JP4108876B2 - Method and apparatus for extrusion molding of hollow resin molded plate - Google Patents

Description

【００３８】
以上のように、押出し速度を速くした場合にあっては成形ダイ１０のヒータ１４ａ〜１４ｃの温度を低速の場合に比較して高い温度としている。これは、成形速度が速くなると押出し生地７９が成形ダイ１０の熱を奪ってしまい成形ダイ１０の溶融部２１ａにおいて押出し生地７９の溶融が不完全となるためである。
【００３９】
このように、成形ダイ１０の溶融部２１ａにおける押出し生地７９の溶融が不完全になると、成形された成形板２９の密度が均一でなくなり、板に巣ができた状態となる。そのため、成形ダイ１０の溶融部２１ａにおける押出し生地７９の溶融を充分に行うべく、該部分におけるヒータ１４ａ〜１４ｃの温度を従来の場合に比較して高温としているのである。
【００４０】
また、２５は冷却管で、成形ダイ１０の成形室２２の徐冷部２１ｂを冷却する冷却手段の一例を示すもので、成形室２２の押出し方向に適当な間隔毎に、この冷却管２５に常温の水又は７０〜８０℃程度までの水あるいは油等の冷却媒体たる冷却液を供給して成形室２２内の押出し生地７９をその外側から冷却する。この冷却管２５の配管は成形室２２内の押出し生地７９の徐冷効果を向上するために成形ダイ１０のダイ出口２３の方向に向けて４分の３を占める徐冷部２１ｂに、成形室２２の上下の成形ダイ１０内に等間隔に多数挿通して配管設置されている。なお、冷却管２５の間隔を次第に狭くするように設けることもでき、あるいは冷却管２５を成形ダイ１０の外壁に接して配設することもできるが、成形室２２内の押出し生地７９を冷却できればよいので、この実施例の構造に限定されない。
【００４１】
〔中子体〕
図２及び図３において、中子体４０は、本実施形態にあっては溶融部２１ａの上下内壁に固着された基部４４と一体的に形成され、前記基部４４から成形ダイ１０の出口に向かって三本の中子体４０が突出形成されて全体として略櫛歯状に形成されている。
【００４２】
前記基部４４と溶融部２１ａの上下内壁との連結部は、図２に示すように平面において流線型に形成されており、溶融部２１ａを流れる押出し生地が抵抗無く流れるよう形成されている。
【００４３】
本実施形態にあっては、長さを６８１mm、基部４４側において高さ３４．５mm、幅２５．４mm、出口側において高さ３３．８mm、幅２４．８mmにその矩形状の断面を徐々に狭めるテーパー状の２本の中子体４０，４０間に、長さを６８１mm、基部４４側において高さ３４．５mm、幅２４．４mm、出口側において高さ３３．８mm、幅２３．８mmにその矩形状の断面を徐々に狭めるテーパー状の中子体４０を１本配置している。
【００４４】
この中子体４０の基部４４を固着する成形ダイ１０の上部内壁面には、成形ダイ１０の壁面を貫通して、水、油等の液体、空気、その他のガス等の冷却媒体を供給する図示せざる冷却媒体の供給源と連通された導入路４１が形成されており、この冷却媒体の導入路４１が成形ダイ１０の壁面及び基部４４を貫通して溶融部２１ａにおける中子体４０に至り、徐冷部２１ｂにおいて中子体４０内に形成された後述の冷却媒体の流路４２に連通している。
【００４５】
この中子体４０内に形成された冷却媒体の導入路４１は、断熱材４３にて包囲されており、導入路４１内を通過する冷却媒体が該部において押出し生地を冷却することを防止すると共に、後述の冷却媒体の流路４２に冷却媒体が導入されたときの冷却効果の向上を図っている。
【００４６】
本実施形態にあっては、外周に断熱材としてミオレックスＰＭＸ−５７５（菱電化成）を配置した直径４mmの金属製パイプにて成形ダイ１０の壁面、基部４４及び中子体４０を貫通し、これを冷却媒体の導入路４１としている。
【００４７】
徐冷部２１ｂにおいて、中子体４０内には中子体４０の中央を貫通する直径２０mmの流路が形成されており、この流路４２内に冷却媒体を流通して徐冷部２１ｂ内の押出し生地７９を中空部の内側より徐冷し得るよう構成している。
【００４８】
この流路４２は、本実施形態にあっては一端において前述のように冷却媒体の導入路４１に連通し、他端を中子体４０の端部において開口させて成形ダイ１０の出口に向かって開口する形状に形成されており、従って、冷却媒体の流路４２内に導入された冷却媒体は、押し出された成形板２９内に形成された中空部を介して、成形ダイ１０外に排出され、冷却媒体が中子体４０内に形成された流路４２及び成形板２９内に形成された中空部を通過するときに押出し生地７９及び成形板２９を内部より徐冷する。
【００４９】
なお、前記冷却媒体の流路４２を前述の構成に代えて、例えば徐冷部２１ｂにおいて中子体４０を成形ダイ１０の出口側の端部で連通する二重管構造とし、この一方を冷却媒体の導入源に連通すると共に、他方を冷却媒体の排出口に連通して、冷却媒体である例えば冷却水や冷却油が、中子体４０内を循環するよう構成しても良く、冷却媒体の流路４２は、押出し生地７９を内側より徐冷し得る構成であれば導入される冷却媒体の種類、その他各種の条件の変更にしたがって種々の設計変更が可能である。
【００５０】
なお、前記中子体４０は、全外表面に０．１〜０．５mm厚のテフロン等フッ素樹脂でなるシートを貼設することもでき、また、成形室２２の容積に応じてその大きさを適宜変更することが可能である。
【００５１】
〔引取手段〕
引取手段３０は、成形ダイ１０の出口側に配置され、成形ダイ１０の出口を介して押し出された成形板を引き取るもので、その一例を図５に示す。
【００５２】
図５に示す実施形態にあっては、この取引手段３０は、無端ベルトに３２て同時に巻回された複数のローラ３１，３１，３１を上下方向に対抗配置して、上下に配置された無端ベルト３２，３２間で成形板２９を挟持し得るよう構成したもので、このローラ３１のうちの少なくとも１つを駆動源に連結された駆動ローラ３１ａとなし、無端ベルト３３を介して上下ローラ３１，３１間に挟持された成形板２９を、前記駆動ローラ３１ａの回転により押出し方向に引き取るよう構成したものである。
【００５３】
この引取手段３０により成形板２９を例えば押出機７０の押出し速度よりも遅い速度にて引き取ると、成形ダイ１０の溶融部２１ａ内における押出し生地は、高密度かつ均一な状態となり、成形される成形板２９に窪みやひけ、たわみ等を生じさせない状態にある。
【００５４】
そして、押出機７０による押出し生地の押出し速度を上昇させると共に、この引取手段３０による成形板２９の引取り速度を、押出機７０による押出し生地の押出し速度よりも遅い速度で上昇すると、成形ダイ２０の溶融部２１ａ内における押出し生地の圧力を一定に保ったまま成形板２９の成形速度を向上させることができ、成形板２９の成形速度の調整を、溶融部２１ａ内の押出し生地７９を高密度としたまま行うことができるよう構成されている。
【００５５】
以上のように構成された中空樹脂成形板の押出成形装置において、本実施形態にあっては一例として押出機７０のホッパ７３内に投入する原材料をセルロース系破砕物と熱可塑性樹脂成形材とを混練して得られた成形材を用いて中空樹脂成形板を製造する例について説明する。尚、本明細書においてセルロース形破砕物と熱可塑性樹脂成形材を混練し、所定の粒径に造粒、粉砕されたものを「木質合成粉」という。
【００５６】
この木質合成粉の原料とされる木粉は、その粒径を熱可塑性樹脂成形材とのなじみを良好とし、成形押し出し時における木粉の摩擦抵抗を減じ成形機の損耗、毀損の防止を図ることより、５０〜３００メッシュ、好ましくは、６０（篩下）〜１５０メッシュ（篩上）とする微細な粉末状とし、成形時における木酸ガスを揮散し、水蒸気あるいは気泡発生のおそれをなくし、表面の肌荒れを防止する意図からその含有水分量を１５wt％以内、好ましくは１１wt％以内、理想的には０〜５wt％の範囲内としたものである。
【００５７】
なお、かかる木粉の特性をさらに向上させるため尿素系樹脂接着剤に木材チップ等の素材を浸漬あるいはこれに添加し、加熱硬化した後５０〜３００メッシュに破砕、微粉末化することが可能であり、かかる木粉の成形方法に於ては、充分な加熱硬化、特に尿素系樹脂接着剤による中和しながらの加熱硬化によって木粉内の木酸は、中和と揮散とにより急速に除去されると共に木粉周面に硬化接着面が設けられ、木粉の含有水分が高められることを有効に防止でき、さらに木粉の滑動性を高め、成形押出し時に於ける摩擦抵抗を特に減じることができる。
【００５８】
熱可塑性樹脂成形材は、前述の廃棄された各種の樹脂成形品をそのままもしくは表面樹脂塗膜を形成した樹脂成形品を複数の各小片に破砕し、前記破砕された個々の各小片に対して、圧縮研削作用を付加して樹脂塗膜を研削、剥離し、前記研削された個々の各小片に対して、微振動に基づいた圧縮衝撃力を付加して圧潰粉砕させ、かつ圧潰粉砕によって剥離された樹脂塗膜を随時に除去し熱可塑性樹脂成形材として素材化した、ＰＶＣ、ＰＥＴ、ＰＰ等の樹脂である。
【００５９】
熱可塑性樹脂成形材は、ＰＰの場合、前記木粉は最大で７５wt％まで混入される。木粉を混入する割合の範囲は２０〜７５wt％相当であるが、好ましくは３０〜７０wt％である。
【００６０】
混入容量は、目的とする耐摩耗特性などの諸特性に合わせて適宜決定されるものであるが、本発明においては、前述の成形時における種々の弊害が除去されることから多量に混入することができる。
【００６１】
ＰＥＴの場合は、木粉は最大で６０wt％まで混入されるが、木粉の混入割合は２０〜６０wt％が良い。
【００６２】
熱可塑性樹脂成形材がＰＶＣのとき、木粉の混入割合は３０〜６０wt％、好ましくは４５wt％である。
【００６３】
なお、押出成形においては、熱可塑性合成樹脂製品の廃材から得られた回収熱可塑性樹脂成形材を再利用して前記押出機内へ投入し、あるいはバージンの熱可塑性樹脂を投入し、あるいはバージンの熱可塑性樹脂と前記回収熱可塑性樹脂成形材をそれぞれ、例えば５０％ずつ投入することもできる。
【００６４】
尚、使用目的に応じて、顔料を添加し、製品に着色することもできる。
【００６５】
また、含有水分量を１５wt％以内とし平均粒径２０メッシュ以下のセルロース系破砕物２０〜７５wt％に対して熱可塑性樹脂成形材２５〜８０wt％をともに攪拌衝撃翼により混合して、摩擦熱によりゲル化混練し、前記ゲル化した混練材料を常温で空冷もしくは、適宜手段により冷却して、さらに粒径８mm以下に整粒して得た木質合成粉を前記押出機７０のホッパ７３内に投入すると、木粉と熱可塑性樹脂成形材との馴染みがより一層良好であり、木粉の摩擦抵抗を減じ得る良好な混練状態の生地が形成される。
【００６６】
〔木質合成粉の製造例〕
以下、本発明の木質合成粉を製造するために用いる各種製造装置について図面を参照しながら説明する。
【００６７】
〔乾燥流動混合混練手段〕
図８において、８０は原材料を各撹拌衝撃翼により撹拌、混合し、且つ、前記混合した材料相互及び各撹拌衝撃翼との摩擦により発生した熱により、各材料を乾燥し、且つ、混練して「混練材料」を形成する乾燥流動混合混練手段で、本実施の形態において、便宜上「ミキサー」という。
【００６８】
８１はミキサー本体で、上面開口を有する円筒形を成し容量が３００リットルのケーシングであり、前記開口はミキサー本体８１内に原材料を投入する投入口９４で、この投入口９４を開閉自在な上蓋８２で被蓋する。上蓋８２には、ミキサー本体８１内で発生した多量の水蒸気を排出するガス排出管９５を連通している。さらに、ミキサー本体８１の底面付近の外周面に１ヶ所の排出口８８を設け、この排出口８８を被蓋する蓋８９をシリンダ９１のロッド先端に設け、シリンダ９１の作動により前記排出口８８を開閉自在に設けている。９３は排出ダクトで、前記排出口８８に連通している。
【００６９】
さらに、ミキサー本体８１の底面の中心には図示せざるモータ３７KW（ＤＣ）の回転駆動手段により８００〜９００rpm/maxで高速回転する軸８３をミキサー本体８１内の上方に向けて軸承し、この軸８３に下から上方へ順にスクレイパー８４、撹拌衝撃翼８５，８６，８７を装着し、軸８３の先端から締付ナット９２で締め付けている。なお、前記各撹拌衝撃翼８５，８６，８７の形状は特に限定されないが、本実施の形態では軸８３を中心に対称を成す２枚羽根である。図８のように３個の撹拌衝撃翼を重ねた場合は全部で６枚の羽根で成り、これら６枚の羽根は平面で３６０度を６等分した等分角（６０度）を成すように互いに交叉した状態で重ねている。なお、複数個の撹拌衝撃翼を設けた場合、撹拌衝撃翼の合計の羽根数で３６０度を等分した角度で互いに交叉して重ねることは原材料を効率良く混練する点で好ましい。
【００７０】
なお、前記スクレイパー８４はミキサー本体８１の底面を僅かに摺接して回転し、ミキサー本体８１内で混練された原材料をミキサー本体８１の底面に残留しないよう掻き出し、且つ原材料を循環するものである。
【００７１】
〔冷却造粒手段〕
図９において、１００は前述した混練材料を混合し撹拌して「造粒原料」を形成する冷却造粒手段であり、本実施の形態では「クーリングミキサー」という。
【００７２】
