, the equilibrium moisture content tended to be lower as the treatment temperature was higher and the specimen was conditioned at high humidity in advance. As an example, FIG. 2 shows the equilibrium moisture content when the humidity control sample at 20 ° C./relative humidity 64% is heat-treated and then the humidity is adjusted at each relative humidity. I can see that This is presumed to be due to a decrease in moisture adsorption points due to decomposition of the wood components.
熱処理試片のASEを図3に示す。処理温度が高く、前もって高湿度で調湿した試片ほどASEは高くなり、個体間のバラツキも小さくなった。また、ASEは220℃処理で最高約70%に達した。 The ASE of the heat treatment specimen is shown in FIG. Samples that were treated at a high temperature and were previously conditioned at high humidity showed higher ASE and less variation between individuals. In addition, ASE reached a maximum of about 70% when treated at 220 ° C.
20℃/相対湿度64%調湿試片を用いた熱処理について、処理時間が1時間と6時間の2種類について比較実験を行った。その結果を図3に示す。処理時間を長くすることでASEは高くなり、個体間のバラツキも小さくなった。また、特に180℃、200℃の比較的低温での処理において、処理時間を長くすることによるASEの向上および品質安定化の効果が顕著であった。 For heat treatment using a 20 ° C./64% relative humidity humidity specimen, a comparative experiment was conducted for two types of treatment times of 1 hour and 6 hours. The result is shown in FIG. By increasing the treatment time, the ASE increased and the variation among individuals also decreased. In particular, in the treatment at relatively low temperatures of 180 ° C. and 200 ° C., the effect of improving the ASE and stabilizing the quality by prolonging the treatment time was remarkable.
これらの結果から、本発明による熱処理によって寸法安定性に優れた熱処理木材が製造できること、特に処理温度が高く、前もって高湿度で調湿した試片では高品質の熱処理木材が安定的に製造できることが明らかとなった。 From these results, heat treated wood excellent in dimensional stability can be produced by the heat treatment according to the present invention, and in particular, a high quality heat treated wood can be stably produced with a specimen having a high treatment temperature and humidity controlled in advance. It became clear.
実施例1よりも試片寸法の大きなスギ心材試片(100mm(L)×50mm(R)×40mm(T))について、温度20℃・相対湿度65%の恒温恒湿室で3週間以上調湿した試片と、温度20℃・相対湿度87%の恒温恒湿室で3週間以上調湿した試片、の2種類を用意した。調湿した試片は質量と寸法を測定して、含水率を算出した後、容量0.9リットルの耐圧容器内に試片を1本入れて密閉した。そして、炭酸ガスボンベから二酸化炭素を容器内に充填させ、220℃/10MPaまで昇温昇圧させて超臨界二酸化炭素の状態にした。熱処理は1時間行い、処理後は容器内の圧力を大気圧まで減圧して試片を取り出した。そして、60℃の乾燥器で48時間減圧乾燥し、質量と寸法を測定して、質量減少率(WL)を求めた。そして、処理試片を温度と相対湿度が20℃/64%の恒温恒湿室内で3週間以上調湿し、試片の質量および寸法を測定して、平衡含水率とASEを算出した。 About a cedar heartwood specimen (100 mm (L) x 50 mm (R) x 40 mm (T)) having a specimen size larger than that of Example 1, it was adjusted for 3 weeks or more in a constant temperature and humidity chamber at a temperature of 20 ° C and a relative humidity of 65%. Two types were prepared: a wet specimen and a specimen conditioned for 3 weeks or more in a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 87%. The humidity-controlled specimen was measured for mass and dimensions, and the moisture content was calculated. Then, a specimen was put in a pressure-resistant container having a capacity of 0.9 liter and sealed. Then, carbon dioxide was filled into the container from a carbon dioxide gas cylinder, and the temperature was raised to 220 ° C./10 MPa to obtain supercritical carbon dioxide. The heat treatment was performed for 1 hour, and after the treatment, the pressure in the container was reduced to atmospheric pressure, and the specimen was taken out. And it dried under reduced pressure for 48 hours with a 60 degreeC drying machine, the mass and the dimension were measured, and mass reduction rate (WL) was calculated | required. Then, the treated specimen was conditioned for 3 weeks or more in a constant temperature and humidity room where the temperature and relative humidity were 20 ° C./64%, the mass and dimensions of the specimen were measured, and the equilibrium moisture content and ASE were calculated.
熱処理による試片の質量減少率とASEを表2に示すが、試片寸法が大きくなっても処理条件が同じであればASEの値がほぼ同じであることが分かる。また、質量減少率は試片寸法の大きい方が若干高い値を示しており、熱処理によるヘミセルロース等の熱分解反応が順調に進行していることが推測される。 The mass reduction rate and ASE of the specimen by heat treatment are shown in Table 2, but it can be seen that the ASE values are almost the same if the treatment conditions are the same even if the specimen dimensions are increased. Moreover, the mass reduction rate shows a slightly higher value when the specimen size is larger, and it is estimated that the thermal decomposition reaction of hemicellulose and the like by the heat treatment proceeds smoothly.
