JP4011220B2

JP4011220B2 - Separation method of resin coating on inner surface of metal tube

Info

Publication number: JP4011220B2
Application number: JP01246099A
Authority: JP
Inventors: 易之谷口; 良治小林; 重樹岸原; 誠熊川
Original assignee: Dai Ichi High Frequency Co Ltd
Current assignee: Dai Ichi High Frequency Co Ltd
Priority date: 1999-01-20
Filing date: 1999-01-20
Publication date: 2007-11-21
Anticipated expiration: 2019-01-20
Also published as: JP2000210937A

Description

【０００１】
【発明の属する技術分野】
本発明は、使用済の、又は不合格の樹脂被覆金属管から樹脂被覆と金属管を分離回収し、資源としての再利用を図るために行う、樹脂被覆分別方法に関し、具体的には内面被覆への適用を可能にした方法に関する。
【０００２】
【従来の技術】
水道管、海水管、薬液配管などの金属管の管内面防食手段として、ポリオレフィン（ポリエチレンなど）、ポリ塩化ビニル、ポリアミド（ナイロンなど）、フッ素樹脂（テフロンなど）などの熱可塑性樹脂による厚膜被覆（通常は０．５〜３ｍｍ程度）が主流をなしている。
【０００３】
更新のために取り外された使用済品、あるいは、工場生産時の不合格品の処分が難題であり、樹脂を加熱軟化させて手剥がしし、樹脂や金属管を資源として再利用し、金属管を再度被覆用途に供することは不可能ではないが、剥がしに多大な手数がかかる。又、剥がした樹脂の資源としての再利用技術が実用的にペイできるレベルにはなかった。特に、塩ビ被覆管は、樹脂が硬質であるために剥がしにくいことから、被覆付きの管体を小切片に切り分けて埋設廃棄せざるを得ない状況にあった。
【０００４】
しかし、廃棄スペースの不足が加速しており、対策が切望されていた。折しも、樹脂の再資源化については、超臨界水処理などにより油脂類に分解して再利用に供する途が開けてきたことから、樹脂被覆を金属管から分別する技術が切望されている。
【０００５】
樹脂被覆を金属母材から分離するために、誘導加熱を利用した種々の方法が先願で提案されている。しかし、これらは、金属管の外周面とか、大径の金属管の内周面のように、アクセス可能に露呈した被覆を対象としたものであり、内径が数１０〜数１００ｍｍの管の内面に施された被覆には適用できない。
小径の金属管の内面に施されている樹脂被覆でも金属管から剥がすことができる方法として、管内面全体を加熱して樹脂被覆の接着強度を低下させると共に軟化させておき、金属管の一端側で樹脂被覆を剥がして掴み代を作り、その掴み代を引っ張ることで樹脂被覆を一端側から他端側までつながった状態で剥がして行く方法が知られている。しかしながら、この方法で樹脂被覆を剥がしてゆく際、加熱状態によっては、或いは剥離すべき樹脂被覆によっては、剥がれた後の樹脂被覆が依然として軟らかく、強度が低くて引きちぎらてしまうことがあるという問題があった。
【０００６】
【発明が解決しようとする課題】
本発明は、かかる状況に鑑みて為されたもので、内径が数１０〜数１００ｍｍといった小径の金属管の内面に施されている樹脂被覆に対しても、容易に且つ効率よく、樹脂被覆を金属管の一端側から他端側までつながった状態で即ち途中で引きちぎられることなく剥がして、金属管から分別することの可能な金属管内面樹脂被覆の分別方法を提供することを目的とする。
【０００７】
【課題を解決するための手段】
本願第一の発明は上記目的を達成するため、金属管の一端側で内面の樹脂被覆を剥がして掴み代を作り、その掴み代を他端方向に反転させると共に管内に挿通させた把持・牽引手段によって金属管の他端に向かって引っ張ることで樹脂被覆を反転させながら剥がしてゆき、その際に、少なくとも、既剥離領域と未剥離領域を分ける剥離前線近傍の管体を加熱して樹脂被覆の接着強度を一過的に低下させて樹脂被覆を剥がし易くし、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却するという構成としたものである。この構成により、樹脂被覆の一端を剥がして形成した掴み代を把持・牽引手段で掴んで他端に向かって直線状に引っ張ってゆくと、剥離前線では管体が局部的に加熱されているため接着強度が低下すると共に樹脂被覆が軟らかくなっていて容易に屈曲でき、しかも樹脂被覆は金属管内面から引き起こされるように引っ張られるため、樹脂被覆が屈曲しながらきわめて円滑に剥がれてゆき、剥がれた後の強制冷却による温度低下により硬くなって引きちぎれにくくなった樹脂被覆を介して引っ張り続けることで、樹脂被覆を金属管の一端から他端までつながった形態で効率良く剥がすことができる。
【０００８】
本願第二の発明は、金属管の一端側で内面の樹脂被覆を剥がしてスパイラル状の掴み代を作り、その掴み代を管内に挿通させた把持・巻付け手段に連結し、次いでその把持・巻付け手段を回転させてその上に樹脂被覆を巻き取ってゆくことで樹脂被覆を剥がし、同時に或いはそれに先立って、前記樹脂被覆にスパイラル状に切り込みを施すことで、金属管内面の樹脂被覆をスパイラル状に剥がしてゆき、その際に、少なくとも、既剥離領域と未剥離領域を分ける剥離前線近傍の管体を加熱して樹脂被覆の接着強度を一過的に低下させて樹脂被覆を剥がし易くし、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却するという構成としたものである。この構成により、把持・巻付け手段を回転させ、その上に樹脂被覆を巻き付けてゆくことで、樹脂被覆を金属管の一端から他端に向かってスパイラル状に剥がしてゆくことができ、その際、剥離前線では管体が局部的に加熱されているため接着強度が低下すると共に樹脂被覆が軟らかくなっていて容易に屈曲でき、しかも樹脂被覆は金属管内面から引き起こされるように引っ張られるため、樹脂被覆が屈曲しながらきわめて円滑に剥がれてゆき、剥がれた後の強制冷却による温度低下により硬くなって引きちぎれにくくなった樹脂被覆を介して巻き取り続けることで、樹脂被覆を金属管の一端から他端までつながった形態で効率良く剥がすことができる。
【０００９】
本願第三の発明は、金属管の一端側で内面の樹脂被覆を剥がして掴み代を作り、その被覆の掴み代を前記一端側から管軸方向の外方に引っ張って筒状の樹脂被覆を管軸方向に引き伸ばし且つ縮径させ、その縮径を利用して金属管内面から剥がしてゆき、その際に、少なくとも、既剥離領域と未剥離領域を分ける剥離前線近傍の管体を加熱して樹脂被覆の接着強度を一過的に低下させて樹脂被覆を剥がし易くし、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却するという構成としたものである。この構成により、剥がした掴み代を管軸方向に引っ張って樹脂被覆を金属管内面から剥がしてゆくと、剥離前線では管体が局部的に加熱されているため接着強度が低下すると共に樹脂被覆が軟らかくなっていて容易に伸張・縮径でき、しかも樹脂被覆は、縮径により金属管内面から引き起こすように引っ張られるため、樹脂被覆が伸張・縮径しながらきわめて円滑に剥がれてゆき、剥がれた後の強制冷却による温度低下により硬くなって引きちぎれにくくなった樹脂被覆を介して引っ張り続けることで、樹脂被覆を金属管の一端から他端までつながった形態で効率良く剥がすことができる。
【００１０】
【発明の実施の形態】
本願第一の発明は、金属管内面に施された樹脂被覆の、管の一端側の端部を剥離させて掴み代を作り、該掴み代を金属管内に挿通させた把持・牽引手段に連結すると共に金属管の他端側を向くように反転させ、次いでその掴み代を前記把持・牽引手段により前記金属管の他端側に引っ張って樹脂被覆を反転させながら管軸方向に剥がしてゆき、その際、少なくとも既剥離領域と未剥離領域とを分ける剥離前線付近の管体を加熱して樹脂被覆の接着強度を一過的に低下させておき、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却することを特徴とする金属管内面樹脂被覆の分別方法である。以下、その実施形態を図面を参照して詳細に説明する。
【００１１】
図１は、本発明の一実施形態によって金属管１の内面に施されている樹脂被覆２を剥がす手順を示すものである。まず、図１（ａ）に示すように、金属管１の一端において、樹脂被覆２の端部を金属管１から剥がし、掴み代２ａを作る。この作業は、金属管１と樹脂被覆２の間に管端側からくさびを打ち込む等の手作業によって行う。この際、管端を加熱して剥がれやすくすることが好ましい。
【００１２】
次に、図１（ｂ）に示すように、剥がした掴み代２ａを管内に挿通させた把持・牽引手段４に連結し且つその掴み代２ａを折り返す。ここで用いる把持・牽引手段４は、掴み代２ａを金属管１の他端に向かって（矢印Ａ方向に）引き抜くことができるものであれば任意であり、本実施形態では、金属管１内に挿入される引抜棒４ａと、その先端に取り付けられ、掴み代２ａに連結するための連結具４ｂと、引抜棒４ａを矢印Ａ方向に引き抜くための駆動装置（図示せず）を備えている。
【００１３】