１０１はミキサー本体で、逆円錐形状を成す容量１０５０リットルのケーシングであり上面を被蓋し、一方、下端に排出口１０７を設け、この排出口１０７をバルブ１０６で開閉自在に設けている。ミキサー本体１０１の外周壁内にジャケット１０２を形成し、このジャケット１０２内に給水管１０８から排水管１０９へ常時、１００リットル/minの冷却水を供給し、クーリングミキサー１００内の原材料の温度を熱可塑性樹脂材料の融点近傍（本実施形態にあっては１００℃以下）まで冷却するよう保持される。なお、ミキサー本体１０１の上壁面にはクーリングミキサー１００内で発生した水蒸気を排出する図示せざる排出ダクトを連通している。
【００７３】
前記ミキサー本体１０１の上壁内の略中心にはアーム１０３が略水平方向に回動可能に軸支され、このアーム１０３は減速装置１１２を介してモータ１１１により約３rpmの速度で回転駆動される。さらに、前記アーム１０３の回転軸は中空軸であり、この中空軸内に独立して回転する他の回転軸を設け、この回転軸にモータ１０５の出力軸を連結している。一方、前記アーム１０３の先端には撹拌破砕翼１０４を軸承し、この撹拌破砕翼１０４は本実施の形態ではスクリュー型を成すものであり、該撹拌破砕翼１０４の回転軸線方向をミキサー本体１０１の内周壁面に沿って略平行に下方へミキサー本体１０１の下端付近まで延長している。撹拌破砕翼１０４はアーム１０３内に設けた歯車等による回転伝達手段を介して前記モータ１０５の出力軸に連結する回転軸に連結され１２０rpmの速度で回転駆動される。
【００７４】
なお、ミキサー本体１０１の上壁には投入口１１３を設け、この投入口１１３に前述したミキサー８０の排出ダクト９３を連通する。
【００７５】
前述したミキサー８０で形成された混練材料は排出ダクト９３を経てクーリングミキサー１００の投入口１１３からミキサー本体１０１内へ投入される。撹拌破砕翼１０４はモータ１０５により１２０rpmの速度で回転し、しかも、アーム１０３が減速装置１１２を介して減速されたモータ１１１の回転力により３rpmの速度で水平方向に回転するので、前記撹拌破砕翼１０４はミキサー本体１０１の内周壁面に沿って円錐を描くように回転し、アーム１０３内の混練材料を撹拌する。
【００７６】
混練材料はジャケット１０２内の冷却水により冷却されたミキサー本体１０１の内周壁面で冷却され、直径約２５mm以下に造粒された「造粒原料」が形成され、この造粒原料はバルブ１０６を開放して排出口１０７より排出される。
【００７７】
なお、この排出口１０７に直径８mmメッシュのスクリーンを設け、この冷却工程において、予備的に粉砕処理を行っても良い。
【００７８】
なお、冷却造粒手段は、上記のクーリングミキサーに限定されず、例えば、ミキサー本体内の混練材料を撹拌する撹拌羽根を設け且つミキサー本体の外周壁面に前述したようなジャケットを設け、このジャケット内を流れる冷却水でミキサー本体内の混練材料を冷却するものであれば良い。
【００７９】
また、ミキサー８０で形成された混練材料は前記ジャケット１０２を備えてない一般的なミキサーを用いて撹拌のみを行なって冷却することも可能であるが、この場合は混練材料を冷却するに長時間を要するので、本実施の形態のようなクーリングミキサーの冷却造粒手段で造粒原料を形成することが望ましい。
【００８０】
〔粉砕手段〕
前記冷却造粒手段で形成された造粒原料は、さらに粉砕手段を使用して粒径８mm以下に粉砕し、「木質合成粉」を形成する。
【００８１】
図１０において、１２０は前述した造粒原料を粉砕する粉砕手段であり、本実施の形態では「カッタミル」を用いている。
【００８２】
１２１はカッタミル本体で、上面開口を有する円筒形を成すケーシングであり、前記開口を開閉自在な蓋１２２で被蓋する。前記蓋１２２はカッタミル本体１２１内に造粒原料を投入する投入口１２３を備えている。
【００８３】
また、前記カッタミル本体１２１内にはカッタミル本体１２１の底面に軸承されて図示せざる回転駆動手段で水平方向に回転するカッタ支持体１２４を設け、このカッタ支持体１２４の外周に上下方向に長い回転刃１２５を３枚を設け、これらの３枚の回転刃１２５はカッタ支持体１２４の回転方向で１２０度の等角度を成すように配設し、３枚の回転刃１２５の刃先は同一の回転軌跡上に位置している。さらに、前記３枚の回転刃１２５の刃先の回転軌跡に対して僅かな隙間を介して二の固定刃１２６を回転刃１２５の刃先の回転軌跡の略対称位置にカッタミル本体１２１に固定し、二の固定刃１２６とカッタ支持体１２４と回転刃１２５とでカッタミル本体１２１内を二分し、投入室１２７と粉砕室１２８を形成する。前記蓋１２２の投入口１２３は前記投入室１２７に連通する。なお、二の固定刃１２６と回転刃１２５との隙間は造粒原料を所望の大きさに粉砕できるよう自在に調整できる。また、粉砕室１２８は前記二の固定刃１２６間を回転刃１２５の回転軌跡の周囲を囲むようにスクリーン１２９で仕切っている。なお、スクリーン１２９は、本実施の形態では８mm以下の大きさの粉砕された「木質合成粉」が通過できるメッシュで形成している。また、粉砕室１２８のカッタミル本体１２１の下端にはカッタミル１２０で前記粉砕物を排出する排出口１３１を設けている。
【００８４】
以上のカッタミル１２０において、蓋１２２の投入口１２３から前述したクーリングミキサー１００で形成した造粒原料を投入し、図示せざる回転駆動手段でカッタ支持体１２４を回転すると、造粒原料はカッタ支持体１２４の回転刃１２５と固定刃１２６間で約８mm以下に切断され「木質合成粉」が形成される。
【００８５】
なお、粉砕手段は、上記のカッタミルに限定されず、例えば、（株）ホーライ社製のハードクラッシャのように、回転刃１２５の回転軸は水平方向に設けられ、二の固定刃１２６間のスクリーン１２９は下方に設けられているものもある。
【００８６】
〔木質合成粉の製造実施例〕
次に、前述した各製造手段を用いて本実施形態において使用した木質合成粉の製造実施例を以下に説明する。
【００８７】
工程１
本工程では、前述した乾燥加圧流動混合混練手段であるミキサー８０を用い、原料の１つである木粉を乾燥させる。
【００８８】
モータを回して撹拌衝撃翼８５，８６，８７およびスクレイパー８４を高速回転し、上蓋８２を開放して投入口９４から木粉を投入する。
【００８９】
ミキサー８０の前記撹拌衝撃翼の回転を８００〜９００rpmに維持すると、撹拌衝撃翼による剪断力が高くなるため剪断力による摩擦熱の発生が向上し、ミキサー８０内の温度は１８０〜１９０℃になり、投入された木粉が乾燥される。
【００９０】
本実施形態にあっては、投入された木粉の含有水分量が０％となるまで乾燥する。また、顔料等として酸化チタン等を添加する場合には、この乾燥工程において前記木粉と共にミキサー８０内にこれを投入する。本実施形態にあっては、木粉１００wt％に対して１０wt％前後の白酸化チタンを投入している。
【００９１】
工程２
以上のように乾燥された木粉５５wt％に対して、熱可塑性樹脂成形材としてＰＰ４５wt％を前記ミキサー８０内に投入し、さらに８００〜９００rpmで撹拌加圧してミキサー８０内の温度を２１０℃に上昇させる。
【００９２】
なお、熱可塑性樹脂成形材の形態は、本実施形態では直径３mm程度の大きさの粒状からなるペレットを使用している。また、熱可塑性樹脂成形材であるＰＰの融点は１６５℃である。
【００９３】
なお、熱可塑性樹脂材料は、熱可塑性合成樹脂製品の廃材から得られた回収熱可塑性樹脂材料を再利用したもの、あるいはバージンの熱可塑性樹脂を投入し、あるいはバージンの熱可塑性樹脂と前記回収熱可塑性樹脂材料をそれぞれ、例えば５０％ずつ用いることもできる。
【００９４】
この工程で、原材料内の木粉によりＰＰは大きな塊とはならず、混合分散に際しても凝集したりせずに粘土状にゲル化する。この工程で、上記粘土状にゲル化したものは直径約１０〜１００mmの塊状の「混練材料」となった。
【００９５】
前記モータを低速にし、シリンダ９１を作動して蓋８９を後退して排出口８８を開放する。ミキサー本体８１内のゲル化した原材料は排出口８８から排出ダクト９３を経て、次工程へ排出される。
【００９６】
工程３
本工程では、前述した冷却乾燥手段であるクーリングミキサー１００を用いる。
【００９７】
前述したミキサー８０で形成された混練材料は排出ダクト９３を経てクーリングミキサー１００の投入口１１３からミキサー本体１０１内へ投入される。撹拌破砕翼１０４はモータ１０５により１２０rpmの速度で回転し、アーム１０３が３rpmの速度で水平方向に回転している。
【００９８】
混練材料はジャケット１０２内に１００リットル/minで導入された冷却水により冷却されたミキサー本体１０１の内周壁面で冷却され、直径約２５mm以下に造粒された「造粒原料」が形成され、この造粒原料はバルブ１０６を開放して排出口１０７より排出される。
【００９９】
混練材料としてのＰＰの融点は１６５℃であり、本製造例では前述したミキサー８０内で２１０℃にゲル化した混練材料をクーリングミキサー１００へ投入して１００℃以下まで冷却する。このクーリングミキサーによる冷却乾燥は効率が良い。このときのジャケット１０２内の冷却水については、給水管１０８から供給する冷却水の温度は３０℃で、排水管１０９より排水される冷却水の温度は４０℃。
【０１００】
工程４
前記工程で形成された造粒原料は、さらにカッタミル１２０を使用して粒径８mm以下に粉砕し成形素材を形成する。
【０１０１】
図１０において、造粒原料はカッタ支持体１２４の回転刃１２５と固定刃１２６間で約８mm以下に切断され「木質合成粉」が形成され、粉砕室１２８のスクリーン１２９のメッシュを通過して排出口１３１より排出される。
【０１０２】
このようにして木粉と熱可塑性樹脂成形材との混合、分散状態を定常的に維持すべく、良好なる流動性を与える木質合成粉が形成され、且つ冷却による凝縮、縮小作用とも相まって、化学的な反応とか接着によらない木質合成粉が形成され、排出口１３１より排出され次工程の押出機７０へ送られる。
【０１０３】
〔成形ダイ内の作用〕
押出機７０より押出ダイ１９及びフランジ１７を介して吐出された押出し生地７９は、溶融部２１ａを経て成形ダイ１０の成形室２２内の押出し方向へ流れる。
【０１０４】
溶融部２１ａ内を流れる押出し生地７９はヒータ１４ａ〜１４ｃにより加熱され、良好な混練状態を保ちながら押出される。押出し生地７９は、細長の矩形状を成す成形室２２内へ押出され、この成形室２２内の徐冷部２１ｂを通過する過程で冷却管２５内を流れる冷却水により外側から冷却されると共に、中子体４０内に形成された冷却媒体の流路４２内に導入された冷却媒体により内側からも冷却されて均一に冷却されて、４６．７mmの肉厚の製品としての中空樹脂成形板２９が成形される。
【０１０５】
中子体４０は、成型ガイド部４１からダイ出口２３方向に向かって徐々にその太さを細く形成されたテーパ形状を成すため、押出し生地の冷却固化に際して中子体が押出し力に対する抵抗になることはない。
【０１０６】
また、溶融部２１ａにおいて、中子体４０内に形成された冷却媒体の導入路４１は断熱材４３により包囲されているため、中子体４０内を流れる冷却媒体が溶融部２１ａ内の押出し生地７９を冷却することはなく、従って溶融部２１ａ内において押出し生地７９の流動性が低下することも防止されている。
【０１０７】
なお、案内部１５、中子体４０の表面にフッ素樹脂のシートを貼設すれば中子体４０の表面を通過する押出し生地７９に対する抵抗は小さいので、押出し生地７９内の特に摩擦抵抗の大きい木粉は案内部１５の表面で大きな抵抗を受けることなく円滑に流動するので、押出し生地７９は均一で高密度の混練状態を保ちながら成形ダイの成形室２２内を押し出される。
【０１０８】
特に、木質合成粉を用いて本発明の押出成形を行なった場合は、押出機７０内では個々の木粉間に樹脂が満遍なく浸透した混練状態の良い押出し生地７９が形成されるため、この押出し生地内の特に木粉が押出機内及び成形ダイ内の壁面で大きな抵抗を受けずに円滑に流動し、より一層均一で高密度の中空樹脂成形板が形成される。
【０１０９】
なお、成形室２２の上下左右の四方の内壁面にフッ素樹脂で成るシートを貼設することもでき、この場合には押出し生地７９が成形室２２を流動する過程において、押出し生地７９は徐冷されながら円滑に押出される。
【０１１０】
フッ素樹脂は、▲１▼約３００℃の耐熱性を有し、▲２▼表面が平滑であり摩擦係数が小さく、▲３▼金属に比べて熱伝導係数が低いという性質を有しているので、押出し生地７９に対して以下に示すような作用をする。
【０１１１】
フッ素樹脂は表面が平滑であり摩擦係数は小さいので、成形室２２内を通過する押出し生地７９内の特に木粉は大きな抵抗を受けずに流動する。そのため押出し生地７９の混練状態は良好な状態を維持して、結果として密度が均一で巣ができずしかも表面が平滑な高品質の中空樹脂成形板が生成される。
【０１１２】
成形室２２の徐冷部２１ｂでは押出し生地７９が冷却されるので押出し生地７９の流動性が悪くなる上、押出し生地７９内の木粉は樹脂に比べて摩擦抵抗が大きく、成形ダイの内壁面も摩擦抵抗が大きく、成形ダイの内壁面を接触して流動する木粉は大きな抵抗を受けることになり円滑に流動しないため押出し生地７９の混練状態を粗密にし巣を形成するなどの悪影響を及ぼすものであったが、成形室２２の内壁面にフッ素樹脂のシートを設けたことにより、押出し生地７９の木粉は成形室２２の内壁面から大きな抵抗を受けることなく円滑に流動するので、押出し生地７９に前述したような悪影響を及ぼすことなく押出し生地７９は均一・高密度の良好な混練状態で成形室２２内を押出される。
