Powder Down the Feed Throat
11. April 2012 11:14
In my career there have been a handful of times where a custom compounder using single-screw extruders have asked me to design a screw for mixing large amounts of powdered additives into the virgin base resin. But single screws do not have the capability to convey powder additives in volumes above 20% in a flood-feed condition. Twin screws are built and design for processing large percentages of powder at the feed, and this is typically done in a starve-feed condition and also at very high screw rpms...normally, two and three times faster then single screws.