TWIN SCREW EXTRUSION SYSTEMS TO PROCESS BIO- BASED ...

scenario is for the gear pump rpm (or screw pump) to be locked to set a constant rate to
the die. The control software uses an algorithm program to analyze the inputs from key
points in the system, makes numerical calculations, and applies corrections to the screw
RPM and feed rate to maintain the gear pump inlet pressure at its set point.
Providing a usable melt to the die and downstream system is only half of the battle. Now
the appropriate die and downstream equipment is required size and cool the extrudate,
such as a film, sheet, fiber, or profile.
Summary: Many processors have struggled to process bio-based formulations because
most of their experience has been with traditional plastics. Once it is understood that
renewable resources tend to be more heat and shear sensitive (and sometimes
increased devolatilization requirements) as compared to standard polymer compounds
then the HSEI twin screw extruder and system can be configured and operated
accordingly.
This is not virgin territory, in that food extrusion has been utilized for decades. Rigid
PVC and other plastics products, such as glass filled compounds, have similar process
requirements. Now that significant development and marketing efforts are being targeted
at “bioplastics” the learning curve will accelerate, and in the foreseeable future
processing of these materials will become commonplace. The flexible and sophisticated
design of the HSEI twin screw extruder makes it the ideal device to process these
materials to make pellets and/or parts.