【０１１３】
また、上述したように押出し生地７９の木粉に対する抵抗力が少なくなり押出し生地７９は均一な密度で成形されるので、製品としての中空樹脂成形板２９の表面にはいわゆる肌荒れが生じることなく平滑な面に仕上がる。
【０１１４】
また、従来は、押出し生地７９の木粉が成形ダイ内で円滑に流動しないために成形ダイのヒータの熱で木粉が焼けてこげ茶色に変色したが、本発明は上述したように押出し生地７９の木粉が円滑に流動するので、木粉が焼けることなく耐衝撃性など品質特性の低下が生じない。
【０１１５】
フッ素樹脂は金属に比べて熱伝導係数が低いので、徐冷効果があり、押出し生地７９の冷却時の歪みを抑える作用をする。
【０１１６】
成形ダイ１０の成形室２２内の徐冷部２１ｂは冷却管２５及び中子体４０内の冷却媒体の流路４２内を流れる冷却水、空気流等の冷却媒体により冷却されるが、フッ素樹脂は金属に比べて熱伝導係数が低いので、成形室２２の冷却温度が成形室２２の内壁面に直接的に急速に熱伝導されないため、成形室２２内の押出し生地７９は急冷されず徐冷されることになる。したがって押出し生地７９が急冷されるときに生じる大きな歪みの発生は防止され、製品としての中空樹脂成形板２９の歪みが少なくなると同時に、表面が平滑となる。
【０１１７】
【発明の効果】
以上説明した本発明の構成により、本発明の方法及び装置により以下に示す顕著な効果を得ることができた。
【０１１８】
成形ダイより押し出された成形板を引き取る引取手段を設けたことにより、成形板の押出し速度を上昇することができると共に、徐冷部において中子体に冷却媒体の流路を形成したことにより、この流路内に冷却媒体を導入することで徐冷部において所定の形状に成形された押出し生地を内部より徐冷することでができ、従って短時間において押出し生地の徐冷を行うことができた。
【０１１９】
従って、製造された成形板の品質を低下させることなく押出し速度を速めることができ、高品質の中空樹脂成形板を高速で製造することのできる方法及び装置を得ることができた。
【図面の簡単な説明】
【図１】本発明の実施形態の押出機の一部縦断面を示す正面図である。
【図２】本発明の実施形態の成形ダイの部分平面図である。
【図３】本発明の実施形態の押出ダイ、フランジ及び成形ダイを連結した状態の中央縦断面図である。
【図４】表１の温度測定箇所を示す押出し成形装置の概略図である。
【図５】引取手段を示す概略図である。
【図６】図３のＪ−Ｊ矢視断面図。
【図７】図２の右側面図。
【図８】本発明の実施例に使用するミキサー（乾燥流動混合混練手段）の要部断面を示す全体正面図である。
【図９】本発明の実施例に使用するクーリングミキサー（冷却造粒手段）の要部断面を示す全体正面図である。
【図１０】本発明の実施例に使用するカッタミル（粉砕手段）の要部断面を示す全体正面図である。
【符号の説明】
１０ 成形ダイ
１４ａ〜１４ｃ ヒータ
１６ 流入口（押出ダイの）
１７ フランジ
１８ 射出口（押出ダイの）
１９ 押出ダイ
２１ａ 溶融部
２１ｂ 徐冷部
２２ 成形室
２５ 冷却管
２９ 成形板
３０ 引取手段
３１ ローラ
３１ａ 駆動ローラ
３３ 無端ベルト
４０ 中子体
４１ 導入路（冷却媒体の）
４２ 流路（冷却媒体の）
４３ 断熱材
４４ 基部
７０ 押出機
７１ スクリュー
７２ ギヤ減速機
７３ ホッパ
７４ バレル
７５ バンドヒータ
７６ スクリーン
７９ 押出し生地
８０ ミキサー（流動混合混練手段）
８１ ミキサー本体
８２ 上蓋
８３ 軸
８４ スクレイパー
８５，８６，８７ 撹拌衝撃翼
８８ 排出口
８９ 蓋
９１ シリンダ
９２ 締付ナット
９３ 排出ダクト
９４ 投入口
９５ ガス排出管
１００ クーリングミキサー
１０１ ミキサー本体
１０２ ジャケット
１０３ アーム
１０４ 撹拌破砕翼
１０５ モータ
１０６ バルブ
１０７ 排出口
１０８ 給水管
１０９ 排水管
１１１ モータ
１１２ 減速装置
１１３ 吸入口
１１４ フレーム
１２０ カッタミル（整粒手段）
１２１ カッタミル本体
１２２ 蓋
１２３ 投入口
１２４ カッタ支持体
１２５ 回転刃
１２６ 固定刃
１２７ 投入室
１２８ 整粒室
１２９ スクリーン
１３１ 排出口[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for extrusion molding of a hollow resin molded plate using a thermoplastic resin molding material and a synthetic wood powder made of cellulosic crushed material as a molding material. In an extruder, a thermoplastic resin molding material or a thermoplastic resin molding material formed with a hollow part suitable for various applications such as parts, or a mixed raw material of cellulose-based crushed material, or a woody synthetic powder composed of these mixed raw materials is used as a molding material The present invention relates to a method and an apparatus for extrusion molding of a hollow resin molded plate that can improve the molding speed without degrading the quality of the molded plate that has been molded and formed into a molded plate having a predetermined thickness.
[0002]
In addition, one or both of the cellulose-based crushed material and the thermoplastic resin molding material may be used in a wide variety of applications such as building waste materials, automobiles, household electrical appliances, etc., as daily life diversifies. In addition, it is possible to reuse the waste materials of various types of thermoplastic synthetic resin products that are used in large quantities and are discarded in large quantities. As a purpose, the present invention relates to a means capable of improving the molding speed without deteriorating the quality of the molded plate in which the hollow portion is formed.
[0003]
[Prior art]
The true specific gravity of wood flour, which is the main molding material of conventional wood composite boards, is 1.4, and the true specific gravity of thermoplastic resin moldings varies depending on the material, but it is about 0.9 to 1.5. A conventional wood synthetic board formed by kneading powder and a thermoplastic resin molding material varies depending on the mixing ratio of the wood powder and the thermoplastic resin molding material and the thermoplastic resin molding material, but the specific gravity is 0.97 to 1. .48, which has a larger true specific gravity than a general wood board (for example, a specific gravity of plywood such as plywood 0.45 to 0.75), so that the conventional wood composite board is heavy. .
[0004]
In order to reduce the weight of such a conventional wood composite board, attempts have been made to form a hollow portion in the wood composite board.
[0005]
Various devices such as offset dies and vacuum sizing devices that form hollow parts have been developed and used as methods for producing resin molded products with hollow parts, but to produce plate-shaped products. In addition, as a means for forming a hollow portion in the thermoplastic resin molding material, an extrusion blow molding machine using a blow mold, an injection blow molding machine, an injection compression molding machine, etc. are used, and so-called solid extrusion molding has been put into practical use. It wasn't.
[0006]
In addition, the formation of the hollow portion by extrusion molding was experimentally performed, and although it is not theoretically impossible, a hollow is formed on the surface of the hollow portion by rapid cooling.
[0007]
Thus, a method for solving the problem and forming a hollow wooden synthetic board by extrusion molding without causing molding defects such as light weight and depression by extrusion molding has been studied. As this method, an extruded dough heated and kneaded by an extruder equipped with a screw is discharged into a molding die provided with a core body in a molding chamber, and the extruded dough is molded to a predetermined thickness and the core body A hollow portion is formed in the molded plate by the above, and the density of the extruded dough extruded to the molding die is increased by suppressing the extrusion force of the molded plate extruded from the molding die by the brake means, and the hollow resin molded plate is molded. There is a method (JP-A-8-118452).
