US 12,403,430 B2
Single-screw extruder
Markus Bornemann, Paderborn (DE); and Juergen Huegelmeyer, Osnabrueck (DE)
Assigned to BATTENFELD-CINCINNATI GERMANY GMBH, Bad Oeynhausen (DE)
Appl. No. 17/793,682
Filed by battenfeld-cincinnati germany gmbh, Bad Oeynhausen (DE)
PCT Filed Nov. 1, 2020, PCT No. PCT/EP2020/080614
§ 371(c)(1), (2) Date Jul. 19, 2022,
PCT Pub. No. WO2021/089444, PCT Pub. Date May 14, 2021.
Claims priority of application No. 10 2019 129 717.6 (DE), filed on Nov. 5, 2019.
Prior Publication US 2023/0046870 A1, Feb. 16, 2023
Int. Cl. B01F 27/00 (2022.01); B01F 23/40 (2022.01); B01F 23/43 (2022.01); B01F 23/47 (2022.01); B01F 27/1143 (2022.01); B01F 27/191 (2022.01); B01F 27/724 (2022.01); B01F 35/92 (2022.01); B01F 35/90 (2022.01); B01F 101/00 (2022.01)
CPC B01F 27/1143 (2022.01) [B01F 23/43 (2022.01); B01F 23/47 (2022.01); B01F 23/482 (2022.01); B01F 27/191 (2022.01); B01F 27/724 (2022.01); B01F 35/92 (2022.01); B01F 2035/99 (2022.01); B01F 2101/2805 (2022.01)] 11 Claims
OG exemplary drawing
 
1. A single-screw extruder for conveying and plasticizing a meltable material, comprising:
a screw; and
a heated cylinder, wherein:
the screw is rotatably held in the heated cylinder,
the screw has a core and a helical main flight, wherein the helical main flight is at a first distance from an internal wall of the cylinder and forms a screw duct together with the cylinder and the core of the screw,
the screw comprises a solids conveying zone, a transition zone, a melting zone, and a melt conveying zone in accordance with changing states of matter of the meltable material,
the first distance from the main flight to the internal wall of the cylinder in a region of the transition zone and the melting zone is configured such that melt is prevented from running over the main flight,
the region of the transition zone and the melting zone has at least two successive, non-overlapping barrier portions,
an overflow flight is arranged in each barrier portion, the overflow flights beginning from an active flank of the main flight, the active flank being defined by rotation of the screw, and ending at a passive flank of the main flight, the overflow flights thereby configured to provide at least three separate ducts, the at least three separate ducts being interconnected merely by a gap formed as a result of a second distance from the overflow flight to the internal wall of the cylinder,
the second distance from the overflow flights to the internal wall of the cylinder in each barrier portion is greater than the first distance from the main flight to the internal wall in order to allow solids and/or melt to cross over,
at least in a region of the first barrier portion, the internal wall of the cylinder is provided at least in part with either at least one cylinder groove extending in parallel with a longitudinal axis of the screw or a helically extending cylinder groove, and
a cylinder-side outside flight surface of one or more overflow flights is chamfered in full or in part over a flight width such that a conical gap that gets narrower in an overflow direction is formed between the internal wall of the cylinder and the cylinder-side outside flight surface.