Container, method of manufacturing the same, and installation jig for cartridge container for discharge gun

A method of manufacturing a container comprising the steps of:

• preparing one pair of surface sections whose material is flexible film and having overlapped sections, and one pair of gusset sections whose width is almost equal to the width of said surface sections;
• folding each gusset section into two parts at a central part in a width direction;
• disposing said gusset sections folded into two parts between the overlapped sections of said surface sections such that the side ends of each of said gusset sections and the side ends of each of said surface sections matches each other;
• heat-sealing the side ends of each of said surface sections, and the side ends of each of said gusset sections so as to form a gusset type container main body;
• forming, at one end portion of said surface sections of said container main body, V-shaped heat-sealed portions, which spread at about 45 degrees on both sides from a position on an axis in a longitudinal direction of said container main body, and cross heat-sealed portions which respectively cross said V-shaped heat-sealed portions in the direction perpendicular to the axis of the longitudinal direction of said container main body;
• cutting portions located adjacent to an end of said V-shaped heat-sealed portions and said cross heat-sealed portions of said container main body so as to form a trapezoid heat-sealed portions at the end of said container main body;
• cutting a zone including a central portion of said trapezoid heat-sealed portions so as to form an opening portion;
• and
• fixing a pouring opening to said opening portion.