PURPOSE: To form a container which is suitable for automatic manufacture and filling operation by a method wherein side panels of a blank are overlapped from each other, a fold line of a bottom panel is set inside and the bottom plate is folded in such a way that it may be present between the adjoining lower portions of the side panels and the overlapped portions of flexible material adjacent to the side panels are combined to each other.

CONSTITUTION: A laminated assembly of a container includes one or two layers of stiff material 1 and flexible material 2. A blank 3 includes side surface portions 5 of large portions 4, 4 and flap portions 6. All these portions are connected around folding lines 7. The blank 3 is provided with a bi-secting fold line 7A for dividing a portion becoming the bottom panel of the container. The blank is folded around the bi-secting folding line 7A set from the end portion to the inside part of it. The side edges are connected through a longitudinal junction line 8. The container rises automatically when material is filled inside the container or an external pressure is applied to the junction line 8. The folding lines 7, bi-secting folding line 7A and the longitudinal junction line 8 may act as hinges in such a manner that the container is raised and formed into a rectangular box.