Processor Tips

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. 


Tim Womer is a recognized authority in plastics processing and machinery with a career spanning more than 35 years. He has designed thousands of screws for all types of single-screw plasticating. He now runs his own consulting company, TWWomer & Associates LLC. Contact: (724) 355-3311;;

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