Patent ID: 8388886

Claim:
A method comprising: folding and sealing an elongated web of plastic film into a four panel configuration including a front panel with right and left side edges, a back panel with right and left side edges, and a pair of gusset panels extending transversely inward from the front and back panels, with a pair of folded corners joining the gusset panels to the front and back panels along the right side edges, with another folded corner joining the gusset panels together, and with the left side edges joined together by a longitudinally extending seam; inserting a fitment between forward ends of the panels; sealing rear ends of the panels together across the folded web; severing the folded web to obtain a blow-molding preform in the four panel configuration with a closed rear end, the fitment at a forward end, the gusset panels extending transversely inward along a right side of the preform, and the longitudinally extending seam at a left side of the preform; placing the preform in a mold cavity; and expanding the preform under fluid pressure that turns the gusset panels outward, and deflects the rear end into a base configured to support the expanded preform in a free-standing upright position.