以上の結果から、本発明による熱処理が試片寸法を大きくしても適用できることが明らかとなった。 From the above results, it became clear that the heat treatment according to the present invention can be applied even when the specimen size is increased.
気乾状態のスギ心材試片(100mm(L)×6mm(R)×6mm(T))を用いて、本発明による熱処理と、従来の乾式法による熱処理を実施し、両者の強度比較を行った。本発明による熱処理は、容量0.9リットルの耐圧容器内に気乾試片を3本入れて密閉し、炭酸ガスボンベから二酸化炭素を容器内に充填させ、200℃/10MPaの温度・圧力で6時間、もしくは220℃/10MPaの温度・圧力で1時間の処理を行った。処理後は容器内の圧力を大気圧まで減圧して試片を取り出した。従来の乾式法による熱処理は、容量0.9リットルの耐圧容器内に気乾試片を3本入れて密閉し、容器内の空気を大気圧の窒素ガスに置換して、200℃で6時間、もしくは220℃で1時間の処理を行った。強度測定は、二点支持中央集中加重方式によって繊維方向の応力−ひずみ図を作成し、曲げヤング率(MOE)および曲げ強さ(MOR)を測定した。 Using an air-dried cedar heartwood specimen (100 mm (L) x 6 mm (R) x 6 mm (T)), the heat treatment according to the present invention and the heat treatment according to the conventional dry method are carried out, and the strength of both is compared It was. In the heat treatment according to the present invention, three air-dried specimens are sealed in a pressure-resistant container having a capacity of 0.9 liter, carbon dioxide is filled into the container from a carbon dioxide gas cylinder, and a temperature and pressure of 200 ° C./10 MPa are used. The treatment was performed for 1 hour at a temperature / pressure of 220 ° C./10 MPa. After the treatment, the pressure inside the container was reduced to atmospheric pressure, and the specimen was taken out. Heat treatment by the conventional dry method is performed by placing three air-dry specimens in a pressure-resistant container with a capacity of 0.9 liter and sealing, and replacing the air in the container with nitrogen gas at atmospheric pressure for 6 hours at 200 ° C. Alternatively, the treatment was performed at 220 ° C. for 1 hour. For strength measurement, a stress-strain diagram in the fiber direction was prepared by a two-point support centralized weighting method, and bending Young's modulus (MOE) and bending strength (MOR) were measured.
実験結果を表3に示す。従来の乾式法による熱処理試片のMOEおよびMORは、未処理試片と比較すると低い値となった。一方、本発明による熱処理試片のMOEおよびMORも未処理試片より低い値を取ったが、乾式法ほど低い値ではなかった。特に220℃・1時間処理では未処理試片のMOEおよびMORとの差はわずかであった。
以上の結果から、従来の乾式法と比べ、本発明による処理法ではMOEおよびMORの低下が抑えられることが示された。なお、この実施例では本発明による処理法と従来法を同じ処理条件で比較しているが、本発明を用いることで処理時間の短縮が期待されるため、強度低下がさらに抑えられる可能性がある。
The experimental results are shown in Table 3. The MOE and MOR of the heat-treated specimen by the conventional dry method were lower than those of the untreated specimen. On the other hand, the MOE and MOR of the heat-treated specimen according to the present invention also took lower values than the untreated specimen, but were not as low as the dry method. In particular, the difference between the MOE and MOR of the untreated specimen was slight when treated at 220 ° C. for 1 hour.
From the above results, it was shown that the treatment method according to the present invention can suppress the decrease in MOE and MOR as compared with the conventional dry method. In this example, the processing method according to the present invention and the conventional method are compared under the same processing conditions. However, since the processing time is expected to be shortened by using the present invention, there is a possibility that the strength reduction can be further suppressed. is there.
本発明は、強度低下と、投入エネルギーが少なく、高い寸法安定性と耐朽性を持った熱処理木材を製造できるので、森林資源の有効活用として有用である。 INDUSTRIAL APPLICABILITY The present invention is useful for effective utilization of forest resources because it can produce heat-treated wood with reduced strength, less energy input, and high dimensional stability and decay resistance.