[0008]
[Problems to be solved by the invention]
According to the invention described in Japanese Patent Application Laid-Open No. 8-118452, the extruded dough has a high density by applying a resistance force in a direction opposite to the extrusion direction by the brake means to the molded plate extruded from the die exit of the molding die. By doing so, the woody synthetic board in which the hollow part was formed can be obtained, without producing molding defects, such as a hollow.
[0009]
However, in the extrusion molding method shown in the prior art, since the extrusion force of the molding plate is suppressed by the brake means as described above, the extrusion speed is as slow as 4 to 5 m per hour, so that the production is There was a problem that the nature was bad.
[0010]
Moreover, even if the extrusion speed of the extruded dough by the extruder is increased, in this case, the extruded plate is extruded before it is sufficiently cooled in the molding die, and in particular, the conventional hollow resin molded plate is molded. In the method, since the cooling of the extruded dough is performed from the outside of the extruded dough by introducing cooling water into the cooling water flow path provided in the wall thickness of the forming die, It takes a long time to be sufficiently cooled.
[0011]
Therefore, when the molded plate is extruded beyond the above-described extrusion speed of 4 to 5 m / h, the molded plate is extruded before being sufficiently cooled to the inside, and thus further cooled after the molded plate is extruded. As a result, sink marks and deflection occur in the molded plate. In particular, the occurrence of sinks and deflections in the ribs formed between the hollow portions that take a long time to complete the cooling is significant. When such sinks and deflections occur, the dimensions, rigidity, The bending strength and the like are not constant, and there is a problem that the quality of the product is uneven.
[0012]
Therefore, an object of the present invention is to solve the above-described drawbacks in the prior art, and it is possible to increase the manufacturing speed in the manufacture of the hollow resin molded plate and to increase the manufacturing speed in this way. Even if it exists, it aims at providing the manufacturing method and apparatus of the hollow resin molding plate which do not produce a bending and sink on a molding plate, and can manufacture the molding plate which has uniform quality at high speed.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the method for extrusion molding a hollow resin sheet of the present invention comprises a molding chamber 22 comprising a melting part 21a for heating the extruded dough 79 and a slow cooling part 21b continuous with the melting part 21a. In addition, the raw material which is heated and kneaded in the molding die 10 provided with the core body 40 which protrudes in parallel with the extrusion direction from the base portion 44 provided in the melting portion 21a and extends to the slow cooling portion 21b of the molding chamber 22 is provided. The extruded dough 79 is extruded to a predetermined thickness and a hollow portion is formed, and the extruded dough 79 extruded to the forming die 10 is extruded from the outside of the extruded dough 79 and the inside of the hollow portion in the slow cooling portion 21b. It is characterized in that it is gradually cooled and the molded plate 29 extruded from the molding die 10 is taken up.
[0014]
In the above-described method, the extrusion speed of the extruded fabric 79 by the screw 71 of the extruder 70 can be adjusted by pulling the molding plate 29 at a speed slower than the extrusion speed.
[0015]
Furthermore, when the extrusion speed of the extruded dough 79 by the extruder 70 is increased, it is preferable that the heating temperature of the extruded dough 79 in the melting part 21a of the forming die 10 is increased.
[0016]
The extrusion molding apparatus for hollow resin molded plates of the present invention heats and kneads the raw material and heats the extruded dough 79 extruded from the extrusion die 19 to the extrusion die 19 of the extruder 70 that extrudes with the screw 71. Parallel to the extrusion direction from a molding chamber 22 comprising a melting portion 21a to be formed, a slow cooling portion 21b for shaping the extruded dough 79 extruded from the melting portion 21a to a predetermined thickness, and a base 44 provided in the melting portion 21a. Is connected to a molding die 10 provided with a core body 40 extending at least to the slow cooling part 21b, and the extruded dough 79 in the slow cooling part 21b of the molding chamber 22 is cooled from the outside of the extruded dough 79. The cooling means such as the cooling pipe 25 is provided in, for example, the wall surface of the molding die 10, the cooling medium flow path 42 is formed in the core body 40 in the slow cooling portion 21 b, and the molding die Characterized by comprising a take-up unit 30 for taking up the molded plate 29 extruded from 0.
[0017]
The cooling medium flow path 42 formed in the core body 40 in the slow cooling section 21b is a cooling medium introduction path that penetrates the core body 40 in the wall surface of the molding die 10, the base 44, and the melting section 21a. 41, and the outer periphery of the introduction path 41 is surrounded by a heat insulating material 43 to prevent the extruded dough 79 in the melting part 21a from being cooled.
