Processing with Barrier Screws

[tbramel]

The company I am working for is starting to phase out old machines with new Wittmann/Battenfelds. The machines were spec'd with Xaloy MeltPro Screws with the Z-Mixer. We run a lot of PP, ABS and PC/ABS in various colors and they have traditionally used mixing nozzles to help with color mixing issues. This is my first experience processing with this type of screw and was wondering if we need to approach the melt preparation phase differently than when using a GP (no purpose) screw? (Back Pressure, Screw Speed and Heat Profile)

[brentb]

Ran a lot of PE with barrier screws. (Eagle and Xaloy) and generally lowered about 15°F across the board. Lowered color LDR also. Since we were running closures at sub- five second cycles, we kept the screw RPMs high and BP low.

Contact Xaloy for more info!


KOM

brent

[rickbatey]

My experience with barrier screws is that you run a reverse heat profile. Hottest in the feed throat and dropping set point toward the nozzle. I'm not a fan of specialty screws but some processes demand them.
Rick.