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OwnerPeter Langos, Manfred Lehmann +1inventors
InventorsPeter Langos, Manfred Lehmann, Stefan Keusch
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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. This is attained in accordance with the invention by making the ejector piston of two concentric cylindrical sleeves which define between them an annular gap in which the two spiral-channel distributor elements are located in opposite disposition inside on the inner surface of the outer cylindrical sleeve and outside on the outer surface of the inner cylindrical sleeve, so that the circumferentially distributed plastic materials of both distributor elements exit at the lower end of the annular gap approximately centrally from the ejector piston into the storage space of the extrusion head.
Extrusion head for a blow molding machine for producing multi-layered hollow plastic bodies, including one or more extruders, attached to a housing (12) of an extrusion head, for feeding molten plastic melt into the extrusion head (10), a central torpedo (14), and two spiral-channel distributor elements for distribution of the plastic melt(s) across the circumference and feeding into an annular storage space (22) which terminates in an annular outlet nozzle (24) through which the plastic melts are expelled by means of an axially movable ejector piston disposed in concentric surrounding relationship to the torpedo (14), wherein the ejector piston is accommodated in the housing and includes an outer cylindrical sleeve (18) having an inner surface configured to form a first one of the spiral channel distributor elements, and an inner cylindrical sleeve (16) having an outer surface configured to form a second one of the spiral-channel distributor elements in confronting relationship to the first distributor element in a single annular gap, which is defined between the outer cylindrical sleeve (18) and the inner cylindrical sleeve (16) approximately centrally in the ejector piston, with the circumferentially distributed plastic melt of both distributor elements exiting at the lower end of the annular gap from the ejector piston.
An extrusion head for a blow molding machine, comprising:
Dependencies are inferred from the claim text.