US 12,076,904 B2
Device and method for producing a dyed and an undyed plastic melt
Ulrich Conrad, Elze (DE); Norbert Kern, Tamm (DE); Markus Schmudde, Murr (DE); Bernhard Stöhrer, Pleidelsheim (DE); and Heiko Hornberger, Hessigheim (DE)
Assigned to Coperion GmbH, Stuttgart (DE)
Appl. No. 16/325,999
Filed by Coperion GmbH, Stuttgart (DE)
PCT Filed Jul. 27, 2017, PCT No. PCT/EP2017/068947
§ 371(c)(1), (2) Date Feb. 15, 2019,
PCT Pub. No. WO2018/033353, PCT Pub. Date Feb. 22, 2018.
Claims priority of application No. 16184547 (EP), filed on Aug. 17, 2016.
Prior Publication US 2020/0139606 A1, May 7, 2020
Int. Cl. B29C 48/00 (2019.01); B29B 7/00 (2006.01); B29B 7/48 (2006.01); B29B 7/60 (2006.01); B29B 7/72 (2006.01); B29B 7/88 (2006.01); B29C 48/285 (2019.01); B29C 48/385 (2019.01); B29C 48/92 (2019.01)
CPC B29C 48/385 (2019.02) [B29B 7/484 (2013.01); B29B 7/487 (2013.01); B29B 7/489 (2013.01); B29B 7/603 (2013.01); B29B 7/72 (2013.01); B29B 7/88 (2013.01); B29C 48/285 (2019.02); B29C 2948/92009 (2019.02); B29C 2948/92828 (2019.02)] 27 Claims
OG exemplary drawing
 
1. A device for selectively producing a dyed plastic granulate from a dyed plastic melt and an undyed plastic granulate from an undyed plastic melt, the device comprising:
a multi-shaft screw extruder for providing a plastic melt, the multi-shaft screw extruder having a housing, a first infeed opening, a second infeed opening, at least two treatment element shafts and at least two mutually penetrating housing bores configured in the housing, both the first infeed opening and the second infeed opening configured to open into the at least two mutually penetrating housing bores, the at least two treatment element shafts being rotatingly drivable in the at least two mutually penetrating housing bores;
a first metering installation for feeding an undyed plastic material through the first infeed opening into the at least two mutually penetrating housing bores;
a second metering installation for feeding at least one dyeing agent through the second infeed opening into the at least two mutually penetrating housing bores; and
a control installation for selecting between a first operating mode for producing the dyed plastic melt which is pelletized to generate the dyed plastic granulate and a second operating mode for producing the undyed plastic melt which is pelletized to generate the undyed plastic granulate;
wherein a first gap is defined between the at least two treatment element shafts, and a width of the first gap in relation to an external diameter of the at least two treatment element shafts is equal to or greater than 0.003 and equal to or less than 0.05 for achieving a self-cleaning of the at least two treatment element shafts: and
wherein the at least two treatment element shafts and a housing internal wall of the housing define a second gap, and a width of the second gap in relation to the external diameter of the at least two treatment element shafts is equal to or greater than 0.004 and equal to or less than 0.03 for achieving a cleaning of the housing internal wall.