PROBLEM TO BE SOLVED: To provide a heat fusion method free from the occurrence of wall thinning, expansion, deformation, pinholes, or the like in heat-fusing, by using a resin film, a hard resin opening of a port which is also used as a medical solution chamber.SOLUTION: A method is provided for sealing the opening end with the resin film using a heat seal die to block the opening end of a cylindrical member made of hard resin and filled with a medical solution inside. The heat seal die used in this case includes an annular seal part contacting the sidewall upper end face of the cylindrical member through a film in heat-sealing a cylindrical recess located at the center of the annular seal part and provided to fit into the heat seal die from the lower face of the heat seal die and heat-resistant resin embedded in the recess with a lower cavity so as not to contact the fused film. In this method, the opening end of the cylindrical member made of hard resin is sealed with the resin film while intercepting radiant heat transferred into the cylindrical member from the heat seal die in heat-sealing.COPYRIGHT: (C)2013,JPO&INPIT【課題】薬液室兼用ポートの硬質樹脂製の開口を樹脂フィルムで熱融着する際に肉薄化、膨張、変形、またはピンホール等が発生することなく熱融着する方法の提供。【解決手段】内部に薬液が充填された硬質樹脂製筒状部材の開口端を閉塞するように樹脂フィルムを前記開口端に熱シール金型でシールする方法において、前記熱シール金型として、熱シール時に前記筒状部材の側壁上端面にフィルムを介して接触する環状シール部と、前記環状シール部の中央に位置し、熱シール金型下面から熱シール金型内部へ嵌入するように設けられた円柱状の凹部と、融着されるフィルムには接触しないような下部空隙を設けて前記凹部に埋設された耐熱性樹脂とを有する熱シール金型を用い、熱シール時に前記熱シール金型から前記筒状部材内へ伝わる輻射熱を遮断しながら、硬質樹脂製筒状部材の開口端に樹脂フィルムをシールする方法。【選択図】図1