[0018]
In addition, the said extrusion die 19 and the said shaping | molding die 10 are connected via the flange 17 provided with the communicating hole, and the heater which overheats the extrusion material | dough 79 in the communicating hole of the said flange 17 can also be provided in the said flange 17. FIG. .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. For the sake of convenience, a hollow resin molded plate made of a crushed cellulosic material and a thermoplastic resin molding material or a woody synthetic powder obtained by gelling, kneading, and pulverizing these is used. An example is mainly explained.
[0020]
(Extruder)
In FIG. 1, 70 is a single screw extruder, but in general, an extruder is usually a screw type, and there are a single screw extruder and a multi-screw extruder, and there are some which have this deformation or a combination of these. In the present invention, any extruder can be used.
[0021]
Reference numeral 71 denotes a screw, which is a single-shaft type. The screw 71 is driven by a motor (not shown) via a gear reducer 72 and rotates in a barrel 74. The cellulosic crushed material and the thermoplastic resin molding material introduced from the hopper 73 are extruded by the rotating screw 71 to the front of the screw 71 while being kneaded. A band heater 75 is provided on the outer surface of the barrel 74, and the cellulosic crushed material and the resin in the barrel 74 are heated by the band heater 75 and are gradually melted while being transported forward along the groove of the screw 71. Things and resins are smelted. Then, it is extruded as an extruded dough 79 from the extrusion die 19 of the flange 17 to the forming die 10 through the screen and the flange 17.
[0022]
(Extrusion die)
1, 3, and 6, the extrusion die 19 at the tip of the barrel 74 is provided with a substantially elliptical injection port 18 having a tip of 65 mm in width and 25 mm in height (see FIG. 6) on the rear end surface of the barrel 74 side. A communication hole that is gradually deformed in cross section is formed from the inflow port 16 having a circular shape of 65 mm in diameter toward the injection port of the extrusion die 19.
[0023]
The extrusion die 19 can be formed in various sizes according to the size of the extruder 70.
[0024]
A flange 17 is attached to the tip of the extrusion die 19. The flange 17 is formed with an inlet having the same shape as the injection port 18 of the extrusion die 19 and an injection port having a width of 97.5 mm and a height of 46.7 mm. The flange 17 is gradually formed from the introduction port to the injection port. A communication hole having a deformed cross section is formed.
[0025]
A heater serving as a heating means may be embedded in the peripheral wall of the communication hole of the flange 17. In this case, the extruded fabric 79 extruded from the extruder 70 flows from the inlet of the flange 17 and flows into the melting part 21a of the forming die 10 through the communication hole while being heated and kept warm by the heater. The flow state of the extruded dough 79 is good. Moreover, since the extrusion die 19 is different from a normal general die, it has a large injection port so that a large amount of molten raw material (woody synthetic powder) is discharged and formed into a shape capable of promoting compaction. Clogging of the die that occurs in the other die does not occur.
[0026]
[Molding die]
2 and 3, reference numeral 10 denotes a forming die, into which an extruded fabric 79 extruded from an extruder 70 is introduced via an extrusion die 19 and an adapter 17, and a melting section 21a for heating the introduced extruded fabric 79; The molding chamber 22 is provided with a slow cooling part 21b for slowly cooling the extruded dough 79 extruded from the melting part 21a. In this embodiment, the melting part 21a is the same as the injection port of the flange 17. A 61 mm long extruded dough passage having a shape inlet and outlet is formed, and a slow cooling portion 21b having the same cross-sectional shape as the inlet of the melting portion 21a is formed, and the molding chamber 22 is constant in the extrusion direction. The cross-sectional shape is formed.
[0027]
In addition, Preferably, the sheet | seat which consists of the below-mentioned fluororesin is affixed on the inner wall face of the molding chamber 22 which consists of the said fusion | melting part 21a and the slow cooling part 21b.
[0028]
The forming chamber 22 is formed in a square shape with a metal spacer (not shown) in which two upper and lower metal plates each provided with heating and cooling means are arranged on both side edges. It adjusts so that the thickness of the target hollow resin molding board may be obtained.
[0029]
For example, the molding die 10 has a rectangular cross section with a width of 230 mm and a height of 250.7 mm, and the distance from the inlet of the molding chamber 22 to the die outlet 23 (distance in the extrusion direction) is 1,000 mm.
[0030]
[Structure in the forming die]
For example, a sheet made of a fluororesin having a thickness of 0.25 mm can be pasted on the inner wall surfaces in the upper, lower, left, and right sides of the molding chamber 22. In addition, it is possible to directly coat the fluororesin on the upper, lower, left and right inner wall surfaces of the molding chamber 22, but in terms of easy replacement, the fluororesin coating process is easy and durable. It is particularly preferable to paste a resin sheet.
[0031]
The fluororesin sheet is particularly preferably obtained by coating a surface of a glass woven fabric with a fluororesin film. Examples of the fluororesin include Teflon TFE, Teflon FEP, Teflon CTFE, and Teflon VdF. The glass woven fabric may be a glass fiber non-woven fabric.
[0032]
The fluororesin coating process described above can be applied to the upper and lower inner wall surfaces of the molding chamber 22, that is, the inner wall surfaces corresponding to the surfaces forming the front and back surfaces of the hollow resin molded plate. It is desirable to apply to the entire inner wall surfaces of the upper, lower, left and right sides of 22.
[0033]
2 and 3, reference numerals 14 a to 14 c are heaters, each of which includes a heating means such as an electric heater, and in order to keep the extruded dough 79 heated and to maintain the fluidity of the extruded dough 79, Three pipes are inserted at equal intervals into the upper and lower molding dies 10 of the molding chamber 22 corresponding to the melted part 21a formed over a quarter of the pipe.
[0034]
In the extrusion molding method for a hollow resin molded plate of the present invention in which the extrusion speed of the hollow resin molded plate is 10 to 20 m / h as an example, the temperature of the heater 14 is extruded at a speed of, for example, 7 m / h or less. The temperature is higher than in the case.
[0035]
As an example, the difference in the temperature of the heater 14 when the extrusion speed of the molded plate is 1 to 7 m / h and when the extrusion speed is 7 m / h or more is shown in the following table.
[0036]
The positions indicated by the respective symbols are as shown in FIG. 4. C1, C2, and C3 are temperature measurement positions in the extruder 70, A is a heater provided on the flange 17, and 14a, 14b, and 14c are molding dies. Each heater is shown.
[0037]

[0038]
As described above, when the extrusion speed is increased, the temperature of the heaters 14a to 14c of the molding die 10 is set higher than that at the low speed. This is because when the forming speed increases, the extruded dough 79 takes heat of the forming die 10 and the melting of the extruded dough 79 becomes incomplete at the melting portion 21a of the forming die 10.
[0039]
As described above, when the melting of the extruded dough 79 in the melting portion 21a of the molding die 10 is incomplete, the density of the molded plate 29 is not uniform, and the plate is nested. Therefore, in order to sufficiently melt the extruded dough 79 in the melting part 21a of the molding die 10, the temperatures of the heaters 14a to 14c in the part are set higher than in the conventional case.
[0040]
A cooling pipe 25 is an example of a cooling means for cooling the slow cooling portion 21b of the molding chamber 22 of the molding die 10. The cooling pipe 25 is provided at appropriate intervals in the extrusion direction of the molding chamber 22. Cooling liquid, which is a cooling medium such as water at normal temperature, water up to about 70 to 80 ° C., or oil, is supplied to cool the extruded dough 79 in the molding chamber 22 from the outside. This cooling pipe 25 is connected to the cooling chamber 21b that occupies three-quarters in the direction of the die outlet 23 of the molding die 10 in order to improve the cooling effect of the extruded dough 79 in the molding chamber 22. A large number of pipes 22 are inserted into the upper and lower forming dies 10 at regular intervals. Note that the interval between the cooling pipes 25 can be provided so as to be gradually reduced, or the cooling pipe 25 can be disposed in contact with the outer wall of the molding die 10, but if the extruded dough 79 in the molding chamber 22 can be cooled. Since it is good, it is not limited to the structure of this embodiment.
[0041]
[Core]
2 and 3, in this embodiment, the core body 40 is integrally formed with a base portion 44 fixed to the upper and lower inner walls of the melting portion 21a, and extends from the base portion 44 toward the outlet of the molding die 10. Thus, the three core bodies 40 are formed so as to protrude and are formed in a substantially comb-like shape as a whole.
[0042]
The connecting portion between the base portion 44 and the upper and lower inner walls of the melting portion 21a is formed in a streamline shape on a plane as shown in FIG. 2, so that the extruded dough flowing through the melting portion 21a flows without resistance.
[0043]
In this embodiment, the rectangular cross section is gradually reduced to a length of 681 mm, a height of 34.5 mm and a width of 25.4 mm on the base 44 side, and a height of 33.8 mm and a width of 24.8 mm on the outlet side. Between the two tapered cores 40, 40 to be narrowed, the length is 681 mm, the height is 34.5 mm, the width is 24.4 mm on the base 44 side, the height is 33.8 mm, and the width is 23.8 mm. One tapered core body 40 that gradually narrows the rectangular cross section is disposed.
[0044]
A cooling medium such as water, liquid such as oil, air, or other gas is supplied to the upper inner wall surface of the molding die 10 to which the base portion 44 of the core body 40 is fixed. An introduction path 41 communicating with a supply source of a cooling medium (not shown) is formed, and the introduction path 41 of the cooling medium passes through the wall surface of the molding die 10 and the base portion 44 to the core body 40 in the melting portion 21a. Finally, the slow cooling portion 21b communicates with a cooling medium passage 42, which will be described later, formed in the core body 40.
[0045]
The cooling medium introduction path 41 formed in the core body 40 is surrounded by a heat insulating material 43 to prevent the cooling medium passing through the introduction path 41 from cooling the extruded dough in the portion. In addition, the cooling effect is improved when the cooling medium is introduced into the cooling medium flow path 42 described later.
[0046]
In this embodiment, the wall of the forming die 10, the base 44, and the core body 40 are penetrated by a metal pipe having a diameter of 4 mm in which Myorex PMX-575 (Ryoden Kasei) is arranged as a heat insulating material on the outer periphery. This is the cooling medium introduction path 41.
