Sulzer Chemtech AG in Switzerland (U.S. office in Tulsa, Okla.) launched its Optifoam physical foaming system for injection molding three years ago. Last fall, it introduced a retrofittable device that operates at much lower pressure for extrusion applications. The system enables physical foaming with injection of nitrogen or CO2 on a conventional single-screw extruder. Sulzer has around a dozen commercial extrusion applications in Europe and will present its Optifoam extrusion device at this month’s SPE Foams conference in Charlotte, N.C. The Optifoam extrusion system consists of a spider-type block containing a torpedo attached to the end of the extruder. Gas is fed to sintered-metal inserts, which infuse gas on both sides of the melt as it passes over the torpedo. The melt then passes through a static mixer to disperse the gas. The device comes in two sizes for up to 6-in. extruders: Optifoam 12 for under 500 lb/hr and Optifoam 22 for over 500 lb/hr. Sulzer has both sizes available for customer testing in Tulsa. Optifoam doesn’t compete with tandem foam lines, because of the lesser degree of density reduction (10% to 25%), but physical foaming doesn’t require a cooling extruder. This technology was based on research performed at the Plastics Processing Institute (IKV) in Aachen, Germany, with support from Sulzer. A paper on that research was delivered at this year’s SPE ANTEC meeting in Milwaukee. (918) 446-6672 • www.sulzer.com
Sulzer Chemtech USA
4019 S. Jackson Ave. Tulsa, OK 74107
Phone (918) 445-6672 Fax (918) 445-6670
Editor PickSizing the Barrier Gap
Here’s a less complex way to properly size the barrier gap for barrier screws.