JP4576023B2

JP4576023B2 - Molding method of wooden material

Info

Publication number: JP4576023B2
Application number: JP2000144990A
Authority: JP
Inventors: 雅人平井
Original assignee: 株式会社山本鉄工所
Priority date: 2000-05-17
Filing date: 2000-05-17
Publication date: 2010-11-04
Anticipated expiration: 2020-05-17
Also published as: JP2001322105A

Description

【０００１】
【発明の属する技術分野】
本発明は、紙パルプ、木質繊維、木質粉体等の水素結合を生ずる木質系素材を乾式で成形する方法に関する。
【０００２】
【従来の技術】
従来、紙パルプ、木質繊維、木質粉体等の木質系素材を水に分散させて、スラリー状としたものを機械的に脱水成形し、その後に加熱乾燥して成形品を得る方法が行われている。この方法は、紙のように薄いものは能率よく製作できるが、厚くて比重の小さいものは能率よく成形できない。それは、スラリー状に分散させるので、木質系素材の繊維同士あるいは粉体同士の摩擦が低減することにより、緻密に集合してしまうからである。又、脱水成形においては、水分をできるかぎり少なくするのが乾燥効率が高く、かつ乾燥収縮が少なくなるということもあって、パルプ成形では、厚み３ｍｍ以下、比重０．５以上のものが一般的に製造されている。また、エネルギー消費に関しては、水分を蒸発させるために大きなエネルギーを必要とする。機械的な脱水では、高圧で脱水成形したとしても含水率を４０％未満にすることが非常に困難であることに起因する。
【０００３】
以上の方法は、比重の高いものしか製造できない。このため、以上の方法で、たとえば、梱包材を製造する場合、クッション性を持たせるためには、形状で対応するしかない。しかしながら、表面がデリケートな物、例えばイチゴ、モモ、ナシ等の傷みやすい青果物の梱包材には使用できない。このことが、以上の方法で製作された成形品の用途を少なく制限している。
【０００４】
また、木質系素材を乾式で成形する方法も開発されているが、この方法は、木質系素材を結合するために接着剤等のバインダーを添加する必要がある。この方法で製造された成形品は、廃棄するときには混合素材廃棄物となり、再資源化が困難になってしまう。
【０００５】
【発明が解決しようとする課題】
木質系素材の乾式で成形して緩衝材を製造する方法は以下の公報に記載される。
(1) 特開平５−２４６４６５号公報
(2) 特開平６−２８５８９０号公報
(3) 特開平６−２９３３６０号公報
(4) 特開平７−３０４０１２号公報
【０００６】
(1)の公報には、古紙を解繊して綿状物とし、この綿状物に水分を供給して湿潤状態部と、非低湿潤状態部とし、湿潤状態部で非低湿潤状態部を覆う粒状部を備えた海面状部とし、綿状物または海面状部に糊材を添加して、成形・乾燥させる緩衝材の製造方法が記載される。
【０００７】
この方法で緩衝材を製造する方法は、綿状物を独特の手法で粒状部を含む海面状に加工して成形するので、製造工程が複雑で能率よく安価に緩衝材を製造できない。また、綿状物を糊材で結合するので、簡単に廃棄できなくなる欠点もある。
【０００８】
(2)の公報には、古紙を乾式で解繊したパルプ繊維を空気移送管に供給し、古紙を解繊するとき、あるいは、パルプ繊維を空気移送する途中で合成樹脂を混合し、空気輸送管の下流端のノズルで成形母型に吹き付けて成形し、その後に加熱圧縮して成形する方法が記載される。
【０００９】
この公報に記載される方法は、ノズルからパルプ繊維を成形母型に吹き付けて成形するので、短時間に能率よく成形することが難しい。また、成形できる形状にも制約を受けて、種々の用途に最適な形状には成形できないことがある。さらに、この方法も、パルプ繊維を合成樹脂で結合するので、簡単には廃棄できなくなる欠点がある。
【００１０】
(3)の公報には、古紙を解繊して綿状物とし、この綿状物を機械的に圧縮して成型すると共に、水を噴霧した後、乾燥してパルプ繊維を接着結合する緩衝材の製造方法が記載される。この製造方法は、図１に示すように、水を添加した綿状物をフォーミングマシン１４のベルトコンベアに供給し、ベルトコンベアの途中に設けている挟圧ローラー１５で圧縮成型して緩衝材を製作する。
【００１１】
この方法は、水の噴霧量を調整して、表面と内部の密度を調整することができる。すなわち、ベルトコンベアの上方に配設しているノズル１６から多量の水を噴霧すると、水はパルプ繊維の内部まで浸透し、少量の水を噴霧すると表面のみに水が浸透する。パルプ繊維は、水が浸透される部分が密に集合されるので、水を多量に噴霧すると、内部まで密に集合して緩衝材が製造され、少量の水を噴霧すると、表面のみを密に集合している緩衝材を製造できる。しかしながら、この製造方法も、成型できる形状に制約を受け、種々の用途に最適な形状に成型することができない欠点がある。また、この方法は、フォーミングマシンで水を添加して加圧成型したものを、加熱乾燥トンネル等で乾燥する必要があり、乾燥に手間がかかると共に、乾燥トンネルが長くなって、設備コストも高価になる欠点がある。
【００１２】
さらに、(4)の公報には、図２の装置を使用して緩衝材を製造する方法が記載される。この図の装置は、水蒸気を噴射する噴射板１８に熱板１９を積層している一対のプレス板１７を備えている水蒸気噴射プレスである。この水蒸気噴射プレスは、一対のプレス板１７の間に、紙を乾湿で解繊した綿状物を供給して成型する。プレス板１７の間に供給された綿状物は、噴射板１８から水蒸気が噴射される。噴射される水蒸気は、綿状物の内部まで浸透して、綿状物に含まれる填料を湿潤、乾燥させて綿状物を接着する。
【００１３】
この方法は、水蒸気を噴射して綿状物に含まれる填料を綿状物を接着できるので、バインダーを添加することなく、あるいはバインダーの添加量を少なくして、綿状物を結合できる特長がある。しかしながら、この方法も、水蒸気を添加した後に、速やかに乾燥することができず、乾燥に時間がかかる欠点がある。さらに、乾燥している途中に成型品が型くずれする欠点もある。
【００１４】
本発明は、従来の以上の欠点を解決することを目的に開発されたもので、本発明の重要な目的は、木質系素材を能率よく種々の形状に成型できると共に、バインダーの添加量を少なく、あるいは皆無にして、しかも高い精度で決められた形状に成型でき、さらに内部まで理想的な状態で速やかに乾燥できる木質系素材の成形方法を提供することにある。
