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US 9,808,978 B2Granted
Screw elements with reduced energy input during the build-up of pressure
AssigneeCovestro Deutschland AG
InventorsMichael Bierdel, Thomas König, Ulrich Liesenfelder
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Abstract
The present invention relates to screw elements with novel, tightly intermeshing, self-cleaning, co-rotating screw profiles for multishaft screw machines with pairs of co-rotating and fully abrading screw shafts, to the use of these screw elements in multishaft screw machines and to a method of generating these screw elements.
Claims21
Screw elements for multiscrew extruders with pairs of co-rotating screws, wherein the screws are fully wiping in pairs, and wherein each screw has one of:
- a generating screw profile and a generated screw profile consisting of arcs with non-infinite radiuses, each of the generating and generated screw profiles being axisymmetric referring to one axis which passes through the point of rotation of the respective screw profile,
- wherein each of the generating screw profile and the generated screw profile comprises one sealing region, one or more transition regions, one channel region, one or more tip regions, one or more flank regions, and one or more grooved regions, and each screw profile consists of a sequence of the one sealing region, one of the transition regions, the one channel region, another of the transition regions, and
- further wherein
- the sealing region consists of a sequence of tip region, flank region, tip region,
- the channel region consists of a sequence of root region, flank region, root region, and
- each transition region is one of the flank regions.
3 more elements
Dependencies are inferred from the claim text.