| 摘要 |
PURPOSE:To prevent the occurrence of excessive melting and incomplete welding of a plastic film for package by a method wherein a heat roller of heat pipe structure in the inside the temperature of which is controlled to a given value is arranged in front of a sealing mechanism. CONSTITUTION:In a heat roller 3, a plurality of heat pipes 14 are fitted in the interior thereof coaxially of a heater 13 fitted in a central axis-form manner. The arrangement is worked to balance dispersion of the temperature of the heater 13 and dispersion of the heat roller 3 is suppressed to a minimum. Thereby, a plastic film 2 for package with which the heat roller 3 is brought into contact can be heated to a constantly given temperature. By previously heating the plastic film 2 to a given temperature before sealing, a need to vary a sealing condition each time the plastic film 2 for package is reeled or in the middle of reeling of the film is eliminated. This constitution causes prevention of the occurrence of excessive fusion and incomplete welding of the plastic film 2 for package. |