次いで、金属管１の管軸方向の小領域を環状に局部的に加熱することの可能な、誘導コイル等の局部加熱手段５を、金属管１の外側に且つ、既剥離領域と未剥離領域とを分ける剥離前線６付近の管体（好ましくは剥離前線６及びこれに隣接する未剥離領域）を加熱しうる位置に配置し、剥離前線６付近の管体を加熱して被覆の接着強度を一過的に低下させると共に把持・牽引手段４を金属管１の他端側へ引っ張って樹脂被覆２を剥がす。この時、剥離前線６では管体１が局部的に加熱されているため接着強度が低下すると共にその部分の樹脂被覆２ｂが軟らかくなっていて容易に屈曲でき、しかも樹脂被覆２は金属管内面から引き起こすように引っ張られるため、樹脂被覆２ｂが屈曲しながら引き起こされ、剥離前線６に集中的に剥がし力が作用することとなり、これによって樹脂被覆２ｂがきわめて円滑に剥がされる。このような剥離進展操作を、局部加熱手段５を管の他端方向へ順次移動させ、従って加熱位置を順次移動させながら進めてゆく。これにより、図１（ｃ）に示すように、剥がされた樹脂被覆２ｃを金属管内面に接着していた状態とは内外面を逆にした形態に反転させながら金属管１の他端側に引き抜いてゆき、最終的には金属管１から分離できる。
【００１４】
ここで、樹脂被覆２が剥がされる際、管体の加熱によって樹脂被覆２も加熱されて軟らかくなるが、剥がれた後は放冷されやすくなり温度が下がって硬くなるので引きちぎられるということはあまりなく、樹脂被覆を金属管の一端から他端までつながった形態で効率良く剥がすことができる。しかしながら、金属管の加熱状態によっては、或いは剥離すべき樹脂被覆によっては、剥がれた後の樹脂被覆２が依然として軟らかく、強度が低くて引きちぎられる恐れのある場合がある。そこで、樹脂被覆を剥がしてゆく途中で引きちぎられることがないよう、剥がした後の樹脂被覆の強度を十分に回復させるため、剥がした樹脂被覆を強制冷却する。強制冷却の方法としては、例えば、金属管内に冷却用の空気を流して空冷する方法、剥がした直後の樹脂被覆に冷却用の空気、ミスト、水等をノズルで直接吹き付ける方法等を挙げることができる。
【００１５】
上記した剥離操作において、局部加熱手段５による金属管１の加熱温度は、接着強度は低下させるが、樹脂被覆２を過度に軟化させることがないように設定するものであり、剥がすべき樹脂被覆２の種類によっても異なるが、通常、８０〜１５０°Ｃ程度とすればよい。
【００１６】
前記したように、この実施形態では、局部加熱手段５で加熱した領域の樹脂被覆を把持・牽引手段４によって剥がしてゆくという剥離進展操作を、局部加熱手段５を管の他端方向へ順次移動させ、従って加熱位置を順次移動させながら進めている。この剥離進展操作を進めてゆく具体的な方法としては、連続的、間欠的などの種々な方法を採ることができ、例えば、次に示すような方法を例示できる。
【００１７】
（１）把持・牽引手段４を連続的に引っ張って樹脂被覆２を連続的に剥がしてゆき、同時にその剥離前線６の移動と連動するように局部加熱手段５を連続的に移動させ、剥離前線６近傍を加熱する方法。
（２）把持・牽引手段４は連続的に引っ張って樹脂被覆２を連続的に剥がしてゆくが、局部加熱手段５は間欠的に移動させて剥離前線６の近傍を加熱する方法。
（３）局部加熱手段５を停止させて、一定領域を加熱した後、把持・牽引手段４を引っ張って加熱した領域の樹脂被覆２を剥がし、次いで、局部加熱手段５を次に剥がすべき領域に移動させてその領域を加熱した後、再度把持・牽引手段４を引っ張って加熱した領域の樹脂被覆２を剥がすというように、局部加熱手段５及び把持・牽引手段４を間欠的に動作させる方法。
（４）局部加熱手段５を金属管１の適当な長さの領域に渡って連続的に移動させてその領域を加熱した後、把持・牽引手段４を引っ張って加熱した領域の樹脂被覆２を剥がし、次いで、局部加熱手段５を再び連続的に移動させて次に剥がすべき領域を加熱し、その後、再度把持・牽引手段４を引っ張って加熱した領域の樹脂被覆２を剥がすというように、局部加熱手段５及び把持・牽引手段４を連続、間欠を組み合わせて動作させる方法。
【００１８】
上記した方法の実施に当たって、局部加熱手段５による金属管１の加熱幅は、局部加熱手段５を連続的に移動させる場合は剥離前線６を所望温度に加熱しうるものであれば、狭いものでよく、例えば、２０〜１００ｍｍ程度でよい。一方、局部加熱手段５を間欠的に移動させる場合には、一度に或る程度広い幅を加熱した方が作業性が良いが、あまり広くすると局部加熱手段５が大型化し、イニシャルコストやランニングコストが高くなるので、これらを考慮して、１００〜５００ｍｍ程度とすることが良い。
【００１９】
把持・牽引手段４によって樹脂被覆を剥がしてゆく際の、把持・牽引手段４の駆動制御方法は任意であり、例えば、把持・牽引手段４の移動速度或いは移動量をほぼ一定とする方式のものでもよいし、把持・牽引手段４が樹脂被覆２に作用させるひっ張り力をほぼ一定とする方式のものでもよいが、後者の場合の方が、剥離動作中に樹脂被覆がちぎれるということが生じにくく、好ましい。すなわち、後者の場合には、把持・牽引手段４が樹脂被覆２に作用させる引っ張り力を、加熱されて剥がれやすくなった樹脂被覆２が剥離しうるが温度が下がった被覆が引きちぎれるには到らないレベルの引っ張り力（例えば、１ｋｇ／ｃｍ幅）に設定しておくと、管体が加熱され、接着強度が上記レベル迄低下した個所で剥離が自動的に起こってこの個所が剥離前線となり、結果的には剥離前線を狙って程よい加熱を施す操作が巧まずして行えることととなるからである。言い換えれば局部加熱手段の進行に合わせて剥離前線が進行するものであり、局部加熱手段による加熱にむらが生じたような場合にも、剥離前線の進行が遅くなるだけであって樹脂被覆の引きちぎれは起こらない。すなわち、剥離前線６と局部加熱手段５の位置関係を精密に管理する必要がなくなるという利点が得られる。
【００２０】
なお、前記した実施形態では剥離進展操作を管端に向かって順次進める際に、金属管１を停止させておき、引抜棒４ａ及び局部加熱手段５を移動させているが、本発明はこの構成に限らず、引抜棒４ａ及び局部加熱手段５を金属管１に対して相対的に移動させれぱよく、例えば、局部加熱手段５を定位置に配置し、金属管１を移動させるように変更してもよい。
【００２１】
以上に説明した方法では、金属管１の内面に貼り付けていた筒状の樹脂被覆２を剥がして反転させて直径を小さくするため、剥がされた後の樹脂被覆２ｃは図２に示すように、円周方向にしわのよった形態となる。ところで、樹脂被覆２が硬い場合などには、図２に示す形状に変形させることが困難な場合がある。図３はこのような問題を解決しうる実施形態を示すものであり、この実施形態では、剥がされた直後の（即ち剥離前線６付近の）樹脂被覆２ｂにカッタ８で管軸方向の切り込みを施しながら、剥離進展操作を行う。このように剥がされた樹脂被覆２を管軸方向に切断してゆくと、図４に示すように、剥がした後の樹脂被覆２ｄを円周方向に部分的に重ねることができ、剥がした後の樹脂被覆２を反転させる操作が円滑となり、掴み代２ａを管の他端側へ引っ張り易くなる。なお、樹脂被覆２に入れる管軸方向の切り込みは図示した１個に限らず、複数個としてもよく、これにより、樹脂被覆を複数の帯状セグメントに分割しつつ剥がすことができる。また、樹脂被覆２に切り込みを入れる位置は、剥がした直後とする場合に限らず、剥がす前の位置（未剥離領域）としてもよく、未剥離領域で樹脂被覆２に切り込みを入れる場合には、剥離前線６の近傍に限らず、離れた位置でもよい。従って、把持・牽引手段４にカッタ８を取り付けておき、その把持・牽引手段４で掴み代２ａを引っ張ってゆく際に、同時に管内面の樹脂被覆２にカッタ８で切り込みを入れていっても良い。更には、樹脂被覆の剥離動作に先立って、管内面の樹脂被覆２に管軸方向の切り込みを入れるように変更してもよい。
【００２２】
樹脂被覆２に切り込みを入れるためのカッタ８としては、図示したナイフ形式のものを用いることが簡便であるが、これに限らず、他の形式のカッタ、例えば、ヤグレーザーを用いたレーザーカッタ等を用いてもよい。ナイフ形式のカッタ８を用いる場合には、未剥離の樹脂被覆２に切り込むと刃先が金属管１の内面に接触して早く摩耗することがあるので、切り込み深さを金属管内面に接触しない程度に留めておくことが好ましい。一方、レーザーカッタではこのような問題がないので、管内面に接着した状態の樹脂被覆２に切り込みを入れる場合に用いることが好ましい。
【００２３】
前記した剥離進展操作を、樹脂被覆に複数の管軸方向の切り込みを入れて複数の帯状セグメントに分割して実施する場合には、図５に示すように、剥がした後の隣接した帯状セグメント２ｄａ、２ｄｂの剥離前線６ａ、６ｂを管軸方向にずらせることも可能である。このように、剥離前線６ａ、６ｂを管軸方向にずらせると、剥がされた帯状セグメント２ｄａ、２ｄｂを円滑に部分的に重なり合わせることができ、樹脂被覆２をきわめて円滑に剥がすことができる。更には、複数の帯状セグメントを同時に剥がす代わりに複数段（通常は２段）に分けて剥がしても良い。例えば、図６に示すように、まず、円周上に１個おきに位置する帯状セグメント２ｄａを剥がし、次いで、残りの帯状セグメント２ｄｂを剥がすようにしてもよい。この場合には、剥がされた帯状セグメント２ｄａ、２ｄｂが互いに干渉しないので、きわめて円滑に剥がすことができる。
【００２４】
なお、図１〜図６に示した各方法において、掴み代を他端側へ引っ張る操作を、軸線を中心とした捩りを加えながら行うことにより、剥離前線の樹脂被覆に捩り力を同時に作用させて剥離を増進させ且つ既剥離部を絞り外径を縮めて引っ張りやすくすることもできる。
【００２５】
以上の実施形態では、金属管１を局部加熱手段５で局部的に加熱しながら剥離動作を行うものとしているが、本発明はこの構成に限らず、樹脂被覆２を剥がす前に、金属管１全体を接着強度が一過的に小さくなるように加熱し、その状態で前記した把持・牽引手段４による剥離動作を行う構成としてもよい。その場合、金属管１の加熱方法は任意の方法を採ることができ、例えば、局部加熱手段５を移動させて金属管全体を加熱するとか、金属管１を炉内に置いて加熱する等の方法を採ることができる。このように金属管１の全体を加熱する構成とすると、局部的に加熱する場合に比べてエネルギーロスは大きくなるが、加熱位置を剥離前線６に合わせて移動させる動作が不要となり、加熱動作が簡単となる。
【００２６】