【００１５】
【課題を解決するための手段】
本発明の木質系素材の成形方法は、紙パルプ、木質繊維、木質粉体等の水分を揮発して水素結合を生ずる木質系素材を加熱して成形する。本発明の成形方法は、木質系素材Ｗを加熱型１の成形室２に充填して、閉鎖状態の成形室２に加熱、加圧水蒸気を噴射して、木質系素材Ｗを加熱、加湿して成形する成形工程と、成形室２を減圧して真空脱気し、木質系素材Ｗに含まれる高温水を蒸発して除去する圧力低下工程とからなる。
【００１６】
さらに、本発明の木質系素材の成形方法は、水分が添加された木質系素材Ｗを閉鎖された加熱型１の成形室２に充填し、あるいは、成形室２に充填された木質系素材Ｗに水分を添加した後、成形室２を閉鎖して、閉鎖された成形室２の圧力を上昇して、成形室２における水の沸点を１００℃よりも高くして、加熱型１で木質系素材Ｗを加熱する加熱加湿工程とすることもできる。
【００１７】
さらに、本発明の木質系素材の成形方法は、成形工程において、好ましくは、成形室２の圧力を０．２〜２Ｍｐａ、好ましくは０．３〜１．５Ｍｐａ、さらに好ましくは０．４〜１．２Ｍｐａとする。
【００１８】
さらに、本発明の木質系素材の成形方法は、圧力低下工程において、好ましくは、成形室２を大気に開放した後、成形室２を大気圧以下に減圧して木質系素材Ｗに含まれる水分を除去する。
【００１９】
【発明の実施の形態】
以下、本発明の実施例を図面に基づいて説明する。ただし、以下に示す実施例は、本発明の技術思想を具体化するための木質系素材の成形方法を例示するものであって、本発明は成形方法を下記のものに特定しない。
【００２０】
さらに、この明細書は、特許請求の範囲を理解し易いように、実施例に示される部材に対応する番号を、「特許請求の範囲の欄」、および「課題を解決するための手段の欄」に示される部材に付記している。ただ、特許請求の範囲に示される部材を、実施例の部材に特定するものでは決してない。
【００２１】
図３は、本発明の木質系素材の成形方法に使用する装置を示す。この成形装置は、木質系素材Ｗを成形室２でもって気密に密閉する状態で成形する加熱型１と、加熱型１を木質系素材Ｗに押圧する押圧機構３と、成形室２に充填している木質系素材Ｗを湿潤状態で加熱するボイラー４とを備える。
【００２２】
図において下側の加熱型１Ｂは、成形室２を形成する周壁５を有する。周壁５は、成形室２の周囲を囲む形状、たとえば、方形状をしている。さらに、周壁５は上面を平面状として、降下した上側の加熱型１Ａの側面から外側に突出する突出部６の下面に密着するようにしている。周壁５の上面には、パッキン７の嵌着溝を設け、ここにパッキン７を入れて固定している。嵌着溝のパッキン７は、降下した上側の加熱型１Ａの突出部６の下面に密着して、成形室２をガス漏れしない状態で、気密に閉塞する。
【００２３】
成形室２を形成する周壁５は、下側の加熱型１Ｂに一体成形され、あるいは、加熱型と別の部材とすることができる。加熱型と別部材の周壁は、加熱型の間にガス漏れしない状態で密着するように、上下両面に嵌着溝を設けて、この嵌着溝にパッキンを嵌着する。周壁５の高さは、圧縮される木質系素材Ｗの厚さを決定する。木質系素材Ｗを圧縮する状態で、周壁５が上側の加熱型１Ａに気密に密着して、成形室２を形成するからである。
【００２４】
図の成形装置は、ボイラー４を連結する多数の貫通孔８を上下の加熱型１に設けている。図の装置は、貫通孔８に、配管９を介して、ボイラー４と真空ポンプ１０を連結している。ボイラー４は、加圧加熱された水蒸気を成形室２に供給して、成形室２の木質系素材Ｗを湿潤な状態として加熱、加圧する。
【００２５】
ボイラー４は、加圧された水蒸気を成形室２に圧入する。ボイラー４から成形室２に供給された水蒸気は、木質系素材Ｗに水分を添加すると共に、木質系素材Ｗを加熱、加圧して所定の形状に成形する。
【００２６】
ボイラー４は、０．２〜２ＭＰａ、好ましくは０．３〜１．５Ｍｐａ、さらに好ましくは０．４〜１．２Ｍｐａに加圧された水蒸気を供給する。水蒸気の温度と圧力が低すぎると、短時間で木質系素材の全体に均一に水分を補給して、加熱状態で成形できなくなる。それは、水蒸気の圧力が低いと、木質系素材の内部まで均一に水分を補給できなくなるからである。水の沸点は、１ＭＰａにおいて１８３℃でである。したがって、圧力を１ＭＰａとする水蒸気は、木質系素材を約１８０℃に加熱できる。成形室２に加圧、加熱された水蒸気を供給すると、木質系素材は水蒸気の熱量により昇温するが、原料を昇温するために熱量を奪われた水蒸気は、覆水して、この水を木質系素材に加湿する。このとき、成形室２の内部圧力を１．０ＭＰａ／ｃｍ^２まで昇圧させると、水は１８０℃の高温で水の状態になって木質系素材を加湿しながら加温する。木質系素材が水蒸気に加熱されて、約１８３℃よりも高くなると、水蒸気は覆水にならずに、木質系素材を透過して内部まで均一に浸透する。木質系素材の内部に向かって浸透する水蒸気は、木質系素材に冷却されて高温の覆水となり、覆水と水蒸気で沸点よりも高温に加熱されると水蒸気はさらに内部まで浸透して、加湿しながら木質系素材を加熱する。水蒸気で加熱された木質系素材は、内部のセルロース繊維を湿潤な状態で高温高圧処理して、結晶構造の変化によって形状記憶機能を賦与される。
【００２７】
真空ポンプ１０は、成形室２を減圧して、木質系素材Ｗを冷却しながら乾燥する。真空ポンプ１０で成形室２を減圧する装置は、成形室２から取り出した木質系素材Ｗを、より少ない水分率に乾燥できると共に、冷却して取り出しできる特長がある。
【００２８】
図３に示す装置は、成形室２に、大気開放弁１１と圧力制御弁１２も連結している。大気開放弁１１は、成形室２を加圧するときと減圧するときに閉弁される。加圧している成形室２の気体を排気するとき、あるいは、減圧された成形室２に外気を吸入させるときに開弁される。圧力制御弁１２は、成形室２の圧力が設定圧力よりも高くなったときに開弁して、成形室２の圧力を設定圧力に調整する。
【００２９】
加熱型１の押圧機構３は、上側の加熱型１Ａに連結している油圧シリンダーである。油圧シリンダーは、上側の加熱型１Ａを押し下げて、成形室２の木質系素材Ｗをプレスすると共に、成形室２を気密に閉塞する。下側の加熱型１Ｂは、水平に固定している。押圧機構は、上下の加熱型を油圧シリンダーに連結して、木質系素材をプレスして成形室を閉塞し、あるいは、下側の加熱型を油圧シリンダーで押し上げて、木質系素材をプレスすることもできる。さらに、押圧機構は、必ずしも油圧シリンダーを使用する必要はない。押圧機構は、たとえば、カムやクランク機構で加熱型を押圧することもできる。
【００３０】
