Method for producing hollow bodies from thermoplastic materials by using an at least three-part blow-molding tool and apparatus for carrying out the method

Abstract

The invention relates to a method for producing hollow bodies from thermoplastic material by using an at least three-part blow-molding tool with at least two blow-mold halves (), which define a mold impression, have part-cavities () and can be displaced toward one another and away from one another in the sense of an opening and closing movement, and also with at least one central tool (), which is displaceable transversely in relation to the opening and closing movement of the blow-mold halves (), the method comprising the extruding or providing and arranging of at least two molten performs () of thermoplastic material in web form between the blow-mold halves () in an opened receiving position, the bringing to bear of the preforms () in the part-cavities () of the blow-mold halves () and molding of them into shells () using sealing elements which are provided on the central tool and are extended from the central tool for the purpose of sealing off the part-cavities before or while the part-cavities are subjected to differential pressure; the joining of at least one insert () in at least one shell () by using the central tool () arranged between the blow-mold halves () and the joining of the shells () to form the closed hollow body by closing the blow-mold halves () while applying clamping force and, if appropriate, the final blow molding of the hollow body.