Abstract: In an extrusion head and an extrusion method for the production of a tubular multilayer preform the extrusion head includes at least two feed paths for feeding plasticised plastic material from one or more extruders to an annular passage arrangement. The annular passage arrangement includes mutually concentric annular passages forming mutually separate flow paths for the various layers of the preform. An annular gap nozzle has an annular gap communicating with the annular passage arrangement, and at least one flow passage communicates with an annular passage of the annular passage arrangement, for the introduction of a translucent viewing strip. The flow passage communicates with the annular passage in question upstream of the annular gap in the region of separation of the flow paths.

Abstract: In an extrusion head and an extrusion method for the production of a tubular multilayer preform the extrusion head includes at least two feed paths for feeding plasticised plastic material from one or more extruders to an annular passage arrangement. The annular passage arrangement includes mutually concentric annular passages forming mutually separate flow paths for the various layers of the preform. An annular gap nozzle has an annular gap communicating with the annular passage arrangement, and at least one flow passage communicates with an annular passage of the annular passage arrangement, for the introduction of a translucent viewing strip. The flow passage communicates with the annular passage in question upstream of the annular gap in the region of separation of the flow paths.

Abstract: The invention concerns a fuel container of plastic material such as a motor vehicle fuel tank, comprising one or more welded seams as seam locations for the body of the container and/or as connecting or sealing seams between the container wall in the region of openings and closure elements or covers welded thereto. At least some of the welded seams are at least partially penetrated by a duct which extends in the longitudinal direction in the seam and which can be filled with air and vented.

Abstract: The invention concerns a fuel container of plastic material such as a motor vehicle fuel tank, having one or more welded seams as seam locations for the body of the container and/or as connecting or sealing seams between the container wall in the region of openings and closure elements or covers welded thereto. At least some of the welded seams are at least partially penetrated by a duct which extends in the longitudinal direction in the seam and which can be filled with air and vented.

Abstract: A double-wall fuel container of plastic material is composed of at least two shell portions which are welded together. The half-shell portions are each in the form of double-wall blow moldings, with a gap being kept free at least in a region-wise manner between the walls of the blow moldings.

Abstract: In a process and apparatus for producing hollow bodies from thermoplastic material by blow molding of preforms using a closing support structure having at least first and second blow molding molds, a common drive means engages a drive plate and a first carrier plate which carries a mold portion. The drive plate is connected to a second carrier plate carrying another mold portion. At least one further carrier plate is arranged displaceably in the opening and closing direction between the first and second carrier plates. At each of its two sides the further carrier plate carries a respective mold portion, each thereof with a mold portion carried by an adjacent carrier plate forming a respective blow molding mold. Each of the two blow molding molds afforded thereby is provided with a means for locking the respective mold in the closed condition thereof.

Abstract: A double-wall fuel container of plastic material is composed of at least two shell portions which are welded together. The half-shell portions are each in the form of double-wall blow moldings, with a gap being kept free at least in a region-wise manner between the walls of the blow moldings.

Abstract: The invention concerns a fuel container of plastic material such as a motor vehicle fuel tank, comprising one or more welded seams as seam locations for the body of the container and/or as connecting or sealing seams between the container wall in the region of openings and closure elements or covers welded thereto. At least some of the welded seams are at least partially penetrated by a duct which extends in the longitudinal direction in the seam and which can be filled with air and vented.