Visit the Multi-Screw
Compounding Zone
flame-retardant (HFFR) electrical cable,
which require either high levels of fillers,
special fillers requiring high shear, or heat-
sensitive fillers and/or blowing agents, an
adjustable dam could be used upstream to
start melting in the first mixing chamber, so
that additional fillers could be introduced to
already melted material in the downstream
mixing chamber.
• Farrel Pomini's R&D; on new mixing
rotors includes development of a version
that imparts a higher level of dispersive
mixing. This High-Dispersion Rotor may
borrow from the NST rotor design of Farrel
Pomini's Banbury batch mixers (produced
by a separate business unit).
• Currently in lab testing is a higher-dis-
persion #15 rotor for CPXL/LCM machines.
It represents a merger of Farrel and Pomini
technologies, as the CPXL #15 rotor substi-
tutes a Farrel-type mixing section for the
Pomini LCM design in the downstream
stage of the mixer.
• The company is exploring the concept of
a Twin-Screw Pump for niche applications
like PET black Masterbatch (BMB), which
contains 30-40% carbon black. Farrel
Pomini says it is very difficult to pump and
pressurize such a compound, so it may be
necessary to substitute a twin-screw for the
current single-screw discharge extruder. To
prevent oxidation of the PET melt, the
mixer and extruder would be close-coupled
to eliminate contact with air. The mixer
would utilize the new CPXL #15 rotor with
multiple adjustable dams.
QUESTIONS ABOUT COMPOUNDING?
Biopolymers like PLA are
considered a promising new
application area for the
'gentle' compounding action
of continuous mixers.
18
JULY 2017
Plastics Technology
PTonline.com
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