JP3758913B2

JP3758913B2 - Series two-stage extrusion equipment

Info

Publication number: JP3758913B2
Application number: JP28063999A
Authority: JP
Inventors: 哲男上地; 祐二佐藤
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 1999-09-30
Filing date: 1999-09-30
Publication date: 2006-03-22
Anticipated expiration: 2019-09-30
Also published as: JP2001096605A

Description

【０００１】
【発明の属する技術分野】
本発明は、直列２段押出装置（以下、タンデム押出機と称す）の吐出量の一定制御に関する。
【０００２】
【従来の技術】
図７は、第１の従来例に係るタンデム押出機の全体構成を示す図である。図７に示すタンデム押出機は、樹脂を可塑化する第１段押出機１０と、この第１段押出機１０で可塑化された樹脂を均質化、計量、昇圧するための第２段押出機２０と、第１段押出機１０と第２段押出機２０とを連結する接続管３０とにより構成されている。
【０００３】
タンデム押出機の吐出量の一定制御に関する従来例としては、図７に示すように、第２段押出機２０の駆動モータ２４１の回転数を一定に保ちつつ、第１段押出機１０と第２段押出機２０とを連結する接続管３０または第２段押出機２０の樹脂流入部２０Ａに圧力検出器２７１を設置し、ここで検出される圧力が予め設定された圧力になるように、回転数調節器１５を介して第１段押出機１０の駆動モータ１４１の回転数を制御する方法がある。
【０００４】
図８は、第２の従来例に係るタンデム押出機の全体構成を示す図である。図８に示すタンデム押出機は、第１段押出機１０と第２段押出機２０とを連結する接続管３０または第２段押出機２０の樹脂流入部２０Ａに圧力検出器２７１を設置し、ここで検出される圧力が予め設定された圧力になるように、回転数調節器１５を介して第１段押出機１０の駆動モータ１４１の回転数を制御するとともに、さらにダイ５０の流入直前の圧力５１１を検出して、この圧力が一定になるように第２段押出機２０の駆動モータ２４１の回転数を制御する。
【０００５】
図９は、第３の従来例に係るタンデム押出機の全体構成を示す図である。特開平０２−１６０５２８号公報では、図９に示すように、第２段押出機２０の回転数を一定に保ちつつ、フィルタ４０の出口またはダイ５０の流入直前の圧力４１２を検出し、この圧力が一定になるように第１段押出機１０の駆動モータ１４１の回転数を制御する方法を提案している。
【０００６】
【発明が解決しようとする課題】
上述した第１〜３のいずれの従来例においても、圧力のみを検出して、押出機の駆動モータを制御する方法では、可塑化樹脂温度の変化に伴う溶融樹脂粘度の変化による圧力変化や、フィルタの目詰まりやダイリップ開度調整に伴う流路抵抗変化による圧力変化にまで応答してしまい、吐出量を一定に保つ精度を上げることができなかった。
【０００７】
本発明の目的は、吐出量の高精度な一定化制御が可能な直列２段押出装置を提供することにある。
【０００８】
【課題を解決するための手段】
上記課題を解決し目的を達成するために、本発明の直列２段押出装置は以下の如く構成されている。
【０００９】
（１）本発明の直列２段押出装置は、第１段押出機と第２段押出機が連結され、前記第２段押出機のスクリュ回転数とシリンダ温度を一定に保ちつつ、前記第２段押出機のスクリュ溝内の樹脂温度を一定とし、前記第２段押出機の入口と出口の圧力差を一定とするとともに、検出された前記第２段押出機内の樹脂温度が目標樹脂温度と異なるときは、その温度差と予め測定された樹脂の物性データに基づいて、前記第２段押出機のスクリュ溝内を流れる樹脂の粘度さらには目標吐出量時の前記第２段押出機の入口と出口の圧力差を推定し、目標圧力差を変更することにより、前記第１段押出機の回転数を制御して、吐出量を高精度に一定にする直列２段押出装置であり、前記第１段押出機は、前記第１段押出機の出口または前記第２段押出機の入口の圧力が目標圧力となるように、前記第１段押出機のスクリュ回転数を制御するとともに、目標圧力を、前記第２段押出機の入口と出口の圧力差とその目標圧力差との差に基づき変更して、吐出量の変動を低減する。
【００１０】
（２）本発明の直列２段押出装置は、第１段押出機と第２段押出機が導管で連結され、前記導管の圧力損失測定区間の温度を一定に保ちつつ、前記圧力損失測定区間の樹脂温度を一定とし、前記圧力損失測定区間の入口と出口の圧力差を一定とするとともに、検出された前記圧力損失測定区間の樹脂温度が目標樹脂温度と異なるときは、その温度差と予め測定された樹脂の物性データに基づいて、前記圧力損失測定区間を流れる樹脂の粘度さらには目標吐出量時の前記圧力損失測定区間の入口と出口の圧力差を推定し、目標圧力差を変更することにより、前記第１段押出機の回転数を制御して、吐出量を高精度に一定にする直列２段押出装置であり、前記第１段押出機は、前記第１段押出機の出口または前記圧力損失測定区間の入口または前記圧力損失測定区間の出口の圧力が目標圧力となるように、前記第１段押出機のスクリュ回転数を制御するとともに、目標圧力を、前記圧力損失測定区間の入口と出口の圧力差とその目標圧力差との差に基づき変更して、吐出量の変動を低減する。
【００１１】
（３）本発明の直列２段押出装置は、第１段押出機と第２段押出機が連結され、前記第２段押出機のスクリュ回転数を一定に保ちつつ、前記第２段押出機のスクリュ溝内の樹脂温度を一定とし、前記第２段押出機の入口と出口の圧力差を一定とするとともに、検出された前記第２段押出機内の樹脂温度が目標樹脂温度と異なるときは、その温度差と予め測定された樹脂の物性データに基づいて、前記第２段押出機のスクリュ溝内を流れる樹脂の粘度さらには目標吐出量時の前記第２段押出機の入口と出口の圧力差を推定し、目標圧力差を変更することにより、前記第１段押出機の回転数を制御して、前記第２段押出機の出口温度が一定となるようにシリンダ温度を変化させて、吐出量と吐出樹脂温度を高精度に一定にする直列２段押出装置であり、前記第１段押出機は、前記第１段押出機の出口または前記第２段押出機の入口の圧力が目標圧力となるように、前記第１段押出機のスクリュ回転数を制御するとともに、目標圧力を、前記第２段押出機の入口と出口の圧力差とその目標圧力差との差に基づき変更して、吐出量の変動を低減する。
【００１２】
【発明の実施の形態】
（第１の実施の形態）
図１は、本発明の第１の実施の形態に係るタンデム押出機（直列２段押出装置、直列２段押出成形装置）の制御システム全体構成図であり、図２は、その制御システム系統図である。図１，図２において図７〜図９と同一な部分には同符号を付してある。また、フィードバック量については正負の符号を付している。