[0047]
In the slow cooling portion 21b, a flow path having a diameter of 20 mm passing through the center of the core body 40 is formed in the core body 40, and a cooling medium is circulated in the flow path 42 so that the inside of the slow cooling portion 21b. The extruded dough 79 is configured to be gradually cooled from the inside of the hollow portion.
[0048]
In this embodiment, the flow path 42 communicates with the cooling medium introduction path 41 at one end as described above, and opens the other end at the end of the core body 40 toward the outlet of the molding die 10. Therefore, the cooling medium introduced into the cooling medium flow path 42 is discharged out of the forming die 10 through the hollow portion formed in the extruded forming plate 29. Then, when the cooling medium passes through the flow path 42 formed in the core body 40 and the hollow portion formed in the molded plate 29, the extruded fabric 79 and the molded plate 29 are gradually cooled from the inside.
[0049]
In place of the above-described configuration, the cooling medium flow path 42 has a double-tube structure in which the core 40 is communicated with the end portion on the outlet side of the molding die 10, for example, in the slow cooling portion 21b. The cooling medium, for example, cooling water or cooling oil may be circulated in the core body 40 by communicating with the medium introduction source and the other with the cooling medium discharge port. The design of the flow path 42 can be changed in accordance with changes in the type of cooling medium introduced and other various conditions as long as the extruded fabric 79 can be gradually cooled from the inside.
[0050]
The core body 40 may be affixed with a sheet made of fluororesin such as Teflon having a thickness of 0.1 to 0.5 mm on the entire outer surface, and the size of the core body 40 depends on the volume of the molding chamber 22. Can be changed as appropriate.
[0051]
[Acquisition means]
The take-up means 30 is arranged on the outlet side of the forming die 10 and takes out the forming plate pushed out through the outlet of the forming die 10, and an example thereof is shown in FIG.
[0052]
In the embodiment shown in FIG. 5, the transaction means 30 includes a plurality of rollers 31, 31, 31 wound simultaneously around an endless belt 32 in an up-down direction and arranged endlessly. The molding plate 29 can be sandwiched between the belts 32, 32. At least one of the rollers 31 is formed as a driving roller 31 a connected to a driving source, and the upper and lower rollers 31 are connected via an endless belt 33. , 31 is formed so as to be pulled in the pushing direction by the rotation of the driving roller 31a.
[0053]
When the forming plate 29 is taken up by the take-up means 30 at a speed slower than the extrusion speed of the extruder 70, for example, the extruded dough in the melting portion 21a of the forming die 10 becomes a high-density and uniform state and is formed. The plate 29 is in a state that does not cause dents, sink marks, deflection, or the like.
[0054]
When the extrusion speed of the extruded dough by the extruder 70 is increased and the take-up speed of the forming plate 29 by the take-up means 30 is increased at a speed slower than the extrusion speed of the extruded dough by the extruder 70, the forming die 20 The molding speed of the molding plate 29 can be improved while keeping the pressure of the extruded dough in the melting portion 21a constant, and the density of the extruded fabric 79 in the melting portion 21a can be adjusted by adjusting the molding speed of the molding plate 29. It is comprised so that it can carry out as it is.
[0055]
In the extrusion apparatus for a hollow resin molding plate configured as described above, in this embodiment, as an example, raw materials to be put into the hopper 73 of the extruder 70 are made of a cellulose-based crushed material and a thermoplastic resin molding material. The example which manufactures a hollow resin molding board using the molding material obtained by kneading | mixing is demonstrated. In the present specification, a crushed cellulosic material and a thermoplastic resin molding material are kneaded, granulated and pulverized to a predetermined particle diameter, and referred to as “woody synthetic powder”.
[0056]
The wood powder used as the raw material for this woody synthetic powder has a good particle size compatibility with the thermoplastic resin molding material, reduces the frictional resistance of the wood powder during molding extrusion, and prevents wear and damage of the molding machine. From that, 50-300 mesh, preferably 60 (under sieve) to 150 mesh (on sieve) in a fine powder form, volatilizes the wood acid gas at the time of molding, eliminating the risk of water vapor or bubble generation, For the purpose of preventing surface roughness, the water content is within 15 wt%, preferably within 11 wt%, ideally within the range of 0-5 wt%.
[0057]
In order to further improve the properties of such wood flour, it is possible to immerse or add materials such as wood chips to urea-based resin adhesives, heat and cure them, and then crush and finely pulverize them to 50 to 300 mesh. Yes, in this method of forming wood flour, wood acid in wood flour is rapidly removed by neutralization and volatilization by sufficient heat curing, especially by heat curing while neutralizing with urea resin adhesive. At the same time, a hardened adhesive surface is provided on the peripheral surface of the wood powder, which can effectively prevent the moisture content of the wood powder from being increased, further improve the sliding property of the wood powder, and particularly reduce the frictional resistance during molding extrusion. Can do.
[0058]
The thermoplastic resin molding material is obtained by crushing the above-mentioned various discarded resin molded products as they are or by crushing a resin molded product having a surface resin coating film into a plurality of small pieces, and for each of the crushed individual pieces. Add a compression grinding action to grind and peel the resin coating, apply a compressive impact force based on micro vibrations to each ground small piece, crush and crush, and peel by crushing and crushing It is a resin such as PVC, PET, PP, etc., which is removed as needed to form a thermoplastic resin molding material.
[0059]
When the thermoplastic resin molding material is PP, the wood powder is mixed up to 75 wt% at maximum. The range of the ratio of mixing wood flour is 20 to 75 wt%, preferably 30 to 70 wt%.
[0060]
The mixing capacity is appropriately determined in accordance with various characteristics such as intended wear resistance characteristics, but in the present invention, various effects are eliminated during the molding described above, so that a large amount is mixed. Can do.
[0061]
In the case of PET, wood powder is mixed up to a maximum of 60 wt%, but the mixing ratio of wood powder is preferably 20 to 60 wt%.
[0062]
When the thermoplastic resin molding material is PVC, the mixing ratio of the wood powder is 30 to 60 wt%, preferably 45 wt%.
[0063]
In extrusion molding, the recovered thermoplastic resin molding material obtained from the waste material of the thermoplastic synthetic resin product is reused and put into the extruder, or virgin thermoplastic resin is put in, or the virgin heat For example, 50% of each of the plastic resin and the recovered thermoplastic resin molding material may be added.
[0064]
Depending on the purpose of use, pigments can be added to color products.
[0065]
In addition, a thermoplastic resin molding material of 25 to 80 wt% is mixed with a stirring impact blade to 20 to 75 wt% of a cellulose-based crushed material having an average particle size of 20 mesh or less with a water content within 15 wt%, and frictional heat is used. Gelated and kneaded, and the gelled kneaded material is air-cooled at room temperature or cooled by appropriate means and further sized to a particle size of 8 mm or less, and then the woody synthetic powder is put into the hopper 73 of the extruder 70. As a result, the familiarity between the wood powder and the thermoplastic resin molding material is further improved, and a dough in a good kneaded state capable of reducing the frictional resistance of the wood powder is formed.
[0066]
[Production example of woody synthetic powder]
Hereinafter, various production apparatuses used for producing the woody synthetic powder of the present invention will be described with reference to the drawings.
[0067]
(Dry fluid mixing kneading means)
In FIG. 8, reference numeral 80 denotes a raw material which is stirred and mixed by each stirring impact blade, and each material is dried and kneaded by heat generated by friction between the mixed materials and each stirring impact blade. In this embodiment, the dry fluid mixing kneading means for forming the “kneading material” is referred to as “mixer” for convenience.
[0068]
Reference numeral 81 denotes a mixer body, which is a casing having a cylindrical shape having an upper surface opening and a capacity of 300 liters. The opening is a charging port 94 for charging raw materials into the mixer body 81, and an upper lid that can be opened and closed freely. Cover with 82. A gas discharge pipe 95 for discharging a large amount of water vapor generated in the mixer main body 81 is communicated with the upper lid 82. Further, a single discharge port 88 is provided on the outer peripheral surface near the bottom surface of the mixer body 81, and a lid 89 for covering the discharge port 88 is provided at the tip of the rod of the cylinder 91. It can be opened and closed freely. A discharge duct 93 communicates with the discharge port 88.
[0069]
Furthermore, a shaft 83 that rotates at a high speed of 800 to 900 rpm / max is supported at the center of the bottom surface of the mixer body 81 by a rotational drive means of a motor 37KW (DC) (not shown). A scraper 84 and stirring impact blades 85, 86, and 87 are attached to 83 in order from the bottom to the top, and tightened with a tightening nut 92 from the tip of the shaft 83. The shape of each of the stirring impact blades 85, 86, 87 is not particularly limited, but in the present embodiment, it is a two-blade that is symmetrical about the shaft 83. When three agitation impact blades are stacked as shown in FIG. 8, the blades are composed of 6 blades in total, and these 6 blades form an equal angle (60 degrees) obtained by dividing 360 degrees into 6 parts on a plane. Are overlapped with each other. In the case where a plurality of stirring impact blades are provided, it is preferable from the viewpoint of efficiently kneading the raw materials that the total number of stirring impact blades cross each other at an angle equally divided by 360 degrees.
[0070]
The scraper 84 rotates while sliding slightly in contact with the bottom surface of the mixer body 81, scrapes the raw materials kneaded in the mixer body 81 so as not to remain on the bottom surface of the mixer body 81, and circulates the raw materials.
[0071]
[Cooling granulation means]
In FIG. 9, reference numeral 100 denotes cooling granulation means for mixing the above-mentioned kneaded materials and stirring them to form a “granulation raw material”, which is called “cooling mixer” in the present embodiment.
[0072]
Reference numeral 101 denotes a mixer body, which is an inverted conical casing having a capacity of 1050 liters. The upper surface of the casing is covered, and a discharge port 107 is provided at the lower end. A jacket 102 is formed in the outer peripheral wall of the mixer body 101, and 100 liter / min of cooling water is constantly supplied from the water supply pipe 108 to the drain pipe 109 in the jacket 102, and the temperature of the raw material in the cooling mixer 100 is heated. The plastic resin material is held to be cooled to near the melting point (in the present embodiment, 100 ° C. or lower). Note that a discharge duct (not shown) for discharging water vapor generated in the cooling mixer 100 is communicated with the upper wall surface of the mixer body 101.
