A device for checking the construction of an extruder screw having a shaft and screw elements that are to be pushed or have been pushed one after the other onto the shaft in a defined sequence. Each screw element has an element-specific external geometry. A recording device being provided for determining information concerning the sequence of the screw elements that are to be pushed on or have been pushed on and for comparing the information determined with target information, which directly or indirectly describes the target sequence.

The invention relates to a method and to an assembly for recycling plastic materials, comprising the following processing steps: a) reprocessing the raw material, wherein the material, if necessary, is comminuted and brought into a fluid-like form and heated and permanently mixed, while preserving the lumpiness and pourability thereof, and optionally the viscosity thereof is increased and/or it is degassed, softened, dried and/or crystallized; b) melting the reprocessed material, at least so much that filtration is possible; c) filtering the melt in order to remove impurities; d) homogenizing the filtered melt; e) degassing the homogenized melt; and f) discharging and/or subsequently processing the melt, such as by granulation, blown film processing, with said processing steps being carried out consecutively in the order listed (FIG. 2).

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.

An extruder for processing hydrocarbon-containing material. The extruder includes a screw that is rotatably positioned in a barrel liner and a heating system positioned about at least a portion of the barrel liner that is designed to heat the hydrocarbon-containing material as the hydrocarbon-containing material moves through the barrel liner.

A compression system includes a compression device and a controller. A treated material is pressed longitudinally through a compression chamber by simultaneously applying a lateral pressure and a two-dimensional cross-section compression which includes a pressure applied in a direction traverse to a direction of transport and a pressure applied in a direction parallel to the direction of transport. The controller controls the two-dimensional cross-section compression applied to the treated material such that, during compression, liquids in the treated material migrate to the outer surface of the treated material upon reaching the outlet orifice.

A method for producing a transparent thermoplastic resin pellet comprising a step of kneading a transparent thermoplastic resin with a kneader under a condition under which a damage history calculated according to the following formula is 500 to 2,500:
Damage history={Residence time (tr)}{Shear rate ()}
Residence time (tr)=(WHL)/Q
Shear rate ()=(DN)/H
in the formulae, W represents a screw groove width (pitch) [cm]; H represents a screw groove depth [cm]; L represents a screw length [cm]; Q represents a resin supply amount [g/s]; D represents a screw diameter [cm]; and N represents a screw rotation number [rps].

The present invention relates to a process for devolatilising polymer-containing media such as, in particular, polymer melts, polymer solutions and dispersions and also devolatilisation apparatuses for carrying out the abovementioned process.

An extruder for processing hydrocarbon-containing material. The extruder includes a screw that is rotatably positioned in a auger barrel and a heating system positioned about at least a portion of the auger barrel that is designed to heat the hydrocarbon-containing material as the hydrocarbon-containing material moves through the auger barrel.

Processes for decrosslinking crosslinked plastic and devulcanizing vulcanized rubber include advancing such materials through single screw or twin screw extruders including special ultrasonic treatment zones wherein threadless shaft (single screw) or shafts (twin screw) rotate under an ultrasonic horn having a distal end aligned with the shaft or shafts and being shaped complimentary thereto. Special arcuate (single screw) or double-arcuate ultrasonic treatment flow paths confine the materials to flow under the horn where the material is subjected to ultrasonic waves to decrosslink the material, in the case of crosslinked plastic, or devulcanize the material, in the case of vulcanized rubber, with the extrudate leaving the die as a continuous stream or rope as is typical of virgin plastic or rubber.

Processes for decrosslinking crosslinked plastic and devulcanizing vulcanized rubber include advancing such materials through single screw or twin screw extruders including special ultrasonic treatment zones wherein threadless shaft (single screw) or shafts (twin screw) rotate under an ultrasonic horn having a distal end aligned with the shaft or shafts and being shaped complimentary thereto. Special arcuate (single screw) or double-arcuate ultrasonic treatment flow paths confine the materials to flow under the horn where the material is subjected to ultrasonic waves to decrosslink the material, in the case of crosslinked plastic, or devulcanize the material, in the case of vulcanized rubber, with the extrudate leaving the die as a continuous stream or rope as is typical of virgin plastic or rubber.