【００１３】
本第１の実施の形態では、第２段押出機２０の回転数と第２段押出機２０のシリンダ温度を一定に保ちつつ、第２段押出機２０の入口に圧力検出器２７１を、第２段押出機２０の出口に圧力検出器２７２を設置して、それらの圧力を検出する。第１段押出機１０の回転数は、第１段押出機１０の出口に設置された圧力検出器１７２によって検出された圧力が、目標圧力設定器６０によって設定される目標圧力になるように、回転数調節器１５１を通じて第１段押出機１０の駆動モータ１４１の回転数を制御して決められる。なお、圧力検出器１７２は、圧力検出器１７１と共用としてもよい。
【００１４】
また、第２段押出機２０の入口と第２段押出機２０の出口に、それぞれ導管３０内を流れる溶融樹脂のための樹脂温度検出器２８１，２８２を設置し、それらで溶融樹脂の温度を検出する。第２段押出機２０の入口の温度検出器２８１で検出される温度が目標温度設定器１６１によって設定される目標樹脂温度となるように、操作量演算器１６２，第１段押出機１０のシリンダ温度調節器１６３を通じて第１段押出機１０のシリンダ１１の温度を変化させる。
【００１５】
また、二つの圧力検出器２７１、２７２の間で検出された圧力差と目標圧力差設定器７０によって設定される目標圧力差との差に基づいて、目標圧力設定器６０によって設定される目標圧力を変更する。なお、樹脂温度検出器２８１、２８２により検出された樹脂温度（片方の値または平均値）が変化した場合は、その変化量に基づいて目標圧力差設定器７０によって設定される目標圧力差を変更するが、精度の若干の低下を許容するなら、本回路は用いなくてもよい。
【００１６】
本タンデム押出機が、目標圧力、目標樹脂温度で運転されているとする。ここで、フィルタ４０の目詰まりや投入原料の温度変化等の吐出量を変化させる外乱（ここでは、例としてフィルタの目詰まりとする。）があったとする。この場合、フィルタの目詰まりにより導管３０の抵抗が増大するため、吐出量が低下し、樹脂温度が上昇しようとする。このとき、第２段押出機２０の入口にて導管３０内を流れる溶融樹脂の温度と目標樹脂温度との差に基づいて、その差が０となるよう、第１段押出機１０のシリンダ温度を低下させることで、樹脂温度の上昇を防止する。さらに、第２段押出機２０の入口と第２段押出機２０の出口のそれぞれの圧力を検出し、それらの圧力差と目標圧力差との差に基づいて、その差が０となるよう、第１段押出機１０の駆動モータ１４１の回転数を増速すべく、第１段押出機１０の出口の圧力１７２の目標圧力を高く再設定する。
【００１７】
なお、温度検出器２８１、２８２により検出される樹脂温度（片方の値または平均値）が変化するときは、予め測定しておいた樹脂の物性データに基づいて、温度上昇分に見合った粘度低下分を推定し、予想される粘度において目標吐出量が達成される第２段押出機２０の入口，出口の圧力差を推定し、その圧力差に前述の目標圧力差を変更（増加）し、これに伴い第１段押出機１０の目標圧力が変更される。こうして、第１段押出機１０は、目標圧力を保つべく、スクリュ１２の回転数を増速して、吐出量の低下を防止する。
【００１８】
このように、第２段押出機２０のスクリュ回転数、シリンダ温度を一定に保ちつつ、第２段押出機２０の入口の樹脂温度を一定、第２段押出機２０の入口，出口の圧力差を一定とするとともに、第２段押出機２０内の樹脂温度が変動したとしても、樹脂温度に見合った目標圧力差に変更して、第１段押出機１０の回転数を制御することで、大きな外乱に対しても、吐出量の高精度な一定化制御が可能となる。
【００１９】
（第２の実施の形態）
図３は、本発明の第２の実施の形態に係るタンデム押出機の制御システム全体構成図であり、図４は、その制御システム系統図である。図３，図４において図１，図２と同一な部分には同符号を付してある。また、フィードバック量については正負の符号を付している。
【００２０】
本第２の実施の形態では、導管３０の途中に温度調節器付の圧力損失設定手段３００を設ける。導管３０の温度を一定に保ちつつ、圧力損失設定手段（圧力損失測定区間）３００の上流に圧力検出器３１１を、下流に圧力検出器３１２を設置して、それらの圧力を検出する。第１段押出機１０の回転数は、第１段押出機１０の出口に設置された圧力検出器１７２によって検出された圧力が、目標圧力設定器６０によって設定される目標圧力になるように、回転数調節器１５２を通じて第１段押出機１０の駆動モータ１４１の回転数を制御して決められる。なお、圧力検出器１７２は、圧力検出器１７１と共用してもよい。
【００２１】
また、圧力損失設定手段３００の上流および下流に、それぞれ導管３０内を流れる溶融樹脂のための樹脂温度検出器３２１、３２２を設置し、それらで溶融樹脂の温度を検出する。第２段押出機２０の入口の温度検出器３２１で検出される温度が目標温度設定器１６１によって設定される目標樹脂温度となるように偏差量演算器１６２、第１段押出機１０のシリンダ温度調整用操作量演算器１６３’を通じて第１段押出機１０のシリンダ温度調節用加熱器（ヒータ）１３を制御してシリンダ１１の温度を変化させる。
【００２２】
また、二つの圧力検出器３１１、３１２の間で検出された圧力差と目標圧力差設定器７０によって設定される目標圧力差との差に基づいて，目標圧力設定器６０によって設定される目標圧力を変更する。なお，樹脂温度検出器３２１、３２２により検出された樹脂温度（片方の値または平均値）が変化した場合は、その変化量に基づいて目標圧力差設定器７０によって設定される目標圧力差を変更するが、精度の若干の低下を許容するなら、本回路は用いなくてもよい。
【００２３】
圧力損失設定手段３００は、導管３０のそのままの抵抗を評価した抵抗値であっても、図３のように、断面積を導管３０より小さくした絞りであってもよい。また、メッシュ等の抵抗体でもよい。
【００２４】
本タンデム押出機が、目標圧力、目標樹脂温度で運転されているとする。ここで、フィルタ４０の目詰まりや投入原料の温度変化等の吐出量を変化させる外乱（ここでは、例としてフィルタの目詰まりとする。）があったとする。この場合、フィルタの目詰まりによる導管３０の抵抗が増大するため、吐出量が低下し、樹脂温度が上昇しようとする。このとき、圧力損失設定手段３００の上流側で導管３０内を流れる溶融樹脂の温度を測定し、その温度と目標樹脂温度との差に基づいて、その差が０となるよう、第１段押出機１０のシリンダ温度を低下させることで、樹脂温度の上昇を防止する。さらに、圧力損失設定手段３００の上流側と下流側のそれぞれの圧力を検出し、それらの圧力差と目標圧力差との差に基づいて、その差が０となるよう、第１段押出機１０の駆動モータ１４１の回転数を増速すべく、第１段押出機１０の出口の圧力の目標圧力を高く再設定する。
【００２５】
