Container filled with a liquid concentrate for making dialysate

A self-standing bag for containing a liquid dialysate for making dialysate for a dialysis treatment, said self-standing bag comprising:

• two flexible elastomeric rectangular side wall sheets each having a horizontal top edge and a horizontal bottom edge and two vertical edges;
• one flexible elastomeric rectangular bottom wall sheet having two horizontal edges and two vertical edges;
• said bag when empty being configurable into a flat configuration in which the bottom wall sheet is sandwiched between the two side wall sheets, the bottom wall sheet being symmetrically single-folded along a line parallel to its horizontal edges, said horizontal edges of the bottom wall sheet coinciding with the horizontal bottom edges of the two side wall sheets, said bag in said flat configuration thus being divided by said line into a lateral four-layer part and a lateral two-layer part;
• said bag including first sloped sealing lines between the side wall sheets in the lateral two-layer part on each side of the bag between a first two points on the horizontal top edges of said side wall sheets, said first two points being spaced from the vertical edges of the side wall sheets by a first distance, and a second two points that are along or spaced from the vertical edges of the side wall sheets by a second distance that is less than said first distance, said second two points being positioned on said line separating the lateral two-layer part from the lateral four-layer part;
• said bag including second sloped sealing lines joining each side wall sheet and the bottom wall sheet in the lateral four-layer part on each side of the bag, said second sloped sealing lines extending between the second two points and third points on the horizontal bottom edges of said side wall sheets, said third points being spaced from the vertical edges of the side wall sheets by a third distance;
• and
• said bag further including third sloped sealing lines on each side of the bag between the third points and fourth points on the vertical edges of both the side wall sheets and the bottom wall sheet in the lateral four-layer part joining only the bottom wall sheet and a neighbouring side wall sheet, the fourth points being spaced from the horizontal bottom edges of the side wall sheets by a fourth distance.