Abstract: A mixing attachment for a screw, in particular an extruder screw in an extruder or in an injection-molding machine, comprising an essentially rotationally symmetrical lateral surface, the diameter of which increases from a first end to a second end of the lateral surface, and a securing device, which is provided in the region of the first end of the lateral surface, for securing the mixing attachment at a downstream end of the screw, wherein the lateral surface is perforated by a plurality of apertures, in particular bores.

Abstract: In a method of cooling a sheet-shaped or web-shaped substrate, such as a plastic sheet or a plastic web, the substrate is moved along a cooling path, and heat radiating from the substrate is absorbed and/or reflected along at least one zone of the cooling path to provide a controlled cooling pattern, by using covering elements which are disposed above and/or below the substrate, whereby the zone can be adjusted by the arrangement and/or number of covering elements.

Abstract: An extruder has a housing, a core centered on an axis, and a sleeve spacedly coaxially surrounding the core and defining therewith an outlet passage. Thus molten material emerges from the passage as a tube. A plurality of radially extending and angularly spaced adjustment screws are threaded into the housing and radially engage the sleeve so that these screws can be screwed in and out to radially displace the sleeve on the housing and thereby adjust the passage. A detecting unit axially downstream of the extruder includes at least one sensor for measuring the thickness of the tube at a plurality of angularly spaced locations and for producing an output corresponding to the respective measured thickness. An adjustment unit including at least one rotary tool engageable with the screws can selectively rotate same and screw same in the housing.