ただし、圧力損失設定手段３００の壁面は、常に一定温度に保たれている。なお、温度検出器３２１，３２２により検出される樹脂温度（片方の値または平均値）が変化するときは、予め測定しておいた樹脂の物性データに基づいて、温度上昇分に見合った粘度低下分を推定し、予測される粘度において目標吐出量が達成される圧力損失設定手段３００の上流側と下流側との圧力差を推定し、その値に前述の目標圧力差を変更（増加）し、これに伴い第１段押出機１０の目標圧力が変更される。こうして、第１段押出機１０は、目標圧力を保つべく、スクリュ１２の回転数を増速して、吐出量の低下を防止する。
【００２６】
このように、圧力損失設定手段３００の導管温度を一定に保ちつつ、圧力損失設定手段３００の入口の樹脂温度を一定、圧力損失設定手段３００の入口，出口の圧力差を一定とするとともに、圧力損失設定手段３００の樹脂温度が変動したとしても、樹脂温度に見合った目標圧力差に変更して、第１段押出機１０の回転数を制御することで、大きな外乱に対しても、吐出量の高精度な一定化制御が可能となる。
【００２７】
（第３の実施の形態）
図５は、本発明の第３の実施の形態に係るタンデム押出機の制御システム全体構成図であり、図６は、その制御システム系統図である。図５，図６において図３，図４と同一な部分には同符号を付してある。また、フィードバック量については正負の符号を付している。
【００２８】
本第３の実施の形態では、第２段押出機２０の回転数を一定に保ちつつ、第２段押出機２０の入口に圧力検出器２７１を、第２段押出機２０の出口に圧力検出器２７２を設置して、それらの圧力を検出する。第１段押出機１０の回転数は、第１段押出機１０の出口に設置された圧力検出器１７２によって検出された圧力が、目標圧力設定器６０によって設定される目標圧力になるように、回転数調節器１５３を通じて第１段押出機１０の駆動モータ１４１の回転数を制御して決められる。なお，圧力検出器２７２は，圧力検出器２７１と共用としてもよい。
【００２９】
また、第２段押出機２０の入口と出口に、それぞれ導管３０内を流れる溶融樹脂のための温度検出器２８１，２８２を設置し，それらの溶融樹脂の温度を検出する。第２段押出機２０の入口の温度検出器２８１で検出される温度が目標温度設定器１６１によって設定される目標樹脂温度となるように温度偏差量演算器１６２，第１段押出機１０のシリンダ温調器用操作量演算器１６３を通じて第１段押出機１０のシリンダ温度調節用加熱器（ヒータ）１３の熱量を変化させる。
【００３０】
また、二つの圧力検出器２７１、２７２の間で検出された圧力差と目標圧力差設定器７０によって設定される目標圧力差との差に基づいて、目標圧力設定器６０によって設定される目標圧力を変更する。なお，樹脂温度検出器２８１，２８２により検出された樹脂温度（片方の値または平均値）が変化した場合は、その変化量に基づいて目標圧力差設定器７０によって設定される目標圧力差を変更するが、精度の若干の低下を許容するなら，本回路は用いなくてもよい。
【００３１】
また、樹脂温度検出器２８２により検出される樹脂温度が目標温度設定器２６１で設定される目標押出樹脂温度になるように、第２段シリンダ２１の温度を調節する。
【００３２】
本タンデム押出機が、目標圧力、目標樹脂温度で運転されているとする。ここで、フィルタ４０の目詰まりや投入原料の温度変化等の吐出量を変化させる外乱（ここでは、例としてフィルタの目詰まりとする。）があったとする。この場合、フィルタの目詰まりによる導管３０の抵抗が増大するため、吐出量が低下し、樹脂温度が上昇しようとする。このとき、第２段押出機２０の入口で導管３０内を流れる溶融樹脂の温度と目標樹脂温度との差に基づいて、その差が０となるよう、第１段押出機１０のシリンダ温度を低下させることで、樹脂温度の上昇を防止する。さらに、第２段押出機２０の入口と出口のそれぞれの圧力を検出し、それらの圧力差と目標圧力差との差に基づいて、その差が０となるよう、第１段押出機１０の駆動モータ１４１の回転数を増速すべく、第１段押出機１０の出口の圧力１７２の目標圧力を高く再設定する。
【００３３】
なお、温度検出器２８１，２８２により検出される樹脂温度（片方の値または平均値）が変化するときは、予め測定しておいた樹脂の物性データに基づいて、温度上昇分に見合った粘度低下分を推定し、予測される粘度において目標吐出量が達成される第２段押出機２０の入口，出口の圧力差を推定し、その圧力差に前述の目標圧力差を変更（増加）し、これに伴い第１段押出機１０の目標圧力が変更される。また、第２段押出機２０の出口の樹脂温度と目標押出樹脂温度との差が０となるように、第２段押出機２０のシリンダ温度を制御する。こうして、第１段押出機１０は、目標圧力を保つべく、スクリュ１２の回転数を増速して、吐出量の低下を防止するとともに、第２段押出機２０から一定温度の溶融樹脂を吐出することができる。
【００３４】
このように、第２段押出機２０のスクリュ回転数を一定に保ちつつ、第２段押出機２０の入口の樹脂温度を一定、第２段押出機２０の入口，出口の圧力差を一定とするとともに、第２段押出機２０内の樹脂温度が変動したとしても、樹脂温度に見合った目標圧力差に変更して、第１段押出機１０の回転数を制御し、また、第２段押出機２０の樹脂温度が一定になるように第２段押出機２０のシリンダ温度を変化させることで、大きな外乱に対しても、吐出量および吐出樹脂温度の高精度な一定化制御が可能となる。
【００３５】
なお、本発明は上記各実施の形態のみに限定されず、要旨を変更しない範囲で適時変形して実施できる。
【００３６】
【発明の効果】
本発明の直列２段押出装置によれば、第２段押出機のスクリュ回転数とシリンダ温度を一定に保ちつつ、前記第２段押出機のスクリュ溝内の樹脂温度を一定とし、前記第２段押出機の入口と出口の圧力差を一定とするとともに、前記第２段押出機２０内の樹脂温度が変動したとしても、樹脂温度に見合った目標圧力差に変更して、第１段押出機の回転数を制御することで、大きな外乱に対しても、吐出量の高精度な一定化制御が可能となる。
【００３７】
本発明の直列２段押出装置によれば、圧力損失測定区間の導管温度を一定に保ちつつ、前記圧力損失測定区間の樹脂温度を一定とし、前記圧力損失測定区間の入口と出口の圧力差を一定とするとともに、前記圧力損失測定区間の樹脂温度が変動したとしても、樹脂温度に見合った目標圧力差に変更して、第１段押出機の回転数を制御することで、大きな外乱に対しても、吐出量の高精度な一定化制御が可能となる。
【００３８】
本発明の直列２段押出装置によれば、第２段押出機のスクリュ回転数を一定に保ちつつ、前記第２段押出機のスクリュ溝内の樹脂温度を一定とし、前記第２段押出機の入口と出口の圧力差を一定とするとともに、前記第２段押出機内の樹脂温度が変動したとしても、樹脂温度に見合った目標圧力差に変更して、第１段押出機の回転数を制御し、また前記第２段押出機の樹脂温度が一定になるように前記第２段押出機のシリンダ温度を変化させることで、大きな外乱に対しても、吐出量および吐出樹脂温度の高精度な一定化制御が可能となる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態に係るタンデム押出機の制御システム全体構成図。
