Patent ID: 7585452

Claim:
A method for producing a container consisting of a substantially stiff outer container and an easily deformable inner pouch which are made from thermoplastic materials that do not form a welded joint with one another, the container comprising a container opening and at least one wall opening in the outer container, by which pressure is compensated in the space between the inner pouch and the outer container, a parison, which consists of at least two tubings, being coextruded and arranged between the opened halves of a blow mold and the blow mold being closed when the parison has reached the length required for producing the container, excess material being squeezed off in the bottom area of the container to be produced, and a web being formed from welded material of the outer container, in which web the welded bottom seam of the inner pouch is clamped and held in axial direction, and the parison being inflated by a pressure medium for contact with the wall of the blow mold and removed from the blow mold, the method comprising the following steps: a) the container opening is sealed, b) the at least one wall opening is formed in that the wall of the outer container is punctured or penetrated by a drill, graver or a piercing needle, with a pressure medium being introduced into the space between the outer container and the inner pouch after full penetration of the wall of the outer container, c) the advance movement of the drill or the piercing needle is stopped as soon as a predetermined first pressure threshold value has been reached in the inner pouch, d) the introduction of the pressure medium into the space between the outer container and the inner pouch is stopped as soon as a predetermined second threshold value has been reached in the inner pouch, e) after pressure relief in the space between the outer container and the inner pouch a pressure medium is introduced into the inner pouch through the container opening to place the inner pouch, which has detached from the container wall, against said wall again.