次に、本願第二の発明を説明する。第二の発明は、金属管内面に施された樹脂被覆の、管の一端側の端部をスパイラル状に剥離させて掴み代を作り、その掴み代を管内に挿通させた把持・巻付け手段に連結し、次いでその把持・巻付け手段を回転させてその上に樹脂被覆を巻き取ってゆくことで樹脂被覆を剥がし、同時に或いはそれに先立って、既剥離領域と未剥離領域とを分ける剥離前線付近若しくは未剥離領域において前記樹脂被覆にスパイラル状に切り込みを施し、これによって金属管内面の樹脂被覆をスパイラル状に剥がしてゆき、その際、少なくとも既剥離領域と未剥離領域とを分ける剥離前線付近の管体を加熱して樹脂被覆の接着強度を一過的に低下させておき、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却することを特徴とする金属管内面樹脂被覆の分別方法である。
【００２７】
図７は、この分別方法の実施形態によって金属管１１の内面に施されている樹脂被覆１２を剥がす状態を示すものである。この実施形態では、図７（ａ）に示すように、金属管１１の一端において、樹脂被覆１２の端部を金属管１１からスパイラル状に剥がして掴み代１２ａを作り、その掴み代１２ａを管内に挿通させた把持・巻付け手段１４に固定し、その把持・巻付け手段１４を回転させることで、その上に剥がした樹脂被覆を巻き取ることができるようにし、更に、剥離前線付近若しくはその上流の未剥離領域の樹脂被覆にスパイラル状に切り込むようにカッタ駆動装置１５Ａに取り付けたカッタ１５を位置させる。ここで用いる把持・巻付け手段１４は、掴み代１２ａを連結可能で且つ剥がした樹脂被覆を巻き取ることができる構成のものであれば任意であり、この実施形態では樹脂被覆を巻き付けることができる棒材を用いている。この把持・巻付け手段１４は、金属管１１内に挿入した後は、管軸方向には移動させないで、その位置で回転のみをさせて、図７（ｂ）に示すように剥がした樹脂被覆１２ｃを長い領域に巻き取ってゆく構成でもよいし、巻付け位置が樹脂被覆の剥離前線１６にほぼ一致するように巻付け手段１４を管軸方向に移動させながら回転させて、剥離した被覆を管軸方向に詰め合わせて巻き取ってゆく構成のものでもよい。一方、カッタ１５を保持したカッタ駆動装置１５Ａは、樹脂被覆１２をスパイラル状に切ることができるよう、回転しながら軸線方向に移動する構成としている。これらの機構は公知の任意のものを使用しうる。
【００２８】
金属管１１の外側には、スパイラル状に剥がしていく樹脂被覆の幅よりも少し大きい管軸方向の領域を環状に局部的に加熱することの可能な誘導コイル等の局部加熱手段１８を、剥離前線１６付近の管体（好ましくは剥離前線１６及びこれに隣接する未剥離領域）を加熱しうる位置に配置し、剥離前線１６付近の管体を加熱して被覆の接着強度を一過的に低下させると共に、カッタ駆動装置１５Ａを回転させながら管軸方向に移動させることでカッタ１５により剥離前線１６付近若しくは下流（なお、本明細書では剥離前線が移動してゆく先を下流とする）の未剥離領域の樹脂被覆１２にスパイラル状に切り込みを施しながら、把持・巻付け手段１４を回転させて剥がした樹脂被覆１２ｃを巻き付けてゆき、これにより、剥離前線１６にある樹脂被覆１２ｂに引っ張り力を作用させて剥がしてゆく。この時、剥離前線１６では管体１１が局部的に加熱されているため接着強度が低下すると共にその位置の樹脂被覆１２ｂが軟らかくなっていて容易に屈曲でき、しかも樹脂被覆１２ｂは金属管内面から引き起こされるように引っ張られるため、樹脂被覆１２ｂが屈曲しながら引き起こされ、剥離前線１６に集中的に剥がし力が作用することとなり、これによって樹脂被覆１２ｂがきわめて円滑に剥がされる。このような剥離進展操作を、局部加熱手段１８を管の他端方向へ順次移動させながら進めてゆくことで、図７（ｂ）に示すように、剥がされた樹脂被覆１２ｃを把持・巻付け手段１４に巻き付けてゆき、最終的には金属管１１から分離できる。
【００２９】
この実施形態では、樹脂被覆１２を円周方向に剥がしてゆくが、一般に管体に施された樹脂被覆は円周方向の接着強度が管軸方向の接着強度よりも低い傾向があるので、剥がしやすいという利点が得られる。
【００３０】
図７に示す実施形態においても、金属管の加熱条件等は図１〜図６に示す実施形態と同様に設定すればよい。また、剥がした直後の樹脂被覆を強制冷却して強度を回復させ、ちぎれにくくする方法も採っている。更に、図７の実施形態でも、剥離進展操作を、局部加熱手段１８を管の他端方向へ順次移動させながら進めてゆく際の具体的な方法としては、図１〜図６の実施形態について説明したものと同様に種々な方法、例えば、剥がし動作と局部加熱手段１８の移動を共に連続的に行う方法とか、一方或いは双方を間欠的に行う方法等を採ることができる。また、把持・巻付け手段１４に樹脂被覆を巻き付けてゆく際の、把持・巻付け手段１４の回転制御方法も任意であり、例えば、一定の回転速度となるように制御する方法、一定のトルクで回転させる方法等を挙げることができる。後者を採用すると、剥離する樹脂被覆にほぼ一定の引っ張り力を作用させることができるので、好ましい。更に、この実施形態では剥離前線１６がスパイラル状に移動するので、管体を局部加熱するための手段としては、図示した金属管１１を環状に加熱する局部加熱手段１８を用いてそれを管軸方向に移動させる構成に限らず、剥離前線１６近傍のみを加熱する局部加熱手段を用い、それをスパイラル状に移動させる構成としてもよい。また、この実施形態に用いるカッタ１５としても、図示したナイフ式のものに限らず、レーザーカッタを用いてもよい。
【００３１】
更に、図７に示す実施形態では、剥離前線１６の近傍で、樹脂被覆１２にカッタ１５でスパイラル状の切り込みを入れているが、切り込みを入れる位置は剥離前線１６から離れた位置としてもよく、更には、剥離を行う前に、金属管内面の樹脂被覆に予めスパイラル状の切り込みを入れておいても良い。図８はスパイラル状の切り込みを入れるための装置の１例を示すものである。図８に示すスパイラル切り込み装置１９は、公転軸１９ａに複数のガイドコロ１９ｂを設けて、この公転軸１９ａを金属管１内に同心状に回転可能とし、更に、形成すべきスパイラルのピッチに等しい間隔を開けて二本のカッタ１９ｃ、１９ｄを取り付けている。この構成により、このスパイラル切り込み装置１９を金属管１内に挿入し、管端から下流側のカッタ１９ｄで樹脂被覆１２にスパイラル状に切り込みを入れ、その切り込みに上流のカッタ１９ｃが入るように設定すると、その後は、単に公転軸１９ａを手で回転させるのみで、上流のカッタ１９ｃがスパイラル状の切り込みで案内されて公転軸１９ａを管軸方向に前進させ、下流のカッタ１９ｄが所定の角度でスパイラル状の切り込みを入れて行くこととなる。かくして、簡単に金属管内面の樹脂被覆１２に一定ピッチのスパイラル状の切り込みを入れることができる。
【００３２】
図７に示す実施形態でも、金属管１１を局部加熱手段１８で局部的に加熱しながら剥離動作を行うものとしているが、本発明はこの構成に限らず、樹脂被覆１２を剥がす前に、金属管１１全体を接着強度が一過的に小さくなるように加熱し、その状態で前記した把持・巻付け手段１６による剥離動作を行う構成としてもよい。
【００３３】
次に、本願第三の発明を説明する。第三の発明は、金属管内面に施された樹脂被覆の、管の一端側の端部を剥離させて掴み代を作り、前記被覆の掴み代を管の一端側から管軸方向の外方へ引っ張って樹脂被覆を伸張・縮径させることで樹脂被覆を剥がしてゆき、その際、少なくとも既剥離領域と未剥離領域とを分ける剥離前線付近の管体を加熱して樹脂被覆の接着強度を一過的に低下させておき、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却することを特徴とする金属管内面樹脂被覆の分別方法である。
【００３４】
図９はこの発明の一実施形態を説明するものであり、この実施形態では、図９（ａ）に示すように、金属管２１の一端側で内面の樹脂被覆２２を剥がして掴み代２２ａを作り、その掴み代２２ａを引っ張り手段２４に連結する。この引っ張り手段２４はウインチ等の駆動装置に連結されており、掴み代２２ａを矢印Ｂで示すように管軸方向の外方に引っ張る構成となっている。そして、金属管２１の管軸方向の一部領域を環状に局部的に加熱することの可能な誘導コイル等の局部加熱手段２５を、金属管２１の外側の、既剥離領域と未剥離領域とを分ける剥離前線２６付近の管体（好ましくは剥離前線２６を含む未剥離領域）を加熱しうる位置に配置し、剥離前線２６付近の管体を加熱して被覆の接着強度を一過的に低下させると共に掴み代２２ａを引っ張り手段２４で引っ張る。これにより、剥離前線２６付近の樹脂被覆２２ｂが引き伸ばされると共に縮径し、金属管２１の内面から剥がされる。この時、剥離前線２６では管体１が局部的に加熱されているため接着強度が低下すると共に樹脂被覆２２ｂが軟らかくなっていて容易に伸張・縮径でき、しかも樹脂被覆２２ｂの下地界面には被覆の伸張に伴って生じる剪断力と縮径によって金属管内面から離れる方向の力が作用するため、樹脂被覆２２ｂがきわめて円滑に剥がされる。また、剥がれた後は樹脂被覆２２ｂが金属管２１から離れて冷えるため、硬くなり、引きちぎられるということがない。このような剥離進展操作を、局部加熱手段２５を管の他端方向へ順次移動させながら進めてゆくことで、図９（ｂ）に示すように、樹脂被覆２２が金属管内面から剥がされてゆき、最終的には金属管２１から分離できる。なお、この方法でも、掴み代を外方へ引っ張る操作を、軸線を中心とした捩りを加えながら行うことにより、剥離前線に捩り力を同時に作用させて剥離を増進させ且つ既剥離部を絞り外径を縮めて引っ張りやすくすることができる。
【００３５】
これらの方法では、前記した他の実施形態のように、金属管内に把持・牽引手段や把持・巻付け手段を通すという必要がなく、また、カッタを必要としないので、剥離作業に必要とする装置を簡単化でき、また、剥離作業が簡単となる等の利点が得られる。
【００３６】