【図２】本発明の第１の実施の形態に係る制御システム系統図。
【図３】本発明の第２の実施の形態に係るタンデム押出機の制御システム全体構成図。
【図４】本発明の第２の実施の形態に係る制御システム系統図。
【図５】本発明の第３の実施の形態に係るタンデム押出機の制御システム全体構成図。
【図６】本発明の第３の実施の形態に係るタンデム押出機の制御システム全体構成図。
【図７】第１の従来例に係るタンデム押出機の全体構成を示す図。
【図８】第２の従来例に係るタンデム押出機の全体構成を示す図。
【図９】第３の従来例に係るタンデム押出機の全体構成を示す図。
【符号の説明】
１０…第１段押出機
１１…シリンダ
１２…スクリュ
１３…加熱器（ヒータ）
１４…駆動装置
１４１…モータ
１４２…減速装置
１５…回転数調節器（偏差量演算器）
１５１…回転数調節器
１５１１…偏差量演算器
１５１２…制御量算出力器
１５２…回転数調節器
１５２１…偏差量演算器
１５２２…制御量算出力器
１５３…回転数調節器
１５３１…偏差量演算器
１５３２…制御量算出力器
１６…シリンダ温度調節装置
１６１…目標温度設定器
１６２…操作量演算器（偏差演算器）
１７１…圧力検出器
１７２…圧力検出器
２０…第２段押出機
２１…シリンダ
２２…スクリュ
２３…加熱器（ヒータ）
２４…駆動装置
２４１…モータ
２４２…減速装置
２６…目標温度設定器
２６１…目標温度設定器
２６２…偏差演算器
２６３…制御量演算装置
２７…溶融樹脂圧力検出器
２７１…第２段入口の溶融樹脂圧力検出器
２７２…第２段出口の溶融樹脂圧力検出器
２８…溶融樹脂温度検出器
２８１…第２段入口の溶融樹脂温度検出器
２８２…第２段出口の溶融樹脂温度検出器
３０…連結管
４０…フイルタ
５０…ダイ
６０…目標圧力設定器
７０…目標差圧設定器
８０…差圧演算器
９０…樹脂粘度の圧力補償演算器
９１…樹脂温度重み付け演算器
９２…樹脂粘度〜圧力補償演算器
１００…偏差量演算器
１１０…偏差量演算器
２００…第１段フイルタ
３００…圧力損失設定手段（圧力損失測定区間）
３１０…圧力検出器
３１１…入口圧力検出器
２１２…出口圧力検出器
３２０…圧力検出器
３２１…入口樹脂温度検出器
３２２…出口樹脂温度検出器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to constant control of the discharge amount of a series two-stage extrusion apparatus (hereinafter referred to as a tandem extruder).
[0002]
[Prior art]
FIG. 7 is a diagram showing the overall configuration of the tandem extruder according to the first conventional example. The tandem extruder shown in FIG. 7 is a first-stage extruder 10 for plasticizing a resin, and a second-stage extruder for homogenizing, weighing, and pressurizing the resin plasticized by the first-stage extruder 10. 20 and a connecting pipe 30 that connects the first-stage extruder 10 and the second-stage extruder 20.
[0003]
As a conventional example related to the constant control of the discharge amount of the tandem extruder, as shown in FIG. 7, while maintaining the rotation speed of the drive motor 241 of the second stage extruder 20, the first stage extruder 10 and the second stage extruder A pressure detector 271 is installed in the connecting pipe 30 connecting the stage extruder 20 or the resin inflow portion 20A of the second stage extruder 20, and rotated so that the pressure detected here becomes a preset pressure. There is a method of controlling the rotation speed of the drive motor 141 of the first stage extruder 10 via the number adjuster 15.
[0004]
FIG. 8 is a diagram showing an overall configuration of a tandem extruder according to a second conventional example. The tandem extruder shown in FIG. 8 has a pressure detector 271 installed in the connecting pipe 30 that connects the first stage extruder 10 and the second stage extruder 20 or the resin inflow part 20A of the second stage extruder 20, The rotational speed of the drive motor 141 of the first stage extruder 10 is controlled via the rotational speed adjuster 15 so that the pressure detected here becomes a preset pressure, and further, immediately before the inflow of the die 50. The pressure 511 is detected, and the rotation speed of the drive motor 241 of the second stage extruder 20 is controlled so that this pressure becomes constant.