さらに、図に示す装置は、加熱型１をプレス状態に保持するクランプ装置１３を備える。図に示すクランプ装置１３は、押圧機構３で押し下げられた上側の加熱型１Ａを所定の位置に保持している。このクランプ装置１３は、上側の加熱型１Ａの突出部６の上面に当接するロック部が出入りして、加熱型１をプレス状態に保持し、あるいは、プレス状態を解除する。加熱型１がプレス状態にあるとき、クランプ装置１３は、ロック部を内側に突出させて、上側の加熱型１Ａの突出部６をロック状態に保持する。加熱型１のプレス状態を解除するときには、クランプ装置１３がロック部を互いに離れる方向に収納して、ロック状態を解除する。このようにクランプ装置１３で加熱型１をプレス状態に保持する成形装置は、押圧機構で加圧プレス状態に保持する必要がないので、押圧機構を簡素化して低コストにできる特長がある。
【００３１】
木質系素材は、水蒸気によらずに加熱型で加熱し、あるいは水蒸気と加熱型の両方で加熱することもできる。加熱型で加熱される木質系素材は、成形室２に充填する前工程で、あるいは、成形室に充填する状態で水分を添加する。加熱型は、たとえば、蒸気やヒータで所定の温度に加熱できる。蒸気で加熱される加熱型は、蒸気を通過させる通路を内部に設けている。ヒータで加熱される加熱型は、内部に電気で加熱されるヒータを内蔵させている。
【００３２】
【実施例】
［実施例１］
以上の成形装置は、以下のようにして木質系素材を成形する。
［木質系素材を成形室に充填する工程］
木質系素材Ｗとして、雑誌や新聞紙等の古紙を乾式で粉砕した後、解繊して綿状にした物を使用する。木質系素材Ｗは、機械的に分散させながら予備成形型で予備成形した後、成形室２に充填する。予備成形とは、成形型に入れやすくするために、乾式で圧縮してあらかじめ成形することである。ただし、本発明の方法は、木質系素材を必ずしも予備成形して成形室に充填する必要はない。予備成形され、あるいは予備成形しない木質系素材を、加熱している加熱型に充填して、加熱型を型閉めして成形室を閉鎖する。加熱型は約１８０℃に加熱している。
【００３３】
［成形工程］
閉鎖された成形室２に水蒸気を供給して木質系素材を成形する。このとき、成形室２の圧力を制御することにより、木質系素材Ｗへの均一な加湿をすることができる。成形室２の圧力は、供給する水蒸気の圧力を調整し、あるいは成形室２に連結している圧力制御弁１２で調整する。成形室２に投入された木質系素材Ｗは、あらかじめ加熱された加熱型１の成形室２に充填されるが、熱伝導が悪いので、加熱型１では表面のみが加熱される。したがって、成形室２に充填した直後において、木質系素材Ｗの中心部の温度は、型投入前とほぼ同じ温度である。その後、成形室２に水蒸気が供給されると、木質系素材Ｗは水蒸気の熱量により昇温する。木質系素材Ｗに供給された水蒸気は、木質系素材Ｗを昇温するために熱が奪われて覆水する。液化した覆水は木質系素材Ｗを加湿する。成形室２の内部圧力を１．０ＭＰａ／ｃｍ^２まで昇圧させると、水分は１８０℃の高温水の状態になり、木質系素材Ｗの温度がこの温度まで上昇した後は覆水せず、木質系素材Ｗの内部に浸透する。内部に浸透する水蒸気は、木質系素材Ｗを加熱しながら覆水となって、木質系素材Ｗを均一に加湿しながら加熱する。
【００３４】
［圧力低下工程］
次に、成形室２の内部圧力を開放して常圧にし、その後、真空吸引して内部圧力を負圧に保持する。この状態で、含水状態で１８０℃に加熱されていた木質系素材Ｗは、内部圧力が低下することよって水分が沸騰して蒸発する。これは水の沸点が１．０Ｍｐａの時は１８３℃であるが、−９０Ｋｐａでは４５℃であることに起因する。
【００３５】
これにより木質系素材Ｗの中心部に含まれていた水分も均一に蒸発して除去される。含水率の高い木質系素材Ｗは、例え１８０℃まで加熱されても、加熱された熱量で水を蒸発させる熱量をすべて補えないこともある。しかしながら、この状態において、木質系素材Ｗは加熱型１で加熱されて、表面から加熱し続けられて含有する水分を蒸発させる。木質系素材Ｗは、含有される水分が蒸発して除去されることにより、水素結合して所定の形状に成形してその形状に保形される。
【００３６】
その後、加熱型１を開いて、成形された木質系素材Ｗを加熱型１から取り出す。
【００３７】
［実施例２］
成形工程を、（１）の加熱加湿工程と（２）の形状記憶成形工程の２工程として木質系素材を成形する以外、実施例１と同様にして木質系素材を成形する。
（１）加熱加湿工程…実施例１の成形工程と同じ
（２）形状記憶成形工程
木質系素材Ｗの全体を１８０℃まで昇温した直後に、実施例１のように、成形室２を減圧することもできるが、木質系素材Ｗに含まれるセルロース繊維は、水分を有する状態で高温高圧処理を行うと結晶構造の変化により形状記憶機能を賦与できるので、一定時間は高温高圧状態を保持させることにより、型くずれしないように成形する。
【００３８】
［実施例３］
以上の成形方法は、成形室２に水蒸気を充填して木質系素材Ｗを加熱するが、木質系素材Ｗに水を添加して、加熱型１が加熱、加圧する以下の方法で木質系素材Ｗを成形することもできる。
【００３９】
［木質系素材を成形室に充填する工程］
木質系素材Ｗとして実施例１と同じものを使用する。木質系素材Ｗに水分を添加して予備成形した後、成形室２に充填する。水分の添加量は１０〜４０重量％、好ましくは約１０〜３０重量％、さらに好ましくは約２０重量％とする。木質系素材Ｗは、成形室２に充填する前に、あるいは、成形室２に充填しながら、あるいはまた、成形室２に充填した後に添加することもできる。予備成形され、あるいは予備成形しない木質系素材Ｗを、加熱している加熱型１に充填して、加熱型１を型閉めして成形室２を閉鎖する。加熱型１を約１８０℃に加熱する。
【００４０】
［成形工程］
閉鎖された成形室２に加圧空気を供給する。このとき、成形室２の圧力を制御することにより、木質系素材Ｗへの均一な加湿をすることができる。成形室２の圧力は、供給する空気圧で調整する。成形室２に投入された木質系素材Ｗは、あらかじめ加熱された加熱型１の成形室２に充填されるが、熱伝導が悪いので、加熱型１では表面のみが加熱される。したがって、成形室２に充填した直後において、木質系素材Ｗの中心部の温度は、型投入前とほぼ同じ温度である。その後、木質系素材Ｗに含まれる水が、加熱型１に加熱されて水蒸気となる。発生した水蒸気は、木質系素材Ｗの内部に浸透する。この水蒸気は、木質系素材Ｗを昇温するために熱が奪われて覆水する。覆水は木質系素材Ｗを加湿する。成形室２の内部圧力を１．０ＭＰａ／ｃｍ^２まで昇圧させると、水分は１８０℃の高温水の状態になり、木質系素材Ｗの温度がこの温度まで上昇した後は覆水せず、木質系素材Ｗの内部に浸透する。内部に浸透する水蒸気は、木質系素材Ｗを加熱しながら覆水となって、木質系素材Ｗを均一に加湿しながら加熱する。
