Abstract: To provide a method for readily forming an easily separable portion having an adhesive strength that is required as a package bag on packaging film, a package bag having an easily separable portion formed by this method, and a filling-packing machine utilizing this method. A method forming an easily separable portion in packaging film by interposing at least two packaging films between a horn emitting ultrasonic waves and an anvil oppositely disposed to the horn, and vibrating the packaging films by the ultrasonic waves, in which a vibratable layer is provided on the packaging film in at least one of the horn side and the anvil side.

Abstract: [PROBLEM TO BE SOLVED] To provide a method for readily forming an easily separable portion having an adhesive strength that is required as a package bag on packaging film, a package bag having an easily separable portion formed by this method, and a filling-packing machine utilizing this method. [SOLUTION] A method forming an easily separable portion in packaging film by interposing at least two packaging films between a horn emitting ultrasonic waves and an anvil oppositely disposed to the horn, and vibrating the packaging films by the ultrasonic waves, in which a vibratable layer is provided on the packaging film in at least one of the horn side and the anvil side.