[0005]
FIG. 9 is a diagram showing an overall configuration of a tandem extruder according to a third conventional example. In Japanese Patent Laid-Open No. 02-160528, as shown in FIG. 9, the pressure 412 immediately before the outlet of the filter 40 or the inflow of the die 50 is detected while the rotation speed of the second stage extruder 20 is kept constant. Has proposed a method of controlling the rotational speed of the drive motor 141 of the first stage extruder 10 so that the current becomes constant.
[0006]
[Problems to be solved by the invention]
In any of the first to third conventional examples described above, in the method of detecting only the pressure and controlling the drive motor of the extruder, the pressure change due to the change in the molten resin viscosity accompanying the change in the plasticized resin temperature, Responding to pressure change due to flow path resistance change accompanying filter clogging or die lip opening adjustment, the accuracy of keeping the discharge rate constant could not be improved.
[0007]
An object of the present invention is to provide a series two-stage extrusion apparatus capable of controlling the discharge amount with high accuracy and constant control.
[0008]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, the series two-stage extrusion apparatus of the present invention is configured as follows.
[0009]
(1) The serial two-stage extrusion apparatus of the present invention includes a first-stage extruder and a second-stage extruder connected to each other, while maintaining the screw rotation speed and the cylinder temperature of the second-stage extruder constant. The resin temperature in the screw groove of the step extruder is made constant, the pressure difference between the inlet and the outlet of the second stage extruder is made constant, and the detected resin temperature in the second stage extruder is the target resin temperature. If they are different, the viscosity of the resin flowing in the screw groove of the second stage extruder and the inlet of the second stage extruder at the target discharge amount based on the temperature difference and the physical property data of the resin measured in advance And the outlet pressure difference, and by changing the target pressure difference, the number of revolutions of the first stage extruder is controlled, and the discharge amount is a series two-stage extrusion apparatus that makes the discharge amount constant with high accuracy, The first stage extruder is the outlet of the first stage extruder or the second stage extruder. The screw speed of the first stage extruder is controlled so that the inlet pressure becomes the target pressure, and the target pressure is determined by the difference between the pressure difference between the inlet and outlet of the second stage extruder and the target pressure difference. Change based on the difference to reduce fluctuations in the discharge rate.
[0010]
(2) In the serial two-stage extrusion apparatus of the present invention, the first-stage extruder and the second-stage extruder are connected by a conduit, and the pressure loss measurement section is maintained while keeping the temperature of the pressure loss measurement section of the conduit constant. When the detected resin temperature in the pressure loss measurement section is different from the target resin temperature, the temperature difference is preliminarily determined. Based on the measured physical property data of the resin, the viscosity of the resin flowing through the pressure loss measurement section and the pressure difference between the inlet and outlet of the pressure loss measurement section at the target discharge amount are estimated, and the target pressure difference is changed. Thus, the first-stage extruder is an in-line two-stage extruder that controls the number of revolutions of the first-stage extruder to make the discharge amount constant with high accuracy. The first-stage extruder is an outlet of the first-stage extruder. Or the entrance or front of the pressure loss measurement section The screw speed of the first stage extruder is controlled so that the pressure at the outlet of the pressure loss measurement section becomes the target pressure, and the target pressure is determined by the pressure difference between the inlet and outlet of the pressure loss measurement section and the target. Change based on the difference with the pressure difference to reduce the fluctuation of the discharge amount.
[0011]
(3) The two-stage extruder of the present invention has a first-stage extruder and a second-stage extruder connected to each other, and the second-stage extruder is configured to keep the screw rotation speed of the second-stage extruder constant. When the resin temperature in the screw groove is constant, the pressure difference between the inlet and outlet of the second stage extruder is constant, and the detected resin temperature in the second stage extruder is different from the target resin temperature Based on the temperature difference and the physical property data of the resin measured in advance, the viscosity of the resin flowing in the screw groove of the second stage extruder and the inlet and outlet of the second stage extruder at the target discharge amount By estimating the pressure difference and changing the target pressure difference, the rotational speed of the first stage extruder is controlled, and the cylinder temperature is changed so that the outlet temperature of the second stage extruder is constant. This is a series two-stage extrusion device that keeps the discharge volume and discharge resin temperature constant with high accuracy. The first stage extruder controls the screw rotation speed of the first stage extruder so that the pressure at the outlet of the first stage extruder or the inlet of the second stage extruder becomes a target pressure. At the same time, the target pressure is changed based on the difference between the pressure difference between the inlet and outlet of the second-stage extruder and the target pressure difference to reduce the variation in the discharge amount.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is an overall configuration diagram of a control system of a tandem extruder (series two-stage extrusion apparatus, series two-stage extrusion molding apparatus) according to the first embodiment of the present invention, and FIG. 2 is a control system system diagram thereof. It is. 1 and 2, the same parts as those in FIGS. 7 to 9 are denoted by the same reference numerals. The feedback amount is given a positive or negative sign.
[0013]
In the first embodiment, the pressure detector 271 is installed at the inlet of the second stage extruder 20 while keeping the rotation speed of the second stage extruder 20 and the cylinder temperature of the second stage extruder 20 constant. A pressure detector 272 is installed at the outlet of the two-stage extruder 20 to detect these pressures. The rotational speed of the first stage extruder 10 is such that the pressure detected by the pressure detector 172 installed at the outlet of the first stage extruder 10 becomes the target pressure set by the target pressure setter 60. It is determined by controlling the rotational speed of the drive motor 141 of the first stage extruder 10 through the rotational speed adjuster 151. The pressure detector 172 may be shared with the pressure detector 171.
[0014]
Also, resin temperature detectors 281 and 282 for the molten resin flowing in the conduit 30 are installed at the inlet of the second stage extruder 20 and the outlet of the second stage extruder 20, respectively, and the temperature of the molten resin is determined by them. To detect. The manipulated variable calculator 162 and the cylinder of the first stage extruder 10 so that the temperature detected by the temperature detector 281 at the inlet of the second stage extruder 20 becomes the target resin temperature set by the target temperature setter 161. The temperature of the cylinder 11 of the first stage extruder 10 is changed through the temperature controller 163.
[0015]
The target pressure set by the target pressure setter 60 is based on the difference between the pressure difference detected between the two pressure detectors 271 and 272 and the target pressure difference set by the target pressure difference setter 70. To change. When the resin temperature (one value or average value) detected by the resin temperature detectors 281 and 282 changes, the target pressure difference set by the target pressure difference setting unit 70 is changed based on the change amount. However, this circuit may not be used if a slight decrease in accuracy is allowed.
