A new die system for extruded polystyrene foam board reduces downtime for product changeovers, according to Extrusion Dies Industries LLC.
EDI said the shorter downtime enables manufacturers to offset much of the loss in productivity caused by switching to a non-ozone-depleting blowing agent. EDI also claims its technology incorporates innovations that enhance control over product dimensions, reduce scrap and eliminate shutdowns for die maintenance.
Under the Montreal Protocol, effective Jan. 1, companies must have moved to a chorine-free, non-hydrochlorofluorocarbon blowing agent. But EDI said process changes needed to accommodate the new blowing agent reduce insulation board production by 30 percent.
The EDI XPS foam board die technology makes it possible to accomplish a product changeover on the fly in only 15 minutes, said Dennis Paradise, vice president of sales and marketing for EDI in Chippewa Falls, Wis.
One of the main innovations is a new type of forming box. As the PS passes through the die, it is charged with a blowing agent. As it exits the die lips, it undergoes a 30-fold increase in volume. In most conventional die systems, the forming box and die lip constitute a single component, so changing the board dimensions requires stopping the line, taking the lip/forming box apart for adjustments, then reassembling the unit. The forming box in the new EDI system is a separate component that is adjusted independently.
A second new component is an adjustable full-manifold internal deckle inside the flow channel of the die.
Other innovations include external edge restrictors that create final-side dimensions as the board emerges from the forming box, and a purge block between the extruder and the die, so a user can do die maintenance while the extruder is temporarily shut down but still full of polymer.
Diversifoam Products reports it has virtually eliminated downtime by using the new XPS die system in its plant in Rockford, Minn. The die can operate at a much higher pressure than the old one, a key feature for running the blowing agents, according to Steve Slavik, operations manager at the foam board maker.
Tel. 715-726-1201, fax 715-726-2205, e-mail [email protected] siondies.com.
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