Abstract: To place material accumulations, which is unavoidable upon blow-molding a bottle, in a separable two-part blow mold form away from a bottom fold line (2) of the bottle, in which the bottom portion of the bottle is formed with a generally inverted V-shaped depression (3) and the apex of the V defines the bottom fold line, the separating seam (9) in the bottom portion is placed at an angle (.alpha.) with respect to the bottom fold line (2), a central region of the bottom separating seam intersecting, at least approximately, the bottle axis (17). The mold form has a body separating plane (12) and an end portion separating plane (16, 23, 25) in which the end portion separating plane is angled by the angle (.alpha.) with respect to the body separating plane.

Abstract: The bottle is made of thin-walled plastic produced by a blow-molding process; a bottom part (3) is pre-formed with an inwardly extending, in cross section essentially V-shaped folded part (13) which defines an elongated inner bottom fold line (8). The inner fold line (8) merges smoothly with body fold lines (15, 15a, 15b) extending longitudinally of the bottle. The inner bottom fold line (8) and the longitudinal fold line are in a single plane; the plane is transverse to the seam or junction lines (9) formed by molding the bottle in a two-part mold. The cross section of the bottle may be circular, rectangular, or hexagonal, and it is unitary with a pouring spout which extends, preferably with a reduced diameter, from the top portion of the bottle, so that, upon folding the bottle along the seam lines and expelling all air from the inside, the bottle can be compressed and reduced to small size upon air-tightly closing the spout.