[0016]
It is assumed that this tandem extruder is operated at a target pressure and a target resin temperature. Here, it is assumed that there is a disturbance (in this example, the filter is clogged) that changes the discharge amount such as clogging of the filter 40 and temperature change of the input raw material. In this case, since the resistance of the conduit 30 increases due to clogging of the filter, the discharge amount decreases and the resin temperature tends to increase. At this time, based on the difference between the temperature of the molten resin flowing in the conduit 30 at the inlet of the second stage extruder 20 and the target resin temperature, the cylinder temperature of the first stage extruder 10 is set so that the difference becomes zero. By lowering, the increase in the resin temperature is prevented. Furthermore, the respective pressures at the inlet of the second stage extruder 20 and the outlet of the second stage extruder 20 are detected, and based on the difference between the pressure difference and the target pressure difference, the difference becomes zero. In order to increase the rotational speed of the drive motor 141 of the first stage extruder 10, the target pressure of the pressure 172 at the outlet of the first stage extruder 10 is reset higher.
[0017]
In addition, when the resin temperature (one value or average value) detected by the temperature detectors 281 and 282 changes, the viscosity decrease corresponding to the temperature increase based on the physical property data of the resin measured in advance. Estimate the pressure difference between the inlet and outlet of the second stage extruder 20 at which the target discharge amount is achieved at the expected viscosity, and change (increase) the aforementioned target pressure difference to the pressure difference, Accordingly, the target pressure of the first stage extruder 10 is changed. Thus, the first stage extruder 10 increases the number of rotations of the screw 12 to keep the target pressure, thereby preventing a decrease in the discharge amount.
[0018]
As described above, the resin temperature at the inlet of the second stage extruder 20 is kept constant while the screw rotation speed and the cylinder temperature of the second stage extruder 20 are kept constant, and the pressure difference between the inlet and outlet of the second stage extruder 20. , And even if the resin temperature in the second stage extruder 20 fluctuates, by changing the target pressure difference corresponding to the resin temperature, by controlling the rotation speed of the first stage extruder 10, Even with a large disturbance, the discharge amount can be controlled with high accuracy.
[0019]
(Second Embodiment)
FIG. 3 is an overall configuration diagram of the control system of the tandem extruder according to the second embodiment of the present invention, and FIG. 4 is a system diagram of the control system. 3 and 4, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. The feedback amount is given a positive or negative sign.
[0020]
In the second embodiment, pressure loss setting means 300 with a temperature controller is provided in the middle of the conduit 30. While keeping the temperature of the conduit 30 constant, a pressure detector 311 is installed upstream of the pressure loss setting means (pressure loss measurement section) 300 and a pressure detector 312 is installed downstream, and these pressures are detected. The rotational speed of the first stage extruder 10 is such that the pressure detected by the pressure detector 172 installed at the outlet of the first stage extruder 10 becomes the target pressure set by the target pressure setter 60. It is determined by controlling the rotational speed of the drive motor 141 of the first stage extruder 10 through the rotational speed adjuster 152. The pressure detector 172 may be shared with the pressure detector 171.
[0021]
Also, resin temperature detectors 321 and 322 for the molten resin flowing in the conduit 30 are installed upstream and downstream of the pressure loss setting means 300, respectively, and the temperature of the molten resin is detected by them. The deviation amount calculator 162 and the cylinder temperature of the first stage extruder 10 so that the temperature detected by the temperature detector 321 at the inlet of the second stage extruder 20 becomes the target resin temperature set by the target temperature setter 161. The cylinder temperature adjusting heater (heater) 13 of the first stage extruder 10 is controlled through the adjusting operation amount calculator 163 ′ to change the temperature of the cylinder 11.
[0022]
The target pressure set by the target pressure setter 60 is based on the difference between the pressure difference detected between the two pressure detectors 311 and 312 and the target pressure difference set by the target pressure difference setter 70. To change. When the resin temperature (one value or average value) detected by the resin temperature detectors 321 and 322 changes, the target pressure difference set by the target pressure difference setting unit 70 is changed based on the change amount. However, this circuit may not be used if a slight decrease in accuracy is allowed.
[0023]
The pressure loss setting means 300 may be a resistance value obtained by evaluating the resistance of the conduit 30 as it is, or a throttle having a cross-sectional area smaller than that of the conduit 30 as shown in FIG. Further, a resistor such as a mesh may be used.
[0024]
It is assumed that this tandem extruder is operated at a target pressure and a target resin temperature. Here, it is assumed that there is a disturbance (in this example, the filter is clogged) that changes the discharge amount such as clogging of the filter 40 and temperature change of the input raw material. In this case, since the resistance of the conduit 30 due to clogging of the filter increases, the discharge amount decreases and the resin temperature tends to increase. At this time, the temperature of the molten resin flowing in the conduit 30 is measured on the upstream side of the pressure loss setting means 300, and the first stage extrusion is performed so that the difference becomes 0 based on the difference between the temperature and the target resin temperature. Lowering the cylinder temperature of the machine 10 prevents the resin temperature from rising. Further, the first-stage extruder 10 detects the respective pressures on the upstream side and the downstream side of the pressure loss setting means 300 and makes the difference zero based on the difference between the pressure difference and the target pressure difference. In order to increase the rotation speed of the drive motor 141, the target pressure of the outlet pressure of the first stage extruder 10 is reset to be high.
[0025]
However, the wall surface of the pressure loss setting means 300 is always kept at a constant temperature. In addition, when the resin temperature (one value or average value) detected by the temperature detectors 321 and 322 changes, the viscosity decrease corresponding to the temperature increase is made based on the physical property data of the resin measured in advance. The pressure difference between the upstream side and the downstream side of the pressure loss setting means 300 at which the target discharge amount is achieved at the predicted viscosity is estimated, and the aforementioned target pressure difference is changed (increased) to that value. Accordingly, the target pressure of the first stage extruder 10 is changed. Thus, the first stage extruder 10 increases the number of rotations of the screw 12 to keep the target pressure, thereby preventing a decrease in the discharge amount.
[0026]
In this way, while keeping the conduit temperature of the pressure loss setting means 300 constant, the resin temperature at the inlet of the pressure loss setting means 300 is constant, the pressure difference between the inlet and outlet of the pressure loss setting means 300 is constant, and the pressure Even if the resin temperature of the loss setting means 300 fluctuates, by changing to the target pressure difference corresponding to the resin temperature and controlling the rotation speed of the first stage extruder 10, the discharge amount can be reduced even for a large disturbance. Can be controlled with high accuracy.
