A barrier screw designed to deliver higher throughput at lower melt temperatures has been introduced by Xaloy. It?s called the Xaloy Fusion screw, and was originally developed at New Castle Industries. (New Castle was acquired by Xaloy in August 2003.)
The Xaloy Fusion separates melt from solids into separate channels. But unlike other barriers, an undulating root profile in the Xaloy Fusion?s metering zone provides what company sources call ?chaotic mixing.? This feature is said to thoroughly homogenize the melt with little or no increase in average melt temperature, according to Tim Womer, engineering manager.
?We ran a test with a 6-inch Fusion screw running a 15- to 20-lb LLDPE part in a 3500-ton press and we took the cycle time down from 55 to 43 seconds because we were able to drop the melt temperature and recovery. That?s a 22% cycle time reduction,? Womer says.
Quick color changeovers are ?no big problem,? Womer reports. The Fusion has been used to successfully run different PE and PP grades. Womer says tests running other materials, such as polyesters, are in the works.
Xaloy Inc., Pulaski, VA