| 摘要 |
PURPOSE:To contrive to reduce the power consumption and to lower the rejection rate, which is caused by sagging and the like by a method wherein high frequency voltage is applied between an upper electrode and a lower electrode, the width of which is slightly larger than that of the upper electrode, under the state that thermoplastic soft synthetic resin sheets having films on both sides are pinched by said electrodes, and at the same time welded part is forcibly cooled. CONSTITUTION:Both thermoplastic soft synthetic resin sheets to be joined together 8 and 8' are pinched between an upper film 5 and a lower film 6 under the condition that the end surfaces 9 and 9' of the joining edges of both the sheets 8 and 8' are butted against each other between an upper electrode 1 and a lower electrode 2. Next, when high frequency voltage is applied through both the upper and the lower films 5 and 6 between the electrodes 1 and 2, leakage current 11 is confined in a narrow region and butted end surfaces 9 and 9' are welded together, since the width of the electrode 2 is made slightly larger than that of the narrower electrode 1. At this time, the welded part is forcibly cooled in a short time by means of cooling water pipes 10 and 10', both of which are imbedded in the electrodes 1 and 2 in advance and made of insulator. As a result, the rejection rate caused by the sagging of the thermoplastic soft synthetic resin sheets and the like is lowered. |