[0027]
(Third embodiment)
FIG. 5 is an overall configuration diagram of a control system of a tandem extruder according to the third embodiment of the present invention, and FIG. 6 is a system diagram of the control system. 5 and 6, the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals. The feedback amount is given a positive or negative sign.
[0028]
In the third embodiment, the pressure detector 271 is provided at the inlet of the second stage extruder 20 and the pressure is detected at the outlet of the second stage extruder 20 while keeping the rotation speed of the second stage extruder 20 constant. A device 272 is installed to detect their pressure. The rotational speed of the first stage extruder 10 is such that the pressure detected by the pressure detector 172 installed at the outlet of the first stage extruder 10 becomes the target pressure set by the target pressure setter 60. It is determined by controlling the rotational speed of the drive motor 141 of the first stage extruder 10 through the rotational speed adjuster 153. The pressure detector 272 may be shared with the pressure detector 271.
[0029]
Further, temperature detectors 281 and 282 for the molten resin flowing in the conduit 30 are respectively installed at the inlet and the outlet of the second stage extruder 20 to detect the temperatures of those molten resins. The temperature deviation amount calculator 162 and the cylinder of the first stage extruder 10 so that the temperature detected by the temperature detector 281 at the inlet of the second stage extruder 20 becomes the target resin temperature set by the target temperature setter 161. The amount of heat of the cylinder temperature adjusting heater (heater) 13 of the first stage extruder 10 is changed through the temperature controller operation amount calculator 163.
[0030]
The target pressure set by the target pressure setter 60 is based on the difference between the pressure difference detected between the two pressure detectors 271 and 272 and the target pressure difference set by the target pressure difference setter 70. To change. When the resin temperature (one value or average value) detected by the resin temperature detectors 281 and 282 changes, the target pressure difference set by the target pressure difference setting unit 70 is changed based on the change amount. However, this circuit may not be used if a slight decrease in accuracy is allowed.
[0031]
Further, the temperature of the second stage cylinder 21 is adjusted so that the resin temperature detected by the resin temperature detector 282 becomes the target extruded resin temperature set by the target temperature setting device 261.
[0032]
It is assumed that this tandem extruder is operated at a target pressure and a target resin temperature. Here, it is assumed that there is a disturbance (in this example, the filter is clogged) that changes the discharge amount such as clogging of the filter 40 and temperature change of the input raw material. In this case, since the resistance of the conduit 30 due to clogging of the filter increases, the discharge amount decreases and the resin temperature tends to increase. At this time, based on the difference between the temperature of the molten resin flowing in the conduit 30 at the inlet of the second stage extruder 20 and the target resin temperature, the cylinder temperature of the first stage extruder 10 is set so that the difference becomes zero. Lowering the temperature prevents the resin temperature from rising. Further, the respective pressures at the inlet and outlet of the second stage extruder 20 are detected, and based on the difference between the pressure difference and the target pressure difference, the first stage extruder 10 In order to increase the rotational speed of the drive motor 141, the target pressure of the pressure 172 at the outlet of the first stage extruder 10 is reset to be high.
[0033]
In addition, when the resin temperature (one value or average value) detected by the temperature detectors 281 and 282 changes, the viscosity decrease corresponding to the temperature increase based on the physical property data of the resin measured in advance. And estimate the pressure difference between the inlet and outlet of the second stage extruder 20 at which the target discharge amount is achieved at the predicted viscosity, and change (increase) the aforementioned target pressure difference to the pressure difference, Accordingly, the target pressure of the first stage extruder 10 is changed. Further, the cylinder temperature of the second stage extruder 20 is controlled so that the difference between the resin temperature at the outlet of the second stage extruder 20 and the target extruded resin temperature becomes zero. Thus, the first stage extruder 10 increases the number of rotations of the screw 12 to maintain the target pressure to prevent the discharge amount from decreasing, and discharges a molten resin at a constant temperature from the second stage extruder 20. can do.
[0034]
Thus, while keeping the screw rotation speed of the second stage extruder 20 constant, the resin temperature at the inlet of the second stage extruder 20 is constant, and the pressure difference between the inlet and outlet of the second stage extruder 20 is constant. In addition, even if the resin temperature in the second stage extruder 20 fluctuates, it is changed to a target pressure difference corresponding to the resin temperature, and the rotational speed of the first stage extruder 10 is controlled. By changing the cylinder temperature of the second stage extruder 20 so that the resin temperature of the extruder 20 becomes constant, it is possible to control the discharge amount and the discharge resin temperature with high accuracy even for a large disturbance. Become.
[0035]
In addition, this invention is not limited only to each said embodiment, In the range which does not change a summary, it can deform | transform suitably and can be implemented.
[0036]
【The invention's effect】
According to the in-line two-stage extrusion apparatus of the present invention, the resin temperature in the screw groove of the second-stage extruder is kept constant while the screw rotation speed and cylinder temperature of the second-stage extruder are kept constant, and the second The pressure difference between the inlet and outlet of the stage extruder is made constant, and even if the resin temperature in the second stage extruder 20 fluctuates, the target pressure difference corresponding to the resin temperature is changed to the first stage extrusion. By controlling the number of revolutions of the machine, it is possible to control the discharge amount with high accuracy even for large disturbances.
[0037]
According to the serial two-stage extrusion apparatus of the present invention, the conduit temperature in the pressure loss measurement section is kept constant, the resin temperature in the pressure loss measurement section is constant, and the pressure difference between the inlet and the outlet in the pressure loss measurement section is determined. Even if the resin temperature in the pressure loss measurement section fluctuates, by changing to the target pressure difference corresponding to the resin temperature and controlling the rotation speed of the first stage extruder, However, it is possible to control the discharge amount with high accuracy.
[0038]
According to the in-line two-stage extrusion apparatus of the present invention, the resin temperature in the screw groove of the second-stage extruder is made constant while keeping the screw rotation speed of the second-stage extruder constant, and the second-stage extruder The pressure difference between the inlet and the outlet of the first stage extruder is made constant, and even if the resin temperature in the second stage extruder fluctuates, the target pressure difference corresponding to the resin temperature is changed to change the rotation speed of the first stage extruder. By controlling and changing the cylinder temperature of the second-stage extruder so that the resin temperature of the second-stage extruder becomes constant, high accuracy of discharge amount and resin temperature even for large disturbances Constant control is possible.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a control system for a tandem extruder according to a first embodiment of the present invention.