なお、この実施形態でも、金属管の加熱条件等は図１〜図６に示す実施形態と同様に設定すればよい。また、剥離直後の樹脂被覆を強制冷却し、強度を回復させる方法も採っている。更に、図９に示す実施形態でも、剥離進展操作を、局部加熱手段２５を管の他端方向へ順次移動させながら進めてゆく際の具体的な方法としては、図１〜図６の実施形態について説明したものと同様に種々の方法、例えば、剥がし動作と局部加熱手段２５の移動を共に連続的に行う方法とか、一方或いは双方を間欠的に行う方法等を採ることができる。また、引っ張り手段２４による樹脂被覆の引っ張り制御方法は任意であり、例えば、引っ張り手段２４の移動速度を一定とする方法、引っ張り手段２４が樹脂被覆に作用させる引っ張り力を一定とする方法を挙げることができるが、後者の方が、樹脂被覆を引きちぎることがないので好ましい。更に、図９の実施形態でも、樹脂被覆２２を剥がす前に、金属管２１全体を接着強度が一過的に小さくなるように加熱し、その状態で掴み代２２ａを引っ張り手段２４で引っ張って剥離動作を行う構成としてもよい。その場合、金属管２１の加熱方法は任意の方法を採ることができ、例えば、局部加熱手段２５を移動させて金属管全体を加熱するとか、金属管２１を炉内に置いて加熱する等の方法を採ることができる。
【００３７】
以上に説明した実施形態ではいずれも、樹脂被覆を剥がすべき金属管を水平に配置しているが、本発明はこれに限らず金属管を垂直或いは斜めに配置するようにしてもよい。金属管を垂直或いは斜めに配置して樹脂被覆を剥がす構成とすると、剥がした直後の樹脂被覆を水で強制冷却した場合の排水処理がやりやすいとか、金属管内に通す把持・牽引手段４、把持・巻付け手段１４、公転軸１９ａ等の自重によるたわみが発生しにくいとか、装置の設置面積を小さくできる等の利点が得られる。
【００３８】
【発明の効果】
以上に説明したように、本願第一、第二、第三の方法はいずれも、金属管内面の樹脂被覆を一端側から他端側までつながった状態で剥がしてゆくことができ、このため、金属管内面にアクセスできないような小径の金属管に対しても実施でき、大径、小径の樹脂被覆金属管を、金属管と樹脂被覆とに分別してそれぞれ再利用することができ、資源の有効利用を図ることができると共に産業廃棄物を少なくできるという効果を有している。また、剥がした樹脂被覆はつながった状態であるので取り扱いが容易であるという効果も有している。
【図面の簡単な説明】
【図１】（ａ）、（ｂ）、（ｃ）は本願第一の発明の実施形態によって、金属管内面から樹脂被覆を剥がす手順を示す概略断面図
【図２】図１（ｃ）におけるＣ−Ｃ矢視概略断面図
【図３】第一の発明の他の実施形態を示す概略断面図
【図４】図３におけるＤ−Ｄ矢視概略断面図
【図５】第一の発明の更に他の実施形態を示す概略断面図
【図６】第一の発明の更に他の実施形態を示す概略断面図
【図７】（ａ）、（ｂ）は本願第二の発明の実施形態によって、金属管内面から樹脂被覆を剥がす手順を示す概略断面図
【図８】金属管内面の樹脂被覆にスパイラル状の切り込みを入れる装置の１例を示す概略断面図
【図９】（ａ）、（ｂ）は本願第三の発明の実施形態によって、金属管内面から樹脂被覆を剥がす手順を示す概略断面図
【符号の説明】
１、１１、２１金属管
２、１２、２２樹脂被覆
２ａ、１２ａ、２２ａ掴み代
２ｂ、１２ｂ、２２ｂ樹脂被覆
４把持・牽引手段
５、１８、２５局部加熱手段
６、１６、２６剥離前線
１４把持・巻付け手段
１５カッタ
２４引っ張り手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin coating separation method for separating and recovering a resin coating and a metal tube from a used or unacceptable resin-coated metal tube and reusing them as resources, specifically, an inner surface coating. The present invention relates to a method that can be applied to.
[0002]
[Prior art]
Thick film coating with thermoplastic resin such as polyolefin (polyethylene, etc.), polyvinyl chloride, polyamide (nylon, etc.), fluororesin (Teflon, etc.) as a means to prevent internal corrosion of metal pipes such as water pipes, seawater pipes and chemical pipes (Usually about 0.5 to 3 mm) is the mainstream.
[0003]
Disposal of used products that have been removed for renewal or rejected at the time of factory production is a difficult task. The resin is heat-softened and removed by hand, and the resin and metal tubes are reused as resources. However, it is not impossible to use it again for coating, but it takes a lot of work to peel off. Moreover, the reuse technology as a resource of the peeled resin was not at a level that could be paid practically. In particular, since the PVC-coated tube is difficult to peel off because the resin is hard, the coated tube must be cut into small pieces and buried.
[0004]
However, the shortage of waste space is accelerating and countermeasures are eagerly desired. As for the recycling of resin, the technology to separate the resin coating from the metal pipe has been eagerly desired because it has been opened to reuse it by decomposing it into oils and fats by supercritical water treatment. .
[0005]
  Various methods using induction heating have been proposed in prior applications in order to separate the resin coating from the metal matrix. However, these are intended for accessible coatings such as the outer peripheral surface of a metal tube or the inner peripheral surface of a large-diameter metal tube, and the inner surface of a tube having an inner diameter of several tens to several hundreds of millimeters. Not applicable to coatings applied to
  As a method of removing the resin coating applied to the inner surface of a small-diameter metal tube from the metal tube, the entire inner surface of the tube is heated to reduce the adhesive strength of the resin coating and soften it, so that one end side of the metal tube A method is known in which the resin coating is peeled off to make a gripping allowance, and the resin coating is peeled off from one end side to the other end side by pulling the gripping allowance. However, when the resin coating is peeled off by this method, depending on the heating state or depending on the resin coating to be peeled off, there is a problem that the resin coating after peeling is still soft and may be torn off due to its low strength. there were.
