When Spirex Corp., Youngstown, Ohio, introduced its Quantum barrier screw at NPE last year, it reported impressive performance improvements in plasticating for injection molding. Spirex since has found that the Quantum screw (which also requires a special barrel) achieves improved output in extrusion, as well. Five commercial extrusion applications have emerged in the past year in cast fi lm and sheet, and Spirex reports 10% to 15% higher output of crystalline resins than with its older MeltPro barrier screw. The applications all involve polyolefi ns, especially PP, which the screw reportedly melts faster and improves mixing of colorants. Extrusion versions of the Quantum screw so far have been 70 to 120 mm diam. and 24:1 L/D, but they could go up to 36:1. Tel: (330) 726-4000 . www.spirex.com
8469 Southern Blvd Youngstown, OH 44512
Phone (330) 726-4000 Fax (330) 726-9437
Editor PickSizing the Barrier Gap
Here’s a less complex way to properly size the barrier gap for barrier screws.