【００４１】
その後、実施例１または２と同じ成形工程と、圧力低下工程で、木質系素材Ｗを成形した後、加熱型１を開いて、成形された木質系素材Ｗを加熱型１から取り出す。
【００４２】
以上の成形方法は、木質系素材Ｗにバインダーを添加しないで成形しているが、木質系素材に少量のバインダーを添加して成形することもできる。バインダーには、たとえば、コンスターチ等が使用できる。バインダーは、成形室に充填する前に、あるいは後で木質系素材に添加する。
【００４３】
【発明の効果】
本発明の木質系素材の成形方法は、木質系素材を能率よく種々の形状に成型できる特長がある。それは、本発明の成形方法が、木質系素材を加熱型の成形室に充填し、閉鎖した成形室に水蒸気を供給し、あるいは、成形室の内部で水蒸気を発生させて、この水蒸気で木質系素材を加圧する状態で湿潤な状態で加熱し、高温高圧状態で一定時間保持して、木質系素材に含まれるセルロースの形状記憶効果で成形し、その後、閉鎖された成形室を減圧して真空脱気して、木質系素材に含まれる高温水を蒸発させて除去するからである。閉鎖されて加圧状態に保持される成形室に供給される水蒸気は、木質系素材の隙間を通過して木質系素材を加熱し、さらに、覆水して木質系素材を湿潤な状態としながら内部に浸透する。この状態で加熱される木質系素材は、内部まで速やかに加熱されながら湿潤な状態となる。この状態で木質系素材を一定の形状に成形し、さらに、この状態で木質系素材を成形室から取り出すことなく、成形室を減圧して含有水分を蒸発、気化させて除去する。この状態で成形された木質系素材の成形品は、加熱、加圧、湿潤状態で所定の形状に成形され、さらに、成形状態で乾燥されるので、所定の形状に型くずれしないように高い精度で正確に成形できる。
【００４４】
この方法で成形される木質系素材は、バインダーの添加量を少なく、あるいは皆無にして、決められた形状に成形できる。また、内部まで理想的な状態で速やかに加熱した後に、充分に乾燥できる特長もある。
【図面の簡単な説明】
【図１】従来の緩衝材の製造方法に使用する装置の概略図
【図２】従来の緩衝材の製造方法に使用する他の装置の概略構成図
【図３】本発明の実施例の木質系素材の成形方法に使用する装置の断面図
【符号の説明】
１…加熱型１Ａ…上側の加熱型１Ｂ…下側の加熱型
２…成形室
３…押圧機構
４…ボイラー
５…周壁
６…突出部
７…パッキン
８…貫通孔
９…配管
１０…真空ポンプ
１１…大気開放弁
１２…圧力制御弁
１３…クランプ装置
１４…フォーミングマシン
１５…挟圧ローラー
１６…ノズル
１７…プレス板
１８…噴射板
１９…熱板
Ｗ…木質系素材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for dry-forming a wood-based material that generates hydrogen bonds, such as paper pulp, wood fiber, and wood powder.
[0002]
[Prior art]
Conventionally, a method has been used in which a woody material such as paper pulp, wood fiber, wood powder, etc. is dispersed in water, and the slurry is mechanically dehydrated and then dried by heating to obtain a molded product. ing. In this method, a thin material such as paper can be manufactured efficiently, but a thick material having a small specific gravity cannot be efficiently formed. This is because the particles are dispersed in the form of a slurry, and the friction between the fibers of the wood-based material or between the powders is reduced, so that they are densely assembled. In dehydration molding, reducing the moisture as much as possible increases the drying efficiency and reduces drying shrinkage. In pulp molding, the thickness is generally 3 mm or less and the specific gravity is 0.5 or more. Is manufactured. As for energy consumption, large energy is required to evaporate moisture. The mechanical dehydration is caused by the fact that it is very difficult to make the water content less than 40% even if dehydration molding is performed at a high pressure.
[0003]
The above method can only produce a product having a high specific gravity. For this reason, when manufacturing a packing material by the above method, for example, in order to give cushioning properties, there is no choice but to deal with the shape. However, it cannot be used for packaging materials of delicate fruits, such as perishable fruits and vegetables such as strawberries, peaches, and pears. This limits the application of the molded product manufactured by the above method.
