Method for producing a container

A method for producing a container for carrying or storing gases or liquids which is made from a thermoplastic plastics material, wherein the method has the following steps:

• in an injection mold having a first mold and a second mold, which, in a first injection molding position, together provides at least one cavity for an upper shell as well as at least one cavity for a lower shell, at least one upper shell and at least one lower shell are produced in parallel in an injection molding method;
• opening the injection mold, wherein the at least one upper shell remains in the first mold and the at least one lower shell remains in the second mold;
• at least one of rotating or displacing at least one of the two molds so that, after the rotation or displacement, the concave inner sides of the shells are directed towards one another and closing the mold to realize a second injection molding position, so that substantially congruent edge regions of the shells come into at least partial planar contact;
• injecting injection molding material into a cavity between or adjoining the edge regions to form a circumferential weld seam between the upper part and lower part;
• and
• opening the injection mold and removing the at least one container.