| 摘要 |
<p>PURPOSE:To enable an efficient and firm sealing of a bottom, by a method wherein a heat and a pressing force are applied to a portion to be sealed during the movement of the tube at a speed in synchronism with the movement of the tube for a given period of time while a long-sized synthetic resin tube is running in one direction, and the heat and the pressing force are removed simultaneously and instantly. CONSTITUTION:A synthetic resin made tube 1, passing between the nip formed at a start end of a tube running passage 6, is fed out of a terminal end of the tube running passage 6 after being conveyed thereto in such a state as brings the tube into press contact with an outer circumference surface of a drum 4 through the driving of a belt 5. During said conveyance, a bag bottom is heated and molten by means of a plurality of heaters 7 mounted on an outer circumference surface of the drum 4. At a time when the tube is fed out of the terminal end of the running passage 6, a molten portion is contracted to form an expanded bottom 2. After a heat and a pressing force are applied for a given period of time while they are displacing at a speed in synchronism with the movement of the tube and applied with the said movement, they are all removed instantly for sealing. This eliminates the need for the tube to suspend its running and permits the increase in a processing efficiency.</p> |