FIG. 2 is a system diagram of the control system according to the first embodiment of the present invention.
FIG. 3 is an overall configuration diagram of a control system of a tandem extruder according to a second embodiment of the present invention.
FIG. 4 is a system diagram of a control system according to a second embodiment of the present invention.
FIG. 5 is an overall configuration diagram of a control system of a tandem extruder according to a third embodiment of the present invention.
FIG. 6 is an overall configuration diagram of a control system of a tandem extruder according to a third embodiment of the present invention.
FIG. 7 is a diagram showing an overall configuration of a tandem extruder according to a first conventional example.
FIG. 8 is a diagram showing an overall configuration of a tandem extruder according to a second conventional example.
FIG. 9 is a diagram showing an overall configuration of a tandem extruder according to a third conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... First stage extruder 11 ... Cylinder 12 ... Screw 13 ... Heater (heater)
DESCRIPTION OF SYMBOLS 14 ... Drive apparatus 141 ... Motor 142 ... Deceleration apparatus 15 ... Speed controller (deviation amount calculator)
151 ... Rotation speed adjuster 1511 ... Deviation amount calculator 1512 ... Control amount calculation force unit 152 ... Rotation number adjuster 1521 ... Deviation amount calculator 1522 ... Control amount calculation force unit 153 ... Rotation number adjuster 1531 ... Deviation amount calculator 1532 ... Control amount calculation force unit 16 ... Cylinder temperature adjustment device 161 ... Target temperature setter 162 ... Manipulation amount calculator (deviation calculator)
171 ... Pressure detector 172 ... Pressure detector 20 ... Second stage extruder 21 ... Cylinder 22 ... Screw 23 ... Heater (heater)
DESCRIPTION OF SYMBOLS 24 ... Drive device 241 ... Motor 242 ... Deceleration device 26 ... Target temperature setter 261 ... Target temperature setter 262 ... Deviation calculator 263 ... Control amount calculator 27 ... Molten resin pressure detector 271 ... Molten resin at the second stage inlet Pressure detector 272 ... Molten resin pressure detector 28 at the second stage outlet ... Molten resin temperature detector 281 ... Molten resin temperature detector 282 at the second stage inlet ... Molten resin temperature detector 30 at the second stage outlet ... Connection pipe DESCRIPTION OF SYMBOLS 40 ... Filter 50 ... Die 60 ... Target pressure setter 70 ... Target differential pressure setter 80 ... Differential pressure calculator 90 ... Resin viscosity pressure compensation calculator 91 ... Resin temperature weighting calculator 92 ... Resin viscosity-pressure compensation calculator DESCRIPTION OF SYMBOLS 100 ... Deviation amount calculator 110 ... Deviation amount calculator 200 ... First stage filter 300 ... Pressure loss setting means (pressure loss measurement section)
310 ... Pressure detector 311 ... Inlet pressure detector 212 ... Outlet pressure detector 320 ... Pressure detector 321 ... Inlet resin temperature detector 322 ... Outlet resin temperature detector

Claims

The first stage extruder and the second stage extruder are connected, and the resin temperature in the screw groove of the second stage extruder is kept constant while keeping the screw rotation speed and cylinder temperature of the second stage extruder constant. When the pressure difference between the inlet and outlet of the second stage extruder is constant, and the detected resin temperature in the second stage extruder is different from the target resin temperature, the temperature difference and the previously measured resin Based on the physical property data, the viscosity of the resin flowing in the screw groove of the second stage extruder and the pressure difference between the inlet and outlet of the second stage extruder at the target discharge amount are estimated, and the target pressure difference is calculated. By changing, it is a serial two-stage extrusion apparatus that controls the rotation speed of the first-stage extruder to make the discharge amount constant with high precision,
The first stage extruder controls the screw rotation speed of the first stage extruder so that the pressure at the outlet of the first stage extruder or the inlet of the second stage extruder becomes a target pressure, An in-line two-stage extrusion apparatus characterized in that a target pressure is changed based on a difference between a pressure difference between an inlet and an outlet of the second-stage extruder and a difference between the target pressure differences to reduce fluctuations in discharge amount.

The first stage extruder and the second stage extruder are connected by a conduit, and the temperature of the pressure loss measurement section of the conduit is kept constant, the resin temperature of the pressure loss measurement section is constant, and the pressure loss measurement section When the pressure difference between the inlet and the outlet is constant, and the detected resin temperature in the pressure loss measurement section is different from the target resin temperature, the pressure difference is determined based on the temperature difference and the physical property data of the resin measured in advance. By estimating the viscosity of the resin flowing through the loss measurement section and the pressure difference between the inlet and the outlet of the pressure loss measurement section at the target discharge amount, and changing the target pressure difference, the rotation speed of the first stage extruder is changed. It is a series two-stage extrusion device that controls and makes the discharge amount constant with high accuracy,
The first stage extruder includes a screw of the first stage extruder so that a pressure at an outlet of the first stage extruder, an inlet of the pressure loss measurement section, or an outlet of the pressure loss measurement section becomes a target pressure. The series is characterized in that the number of revolutions is controlled, and the target pressure is changed based on the difference between the pressure difference between the inlet and the outlet of the pressure loss measurement section and the target pressure difference to reduce the variation in the discharge amount. Two-stage extrusion equipment.

A first stage extruder and a second stage extruder are connected, and the resin temperature in the screw groove of the second stage extruder is kept constant while keeping the screw rotation speed of the second stage extruder constant, When the pressure difference between the inlet and outlet of the two-stage extruder is constant, and the detected resin temperature in the second-stage extruder is different from the target resin temperature, the temperature difference and pre-measured physical property data of the resin Based on the above, the viscosity of the resin flowing in the screw groove of the second stage extruder and the pressure difference between the inlet and outlet of the second stage extruder at the target discharge amount are estimated, and the target pressure difference is changed. By controlling the rotation speed of the first stage extruder, the cylinder temperature is changed so that the outlet temperature of the second stage extruder is constant, and the discharge amount and the resin temperature are made constant with high accuracy. An in-line two-stage extrusion device,
The first stage extruder controls the screw rotation speed of the first stage extruder so that the pressure at the outlet of the first stage extruder or the inlet of the second stage extruder becomes a target pressure, An in-line two-stage extrusion apparatus characterized in that a target pressure is changed based on a difference between a pressure difference between an inlet and an outlet of the second-stage extruder and a difference between the target pressure differences to reduce fluctuations in discharge amount.