[0004]
In addition, a method of forming a wood-based material by a dry method has been developed. In this method, it is necessary to add a binder such as an adhesive in order to bond the wood-based material. When the molded product manufactured by this method is discarded, it becomes a mixed material waste, which makes it difficult to recycle.
[0005]
[Problems to be solved by the invention]
A method for producing a buffer material by dry molding of a wood-based material is described in the following publication.
(1) Japanese Patent Laid-Open No. 5-246465
(2) Japanese Patent Laid-Open No. 6-285890
(3) JP-A-6-293360
(4) Japanese Patent Laid-Open No. 7-304012 [0006]
In the publication of (1), waste paper is defibrated to form a cotton-like product, and moisture is supplied to the cotton-like product to obtain a wet state portion and a non-low wet state portion. A method for producing a cushioning material is described in which a sea surface-shaped portion having a granular portion covering the surface is added, and a paste is added to the cotton-like material or the sea surface-shaped portion, followed by molding and drying.
[0007]
In the method of manufacturing the cushioning material by this method, the cotton-like material is processed into a sea surface shape including a granular portion by a unique method and molded, so that the manufacturing process is complicated and the cushioning material cannot be manufactured efficiently and inexpensively. In addition, since the cotton-like material is bonded with a paste material, there is a disadvantage that it cannot be easily discarded.
[0008]
In the gazette of (2), pulp fibers obtained by defibrating waste paper are supplied to an air transfer pipe, and when the used paper is defibrated or mixed with synthetic resin during air transfer of pulp fibers, pneumatic transport A method is described in which a nozzle is formed by spraying on a forming die with a nozzle at the downstream end of the tube, and then heated and compressed.
[0009]
Since the method described in this publication is formed by spraying pulp fibers from a nozzle onto a forming matrix, it is difficult to efficiently form in a short time. In addition, the shape that can be molded is also limited, and it may not be possible to mold the shape optimal for various applications. Furthermore, this method also has a drawback that it cannot be easily discarded because the pulp fibers are bonded with a synthetic resin.
[0010]
In the gazette of (3), a waste paper is defibrated to form a cotton-like material, and the cotton-like material is mechanically compressed and molded, sprayed with water, dried, and a buffer for adhesively bonding pulp fibers. A method of manufacturing the material is described. In this manufacturing method, as shown in FIG. 1, a cotton-like product added with water is supplied to a belt conveyor of a forming machine 14 and compression-molded by a pressure roller 15 provided in the middle of the belt conveyor to provide a cushioning material. To manufacture.
[0011]
In this method, the density of the surface and the inside can be adjusted by adjusting the spray amount of water. That is, when a large amount of water is sprayed from the nozzle 16 disposed above the belt conveyor, the water penetrates into the pulp fiber, and when a small amount of water is sprayed, the water penetrates only on the surface. Since the pulp fiber is densely gathered in the water-penetrating part, when a large amount of water is sprayed, the buffer material is produced by densely gathering to the inside, and when a small amount of water is sprayed, only the surface is densely packed. Collecting cushioning material can be manufactured. However, this manufacturing method is also limited by the shape that can be molded, and has a drawback that it cannot be molded into a shape optimal for various applications. In addition, in this method, it is necessary to dry a pressure-molded product with water added by a forming machine, using a heat-drying tunnel or the like, which takes time for drying, lengthens the drying tunnel, and increases the equipment cost. There are disadvantages to become.
[0012]
Furthermore, the publication (4) describes a method of manufacturing a cushioning material using the apparatus of FIG. The apparatus in this figure is a water vapor injection press provided with a pair of press plates 17 in which a hot plate 19 is laminated on an injection plate 18 for injecting water vapor. This steam jet press is formed by supplying a cotton-like material obtained by defibrating paper between a pair of press plates 17 by dry and wet. The cotton-like material supplied between the press plates 17 is sprayed with water vapor from the spray plate 18. The sprayed water vapor penetrates to the inside of the cotton-like material, wets and dries the filler contained in the cotton-like material, and bonds the cotton-like material.
[0013]
This method has the feature that the cotton-like material can be bonded without adding a binder or by reducing the amount of the binder added since the filler contained in the cotton-like material can be bonded by spraying water vapor. is there. However, this method also has a drawback that it cannot be dried quickly after adding water vapor, and it takes time to dry. Furthermore, there is also a drawback that the molded product loses its shape during drying.
[0014]
The present invention was developed for the purpose of solving the above-mentioned drawbacks. An important object of the present invention is that the wood-based material can be efficiently molded into various shapes, and the amount of binder added is small. Another object of the present invention is to provide a method for molding a wood-based material that can be molded into a shape determined with high accuracy and can be quickly dried to the inside in an ideal state.
[0015]
[Means for Solving the Problems]
In the method for molding a wood-based material according to the present invention, a wood-based material that forms hydrogen bonds by volatilizing water such as paper pulp, wood fiber, wood powder, etc. is formed by heating. In the molding method of the present invention, the wood material W is filled in the molding chamber 2 of the heating mold 1 and heated and pressurized steam is injected into the molding chamber 2 in a closed state to heat and humidify the wood material W. The molding process includes a molding process and a pressure reduction process in which the molding chamber 2 is depressurized and vacuum degassed to evaporate and remove high-temperature water contained in the wood-based material W.
[0016]
Furthermore, in the method for molding a wood-based material according to the present invention, the wood-based material W to which moisture has been added is filled in the molding chamber 2 of the closed heating mold 1 or the wood-based material W filled in the molding chamber 2 is filled. After adding moisture, the molding chamber 2 is closed, the pressure in the closed molding chamber 2 is increased, and the boiling point of water in the molding chamber 2 is made higher than 100 ° C. It can also be set as the heating humidification process which heats the raw material W.
[0017]
Furthermore, in the molding method of the woody material of the present invention, in the molding step, the pressure in the molding chamber 2 is preferably 0.2 to 2 Mpa, preferably 0.3 to 1.5 Mpa, more preferably 0.4 to 1. .2 Mpa.
[0018]
Furthermore, in the method for molding a wood-based material of the present invention, in the pressure reduction step, preferably, after the molding chamber 2 is opened to the atmosphere, the molding chamber 2 is depressurized to an atmospheric pressure or lower so that moisture contained in the wood-based material W is contained. Remove.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. However, the examples shown below exemplify a method of forming a wood-based material for embodying the technical idea of the present invention, and the present invention does not specify the forming method as follows.
[0020]
Further, in this specification, in order to facilitate understanding of the scope of claims, the numbers corresponding to the members shown in the embodiments are referred to as “claims” and “means for solving the problems”. It is added to the member shown by. However, the members shown in the claims are not limited to the members in the embodiments.
