| 摘要 |
PURPOSE:To permit the formation of a packaging bag with the sealing portions firmly attached together, by providing one heating roll with a projection portion on its side face, the other heating roll on its side face with a recess portion engageable with said projection portion and at least either thereof with a cooling means. CONSTITUTION:One heating roll 31 is provided with a belt-shaped projection portion 32 on its surface and the other heating roll 33 with a recess portion 34 mating with the projection portion 32. This provision results in increased contact area between these rolls and therefore increased sealing strength of the sealing portion 36 of a packaging bag 35, making the firm attachment possible. In order to prevent the occurrence of a phenomenon that heat is not dissipated from the heat sealing portion 36 after sealing the packaging bag 35 due to the increased contact area, a hollow gas passageway 37 is provided in the interior of the heating roll 31, through which cooling air passes. |
