| 摘要 |
PURPOSE:To enhance the impact resistance of a standing bag by a method wherein a score on each of two side faces of a bag is bent reversely from its original folded condition starting at the end of its opening, the sides of the bag are pulled out to form two open surfaces with the inside of the bag exposed to the outside and a bottom forming sheet is heat sealed to the open surfaces. CONSTITUTION:A bag 10 is formed by a general method, and then a cut 15 is inwardly made a predetermined distance from each of the four corners of the mouth ends of the bag 10. In order to open the mouth part of the bag 10, a score 23 on each of two side faces 21 is bent reversely from its original folded condition to an end H of the score at the bag mouth starting at an arbitrary point P on the score 23 and the sides of the bag are folded while being pulled out to form reverse scores 23a, thereby making up open surfaces 11a and 21a with the inside of the bag exposed to the outside. A square-shaped bottom forming sheet 30 is then placed on these open surfaces 11a and 21a, the peripheral edge of the sheet is entirely heat sealed thereto and excessive tabs 29 and projecting parts 28 are cut off from the bag to complete a standing bag. |