[0021]
FIG. 3 shows an apparatus used in the method for forming a wood-based material of the present invention. This molding apparatus fills the molding chamber 2 with a heating mold 1 that molds the wood-based material W in a state of being hermetically sealed in the molding chamber 2, a pressing mechanism 3 that presses the heating mold 1 against the wood-based material W, and the like. And a boiler 4 that heats the wood-based material W in a wet state.
[0022]
In the drawing, the lower heating die 1 </ b> B has a peripheral wall 5 that forms a molding chamber 2. The peripheral wall 5 has a shape surrounding the periphery of the molding chamber 2, for example, a square shape. Further, the peripheral wall 5 has a flat upper surface so as to be in close contact with the lower surface of the protruding portion 6 protruding outward from the side surface of the lowered upper heating die 1A. A fitting groove for the packing 7 is provided on the upper surface of the peripheral wall 5, and the packing 7 is inserted and fixed therein. The packing 7 in the fitting groove is in close contact with the lower surface of the projecting portion 6 of the lowered upper heating die 1A, and hermetically closes the molding chamber 2 without causing gas leakage.
[0023]
The peripheral wall 5 forming the molding chamber 2 can be integrally formed with the lower heating die 1B, or can be a separate member from the heating die. The peripheral wall of the heating mold and the separate member is provided with fitting grooves on both upper and lower surfaces so that the gas does not leak between the heating mold and the packing is fitted into the fitting groove. The height of the peripheral wall 5 determines the thickness of the wooden material W to be compressed. This is because, in a state where the wood-based material W is compressed, the peripheral wall 5 is hermetically adhered to the upper heating die 1A to form the molding chamber 2.
[0024]
In the illustrated molding apparatus, a number of through holes 8 for connecting the boiler 4 are provided in the upper and lower heating dies 1. In the illustrated apparatus, a boiler 4 and a vacuum pump 10 are connected to a through hole 8 via a pipe 9. The boiler 4 supplies the pressurized water vapor to the molding chamber 2 to heat and pressurize the wood-based material W of the molding chamber 2 in a wet state.
[0025]
The boiler 4 press-fits pressurized water vapor into the molding chamber 2. The water vapor supplied from the boiler 4 to the molding chamber 2 adds moisture to the wood-based material W and heats and pressurizes the wood-based material W to form a predetermined shape.
[0026]
The boiler 4 supplies water vapor pressurized to 0.2 to 2 MPa, preferably 0.3 to 1.5 Mpa, more preferably 0.4 to 1.2 Mpa. If the temperature and pressure of the water vapor are too low, the entire wood-based material is uniformly replenished in a short time, making it impossible to mold in a heated state. This is because when the water vapor pressure is low, water cannot be replenished evenly into the woody material. The boiling point of water is 183 ° C. at 1 MPa. Therefore, water vapor with a pressure of 1 MPa can heat the wood-based material to about 180 ° C. When pressurized and heated water vapor is supplied to the molding chamber 2, the temperature of the wood-based material is raised by the amount of heat of the water vapor, but the water vapor deprived of heat to raise the temperature of the raw material is covered with water, Humidify woody materials. At this time, when the internal pressure of the molding chamber 2 is increased to 1.0 MPa / cm ² , the water enters a water state at a high temperature of 180 ° C. and heats the wood-based material while humidifying it. When the wood-based material is heated to water vapor and becomes higher than about 183 ° C., the water vapor does not become water-covered, but permeates the wood-based material and penetrates uniformly into the interior. Water vapor that permeates into the interior of the wood-based material is cooled by the wood-based material to become high-temperature water-covering, and when heated to a temperature higher than the boiling point with water-covered water and water vapor, the water-vapor penetrates further into the interior and humidifies Heat wood-based materials. The wood-based material heated with water vapor is subjected to a high-temperature and high-pressure treatment in the wet cellulose fiber inside, and is given a shape memory function by changing the crystal structure.
[0027]
The vacuum pump 10 depressurizes the molding chamber 2 and dries while cooling the wood-based material W. The apparatus for depressurizing the molding chamber 2 with the vacuum pump 10 has a feature that the wood-based material W taken out from the molding chamber 2 can be dried to a lower moisture content and cooled and taken out.
[0028]
In the apparatus shown in FIG. 3, an atmosphere release valve 11 and a pressure control valve 12 are also connected to the molding chamber 2. The air release valve 11 is closed when pressurizing and depressurizing the molding chamber 2. The valve is opened when the pressurized gas in the molding chamber 2 is exhausted or when the outside air is sucked into the decompressed molding chamber 2. The pressure control valve 12 is opened when the pressure in the molding chamber 2 becomes higher than the set pressure, and adjusts the pressure in the molding chamber 2 to the set pressure.
[0029]
The pressing mechanism 3 of the heating die 1 is a hydraulic cylinder connected to the upper heating die 1A. The hydraulic cylinder pushes down the upper heating die 1A to press the wooden material W of the molding chamber 2 and closes the molding chamber 2 in an airtight manner. The lower heating die 1B is fixed horizontally. The pressing mechanism connects the upper and lower heating dies to the hydraulic cylinder, presses the wood material, closes the molding chamber, or pushes the lower heating die with the hydraulic cylinder to press the wood material. You can also. Furthermore, the pressing mechanism does not necessarily need to use a hydraulic cylinder. The pressing mechanism can also press the heating mold with a cam or a crank mechanism, for example.
[0030]
Furthermore, the apparatus shown in the figure includes a clamping device 13 that holds the heating die 1 in a pressed state. The clamping device 13 shown in the drawing holds the upper heating die 1A pushed down by the pressing mechanism 3 in a predetermined position. In the clamping device 13, the lock portion that comes into contact with the upper surface of the protruding portion 6 of the upper heating die 1 </ b> A enters and exits to hold the heating die 1 in a pressed state, or release the pressed state. When the heating die 1 is in the pressed state, the clamp device 13 causes the lock portion to protrude inward, and holds the protruding portion 6 of the upper heating die 1A in the locked state. When the pressing state of the heating die 1 is released, the clamping device 13 stores the lock portions in directions away from each other to release the locked state. As described above, the molding apparatus that holds the heating die 1 in the pressed state by the clamping device 13 does not need to be held in the pressure press state by the pressing mechanism, and thus has a feature that the pressing mechanism can be simplified and reduced in cost.
