Abstract: The present invention relates to a method and a device for cleaning extrusion heads (10) in the extrusion of thermoplastic plastic materials which are ejected or extruded as tubular preform (12) from an extrusion nozzle (14). For removing interfering deposits and cakings (20) on the discharge nozzle (14), according to the present invention the tubular preform (12) is briefly deflected and upset, wherein the deposits (20) adhering in a proximate region of the discharge nozzle (14) are wiped off from the tubular preform (12) and transported away. Advantageously, the tubular preform (12) is during its deflection itself used as cleaning element, wherein the cleaning takes place automatically during the continuous operation of the continuous extrusion without interrupting the production process.

Abstract: The present invention relates to a method and a device for cleaning extrusion heads (10) in the extrusion of thermoplastic plastic materials which are ejected or extruded as tubular preform (12) from an extrusion nozzle (14). For removing interfering deposits and cakings (20) on the discharge nozzle (14), according to the present invention the tubular preform (12) is briefly deflected and upset, wherein the deposits (20) adhering in a proximate region of the discharge nozzle (14) are wiped off from the tubular preform (12) and transported away. Advantageously, the tubular preform (12) is during its deflection itself used as cleaning element, wherein the cleaning takes place automatically during the continuous operation of the continuous extrusion without interrupting the production process.

Abstract: The invention relates to a method and a device for the production of blow-molded two- or multi-layer containers made of thermoplastic, and a plastic container produced accordingly, having view strips, particularly for storage and for transport of contents. To this end, molten plastic material is deflected in an extrusion head (10) from the inner, natural-colored layer (34) of the tubular preform (18) into the outer layer (36) in a process technical step, and incorporated there, whereby a view strip (24) is formed in the colored outer plastic layer (36).

Abstract: The invention relates to a method and a device for the production of blow-molded two- or multi-layer containers made of thermoplastic, and a plastic container produced accordingly, having view strips, particularly for storage and for transport of contents. To this end, molten plastic material is deflected in an extrusion head (10) from the inner, natural-colored layer (34) of the tubular preform (18) into the outer layer (36) in a process technical step, and incorporated there, whereby a view strip (24) is formed in the colored outer plastic layer (36).

Abstract: The invention relates to an extrusion head (10) for a blow molding machine for producing two-layered hollow plastic bodies, including one or more extruders, connected to the extrusion head housing (12), for supply of molten plastic melt. In particular when using different plastic materials of different viscosities, it is very important to create for both materials substantially the same rheological flow conditions when distributed across the circumference to form a tubular parison.