[0073]
An arm 103 is pivotally supported at a substantially center in the upper wall of the mixer body 101 so as to be rotatable in a substantially horizontal direction. The arm 103 is rotationally driven by a motor 111 through a speed reducer 112 at a speed of about 3 rpm. . Further, the rotating shaft of the arm 103 is a hollow shaft, and another rotating shaft that rotates independently is provided in the hollow shaft, and the output shaft of the motor 105 is connected to the rotating shaft. On the other hand, a stirring crushing blade 104 is supported at the tip of the arm 103, and this stirring crushing blade 104 forms a screw type in the present embodiment. Along the inner peripheral wall surface, it extends downward substantially parallel to the vicinity of the lower end of the mixer body 101. The stirring and crushing blade 104 is connected to a rotating shaft connected to the output shaft of the motor 105 through a rotation transmitting means such as a gear provided in the arm 103 and is driven to rotate at a speed of 120 rpm.
[0074]
An inlet 113 is provided on the upper wall of the mixer main body 101, and the outlet duct 93 of the mixer 80 is communicated with the inlet 113.
[0075]
The kneaded material formed by the mixer 80 described above is fed into the mixer body 101 from the inlet 113 of the cooling mixer 100 through the discharge duct 93. The stirring and crushing blade 104 is rotated at a speed of 120 rpm by the motor 105, and the arm 103 is rotated in the horizontal direction at a speed of 3 rpm by the rotational force of the motor 111 decelerated through the speed reducer 112. 104 rotates so that a cone may be drawn along the inner peripheral wall surface of the mixer main body 101, and the kneading | mixing material in the arm 103 is stirred.
[0076]
The kneaded material is cooled by the inner peripheral wall surface of the mixer body 101 cooled by the cooling water in the jacket 102 to form a “granulated raw material” granulated to a diameter of about 25 mm or less. It is opened and discharged from the discharge port 107.
[0077]
Note that a screen having a mesh diameter of 8 mm may be provided at the discharge port 107, and preliminary pulverization may be performed in the cooling step.
[0078]
The cooling granulation means is not limited to the above cooling mixer. For example, a stirring blade for stirring the kneaded material in the mixer body is provided, and a jacket as described above is provided on the outer peripheral wall surface of the mixer body. As long as the kneading material in the mixer body is cooled with cooling water flowing through the mixer, it is sufficient.
[0079]
The kneaded material formed by the mixer 80 can be cooled only by stirring using a general mixer not provided with the jacket 102. In this case, however, it takes a long time to cool the kneaded material. Therefore, it is desirable to form the granulation raw material by the cooling granulation means of the cooling mixer as in the present embodiment.
[0080]
[Crushing means]
The granulation raw material formed by the cooling granulation means is further pulverized to a particle size of 8 mm or less using a pulverization means to form “woody synthetic powder”.
[0081]
In FIG. 10, reference numeral 120 denotes a pulverizing means for pulverizing the granulation raw material described above, and a “cutter mill” is used in the present embodiment.
[0082]
A cutter mill body 121 is a cylindrical casing having an upper surface opening, and the opening is covered with a lid 122 that can be freely opened and closed. The lid 122 includes an input port 123 through which the granulated raw material is input into the cutter mill main body 121.
[0083]
Further, in the cutter mill main body 121, there is provided a cutter support 124 that is supported on the bottom surface of the cutter mill main body 121 and rotates in the horizontal direction by a rotation driving means (not shown). Three blades 125 are provided, and these three rotary blades 125 are disposed so as to form an equal angle of 120 degrees with respect to the rotation direction of the cutter support 124, and the blade tips of the three rotary blades 125 rotate the same. Located on the trajectory. Further, the two fixed blades 126 are fixed to the cutter mill main body 121 at a substantially symmetrical position with respect to the rotation trajectory of the cutting edge of the rotary blade 125 through a slight gap with respect to the rotation trajectory of the cutting edge of the three rotary blades 125. The fixed blade 126, the cutter support 124, and the rotary blade 125 divide the cutter mill main body 121 into two, thereby forming the input chamber 127 and the crushing chamber 128. The charging port 123 of the lid 122 communicates with the charging chamber 127. The gap between the two fixed blades 126 and the rotary blades 125 can be freely adjusted so that the granulated raw material can be pulverized to a desired size. The crushing chamber 128 partitions the two fixed blades 126 with a screen 129 so as to surround the rotation locus of the rotary blade 125. In this embodiment, the screen 129 is formed of a mesh through which pulverized “woody synthetic powder” having a size of 8 mm or less can pass. A discharge port 131 for discharging the pulverized material by the cutter mill 120 is provided at the lower end of the cutter mill main body 121 of the pulverization chamber 128.
[0084]
In the cutter mill 120 described above, when the granulated raw material formed by the cooling mixer 100 described above is input from the inlet 123 of the lid 122 and the cutter support 124 is rotated by a rotation driving means (not shown), the granulated raw material is the cutter support. The “woody synthetic powder” is formed by cutting between 124 rotary blades 125 and fixed blades 126 to about 8 mm or less.
[0085]
The crushing means is not limited to the above-mentioned cutter mill. For example, as in a hard crusher manufactured by Horai Co., Ltd., the rotation axis of the rotary blade 125 is provided in the horizontal direction, and the screen between the two fixed blades 126 is provided. Some 129 are provided below.
[0086]
[Production Example of Woody Synthetic Powder]
Next, the manufacture example of the woody synthetic powder used in this embodiment using each manufacturing means mentioned above is demonstrated below.
[0087]
Process 1
In this step, the wood powder which is one of the raw materials is dried using the mixer 80 which is the above-described dry pressure fluid mixing kneading means.
[0088]
The motor is rotated to rotate the stirring impact blades 85, 86, 87 and the scraper 84 at a high speed, the upper lid 82 is opened, and wood powder is charged from the charging port 94.
[0089]
If the rotation of the agitation impact blade of the mixer 80 is maintained at 800 to 900 rpm, the shear force by the agitation impact blade increases, so the generation of frictional heat due to the shear force is improved, and the temperature in the mixer 80 becomes 180 to 190 ° C. The input wood flour is dried.
[0090]
In the present embodiment, drying is performed until the moisture content of the input wood flour becomes 0%. Moreover, when adding titanium oxide etc. as a pigment etc., this is thrown in in the mixer 80 with the said wood flour in this drying process. In the present embodiment, about 10 wt% of white titanium oxide is added to 100 wt% of the wood flour.
[0091]
Process 2
PP55 wt% as a thermoplastic resin molding material is put into the mixer 80 with respect to 55 wt% of the dried wood flour as described above, and further stirred and pressurized at 800 to 900 rpm to bring the temperature in the mixer 80 to 210 ° C. Raise.
[0092]
In addition, the form of the thermoplastic resin molding material uses pellets made of particles having a diameter of about 3 mm in this embodiment. The melting point of PP, which is a thermoplastic resin molding material, is 165 ° C.
[0093]
Note that the thermoplastic resin material is a material obtained by reusing a recovered thermoplastic resin material obtained from a waste material of a thermoplastic synthetic resin product, a virgin thermoplastic resin, or a virgin thermoplastic resin and the recovered heat. For example, 50% of each plastic resin material can be used.
[0094]
In this process, the PP does not become a large lump due to the wood powder in the raw material, and does not agglomerate during mixing and dispersion, but gels in a clay form. In this step, the material gelled in the form of clay became a massive “kneading material” having a diameter of about 10 to 100 mm.
[0095]
The motor is set to low speed, the cylinder 91 is operated, the lid 89 is retracted, and the discharge port 88 is opened. The gelatinized raw material in the mixer body 81 is discharged from the discharge port 88 through the discharge duct 93 to the next process.
[0096]
Process 3
In this step, the cooling mixer 100 which is the cooling and drying means described above is used.
[0097]
The kneaded material formed by the mixer 80 described above is fed into the mixer body 101 from the inlet 113 of the cooling mixer 100 through the discharge duct 93. The stirring crushing blade 104 is rotated by a motor 105 at a speed of 120 rpm, and the arm 103 is rotated in a horizontal direction at a speed of 3 rpm.
[0098]
The kneaded material is cooled by the inner peripheral wall surface of the mixer body 101 cooled by cooling water introduced at 100 liters / min into the jacket 102, and a “granulated raw material” granulated to a diameter of about 25 mm or less is formed. The granulated raw material is discharged from the discharge port 107 by opening the valve 106.
[0099]
The melting point of PP as a kneaded material is 165 ° C. In this production example, the kneaded material gelled to 210 ° C. in the mixer 80 described above is charged into the cooling mixer 100 and cooled to 100 ° C. or lower. Cooling and drying with this cooling mixer is efficient. Regarding the cooling water in the jacket 102 at this time, the temperature of the cooling water supplied from the water supply pipe 108 is 30 ° C., and the temperature of the cooling water discharged from the drain pipe 109 is 40 ° C.
[0100]
Process 4
The granulated raw material formed in the above process is further pulverized to a particle size of 8 mm or less using a cutter mill 120 to form a molding material.
[0101]
In FIG. 10, the granulated raw material is cut to about 8 mm or less between the rotary blade 125 and the fixed blade 126 of the cutter support 124 to form “woody synthetic powder”, which passes through the mesh of the screen 129 of the crushing chamber 128 and is discharged. It is discharged from the outlet 131.
[0102]
Thus, in order to maintain the mixing and dispersion state of the wood powder and the thermoplastic resin molding material constantly, the woody synthetic powder giving good fluidity is formed and coupled with the condensation and reduction action by cooling, the chemical A synthetic wood powder that does not depend on the reaction or adhesion is formed, discharged from the discharge port 131 and sent to the extruder 70 in the next step.
[0103]
[Operation in the forming die]
The extruded dough 79 discharged from the extruder 70 through the extrusion die 19 and the flange 17 flows in the extrusion direction in the molding chamber 22 of the molding die 10 through the melting part 21a.