[0031]
The wood-based material can be heated by a heating type without using water vapor, or can be heated by both water vapor and a heating type. The wood-based material heated by the heating mold is added with water in a pre-process for filling the molding chamber 2 or in a state of filling the molding chamber. The heating mold can be heated to a predetermined temperature with, for example, steam or a heater. The heating type heated by steam is provided with a passage through which steam passes. The heating type heated by the heater incorporates a heater heated by electricity.
[0032]
【Example】
[Example 1]
The above forming apparatus forms a wood-based material as follows.
[Process of filling wood material into molding room]
As the wood-based material W, a waste paper such as a magazine or a newspaper is pulverized by a dry method, and then defibrated and made into a cotton-like material. The wood-based material W is preliminarily molded with a preforming mold while being mechanically dispersed, and then filled into the molding chamber 2. Preliminary molding is to form in advance by compressing in a dry manner so that it can be easily put into a mold. However, in the method of the present invention, it is not always necessary to preform the wood-based material and fill the molding chamber. A wood-based material that has been preformed or not preformed is filled into a heating heating mold, and the heating mold is closed to close the molding chamber. The heating mold is heated to about 180 ° C.
[0033]
[Molding process]
A wooden material is formed by supplying water vapor to the closed forming chamber 2. At this time, the wooden material W can be uniformly humidified by controlling the pressure in the molding chamber 2. The pressure in the molding chamber 2 is adjusted by adjusting the pressure of the supplied water vapor or by the pressure control valve 12 connected to the molding chamber 2. The wood-based material W put into the molding chamber 2 is filled in the molding chamber 2 of the heating mold 1 that has been heated in advance. However, since the heat conduction is poor, only the surface of the heating mold 1 is heated. Accordingly, immediately after the molding chamber 2 is filled, the temperature of the central portion of the wood-based material W is substantially the same as that before the mold is inserted. Thereafter, when steam is supplied to the molding chamber 2, the temperature of the wood-based material W is raised by the amount of heat of the steam. The water vapor supplied to the wooden material W is deprived of heat and covered with water in order to raise the temperature of the wooden material W. The liquefied water covering humidifies the wood-based material W. When the internal pressure of the molding chamber 2 is increased to 1.0 MPa / cm ² , the moisture becomes a state of high-temperature water at 180 ° C., and the water is not covered after the temperature of the wood-based material W rises to this temperature. It penetrates inside the material W. The water vapor penetrating into the inside becomes water-covering while heating the wood-based material W, and heats the wood-based material W while uniformly humidifying it.
[0034]
[Pressure drop process]
Next, the internal pressure of the molding chamber 2 is released to normal pressure, and then vacuum suction is performed to keep the internal pressure at a negative pressure. In this state, the wood-based material W that has been heated to 180 ° C. in a water-containing state evaporates due to the boiling of water due to the decrease in internal pressure. This is because the boiling point of water is 183 ° C. when the boiling point is 1.0 Mpa, but 45 ° C. when −90 Kpa.
[0035]
As a result, the water contained in the center of the woody material W is also uniformly evaporated and removed. Even if the wood-based material W having a high water content is heated to 180 ° C., it may not be able to compensate for all the heat that evaporates the water with the heated heat. However, in this state, the wood-based material W is heated by the heating mold 1 and is continuously heated from the surface to evaporate the contained water. The woody material W is hydrogen-bonded and formed into a predetermined shape by retaining the contained water by evaporating and removing it, so that the shape is retained.
[0036]
Thereafter, the heating mold 1 is opened, and the molded wood material W is taken out of the heating mold 1.
[0037]
[Example 2]
The wood-based material is formed in the same manner as in Example 1 except that the wood-based material is formed as two steps of the heating and humidifying step (1) and the shape memory forming step (2).
(1) Heating and humidifying step: Same as the molding step of Example 1 (2) Shape memory molding step Immediately after the temperature of the entire wood material W is raised to 180 ° C., the molding chamber 2 is decompressed as in Example 1. However, the cellulose fibers contained in the wood-based material W can be given a shape memory function by changing the crystal structure when subjected to high-temperature and high-pressure treatment in a state having moisture, so that the high-temperature and high-pressure state is maintained for a certain period of time. Thus, it is molded so as not to lose its shape.
[0038]
[Example 3]
In the molding method described above, the molding chamber 2 is filled with water vapor to heat the wood-based material W, but water is added to the wood-based material W and the heating die 1 is heated and pressurized by the following method. W can also be formed.
[0039]
[Process of filling wood material into molding room]
The same woody material W as in Example 1 is used. After the moisture is added to the wood-based material W and preformed, the molding chamber 2 is filled. The amount of water added is 10 to 40% by weight, preferably about 10 to 30% by weight, and more preferably about 20% by weight. The wood-based material W can be added before filling the molding chamber 2, while filling the molding chamber 2, or after filling the molding chamber 2. The wood-based material W that is preformed or not preformed is filled in the heating mold 1 that is heated, the heating mold 1 is closed, and the molding chamber 2 is closed. Heating mold 1 is heated to about 180 ° C.
[0040]
[Molding process]
Pressurized air is supplied to the closed molding chamber 2. At this time, the wooden material W can be uniformly humidified by controlling the pressure in the molding chamber 2. The pressure in the molding chamber 2 is adjusted by the supplied air pressure. The wood-based material W put into the molding chamber 2 is filled in the molding chamber 2 of the heating mold 1 that has been heated in advance. However, since the heat conduction is poor, only the surface of the heating mold 1 is heated. Accordingly, immediately after the molding chamber 2 is filled, the temperature of the central portion of the wood-based material W is substantially the same as that before the mold is inserted. Thereafter, water contained in the wood-based material W is heated by the heating mold 1 to become water vapor. The generated water vapor penetrates into the woody material W. This water vapor is deprived of heat in order to raise the temperature of the wood-based material W and is covered with water. The water covering humidifies the wooden material W. When the internal pressure of the molding chamber 2 is increased to 1.0 MPa / cm ² , the moisture becomes a state of high-temperature water at 180 ° C., and the water is not covered after the temperature of the wood-based material W rises to this temperature. It penetrates inside the material W. The water vapor penetrating into the inside becomes water-covering while heating the wood-based material W, and heats the wood-based material W while uniformly humidifying it.
[0041]
Thereafter, the wood-based material W is molded in the same molding process and pressure reduction process as in Example 1 or 2, and then the heating mold 1 is opened, and the molded wood-based material W is taken out from the heating mold 1.
