Device and method for producing plastic granulate

Patent metadata

Field	Value
Publication number	US-11273576-B2
Application number	US-201716325951-A
Country	US
Kind code	B2
Filing date	Jul 27, 2017
Priority date	Aug 17, 2016
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A device for producing dyed plastic granulate and undyed plastic granulate includes a multi-shaft screw extruder and an underwater pelletizing installation. A granulate changeover unit which separates the dyed plastic granulate from the undyed plastic granulate is disposed in a conveying direction downstream of the underwater pelletizing installation. The dyed plastic granulate is separated from the pelletizing water via a first separator installation, and the undyed plastic granulate is separated from the pelletizing water via a second separator installation. The separator installations are disposed so as to be mutually parallel. The device enables a simple, flexible and economical selective production of the dyed plastic granulate and the undyed plastic granulate.

First claim

The invention claimed is:

1. A device for producing plastic granulate, the device comprising:
a multi-shaft screw extruder for providing a plastic melt;
an underwater pelletizing installation for producing plastic granulate that is located in pelletizing water from the plastic melt;
a granulate changeover unit configured for separating dyed plastic granulate and undyed plastic granulate and configured for separating a post-treatment into a first post-treatment circuit for the dyed plastic granulate and a second post-treatment circuit for the undyed plastic granulate, the granulate changeover unit being disposed downstream of the underwater pelletizing installation in a conveying direction;
a first separator installation configured for separating the dyed plastic granulate from the pelletizing water, the first separator installation being disposed downstream of the granulate changeover unit in the conveying direction and being part of the first post-treatment circuit; and
a second separator installation configured for separating the undyed plastic granulate from the pelletizing water, the second separator installation being disposed downstream of the granulate changeover unit in the conveying direction and being part of the second post-treatment circuit and the second separator installation being parallel with the first separator installation.

2. The device as claimed in claim 1 , wherein a pelletizing water changeover unit for feeding the pelletizing water from the first separator installation or the second separator installation to the underwater pelletizing installation is disposed between the first separator installation, the second separator installation and the underwater pelletizing installation.

3. The device as claimed in claim 2 , wherein a first pelletizing water container is disposed between the first separator installation and the pelletizing water changeover unit, and a second pelletizing water container is disposed between the second separator installation and the pelletizing water changeover unit.

4. The device as claimed in claim 2 , wherein a first pelletizing water pump is disposed between the first separator installation and the pelletizing water changeover unit, and a second pelletizing water pump is disposed between the second separator installation and the pelletizing water changeover unit.

5. The device as claimed in claim 1 , wherein a pelletizing water container for feeding the pelletizing water from the first separator installation and the second separator installation is disposed between the first separator installation, the second separator installation and the underwater pelletizing installation.

6. The device as claimed in claim 1 , wherein a pelletizing water pump is disposed between the first separator installation, the second separator installation and the underwater pelletizing installation.

7. The device as claimed in claim 6 , wherein the pelletizing water pump is disposed between a pelletizing water container and the underwater pelletizing installation.

8. The device as claimed in claim 1 , wherein at least one filter installation is disposed between the underwater pelletizing installation and at least one of the first separator installation and the second separator installation.

9. The device as claimed in claim 8 , wherein the at least one filter installation comprises at least two pelletizing water filters disposed parallel to each other.

10. The device as claimed in claim 8 , wherein the at least one filter installation is disposed between a pelletizing water container and the underwater pelletizing installation.

11. The device as claimed in claim 1 , wherein a color granulate changeover unit for separating dyed plastic granulate and impure plastic granulate in a changeover of production from dyed plastic granulate to undyed plastic granulate is disposed downstream of the first separator installation.

12. The device as claimed in claim 11 , wherein at least one first storage container for storing the dyed plastic granulate, and at least one second storage container for storing the impure plastic granulate are disposed downstream of the color granulate changeover unit.

13. The device as claimed in claim 12 , wherein a return feed line for returning the impure plastic granulate in the production of the dyed plastic granulate extends from the at least one second storage container to the multi-shaft screw extruder.

14. The device as claimed in claim 12 , wherein a classification installation for classifying the impure plastic granulate is disposed between the color granulate changeover unit, the at least one second storage container and another second storage container.

15. The device as claimed in claim 1 , wherein the multi-shaft screw extruder comprises a first infeed opening for feeding undyed plastic material, and the multi-screw extruder comprises a second infeed opening for feeding at least one of dyeing agent and impure plastic granulate, wherein a first pelletizing water container is connected to the first separator installation, the first pelletizing water container being configured to receive the pelletizing water from the first separator installation, wherein a second pelletizing water container is connected to the second separator installation, the second pelletizing water container being configured to receive the pelletizing water from the second separator installation.

16. The device as claimed in claim 1 , wherein the multi-shaft screw extruder comprises a housing having at least two mutually penetrating housing bores configured in the housing, wherein associated treatment element shafts are rotatingly drivable in the at least two mutually penetrating housing bores, the associated treatment element shafts being configured to mutually mesh and to scrape an internal wall of the housing.

17. A method for producing plastic granulate, the method comprising the following method steps:
providing a device for producing plastic granulate, the device comprising a multi-shaft screw extruder for providing a plastic melt, an underwater pelletizing installation for producing plastic granulate that is located in pelletizing water from the plastic melt, a granulate changeover unit configured for separating dyed plastic granulate and undyed plastic granulate and for separating a post-treatment into a first post-treatment circuit for the dyed plastic granulate and a second post-treatment circuit for the undyed plastic granulate, a first separator installation for separating the dyed plastic granulate from the pelletizing water and a second separator installation for separating the undyed plastic granulate from the pelletizing water, the granulate changeover unit being disposed downstream of the underwater pelletizing installation in a conveying direction, the first separator installation being disposed downstream of the granulate changeover unit in the conveying direction and being part of the first post-treatment circuit, the second separator installation being disposed downstream of the granulate changeover unit in the conveying direction and being part of the second post-treatment circuit and the second separator installation being parallel with the first separator installation;
producing the dyed plastic granulate via the multi-shaft screw extruder and the underwater pelletizing installation, and separating the dyed plastic granulate via the first separator installation;
changing over the granulate changeover unit;
producing the undyed plastic granulate via the multi-shaft screw extruder and the underwater pelletizing installation, and separating the

Assignees

• Coperion Gmbh

Inventors

• Conrad Ulrich
• Kern Norbert
• Schmudde Markus
• Stöhrer Bernhard
• Hornberger Heiko

Classifications

• B29B7/748

  Plants (B29B7/7433, B29B7/7485, B29B7/7495 take precedence) · CPC title

• B29C48/0022

  combined with cutting · CPC title

• B29B9/065

  under-water, e.g. underwater pelletizers · CPC title

• B29C48/04

  Particle-shaped (making granules B29B9/00) · CPC title

• B29B9/12 Primary

  characterised by structure or composition · CPC title