A new mixing section called the Elongator from Randcastle Extrusion Systems Inc., Cedar Grove, N.J., is a spiral version of the company's fl uted Recirculator mixing section. By twisting the fl utes, molten material doesn't fl ow backward and forward over the fl utes, but only forward, so the new version offers elongational but not distributive mixing. Both the length and degree of twist of the fl utes can be varied. In recent trials a lab-scale (1-in.-diam.) Elongator mixing screw processed rigid PVC at 96 rpm, more than three times faster than standard PVC screws, which typically run at 30 rpm. The 36:1 L/D test screw has three Elongator sections-in the beginning, middle and tip of the screw. A 5D section with a shallow twist is followed by two 3D sections with a steeper twist. Randcastle is scaling the screw up to 3.5 in. diam. for production of a 20% CaCO3-fi lled PVC profi le. Tel: (973) 2391150 . www.randcastle.com
Randcastle Extrusion Systems
220 Little Falls Road Unit 6 Cedar Grove, NJ 07009
Phone (973) 239-1150 Fax (973) 239-0830
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