Abstract: The stiffness of a flexible, substantially parallelepipedal container formed by shaping and welding a film which is made of a synthetic material and which is to enclose a liquid to be packaged, is improved by applying, before shaping, a second layer of a film formed of an identical or a different material, as a top film, to the surface of the film forming the container which does not subsequently come into contact with the liquid to be packaged. The top film includes a plurality of strips corresponding to the vertical surfaces of the final container which are welded to the film forming the container before shaping, along lines corresponding to the edges of the final parallelepipedal container.

Abstract: The stiffness of a flexible, substantially parallelepipedal container formed by shaping and welding a film which is made of a synthetic material and which is to enclose a liquid to be packaged, is improved by applying, before shaping, a second layer of a film formed of an identical or a different material, as a top film, to the surface of the film forming the container which does not subsequently come into contact with the liquid to be packaged. The top film includes a plurality of strips corresponding to the vertical surfaces of the final container which are welded to the film forming the container before shaping, along lines corresponding to the edges of the final parallelepipedal container.

Abstract: An opening-closing device for a flexible containing a liquid includes a cylindrical spout attached to the outer surface of the bag, and a stopper for the spout which includes a blade for perforating an area of the bag located within the spout when the bag is to be opened. An arrangement of tongues or wings extend from the sides of the spout so that a user may grip the tongue or wing while perforating the area of the bag within the spout upon insertion of the stopper.

Abstract: Opening-closing device for a bag of flexible synthetic material obtained from a material in the form of a film, of the type comprising a threaded drum which is attached to a wall of the said bag and interacts with a stopper capable of being screwed onto the said drum and comprising teeth making it possible to cut out the wall in the region of the central orifice of the drum to permit the opening of the said bag, characterized in that it comprises a means which is integral with the drum (2) and/or the stopper (1) and makes it possible to protect the opposite wall of the bag against the teeth (5) of the said stopper.According to an alternative form, the shoulder (7) of the drum (2) comprises a substantially cylindrical collar (8) dimensioned in such a way that the ends of the teeth cannot exceed its edge (9).