[0006]
[Problems to be solved by the invention]
  The present invention has been made in view of such a situation, and it is easy and efficient even for a resin coating applied to the inner surface of a small-diameter metal tube having an inner diameter of several tens to several hundreds of millimeters.In a state where the resin coating is connected from one end side to the other end side of the metal tube, that is, without being torn on the wayAn object of the present invention is to provide a method for separating resin coating on the inner surface of a metal tube that can be peeled off and separated from the metal tube.
[0007]
[Means for Solving the Problems]
  In order to achieve the above object, the first invention of this application peels off the resin coating on the inner surface of one end of the metal tube to create a grip allowance, reverses the grip allowance in the other end direction, and inserts it into the tube. By pulling toward the other end of the metal tube by means, the resin coating is peeled off while reversing, and at that time, at least the tube body in the vicinity of the peeling front that separates the peeled area and the unpeeled area is heated to be resin coated Easy to peel off the resin coating by temporarily lowering the adhesive strength ofFurthermore, when peeling off the resin coating, the resin coating immediately after peeling is forcibly cooled.It is the composition of doing. With this configuration, when the gripping allowance formed by peeling one end of the resin coating is gripped by the gripping and pulling means and pulled straight toward the other end, the tube body is locally heated at the peeling front. After the adhesive strength is reduced and the resin coating is soft and can be bent easily, and the resin coating is pulled so as to be caused from the inner surface of the metal tube, the resin coating is bent off very smoothly while being bent and peeled off ofBy forced coolingBy continuing to pull through the resin coating that has become hard due to the temperature drop and has become difficult to tear, the resin coating can be efficiently peeled in a form in which the metal tube is connected from one end to the other end.
[0008]
  The second invention of the present application is to remove the resin coating on the inner surface of one end of the metal tube to make a spiral grip, and connect the grip to the gripping / winding means inserted through the tube, By rotating the winding means and winding the resin coating on it, the resin coating is peeled off, and at the same time or in advance, the resin coating is cut in a spiral shape so that the resin coating on the inner surface of the metal tube is formed. It peels off in a spiral shape, and at that time, at least, the tube near the peeling front that separates the peeled area and the non-peeled area is heated to temporarily lower the adhesive strength of the resin coating, making it easy to peel off the resin coatingFurthermore, when peeling off the resin coating, the resin coating immediately after peeling is forcibly cooled.It is the composition of doing. With this configuration, by rotating the gripping and winding means and winding the resin coating thereon, the resin coating can be peeled off spirally from one end of the metal tube to the other end. In the peeling front, since the tube body is locally heated, the adhesive strength decreases and the resin coating is soft and can be bent easily, and the resin coating is pulled so as to be caused from the inner surface of the metal tube. The coating is peeled off very smoothly while it is bent.By forced coolingBy continuing to wind through the resin coating that has become hard due to the temperature drop and has become difficult to tear, the resin coating can be efficiently peeled in a form in which the metal tube is connected from one end to the other end.
[0009]
  In the third invention of the present application, the resin coating on the inner surface is peeled off at one end side of the metal tube to make a grip allowance, and the grip allowance of the coating is pulled outward in the tube axis direction from the one end side to form a cylindrical resin coating. The tube is stretched and contracted in the tube axis direction and peeled off from the inner surface of the metal tube by using the contracted diameter. At that time, at least the tube body in the vicinity of the stripping front that separates the stripped region from the stripped region is heated. Easy to peel off the resin coating by temporarily reducing the adhesive strength of the resin coatingFurthermore, when peeling off the resin coating, the resin coating immediately after peeling is forcibly cooled.It is the composition of doing. With this structure, if the resin grip is peeled from the inner surface of the metal tube by pulling the peeled grip allowance in the tube axis direction, the tube body is locally heated at the peeling front, and the adhesive strength is reduced and the resin coating is reduced. Since it is soft and can be easily expanded and contracted, and the resin coating is pulled from the inner surface of the metal tube due to the contraction, the resin coating is peeled off very smoothly while extending and contracting, ofBy forced coolingBy continuing to pull through the resin coating that has become hard due to the temperature drop and has become difficult to tear, the resin coating can be efficiently peeled in a form in which the metal tube is connected from one end to the other end.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
  The first invention of the present application is a resin coating applied to the inner surface of the metal tube, and the end of one end side of the tube is peeled off to make a grip allowance, and the grip allowance is connected to the gripping and pulling means inserted through the metal tube. And reversing it so that it faces the other end of the metal tube, and then pulling the grip allowance to the other end side of the metal tube by the gripping and pulling means and detaching it in the tube axis direction while reversing the resin coating, At that time, heat the tube near the peeling front that separates at least the peeled area and the unpeeled area to temporarily reduce the adhesive strength of the resin coating.Furthermore, when the resin coating is peeled off, the resin coating immediately after peeling is forcibly cooled.This is a method for separating resin coating on the inner surface of a metal tube. Hereinafter, the embodiment will be described in detail with reference to the drawings.
[0011]
FIG. 1 shows a procedure for removing a resin coating 2 applied to the inner surface of a metal tube 1 according to an embodiment of the present invention. First, as shown in FIG. 1A, at one end of the metal tube 1, the end of the resin coating 2 is peeled off from the metal tube 1 to make a grip allowance 2a. This operation is performed manually such as driving a wedge between the metal tube 1 and the resin coating 2 from the tube end side. At this time, it is preferable that the tube end is heated to be easily peeled off.
[0012]
Next, as shown in FIG. 1 (b), the gripping allowance 2a that has been peeled off is connected to the gripping and pulling means 4 inserted into the pipe, and the gripping allowance 2a is folded back. The gripping / towing means 4 used here is arbitrary as long as the gripping allowance 2a can be pulled out toward the other end of the metal tube 1 (in the direction of arrow A). A pull-out rod 4a to be inserted into the head, a connecting member 4b for attaching to the gripping allowance 2a, and a drive device (not shown) for pulling out the pull-out rod 4a in the direction of arrow A. .
[0013]
Next, the local heating means 5 such as an induction coil capable of locally heating the small region in the tube axis direction of the metal tube 1 is formed outside the metal tube 1 and the already peeled region and the unseparated region. The pipe body in the vicinity of the peeling front 6 (preferably the peeling front 6 and the unpeeled area adjacent thereto) is disposed at a position where it can be heated, and the pipe body in the vicinity of the peeling front 6 is heated to increase the adhesive strength of the coating The resin coating 2 is peeled off by temporarily lowering the gripping and pulling means 4 toward the other end of the metal tube 1. At this time, since the tubular body 1 is locally heated at the peeling front 6, the adhesive strength is reduced and the resin coating 2b of the portion is soft and can be easily bent. Moreover, the resin coating 2 is formed from the inner surface of the metal tube. Since the resin coating 2b is bent while being pulled, the peeling force acts on the peeling front 6, and the resin coating 2b is peeled off very smoothly. Such peeling progress operation is advanced while the local heating means 5 is sequentially moved in the direction of the other end of the pipe, and thus the heating position is sequentially moved. As a result, as shown in FIG. 1 (c), the resin coating 2c is peeled off to the other end side of the metal tube 1 while reversing the inner and outer surfaces from the state where the resin coating 2c is adhered to the inner surface of the metal tube. It can be pulled out and finally separated from the metal tube 1.
[0014]
  Here, when the resin coating 2 is peeled off, the resin coating 2 is also heated and softened by heating the tubular body, but after being peeled off, the resin coating 2 is easily cooled and becomes harder as the temperature decreases and is torn off.not reallyIn addition, the resin coating can be efficiently peeled in a form in which the resin coating is connected from one end to the other end of the metal tube.HoweverDepending on the heating state of the metal tube or depending on the resin coating to be peeled off, the resin coating 2 after peeling may still be soft and have a low strength and may be torn.Therefore, in order not to be torn off while peeling the resin coating,The strength of the resin coating after peelingEnoughIn order to recover, the peeled resin coating is forcibly cooled. Examples of the forced cooling method include a method of cooling air by flowing cooling air into a metal tube, a method of directly blowing cooling air, mist, water, etc. with a nozzle to the resin coating immediately after peeling. it can.
[0015]
In the above-described peeling operation, the heating temperature of the metal tube 1 by the local heating means 5 is set so that the adhesive strength is lowered but the resin coating 2 is not excessively softened, and the resin coating 2 to be peeled off. Usually, the temperature may be about 80 to 150 ° C., although it varies depending on the type of the material.
[0016]
As described above, in this embodiment, the peeling heating operation in which the resin coating in the region heated by the local heating means 5 is peeled off by the gripping / pulling means 4 is sequentially moved in the direction of the other end of the pipe. Therefore, the heating position is advanced while being sequentially moved. As a specific method for proceeding with the peeling progress operation, various methods such as continuous and intermittent can be employed. For example, the following methods can be exemplified.
