| A 2.5-in. diam. single screw with two Elongator mixing sections, built by Randcastle Extrusion Systems Inc., Cedar Grove, N.J., can process rigid PVC dryblend at 70 rpm for 150-lb/hr output. A single-screw extruder typically processes PVC from pellets at about 30 rpm and can’t process low-bulk-density dryblend at all. Tests with the new screw were conducted in late April on a 32:1 L/D NRM single-screw extruder with a 40-hp motor and air-cooled barrel. Results were reported at SPE’s ANTEC meeting in Milwaukee last month. (A single screw with Elongator mixing sections has already been shown to run rigid PVC pellets at 96 rpm.)
Randcastle will offer Elongator screws at 2.5-in. and larger diameters. The target market is single-screw extruders producing profiles from pellets, since the new screw can process less expensive dryblend, says president Keith Luker, shown here with Randcastle’s first full-size Elongator screw. (973) 239-1150 • www.randcastle.com |
