CHICAGO — The Beringer Division of John Brown Plastics Machinery introduced at NPE 1997 a polymer diverter valve designed for large compounding and resin finishing lines.
The valve directs the polymer flow from an extruder or melt pump to a discharge bin, or straight through to the downstream filtration apparatus or pelletizer. Directional flow control allows degraded or off-spec material residing in the upstream equipment to be purged without contaminating the screening and pelletizing equipment.
It can be operated independently or through a customer-supplied programmable logic controller. With the PLC, a button activates mixer and melt-pump purge, the diverter valve is closed and the pelletizer starts.
The valve also prevents die-hole freezing on underwater pelletizers and allows nearly instantaneous flow through the die. Polypropylene can freeze off or smear on the die plate if cut at less than perfectly timed pelletizing process conditions.
Features unique to the valve include preloaded, self-compensating, spring-driven seals and cored steam or oil heating.
In the event of a downstream blockage or runaway reaction, a rupture disk provides limited pressure relief.
Also at NPE, held June 16-20 in Chicago, Beringer exhibited its line of jet cleaners, equipment for removing residue from process parts and tooling.
The cleaners use electric heat in a vacuum chamber to remove polymeric residue.
John Brown Plastics Machinery operates six divisions in the United States and one in Milan, Italy. Beringer is in Marblehead, Mass.