[0017]
(1) The gripping / pulling means 4 is continuously pulled to peel off the resin coating 2 continuously, and at the same time, the local heating means 5 is continuously moved so as to be interlocked with the movement of the peeling front 6, and the peeling front A method in which the vicinity of 6 is heated.
(2) A method in which the gripping / pulling means 4 is continuously pulled to peel off the resin coating 2 continuously, but the local heating means 5 is intermittently moved to heat the vicinity of the peeling front 6.
(3) After the local heating means 5 is stopped and a certain area is heated, the resin coating 2 in the heated area is peeled off by pulling the gripping / pulling means 4, and then the local heating means 5 is moved to the area to be peeled next. A method in which the local heating means 5 and the gripping / pulling means 4 are operated intermittently, such as, after moving and heating the area, pulling the gripping / pulling means 4 again to peel off the resin coating 2 in the heated area.
(4) The local heating means 5 is continuously moved over an area of an appropriate length of the metal tube 1 to heat the area, and the resin coating 2 in the heated area is pulled by pulling the gripping / towing means 4. Then, the local heating means 5 is continuously moved again to heat the region to be peeled next, and then the gripping / pulling means 4 is pulled again to peel off the resin coating 2 in the heated region. A method in which the heating means 5 and the gripping / towing means 4 are operated in combination of continuous and intermittent.
[0018]
In carrying out the above-described method, the heating width of the metal tube 1 by the local heating means 5 is narrow as long as the peeling front 6 can be heated to a desired temperature when the local heating means 5 is continuously moved. For example, about 20-100 mm may be sufficient. On the other hand, when the local heating means 5 is moved intermittently, the workability is better if a certain width is heated at a time, but if it is too wide, the local heating means 5 becomes larger and the initial cost and running cost are increased. In view of these, it is preferable to set the thickness to about 100 to 500 mm.
[0019]
When the resin coating is peeled off by the gripping / pulling means 4, the drive control method of the gripping / pulling means 4 is arbitrary. For example, a method in which the moving speed or the movement amount of the gripping / pulling means 4 is made almost constant. Alternatively, the gripping / pulling means 4 may be of a type in which the tension force applied to the resin coating 2 is substantially constant. However, in the latter case, the resin coating may be broken during the peeling operation. It is difficult and preferable. That is, in the latter case, the tensile force that the gripping / pulling means 4 acts on the resin coating 2 can be peeled off by the resin coating 2 that is easily peeled off by heating, but the coating at a reduced temperature is torn off. If the tension is set to a level that is not too high (for example, 1 kg / cm width), the pipe will be heated and peeling will occur automatically where the adhesive strength has dropped to the above level, and this will be the peeling front. As a result, it is possible to skillfully perform an operation of applying moderate heating aiming at the peeling front. In other words, the peeling front advances in accordance with the progress of the local heating means, and even if the heating by the local heating means is uneven, the progress of the peeling front is only slowed and the resin coating is torn off. Does not happen. That is, there is an advantage that it is not necessary to precisely manage the positional relationship between the peeling front 6 and the local heating means 5.
[0020]
In the above-described embodiment, when the peeling progress operation is sequentially advanced toward the tube end, the metal tube 1 is stopped and the extraction rod 4a and the local heating means 5 are moved. However, the drawing rod 4a and the local heating means 5 may be moved relative to the metal tube 1. For example, the local heating means 5 is arranged at a fixed position and the metal tube 1 is moved. May be.
[0021]
In the method described above, the cylindrical resin coating 2 attached to the inner surface of the metal tube 1 is peeled off and inverted to reduce the diameter, so that the resin coating 2c after peeling is as shown in FIG. The shape is wrinkled in the circumferential direction. By the way, when the resin coating 2 is hard, it may be difficult to deform into the shape shown in FIG. FIG. 3 shows an embodiment that can solve such a problem. In this embodiment, the resin coating 2b immediately after being peeled (that is, in the vicinity of the peeling front 6) is cut with a cutter 8 in the tube axis direction. While performing, peeling progress operation is performed. When the resin coating 2 peeled in this way is cut in the tube axis direction, the resin coating 2d after peeling can be partially overlapped in the circumferential direction as shown in FIG. The operation of reversing the resin coating 2 becomes smooth, and the grip margin 2a is easily pulled toward the other end of the tube. The number of cuts in the tube axis direction to be inserted into the resin coating 2 is not limited to the one shown in the figure, and a plurality of cuts may be provided, whereby the resin coating can be peeled off while being divided into a plurality of strip segments. In addition, the position where the cut is made in the resin coating 2 is not limited to the case immediately after peeling, and may be the position before peeling (unpeeled area). When the notch is made in the resin coat 2 in the non-peeled area, It is not limited to the vicinity of the peeling front 6, but may be a remote position. Therefore, when the cutter 8 is attached to the gripping / towing means 4 and the gripping allowance 2a is pulled by the gripping / towing means 4, the resin coating 2 on the inner surface of the pipe is cut with the cutter 8 at the same time. good. Furthermore, prior to the peeling operation of the resin coating, the resin coating 2 on the inner surface of the tube may be changed so as to be cut in the tube axis direction.
[0022]
As the cutter 8 for making a cut into the resin coating 2, it is easy to use the illustrated knife type, but not limited to this, other types of cutters such as a laser cutter using a yag laser, etc. May be used. When the knife type cutter 8 is used, the cutting edge may come into contact with the inner surface of the metal tube 1 when it is cut into the unpeeled resin coating 2, so that the cutting depth does not contact the inner surface of the metal tube. It is preferable to keep it in the range. On the other hand, since the laser cutter does not have such a problem, it is preferable to use it when cutting the resin coating 2 adhered to the inner surface of the tube.
[0023]
In the case where the above-described peeling progress operation is performed by dividing the resin coating into a plurality of incisions in the tube axis direction and dividing it into a plurality of strip segments, as shown in FIG. It is also possible to shift the 2 db peeling fronts 6a and 6b in the tube axis direction. As described above, when the peeling fronts 6a and 6b are shifted in the tube axis direction, the strip-like strip segments 2da and 2db can be partially overlapped smoothly, and the resin coating 2 can be peeled off very smoothly. Furthermore, instead of peeling a plurality of strip-like segments at the same time, they may be separated into a plurality of stages (usually two stages). For example, as shown in FIG. 6, first, every other strip segment 2da located on the circumference may be peeled, and then the remaining strip segment 2db may be stripped. In this case, the strip-shaped segments 2da and 2db that have been peeled off do not interfere with each other, and can be peeled off very smoothly.
[0024]
In addition, in each method shown in FIGS. 1 to 6, the operation of pulling the gripping margin toward the other end side is performed while twisting about the axis, so that the twisting force is simultaneously applied to the resin coating of the peeling front. Thus, the peeling can be promoted and the already peeled portion can be easily pulled by reducing the outer diameter of the throttle.
[0025]
In the above embodiment, the peeling operation is performed while the metal tube 1 is locally heated by the local heating means 5, but the present invention is not limited to this configuration, and the metal tube 1 is removed before the resin coating 2 is peeled off. The whole may be heated so that the adhesive strength is temporarily reduced, and in this state, the peeling operation by the gripping and pulling means 4 may be performed. In that case, the heating method of the metal tube 1 can take any method. For example, the local heating means 5 is moved to heat the entire metal tube, or the metal tube 1 is placed in a furnace and heated. The method can be taken. When the entire metal tube 1 is heated as described above, energy loss is larger than when locally heated, but the operation of moving the heating position in accordance with the peeling front 6 becomes unnecessary, and the heating operation is not performed. It will be easy.
[0026]
  Next, the second invention of the present application will be described. The second invention is a gripping / winding means in which the end of one end of the tube of the resin coating applied to the inner surface of the metal tube is spirally peeled to make a grip allowance, and the grip allowance is inserted into the tube Next, the resin coating is peeled off by rotating the gripping / winding means and winding the resin coating on it, and at the same time or in advance, a peeling front that separates the peeled area and the non-peeled area In the vicinity or in the unpeeled area, the resin coating is cut in a spiral shape, thereby peeling the resin coating on the inner surface of the metal tube in a spiral shape, and at that time, at least near the peeling front that separates the already peeled area and the unpeeled area The tube body is heated to temporarily reduce the adhesive strength of the resin coating.Furthermore, when the resin coating is peeled off, the resin coating immediately after peeling is forcibly cooled.This is a method for separating resin coating on the inner surface of a metal tube.
[0027]
FIG. 7 shows a state in which the resin coating 12 applied to the inner surface of the metal tube 11 is peeled off according to this embodiment of the separation method. In this embodiment, as shown in FIG. 7A, at one end of the metal tube 11, the end portion of the resin coating 12 is spirally peeled off from the metal tube 11 to form a grip allowance 12a. It is fixed to the gripping / winding means 14 inserted through and rotated by the gripping / winding means 14 so that the resin coating peeled off can be taken up. The cutter 15 attached to the cutter driving device 15A is positioned so as to cut in a spiral shape into the resin coating in the upstream unpeeled region. The gripping / winding means 14 used here is arbitrary as long as the gripping allowance 12a can be connected and can take up the peeled resin coating. In this embodiment, the resin coating can be wound. Bar material is used. This gripping and winding means 14 is not moved in the direction of the tube axis after being inserted into the metal tube 11, but only rotated at that position and peeled off as shown in FIG. 7 (b). 12c may be wound around a long region, or the winding means 14 is rotated while moving in the tube axis direction so that the winding position substantially coincides with the peeling front 16 of the resin coating. It may be configured so as to be packed in the tube axis direction and wound up. On the other hand, the cutter driving device 15A holding the cutter 15 is configured to move in the axial direction while rotating so that the resin coating 12 can be cut in a spiral shape. Any known mechanism can be used.
