A flexible package including a package body including a first side-surface film and a second side-surface film sealed in a peripheral portion. The package body has sealed portions formed in side edge portions such that a non-sealed portion is formed in at least one of the sealed portions. The non-sealed portion has a gas injection portion containing a gas which has a specific heat at constant volume of 0.67 kJ/kg.Math.deg or higher at 0 C. and 1 atm. The gas injection portion has a diameter of from 3 to 50 mm and is formed such that a repelling force is from 4 to 30 N at 23 C. and 1 atm when an entire gas injection portion is nipped from both sides of the first and second side-surface films and squeezed until a nipped gas injection portion has a width equal to a half of the diameter of the gas injection portion.

A flexible package having an inner sheet having a first surface and a second surface. The flexible package has an article reservoir for accepting an article to be shipped and one or more expansion chambers. The expansion chambers can be inflated or otherwise expanded to provide structure to the flexible package and to protect the article in the article reservoir.

A flexible package having an inner sheet having a first surface and a second surface. The flexible package has an article reservoir for accepting an article to be shipped and one or more expansion chambers. The expansion chambers can be inflated or otherwise expanded to provide structure to the flexible package and to protect the article in the article reservoir.

A flexible package having an inner sheet having a first surface and a second surface. The flexible package has an article reservoir for accepting an article to be shipped and one or more expansion chambers. The expansion chambers can be inflated or otherwise expanded to provide structure to the flexible package and to protect the article in the article reservoir.

A flexible package having an inner sheet having a first surface and a second surface. The flexible package has an article reservoir for accepting an article to be shipped and one or more expansion chambers. The expansion chambers can be inflated or otherwise expanded to provide structure to the flexible package and to protect the article in the article reservoir.

A method of manufacturing a pouch container, includes: forming a pouch bag having one open end, by fusion-bonding a resin layer on an inner side of an end of a first film, with a resin layer on an inner side of an end of one or more second films; molding a mouth part member made of a resin, including a brim portion and a standing portion; attaching a lower surface of the brim portion of the mouth part member made of the resin to an outer resin layer of the first film of the pouch bag, by integrating the resins, using one of ultrasonic, heat, or high-frequency welding; filling the pouch bag with contents from the one open end of the pouch bag; and sealing an inside by fusion-bonding the one open end of the pouch bag to seal the pouch bag.

A method of manufacturing a pouch container, includes: forming a pouch bag having one open end, by fusion-bonding a resin layer on an inner side of an end of a first film, with a resin layer on an inner side of an end of one or more second films; molding a mouth part member made of a resin, including a brim portion and a standing portion; attaching a lower surface of the brim portion of the mouth part member made of the resin to an outer resin layer of the first film of the pouch bag, by integrating the resins, using one of ultrasonic, heat, or high-frequency welding; filling the pouch bag with contents from the one open end of the pouch bag; and sealing an inside by fusion-bonding the one open end of the pouch bag to seal the pouch bag.