[0042]
In the above forming method, the wood-based material W is molded without adding a binder, but the wood-based material can be molded by adding a small amount of a binder. For example, a starch or the like can be used as the binder. The binder is added to the wood-based material before or after filling the molding chamber.
[0043]
【The invention's effect】
The method for molding a wood-based material of the present invention has the advantage that the wood-based material can be efficiently molded into various shapes. In the molding method of the present invention, a wood-based material is filled in a heating mold chamber, and water vapor is supplied to the closed molding chamber, or water vapor is generated inside the molding chamber, and this water vapor generates a wood-based material. Heat the material in a wet state under pressure, hold it at high temperature and high pressure for a certain period of time, shape it with the shape memory effect of cellulose contained in the wood-based material, and then reduce the vacuum in the closed molding chamber This is because the high temperature water contained in the wood-based material is removed by evaporating. The water vapor supplied to the molding chamber that is closed and held in a pressurized state passes through the gaps in the wood-based material, heats the wood-based material, and further covers the water while keeping the wood-based material wet. To penetrate. The wood-based material heated in this state becomes wet while being rapidly heated to the inside. In this state, the wood-based material is formed into a certain shape, and in this state, without removing the wood-based material from the molding chamber, the molding chamber is decompressed to evaporate and vaporize the contained water. The wood-based material molded product molded in this state is molded into a predetermined shape under heating, pressurization, and wet conditions, and further dried in the molded state, so that it does not lose its shape into a predetermined shape with high accuracy. Can be molded accurately.
[0044]
The wood-based material molded by this method can be molded into a predetermined shape with little or no added binder. In addition, there is also a feature that it can be sufficiently dried after being heated up to the inside in an ideal state.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an apparatus used in a conventional method for manufacturing a cushioning material. FIG. 2 is a schematic configuration diagram of another device used in a conventional method for manufacturing a cushioning material. Sectional view of the equipment used for the molding method
DESCRIPTION OF SYMBOLS 1 ... Heating type | mold 1A ... Upper heating type | mold 1B ... Lower heating type | mold 2 ... Molding chamber 3 ... Pressing mechanism 4 ... Boiler 5 ... Perimeter wall 6 ... Protrusion part 7 ... Packing 8 ... Through-hole 9 ... Piping 10 ... Vacuum pump 11 ... Air release valve 12 ... Pressure control valve 13 ... Clamping device 14 ... Forming machine 15 ... Narrowing roller 16 ... Nozzle 17 ... Press plate 18 ... Jet plate 19 ... Heat plate W ... Wooden material

Claims

In a method of heating and molding a wood-based material that generates hydrogen bonds by volatilizing moisture such as paper pulp, wood fiber, wood powder,
Filling the molding chamber (2) of the heating mold (1) with the wooden material (W), heating the molding chamber (2) in the closed state, and spraying pressurized steam to heat the wooden material (W). The molding process of humidifying and molding
After spraying pressurized water vapor to heat and humidify the wood-based material (W), hold the wood-based material (W) in the molding chamber (2) in a heated state at a pressure of 0.2 to 2 MPa for a certain period of time. Then, due to the shape memory effect of cellulose contained in the wood-based material (W), including a shape memory molding step of molding the outer shape of the wood-based material (W) into the shape of the molding chamber (2) ,
A method for molding a wood-based material, comprising a pressure reduction step of depressurizing and vacuum degassing the molding chamber (2) and evaporating and removing high-temperature water contained in the wood-based material (W) after the molding step.

In the molding process, the wood material (W) is filled into the molding chamber (2) of the heating mold (1), heated into the molding chamber (2) in the closed state, and pressurized water vapor is sprayed to the wood material (W Heating and humidifying molding step to mold by heating and humidifying,
The woody material (W) in the molding chamber (2) is kept in a heated state at a pressure of 0.2-2 Mpa for a certain period of time, and the woody material is obtained by the shape memory effect of cellulose contained in the woody material (W). The method for forming a wood-based material according to claim 1, further comprising a shape memory forming step of forming the outer shape of the system material (W) into the shape of the molding chamber (2).

In the molding process, the pressure in the molding chamber (2) is set to 0.2 to 2 MPa, and in the pressure lowering process, the molding chamber (2) is opened to the atmosphere, and then the molding chamber (2) is depressurized to an atmospheric pressure or below to make wood. The method for forming a wood-based material according to claim 1, wherein moisture contained in the system material (W) is removed.

In a method of heating and molding a wood-based material that generates hydrogen bonds by volatilizing moisture such as paper pulp, wood fiber, wood powder,
Fill the wood-based material (W) filled with moisture into the molding chamber (2) of the closed heating mold (1), or add moisture to the wood-based material (W) filled in the molding chamber (2). After the addition, the molding chamber (2) is closed, the pressure of the closed molding chamber (2) is increased, the boiling point of water in the molding chamber (2) is made higher than 100 ° C., and the heating mold ( The molding process of heating the wood-based material (W) in 1)
The woody material (W) in the molding chamber (2) is kept in a heated state at a pressure of 0.2-2 Mpa for a certain period of time, and the woody material is obtained by the shape memory effect of cellulose contained in the woody material (W). Including a shape memory molding process for molding the outer shape of the system material (W) into the shape of the molding chamber (2) ,
A method for molding a wood-based material, comprising a pressure reduction step of depressurizing and vacuum degassing the molding chamber (2) and evaporating and removing high-temperature water contained in the wood-based material (W) after the molding step.

The molding process fills the closed heating mold (1) with the wood-based material (W) to which moisture has been added (2), or the wood-based material (W) filled into the molding chamber (2). ), Water is added, the molding chamber (2) is closed, the pressure in the closed molding chamber (2) is increased, and the boiling point of water in the molding chamber (2) is raised above 100 ° C. A heating and humidifying step of heating the wood-based material (W) with the heating mold (1),
The woody material (W) in the molding chamber (2) is kept in a heated state at a pressure of 0.2-2 Mpa for a certain period of time, and the woody material is obtained by the shape memory effect of cellulose contained in the woody material (W). The method for forming a wood-based material according to claim 4, comprising a shape memory forming step of forming the outer shape of the system material (W) into the shape of the molding chamber (2).

In the molding process, the pressure in the molding chamber (2) is set to 0.2 to 2 MPa, and in the pressure lowering process, the molding chamber (2) is opened to the atmosphere, and then the molding chamber (2) is depressurized to an atmospheric pressure or below to make wood. The method for forming a wood-based material according to claim 4, wherein moisture contained in the system material (W) is removed.