Free standing bag

Claim 1

Bag of limp plastic material capable to stand free, when expanded, comprising a front wall (10) of stiffened plastic material having side edges (11, 12), a top edge (13) and a bottom edge (14); a back wall (20) of stiffened plastic material having side edges (21, 22), a top edge (23) and a bottom edge (24); a bottom panel (30) of stiffened plastic material joined to said bottom edges (14, 24) of said front and back panels (10, 20) and formed with a central crease line (35); a pair of gussetted side walls (40, 50) of stiffened plastic material, each said side walls being joined (41, 51; 42, 52) to the side edge (11, 21; 12, 22) of the front and back walls (10, 20); said plastic material being embossed along embossing lines having a vectorial direction longitudinally of said bag, the front, back and side walls being free from embossing crease lines extending transversely of the bag; the junction (34a, 34b) of the side edges of said bottom panel (30) and the bottom edges (14, 24) of said front and back walls (10, 20) forming a bottom edge crease line (36a, 36b); the central crease line (35) of the bottom panel being parallel to said bottom edge crease lines (36a, 36b) and the bottom panel being folded inwardly, with respect to the top edge of the side walls of the bag, to fold the bottom panel within the outline of the front and back walls (10, 20) when the bag is flat, without introducing a crease into either of said walls, the bottom panel (30) being formed integrally with the front and back walls (10, 20) and the central crease line (35) of the bottom panel (30) being defined by a plastic heat seam line interconnecting the material forming the front and back walls (10, 20); a central point (A) of the respective bottom edge of the side walls being folded over said bottom panel (30) at the central crease line; the side walls (40, 50) each being formed with a longitudinal central crease line (45, 55) parallel to said side edges (41, 51; 42, 52) and a transverse crease (46, 56), forming an interconnecting continuation of said bottom edge crease line (36a, 36b) and continuing said crease line around said bag; the width of said side wall being the same as the width of saId bottom panel; and a pair of triangular crease line (47, 48, 57, 58) extending at angles of about 45* from the intersections of the bottom edge crease lines (36a, 36b) at the junctions of the bottom panel (30) and said front and back walls (10, 20), respectively, and the side walls (40, 50), to the longitudinal central crease line (45, 55) of the side walls (40, 50).