[0028]
On the outside of the metal tube 11, a local heating means 18 such as an induction coil capable of locally heating a region in the tube axis direction slightly larger than the width of the resin coating to be peeled in a spiral shape is peeled off. The pipe body in the vicinity of the front line 16 (preferably the peeling front line 16 and the unpeeled region adjacent thereto) is disposed at a position where it can be heated, and the pipe body in the vicinity of the peeling front line 16 is heated to temporarily increase the adhesive strength of the coating. In addition to lowering, the cutter driving device 15A is moved in the tube axis direction while rotating, so that the cutter 15 is near or downstream of the peeling front 16 (in this specification, the point to which the peeling front moves is downstream). The resin coating 12c that has been peeled off by rotating the gripping / winding means 14 is wound around the resin coating 12 in the unpeeled region while being spirally cut, so that the resin coating 12c is on the peeling front 16 Yuku peeled by applying a tensile force to the fat coating 12b. At this time, since the tube body 11 is locally heated at the peeling front 16, the adhesive strength is reduced and the resin coating 12 b at that position is soft and can be easily bent. Moreover, the resin coating 12 b can be bent from the inner surface of the metal tube. Since the resin coating 12b is bent as it is pulled, the resin coating 12b is bent and a peeling force acts on the peeling front 16 in a concentrated manner, whereby the resin coating 12b is peeled off very smoothly. By proceeding with such a peeling progress operation while sequentially moving the local heating means 18 in the direction of the other end of the tube, as shown in FIG. 7B, the peeled resin coating 12c is gripped and wound. It can be wound around the means 14 and finally separated from the metal tube 11.
[0029]
In this embodiment, the resin coating 12 is peeled off in the circumferential direction. Generally, however, the resin coating applied to the tube tends to have a lower adhesive strength in the circumferential direction than the adhesive strength in the tube axis direction. The advantage that it is easy is obtained.
[0030]
  Also in the embodiment shown in FIG. 7, the heating condition of the metal tube may be set similarly to the embodiment shown in FIGS. 1 to 6. In addition, the resin coating immediately after peeling is forcibly cooled to restore strength, making it difficult to tear off.I also have a method. Furthermore, also in the embodiment of FIG. 7, as a specific method for proceeding with the peeling progress operation while sequentially moving the local heating means 18 toward the other end of the tube, the embodiment of FIGS. Various methods similar to those described, for example, a method in which the peeling operation and the movement of the local heating means 18 are both performed continuously, or a method in which one or both are performed intermittently can be employed. Further, the rotation control method of the gripping / winding means 14 when the resin coating is wound around the gripping / winding means 14 is arbitrary. For example, a method of controlling the rotation to be a constant rotational speed, a constant torque And the like. Employing the latter is preferable because an almost constant tensile force can be applied to the resin coating to be peeled off. Further, in this embodiment, since the peeling front 16 moves in a spiral shape, as a means for locally heating the tube body, a local heating means 18 for annularly heating the metal tube 11 shown in the figure is used as the tube axis. It is good also as a structure which uses not only the structure moved to a direction but the local heating means which heats only the peeling front 16 vicinity, and makes it move spirally. Also, the cutter 15 used in this embodiment is not limited to the illustrated knife type, and a laser cutter may be used.
[0031]
Further, in the embodiment shown in FIG. 7, a spiral cut is made in the resin coating 12 with a cutter 15 in the vicinity of the peeling front 16, but the position where the cut is made may be a position away from the peeling front 16, Furthermore, before performing peeling, a spiral cut may be made in advance on the resin coating on the inner surface of the metal tube. FIG. 8 shows an example of an apparatus for making a spiral cut. The spiral cutting device 19 shown in FIG. 8 is provided with a plurality of guide rollers 19b on the revolution shaft 19a, and the revolution shaft 19a can be rotated concentrically in the metal tube 1, and is equal to the pitch of the spiral to be formed. Two cutters 19c and 19d are attached with a gap. With this configuration, the spiral cutting device 19 is inserted into the metal tube 1, and the resin coating 12 is cut in a spiral shape with a cutter 19d on the downstream side from the tube end, and the upstream cutter 19c is set in the cut. Then, simply by rotating the revolving shaft 19a by hand, the upstream cutter 19c is guided by a spiral cut to advance the revolving shaft 19a in the tube axis direction, and the downstream cutter 19d is moved at a predetermined angle. A spiral cut will be made. Thus, it is possible to easily make spiral cuts with a constant pitch in the resin coating 12 on the inner surface of the metal tube.
[0032]
In the embodiment shown in FIG. 7 as well, the metal tube 11 is subjected to the peeling operation while being locally heated by the local heating means 18, but the present invention is not limited to this configuration, and before the resin coating 12 is peeled off, It is good also as a structure which heats the whole pipe | tube 11 so that adhesive strength may become temporarily small, and performs peeling operation | movement by the above-mentioned holding | grip and winding means 16 in the state.
[0033]
  Next, the third invention of the present application will be described. According to a third aspect of the present invention, the resin coating applied to the inner surface of the metal pipe is peeled off at one end of the pipe to make a grip allowance. The resin coating is peeled off by stretching the resin coating by stretching the resin coating, and at that time, at least the tube near the peeling front that separates the peeled area from the peeled area is heated to increase the adhesive strength of the resin coating. Decrease temporarilyFurthermore, when the resin coating is peeled off, the resin coating immediately after peeling is forcibly cooled.This is a method for separating resin coating on the inner surface of a metal tube.
[0034]
FIG. 9 illustrates an embodiment of the present invention. In this embodiment, as shown in FIG. 9 (a), the resin coating 22 on the inner surface is peeled off at one end of the metal tube 21, and the grip allowance 22a is set. The gripping allowance 22a is connected to the pulling means 24. The pulling means 24 is connected to a drive device such as a winch, and is configured to pull the grip allowance 22a outward as indicated by an arrow B in the tube axis direction. Then, the local heating means 25 such as an induction coil capable of locally heating a partial region in the tube axis direction of the metal tube 21 is formed on the outer side of the metal tube 21 with the already peeled region and the unpeeled region. The pipe body in the vicinity of the peeling front 26 (preferably, the unpeeled region including the peeling front 26) is disposed at a position where it can be heated, and the pipe in the vicinity of the peeling front 26 is heated to temporarily increase the adhesive strength of the coating. The gripping allowance 22a is pulled by the pulling means 24 while being lowered. As a result, the resin coating 22b in the vicinity of the peeling front 26 is stretched and reduced in diameter, and peeled off from the inner surface of the metal tube 21. At this time, since the tube body 1 is locally heated at the peeling front 26, the adhesive strength is reduced and the resin coating 22b is soft and can be easily expanded and contracted. Since the force in the direction away from the inner surface of the metal tube acts due to the shearing force and the reduced diameter caused by the extension of the coating, the resin coating 22b is peeled off very smoothly. Moreover, since the resin coating 22b is separated from the metal tube 21 and is cooled after being peeled off, the resin coating 22b is not hardened and torn off. By proceeding such a peeling progress operation while sequentially moving the local heating means 25 toward the other end of the pipe, the resin coating 22 is peeled off from the inner surface of the metal pipe as shown in FIG. 9B. Finally, it can be separated from the metal tube 21. Even in this method, the operation of pulling the gripping portion outward is performed while applying a twist about the axis, so that the torsional force is simultaneously applied to the peeling front to promote peeling and the already peeled portion is removed from the throttle. The diameter can be reduced to facilitate pulling.
[0035]
In these methods, unlike the other embodiments described above, it is not necessary to pass the gripping / towing means or the gripping / winding means through the metal tube, and it is not necessary to use a cutter. Advantages such as simplification of the apparatus and easy peeling work can be obtained.
[0036]
  In this embodiment, the heating conditions for the metal tube and the like may be set similarly to the embodiment shown in FIGS. Also, a method of forcibly cooling the resin coating immediately after peeling to restore strengthAlso adopts. Furthermore, also in the embodiment shown in FIG. 9, as a specific method for proceeding the peeling progress operation while sequentially moving the local heating means 25 toward the other end of the pipe, the embodiment shown in FIGS. As described above, various methods can be employed, for example, a method in which the peeling operation and the movement of the local heating means 25 are both performed continuously, or a method in which one or both are performed intermittently. Moreover, the tension control method of the resin coating by the tension means 24 is arbitrary, and examples thereof include a method of making the moving speed of the tension means 24 constant and a method of making the tensile force that the tension means 24 acts on the resin coating constant. However, the latter is preferable because it does not tear the resin coating. Furthermore, also in the embodiment of FIG. 9, before the resin coating 22 is peeled off, the entire metal tube 21 is heated so that the adhesive strength is temporarily reduced, and in this state, the gripping allowance 22a is pulled by the pulling means 24 and peeled off. It is good also as a structure which performs operation | movement. In that case, the heating method of the metal tube 21 can take any method. For example, the local heating means 25 is moved to heat the entire metal tube, or the metal tube 21 is placed in a furnace and heated. The method can be taken.
