Vertical bag-making/filling/packaging machine, manufacturing method of film packaging bag with content

A vertical bag-making/filling/packaging machine, comprising:

• a film supplying portion which lets out a film from a roll;
• a bag-making guide which folds the film into a tubular shape and changes a conveying direction downward;
• a vertical sealing portion which thermally seals side edges of the film to each other in an up-down direction so as to make the film into a tubular shape;
• a film conveying portion which conveys the film downward;
• a filling portion which loads a content into an interior of the film;
• a lateral sealing portion which thermally seals the film in a left-right direction so as to make a bag body;
• a square-bottom sealing portion which expands a bottom of the bag body to a rectangular shape from an inside and thermally seals the bottom to make a rectangular bottom surface;
• and
• a cutter which cuts off the bag body from the film, wherein
• the square-bottom sealing portion comprises:
• a square-bottom molding portion which expands a bottom part of the bag body into a rectangular shape from the inside and folds both corner parts of the bag body into a triangle;
• and
• a square-bottom heater which thermally seals the both corner parts in a front-back direction,
• the square-bottom molding portion comprises:
• four first guide rods in contact with an inner surface of the film;
• and
• a first-guide-rod driving portion which moves the four first guide rods in four corner directions,
• the lateral sealing portion comprises:
• a flat molding portion which flattens the film;
• and
• a lateral heater which sandwiches the film in a left-right direction and thermally seals the film,
• the flat molding portion comprises:
• two second guide rods brought into contact with the inner surface of the film;
• and
• a second-guide-rod driving portion which moves the two second guide rods in the left-right direction,
• when the first-guide-rod driving portion moves the four first guide rods outward in the four corner directions, the second-guide-rod driving portion moves the two second guide rods inward in the left-right direction, and
• when the first-guide-rod driving portion moves the four first guide rods inward in the four corner directions, the second-guide-rod driving portion moves the two second guide rods outward in the left-right direction.