Method for producing a container from thermoplastic material

A method for producing a container from thermoplastic material having a connection element passing through a wall thereof, comprising:

• heating thermoplastic material,
• making at least one preform from the heated thermoplastic material,
• introducing the at least one preform of the heated thermoplastic material into a multipart molding tool having at least one cavity defining at least one molding recess, wherein the heated thermoplastic material has a tool side which faces the at least one cavity and a molding recess side opposite the tool side,
• molding the at least one preform with the multipart molding tool using differential pressure to form shell intermediates,
• joining the shell intermediates to form a hollow body, wherein the shell intermediates are welded to one another,
• piercing the heated thermoplastic material from the tool side by a mandrel to produce an opening in the heated thermoplastic material,
• inserting a connection element into the opening formed in the heated thermoplastic material from the molding recess side, and
• connecting the connection element to the heated thermoplastic material,
• wherein the opening produced by the mandrel is sized before or during the insertion of the connection element into the opening, and
• wherein the sizing is carried out by at least one sizing sleeve inserted into the opening from the tool side.