Liquid storage bag

A liquid storage bag comprising:

• a bag body having a top portion and a bottom portion, said bag body having an internal space therein;
• an opening and closing device having ends in said top portion;
• heat seals provided adjacent both ends of said opening and closing device;
• a liquid outlet provided on said bottom portion;
• a peelable partition wall having ends configured to divide in a liquid-tight manner said internal space into a lower space and an upper space;
• and
• including a hanging device adjacent one end of said opening and closing device, one end of said peelable partition wall, and one heat seal,
• wherein said partition wall has end portions and a central portion located at a center of said partition wall halfway between said end portions, said central portion having a convex shape,
• wherein said partition wall has a width that increases continuously from a reduced width portion at said center portion to increased width portions at said end portions where said width is defined as a distance between said upper space and said lower space, and
• said width of said end portions are at least two times greater than said width of said center portion.