| 摘要 |
PURPOSE:To enable complete sealing while preventing a pin hole from being generated on a step at an adhered portion by a method wherein portions to be sealed at the upper or lower ends of a cylindrical body are heated and presealed, and then ultrasonic sealing is performed. CONSTITUTION:In process I, after a vessel 1 which is composed by closing the lower opening end of a cylindrical body formed by adhering the ends of a sheet having a thermal plastic resin layer on the surface of paper is filled with contents, the inner faces of portions 3 to be sealed at an upper opening end 2 are heated in an oven 4. At this time the front of the inner of the portion 3 to be sealed may be heated or only a step portion formed at the adhered portion of the cylindrical body may be heated. Next in process II, portions 3 to be sealed are presealed by adhering fused thermal plastic resin layers by press-heating or pressing. After being carried through processes III and IV, in process V, the portion 3 to be sealed which has been presealed is sealed by an ultrasonic sealing machine 5 to complete sealing. |
