Features of two-stage re-pelletizing system:
1. segmented filtering principle, fore filtering in the first extruder, and fine filtering in the second extruder, to deduce the frequency of filtering sieves changing
2. thanks to separated filtering system in two-stage extruder, system can realize steady extrusion job
3. has one more volatilization between first and second extruder
4.second stage's extruder can present low temperature extrusion, which can guarantee the final production's quality