System for processing of low viscosity polymers

Patent metadata

Field	Value
Publication number	US-11077585-B2
Application number	US-201515535792-A
Country	US
Kind code	B2
Filing date	Dec 10, 2015
Priority date	Dec 18, 2014
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

Disclosed herein is a system comprising a first pump; a pelletization system that comprises an underwater pelletizer; where the pelletization system is located downstream of the first pump and is in fluid communication with it; a direct line that is located downstream of the first pump and upstream of the pelletization system; where the direct line does not contain a pump or a heat exchanger; and a bypass line that is located downstream of the first pump and upstream of the pelletization system; where the bypass line comprises a second pump; where the first pump is operative to discharge the polymer to the pelletization system via the direct line when the polymer has a melt viscosity greater than 10 5 centipoise; and where the first pump is operative to discharge the polymer to the pelletization system via the bypass line when the polymer has a melt viscosity less than 10 5 centipoise.

First claim

What is claimed is:

1. A system comprising:
a first pump;
a pelletization system that comprises an underwater pelletizer; where the pelletization system is located downstream of the first pump and is in fluid communication with the first pump;
a direct line that is located downstream of the first pump and upstream of the pelletization system; where the direct line does not contain a pump or a heat exchanger; and
a bypass line that is located downstream of the first pump and upstream of the pelletization system; where the bypass line comprises a second pump; where the first pump is operative to discharge a polymer to the pelletization system via the direct line when the polymer has a melt viscosity greater than 10 5 centipoise; where the first pump is operative to discharge the polymer to the pelletization system via the bypass line when the polymer has a melt viscosity less than 10 5 centipoise,
wherein the bypass line further comprises a heat exchanger that is configured to cool the polymer; and wherein the heat exchanger is located downstream of the second pump and upstream of the palletization system.

2. The system of claim 1 , where the first pump discharges the polymer at a pressure of less than 15 kilograms per square centimeter when the polymer has the melt viscosity greater than 10 5 centipoise.

3. The system of claim 1 , where the second pump discharges the polymer at a pressure of 15 to 150 kilograms per square centimeter when the polymer has a melt viscosity less than 10 3.9 centipoise.

4. The system of claim 1 , where the bypass line contacts the direct line via a line that contains a valve.

5. The system of claim 1 , further comprising a reactor and a devolatilizer;
where the reactor and the devolatilizer are disposed upstream of the first pump and where the reactor and the devolatilizer are in fluid communication with one another and with the first pump.

6. The system of claim 5 , further comprising a plurality of devolatilizers that remove solvent from the polymer; where the plurality of devolatilizers are in fluid communication with each other.

7. The system of claim 1 , where the first pump and the second pump are each a gear pump.

Assignees

• Dow Global Technologies Llc

Inventors

• Zogg Jr Michael J
• Gambrel Timothy W
• Van Leeuwen Johan

Classifications

• B29C48/365

  using pumps, e.g. piston pumps · CPC title

• B29B9/065 Primary

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

• B29C48/78

  Thermal treatment of the extrusion moulding material or of preformed parts or layers, e.g. by heating or cooling · CPC title

• B29C48/285

  Feeding the extrusion material to the extruder · CPC title

• B29C48/695

  Flow dividers, e.g. breaker plates · CPC title