Lindauer Dornier Gesellschaft Mbh

Friedrich Mueller

Andreas Rutz

Udo Bock

A plasticating screw for an extruder or an extrusion press has a thread change, whereby the volume of the transporting cross-section does not change and thus a pressure increase in the region of the thread is avoided. To this end, in the region wherein a first and a second screw thread of the plasticating screw overlap, the thread width outside the overlapping region is equal to d and the thread width inside the overlapping region is equal to &#xbd; d.

Plasticating screw for an extruder or extrusion press, having a narrower land width in the transition region

A flow control valve such as a melt flow control valve includes a cock plug body (,) rotatably arranged in a housing (,) having a single melt inlet port (,) extending axially relative to the rotatable cock plug body (,), and at least two melt outlet ports (,) extending radially relative to the cock plug body (,). The cock plug body has a flow passage including an axially extending inflow portion (,) and at least one radially extending outflow portion (,) to selectively communicate the inlet port (,) with a selected one of the outlet ports (,). The cock plug body (,) further has at least one pre-flooding passage (,) extending from the main flow channel to an opening radially displaced from the outflow portion (,), so that a pre-flooding partial flow of melt can flow from the flow channel into the next outlet port, when the cock plug body begins to be rotationally switched from one to the next outlet port.

Cock-type melt flow control valve

A filter for filtering plastic melt prior to feeding the melt into an extruder nozzle, for example a thermoplastic film extruder nozzle, has preferably two filter housings for holding respective exchangeable filter cartridges. Both filter housings are articulated by hinges to a column mounting so that one filter housing can be serviced while the other filter housing with its filter cartridge is in a filtering position and vice versa. A single filter may be used alternatively. In both instances the column mounting may include at least one, preferably two, mounting columns.

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Kressbronn, Germany

Friedrich Mueller