2 Twin screw extrusion systems installed for dryer-less
PET direct sheet testing @ Leistritz NJ process laboratory
Leistritz has installed ZSE-27 and ZSE-50 MAXX twin screw extrusion systems and related auxiliary equipment in its' New Jersey process laboratory to process "wet" PET on a twin screw extruder in
combination with direct sheet extrusion. PET is typically dried before being processed on a single screw extruder to avoid hydrolysis/degradation. Undried PET, pellets or regrind, is metered into a corotating
twin screw extruder that is equipped with multi-stage vacuum venting to minimize and avoid hydrolysis. A gear pump, screen changer and flexible lip sheeting die are attached to the twin screw extruder prior to a 3-roll stack that cools and forms the PET sheet. The result is a quality product with dramatically less energy consumption.
PET processes are heat and shear sensitive, as well as torque intensive. The Leistritz ZSE-MAXX series is particularly suited for this application due to increased torque capabilities combined with a higher 1.66 OD/ID ratio as compared to competitive twin screw extruders. The ZSE-MAXX series also integrates an improved barrels cooling design for increased heat transfer capabilities, which is particularly beneficial for PET processes.
The following equipment is currently available for PET demonstrations/development trials:
- ZSE-27 and ZSE-50 MAXX model twin screw extruders
- Loss-in-weight feeders for pellets, regrind, powders and liquids
- Screen changers and gear pumps
- Sheeting dies from 10" to 40" width
- Water-ring, oil ring and rotary-vane vacuum pumps
- 3-roll stacks, 14" wide and 42" wide
In addition to the equipment denoted above, a wide variety of additional auxiliary equipment is available to support a range of processes, including desiccant dryers, coextrusion tooling, a supercritical injection unit, strand and underwater pelletizing systems.
For additional information contact Charlie Martin at 908/685-2333 x616 or cmartin@alec-usa.com.