1 耐圧容器
2 大気圧解放用バルブ
3 ヒーター
4 圧力計
5 温度計
6 バルブ
7 加圧ポンプ
8 バルブ
9 充填容器
10 背圧弁
DESCRIPTION OF
Claims (1)
Heat treatment characterized by pressurizing and heating wood having an average water content of 10.7 to 16.7% in supercritical carbon dioxide at a pressurizing pressure of 7.4 to 30 MPa and a heating temperature of 150 to 250 ° C. Wood manufacturing method.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012044979A JP5965670B2 (en) | 2012-03-01 | 2012-03-01 | Process for producing heat-treated wood |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012044979A JP5965670B2 (en) | 2012-03-01 | 2012-03-01 | Process for producing heat-treated wood |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2013180460A JP2013180460A (en) | 2013-09-12 |
JP5965670B2 true JP5965670B2 (en) | 2016-08-10 |
Family
ID=49271481
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2012044979A Expired - Fee Related JP5965670B2 (en) | 2012-03-01 | 2012-03-01 | Process for producing heat-treated wood |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP5965670B2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2998087B1 (en) * | 2014-09-01 | 2023-06-07 | SAGA Wood Holding AS | Manufacturing method for a high durability, high insulating composite timber member and a composite timber member |
ES2660426T3 (en) * | 2015-11-18 | 2018-03-22 | SWISS KRONO Tec AG | OSB wood-oriented material board (oriented strand board) with improved properties and production process |
PT3178622T (en) * | 2015-12-07 | 2018-10-30 | SWISS KRONO Tec AG | Method of manufacturing of wood material board with reduced emission of volatile organic compounds (vocs) |
DK179238B1 (en) * | 2016-07-15 | 2018-02-26 | Wtt Holding Aps | A thermo treatment process for wood |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5818205B2 (en) * | 1980-03-26 | 1983-04-12 | 宮城県 | How to process wood into a buried wood shape |
JPS59101311A (en) * | 1982-11-30 | 1984-06-11 | 日本酸素株式会社 | Antiseptic treatment method of wood |
JPH03108501A (en) * | 1989-06-02 | 1991-05-08 | Aica Kogyo Co Ltd | Manufacture of ligneous material introduced and treated with synthetic resin |
JP2003285301A (en) * | 2002-03-29 | 2003-10-07 | Forestry & Forest Products Research Institute | Method for improving permeability of lumber by supercritical carbon dioxide treatment, permeability improving apparatus, and lumber impregnated with chemicals |
JP4167993B2 (en) * | 2004-03-05 | 2008-10-22 | 株式会社神戸製鋼所 | Drug impregnation method |
JP4686775B2 (en) * | 2006-02-15 | 2011-05-25 | 独立行政法人森林総合研究所 | Method for modifying wood |
JP5060791B2 (en) * | 2007-01-26 | 2012-10-31 | 独立行政法人森林総合研究所 | Method for drying wood, method for penetrating chemicals into wood and drying apparatus |
-
2012
- 2012-03-01 JP JP2012044979A patent/JP5965670B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JP2013180460A (en) | 2013-09-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Yongjian et al. | Increased dimensional stability of Chinese fir through steam-heat treatment | |
US10315331B2 (en) | Thermo treatment process for wood | |
KR102110787B1 (en) | Process for the acetylation of wood and acetylated wood | |
Shi et al. | Mechanical behaviour of Quebec wood species heat-treated using ThermoWood process | |
JP5775825B2 (en) | Surface-reinforced natural wood mold material and method for producing the same | |
JP5060791B2 (en) | Method for drying wood, method for penetrating chemicals into wood and drying apparatus | |
JP5965670B2 (en) | Process for producing heat-treated wood | |
EP2091705B1 (en) | Improvements relating to wood drying | |
Majka et al. | Effects of cyclic changes in relative humidity on the sorption hysteresis of thermally modified spruce wood | |
Yang et al. | Effects of temperature and duration of heat treatment on the physical, surface, and mechanical properties of Japanese cedar wood | |
JP4686775B2 (en) | Method for modifying wood | |
Jiang et al. | Impact of DMDHEU resin treatment on the mechanical properties of poplar | |
Taşdelen et al. | Some physical and mechanical properties of maritime pine and poplar exposed to oil-heat treatment | |
Ishikawa et al. | In situ measurement of wood moisture content in high-temperature steam | |
FI118139B (en) | A method for treating a piece of solid wood | |
US10486329B2 (en) | Methods and systems for impregnating wood with a polymer solution and products thereof | |
CN109159232A (en) | A kind of heat modification treatment process of bamboo or timber | |
JP2009172787A (en) | Method for producing heat-treated lumber | |
US20180111286A1 (en) | Process of Improving the Dimensional Stability of Wood and Dimensional Stabile Wood Thereof | |
Song et al. | Effect of different boiling treatments on physical properties of cork from Quercus variabilis | |
Lin et al. | The composite wood impregnated with silicon sol solution | |
JP2022131431A (en) | Heat treatment method for lumber and heat-treated lumber | |
JP2010269593A (en) | Method of modifying lumber, and modified lumber | |
WO2024014037A1 (en) | Method for producing modified wood | |
RU2551141C1 (en) | Round timber drying method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20150223 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20151211 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20160105 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20160212 |
|
RD03 | Notification of appointment of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7423 Effective date: 20160212 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20160212 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20160628 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20160704 |
|
R150 | Certificate of patent or registration of utility model |
Ref document number: 5965670 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
LAPS | Cancellation because of no payment of annual fees |