[0037]
In any of the embodiments described above, the metal tube from which the resin coating is to be peeled is disposed horizontally, but the present invention is not limited to this, and the metal tube may be disposed vertically or obliquely. If the metal tube is arranged vertically or diagonally and the resin coating is peeled off, it is easy to perform drainage treatment when the resin coating immediately after peeling is forcibly cooled with water, or the gripping / pulling means 4 passed through the metal tube, gripping -It is possible to obtain advantages such as that the winding means 14 and the revolution shaft 19a are less likely to bend due to their own weight, and that the installation area of the apparatus can be reduced.
[0038]
【The invention's effect】
As explained above, any of the first, second and third methods of the present application can be peeled off in a state where the resin coating on the inner surface of the metal tube is connected from one end side to the other end side. It can also be applied to small-diameter metal pipes that do not allow access to the inner surface of the metal pipe. Large- and small-diameter resin-coated metal pipes can be separated into metal pipes and resin-coated pipes for reuse. It has the effect that it can be used and industrial waste can be reduced. Further, since the peeled resin coating is in a connected state, it has an effect that it is easy to handle.
[Brief description of the drawings]
FIGS. 1 (a), (b), and (c) are schematic cross-sectional views showing a procedure for removing a resin coating from an inner surface of a metal tube according to an embodiment of the first invention of the present application.
FIG. 2 is a schematic cross-sectional view taken along the line CC in FIG.
FIG. 3 is a schematic cross-sectional view showing another embodiment of the first invention.
4 is a schematic sectional view taken along the line DD in FIG. 3;
FIG. 5 is a schematic cross-sectional view showing still another embodiment of the first invention.
FIG. 6 is a schematic cross-sectional view showing still another embodiment of the first invention.
FIGS. 7A and 7B are schematic cross-sectional views showing a procedure for removing a resin coating from the inner surface of a metal tube according to an embodiment of the second invention of the present application.
FIG. 8 is a schematic cross-sectional view showing an example of an apparatus for making a spiral cut in a resin coating on the inner surface of a metal tube
FIGS. 9A and 9B are schematic cross-sectional views showing a procedure for removing a resin coating from the inner surface of a metal tube according to an embodiment of the third invention of the present application.
[Explanation of symbols]
1, 11, 21 Metal tube
2, 12, 22 Resin coating
2a, 12a, 22a
2b, 12b, 22b Resin coating
4 Gripping and pulling means
5, 18, 25 Local heating means
6, 16, 26 Peeling front
14 Gripping and winding means
15 cutters
24 Pulling means

Claims

金属管内面に施された樹脂被覆の、管の一端側の端部を剥離させて掴み代を作り、該掴み代を金属管内に挿通させた把持・牽引手段に連結すると共に金属管の他端側を向くように反転させ、次いでその掴み代を前記把持・牽引手段により前記金属管の他端側に引っ張って樹脂被覆を反転させながら管軸方向に剥がしてゆき、その際、少なくとも既剥離領域と未剥離領域とを分ける剥離前線付近の管体を加熱して樹脂被覆の接着強度を一過的に低下させておき、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却することを特徴とする金属管内面樹脂被覆の分別方法。The end of one end of the tube of the resin coating applied to the inner surface of the metal tube is peeled off to make a grip allowance, and the other end of the metal tube is connected to the gripping / pulling means inserted through the metal tube. Then, the grip is pulled toward the other end of the metal tube by the gripping and pulling means and peeled off in the tube axis direction while reversing the resin coating. At this time, at least the already peeled area When the tube near the peeling front that separates the unpeeled area is heated to temporarily reduce the adhesive strength of the resin coating, and when the resin coating is peeled off, the resin coating immediately after peeling A method for separating resin coating on the inner surface of a metal tube, characterized by forcibly cooling the tube.

前記樹脂被覆を金属管の管軸方向に剥がしてゆく際若しくはそれに先立って、前記剥離前線付近若しくは未剥離領域において前記樹脂被覆に管軸方向の切り込みを施し、前記掴み代を管の他端側へ引っ張りやすくすることを特徴とする請求項１記載の金属管内面樹脂被覆の分別方法。 When the resin coating is peeled off in the tube axis direction of the metal tube or prior thereto, the resin coating is cut in the tube axis direction in the vicinity of the peeling front or in the unpeeled region, and the grip allowance is provided on the other end side of the tube 2. The method for separating the resin coating on the inner surface of a metal tube according to claim 1, wherein the resin coating is easily pulled.

前記樹脂被覆を金属管の管軸方向に剥がしてゆく際若しくはそれに先立って、前記剥離前線付近若しくは未剥離領域において前記樹脂被覆に管軸方向の複数の切り込みを施して前記樹脂被覆を複数の帯状セグメントに分割し且つ隣接した帯状セグメントの剥離前線を管軸方向にずらせて剥がしてゆくことを特徴とする請求項１記載の金属管内面樹脂被覆の分別方法。 When the resin coating is peeled off in the tube axis direction of the metal tube or prior thereto, a plurality of cuts in the tube axis direction are applied to the resin coating in the vicinity of the peeling front or in an unpeeled region to form the resin coating into a plurality of strips. 2. The method for separating a resin coating on the inner surface of a metal tube according to claim 1, wherein the stripping front of the adjacent strip-shaped segment is shifted in the tube axis direction and separated.

金属管内面に施された樹脂被覆の、管の一端側の端部をスパイラル状に剥離させて掴み代を作り、その掴み代を管内に挿通させた把持・巻付け手段に連結し、次いでその把持・巻付け手段を回転させてその上に樹脂被覆を巻き取ってゆくことで樹脂被覆を剥がし、同時に或いはそれに先立って、既剥離領域と未剥離領域とを分ける剥離前線付近若しくは未剥離領域において前記樹脂被覆にスパイラル状に切り込みを施し、これによって金属管内面の樹脂被覆をスパイラル状に剥がしてゆき、その際、少なくとも既剥離領域と未剥離領域とを分ける剥離前線付近の管体を加熱して樹脂被覆の接着強度を一過的に低下させておき、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却することを特徴とする金属管内面樹脂被覆の分別方法。The end of one side of the tube of the resin coating applied to the inner surface of the metal tube is spirally peeled to make a grip allowance, and the grip allowance is connected to the gripping / winding means inserted into the tube, and then Rotate the gripping / winding means and wind up the resin coating on it to peel off the resin coating. The resin coating is cut in a spiral shape, thereby peeling off the resin coating on the inner surface of the metal tube in a spiral shape. the adhesive strength of the resin-coated keep transiently reduced Te, further, the when Yuku peeling the resin-coated metal tube surface resin, characterized in that forced cooling of the resin-coated immediately after peeling Method of sorting covered.

金属管内面に施された樹脂被覆の、管の一端側の端部を剥離させて掴み代を作り、前記被覆の掴み代を管の一端側から管軸方向の外方へ引っ張って樹脂被覆を管軸方向に引き伸ばし且つ縮径させることで樹脂被覆を剥がしてゆき、その際、少なくとも既剥離領域と未剥離領域とを分ける剥離前線付近の管体を加熱して樹脂被覆の接着強度を一過的に低下させておき、更に、前記樹脂被覆を剥がしてゆく際に、剥がした直後の樹脂被覆を強制冷却することを特徴とする金属管内面樹脂被覆の分別方法。The end of one end of the tube of the resin coating applied to the inner surface of the metal tube is peeled off to create a grip allowance, and the grip allowance of the coating is pulled outward from the end of the tube in the axial direction of the tube. The resin coating is peeled off by stretching and reducing the diameter in the tube axis direction. At this time, at least the tube body near the peeling front that separates the peeled area and the non-peeled area is heated to temporarily pass the adhesive strength of the resin coating The method further comprises forcibly cooling the resin coating immediately after peeling off when the resin coating is peeled off .

前記剥離前線付近の管体を、その外側に配置した局部加熱手段で局部的に加熱し、加熱した領域の樹脂被覆を剥がしてゆくという剥離進展操作を、前記局部加熱手段を前記金属管に対して相対的に順次移動させながら進めてゆくことを特徴とする請求項１から５のいずれか１項記載の金属管内面樹脂被覆の分別方法。 The tube near the peeling front is locally heated by a local heating means arranged outside the peeling front, and the peeling heating operation of peeling off the resin coating in the heated region is performed on the local heating means with respect to the metal pipe. 6. The method for separating resin coating on the inner surface of a metal tube according to any one of claims 1 to 5, wherein the metal tube inner surface resin coating is proceeded while being moved relatively sequentially.

前記樹脂被覆を剥がしてゆく際に、樹脂被覆に作用させる引っ張り力をほぼ一定に維持することを特徴とする請求項１から６のいずれか１項記載の金属管内面樹脂被覆の分別方法。The method for separating resin coating on the inner surface of a metal tube according to any one of claims 1 to 6, wherein a tensile force applied to the resin coating is maintained substantially constant when the resin coating is peeled off.