[0104]
The extruded dough 79 flowing in the melting part 21a is heated by the heaters 14a to 14c and extruded while maintaining a good kneaded state. The extruded dough 79 is extruded into a molding chamber 22 having an elongated rectangular shape and cooled from the outside by cooling water flowing in the cooling pipe 25 in the process of passing through the slow cooling part 21b in the molding chamber 22, The hollow resin molded plate 29 as a product having a thickness of 46.7 mm is cooled from the inside by the cooling medium introduced into the flow path 42 of the cooling medium formed in the core body 40 and is uniformly cooled. Is formed.
[0105]
Since the core body 40 has a tapered shape in which the thickness gradually decreases from the molding guide portion 41 toward the die outlet 23, the core body becomes resistant to the extrusion force when the extruded dough is cooled and solidified. There is nothing.
[0106]
Further, in the melting part 21a, the cooling medium introduction path 41 formed in the core body 40 is surrounded by the heat insulating material 43, so that the cooling medium flowing in the core body 40 is extruded through the melted part 21a. 79 is not cooled, so that the fluidity of the extruded dough 79 is prevented from being lowered in the melting part 21a.
[0107]
In addition, since the resistance with respect to the extrusion material | dough 79 which passes the surface of the core body 40 is small if a sheet | seat of a fluororesin is stuck on the surface of the guide part 15 and the core body 40, especially the frictional resistance in the extrusion material | dough 79 is large. Since the wood flour smoothly flows on the surface of the guide portion 15 without receiving a large resistance, the extruded dough 79 is pushed out of the molding chamber 22 of the molding die while maintaining a uniform and high density kneaded state.
[0108]
In particular, when the extrusion molding of the present invention is performed using a woody synthetic powder, an extruded dough 79 having a good kneading state in which the resin is uniformly infiltrated between the individual wood powders is formed in the extruder 70. In particular, the wood powder in the dough flows smoothly without receiving great resistance on the wall surfaces in the extruder and the molding die, and a more uniform and high-density hollow resin molded plate is formed.
[0109]
In addition, sheets made of fluororesin can be attached to the inner wall surfaces of the upper, lower, left, and right sides of the molding chamber 22. In this case, the extruded fabric 79 is gradually cooled in the process in which the extruded fabric 79 flows through the molding chamber 22. It is extruded smoothly while being.
[0110]
Fluorine resin has the following properties: (1) heat resistance of about 300 ° C, (2) smooth surface, small friction coefficient, and (3) low thermal conductivity coefficient compared to metal. The following action is exerted on the extruded dough 79.
[0111]
Since the surface of the fluororesin is smooth and the coefficient of friction is small, the wood powder in the extruded dough 79 that passes through the molding chamber 22 flows without receiving a large resistance. For this reason, the kneaded state of the extruded dough 79 is maintained in a good state, and as a result, a high-quality hollow resin molded plate having a uniform density, no nest, and a smooth surface is produced.
[0112]
Since the extruded dough 79 is cooled in the slow cooling section 21b of the molding chamber 22, the fluidity of the extruded dough 79 is deteriorated, and the wood powder in the extruded dough 79 has a larger frictional resistance than the resin, and the inner wall surface of the forming die. However, the wood powder that flows by contacting the inner wall surface of the molding die is subjected to a large resistance and does not flow smoothly. However, by providing a fluororesin sheet on the inner wall surface of the molding chamber 22, the wood flour of the extruded dough 79 flows smoothly without receiving great resistance from the inner wall surface of the molding chamber 22. The extruded dough 79 is extruded through the molding chamber 22 in a uniform and high-density kneaded state without adversely affecting the dough 79 as described above.
[0113]
Further, as described above, the resistance to the wood flour of the extruded dough 79 is reduced, and the extruded dough 79 is formed with a uniform density. Therefore, the surface of the hollow resin molded plate 29 as a product is smooth without so-called rough skin. Finished on a nice surface.
[0114]
In the past, the wood powder of the extruded dough 79 did not flow smoothly in the forming die, so that the wood powder was burnt and turned brown by the heat of the heater of the forming die. Since 79 wood powder flows smoothly, the wood powder does not burn, and quality characteristics such as impact resistance are not deteriorated.
[0115]
Since the fluorocarbon resin has a lower thermal conductivity coefficient than that of a metal, it has a slow cooling effect and acts to suppress distortion during cooling of the extruded dough 79.
[0116]
The slow cooling portion 21b in the molding chamber 22 of the molding die 10 is cooled by a cooling medium such as cooling water flowing through the cooling pipe 25 and the cooling medium flow path 42 in the core body 40, an air flow, etc. Has a lower thermal conductivity coefficient than that of metal, and therefore, the cooling temperature of the molding chamber 22 is not rapidly and directly conducted to the inner wall surface of the molding chamber 22, so that the extruded fabric 79 in the molding chamber 22 is not cooled rapidly but is gradually cooled. Will be. Therefore, the occurrence of large distortion that occurs when the extruded dough 79 is rapidly cooled is prevented, and the distortion of the hollow resin molded plate 29 as a product is reduced, and at the same time, the surface becomes smooth.
[0117]
【The invention's effect】
With the configuration of the present invention described above, the following remarkable effects can be obtained by the method and apparatus of the present invention.
[0118]
By providing a take-up means for taking out the molded plate extruded from the molding die, it is possible to increase the extrusion speed of the molded plate, and by forming a cooling medium flow path in the core body in the slow cooling part, By introducing a cooling medium into the flow path, the extruded dough formed into a predetermined shape in the slow cooling part can be gradually cooled from the inside, and thus the extruded dough can be gradually cooled in a short time. It was.
[0119]
Accordingly, the extrusion speed can be increased without deteriorating the quality of the produced molded plate, and a method and apparatus capable of producing a high-quality hollow resin molded plate at a high speed can be obtained.
[Brief description of the drawings]
FIG. 1 is a front view showing a partial longitudinal section of an extruder according to an embodiment of the present invention.
FIG. 2 is a partial plan view of a forming die according to an embodiment of the present invention.
FIG. 3 is a central longitudinal sectional view showing a state in which an extrusion die, a flange and a molding die according to an embodiment of the present invention are connected.
4 is a schematic view of an extrusion molding apparatus showing the temperature measurement points in Table 1. FIG.
FIG. 5 is a schematic view showing take-up means.
6 is a cross-sectional view taken along the line JJ in FIG. 3;
7 is a right side view of FIG.
FIG. 8 is an overall front view showing a cross-section of the main part of a mixer (dry fluid mixing kneading means) used in an example of the present invention.
FIG. 9 is an overall front view showing a cross section of the main part of a cooling mixer (cooling granulation means) used in an embodiment of the present invention.
FIG. 10 is an overall front view showing a cross-section of the main part of a cutter mill (pulverizing means) used in an embodiment of the present invention.
[Explanation of symbols]
10 Molding die
14a-14c heater
16 Inlet (extrusion die)
17 Flange
18 Injection port (for extrusion die)
19 Extrusion die
21a Melting part
21b Slow cooling part
22 Molding room
25 Cooling pipe
29 Molded plate
30 Picking means
31 Laura
31a Driving roller
33 Endless belt
40 core body
41 Introduction path (cooling medium)
42 Flow path (for cooling medium)
43 Insulation
44 base
70 Extruder
71 screw
72 Gear reducer
73 Hopper
74 barrels
75 band heater
76 screens
79 Extruded dough
80 mixer (fluid mixing kneading means)
81 Mixer body
82 Upper lid
83 axes
84 Scraper
85, 86, 87 Stirring impact blade
88 outlet
89 lid
91 cylinders
92 Tightening nut
93 Discharge duct
94 slot
95 Gas exhaust pipe
100 Cooling mixer
101 Mixer body
102 jacket
103 arms
104 Stir crushing blade
105 motor
106 Valve
107 outlet
108 Water supply pipe
109 Drain pipe
111 motor
112 Reduction gear
113 Suction port
114 frames
120 Cutter mill (size adjusting means)
121 Cutter mill body
122 lid
123 slot
124 Cutter support
125 rotary blade
126 Fixed blade
127 Input room
128 sizing chamber
129 screen
131 outlet

Claims (6)

A molding chamber comprising a melting section for heating the extruded dough and a slow cooling section continuous with the melting section, and protruding in parallel to the extrusion direction from a base provided in the melting section, at least in the slow cooling section of the molding chamber Extruded dough extruded into a forming die is formed by extruding a heated and kneaded raw material with a screw into a forming die provided with an extending core body to form an extruded dough to a predetermined thickness and forming a hollow portion. A method for extruding a hollow resin molded plate, characterized in that, in the slow cooling portion, the molded plate is gradually cooled from the outside of the extruded dough and the inside of the hollow portion, and the molded plate extruded from the molding die is taken up. 2. The extrusion molding method for a hollow resin molding plate according to claim 1, wherein the extrusion rate of the extruded dough by the screw of the extruder is adjusted by pulling the molding plate at a speed slower than the extrusion speed. The method for extruding a hollow resin molded plate according to claim 1 or 2, wherein when the extrusion speed of the extruded dough by the extruder is increased, the heating temperature of the extruded dough in the melting portion of the forming die is increased. A raw material is heated and kneaded, and an extrusion die of an extruder that extrudes with a screw is provided with a melting part for heating the extruded dough extruded from the extrusion die, and slow cooling for gradually cooling the extruded dough extruded from the melting part. And a molding die provided with a core body that protrudes in parallel with the extrusion direction from the base portion provided in the melting portion and extends to at least the slow cooling portion, and is connected to the inside of the slow cooling portion of the molding chamber. A cooling means for cooling the extruded dough from the outside of the extruded dough is provided in the forming die, a flow path for the cooling medium is formed in the core body in the slow cooling part, and the forming plate extruded from the forming die is taken up. A hollow resin molding plate extrusion molding apparatus comprising a take-up means. The flow path of the cooling medium formed in the core body in the slow cooling portion is communicated with the cooling medium introduction path that penetrates the core body in the wall surface of the molding die, the base portion, and the melting portion, and the introduction 5. The hollow resin molded plate extrusion molding apparatus according to claim 4, wherein the outer periphery of the path is surrounded by a heat insulating material. The said extrusion die and the said shaping | molding die are connected through the flange provided with the communicating hole, The heater which overheats the extrusion material | dough in the communicating hole of the said flange was provided in the said flange. The extrusion molding apparatus of the hollow resin molding plate of description.

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