control of the process.” Dosing pumps take molten aluminum from the bottom of the furnace and transfer it to the mold to distribute the prescribed amount of metal. Dosing furnaces that transfer metal directly to the mold with or without a pressure pump also can be incorporated. For instance, in tilt-pour
permanent mold lines, with multiple molds on a turntable, a dosing furnace can be positioned so that the molds come around to the furnace, which distributes the programmed amount of metal for that mold. “You can mix and match sizes and
interface with the furnace so that mold 1 gets 5 lbs., mold 2 gets 7 lbs.,
and so on,” said Dave Kozman, director of sales, Striko Dynarad, Zeeland, Mich. “You are not restricted to one part and one size.” Dosing pumps and furnaces
also can be incorporated into aluminum green sand lines. Dos- ing pumps can direct metal from the furnace to the mold without exposing the metal to oxygen until the point of pouring. Or, a short run that requires 50 molds, each with a few sprues or pouring holes, can be accommodated with a dosing furnace on an XYZ axis table, moving side to side or up and down to position itself cor- rectly above each sprue. Similarly, a dosing furnace can pour large castings, giving the advantage of an enclosed pour that holds the temperature within 4-6 degrees throughout the whole process. Dosing pumps can be pur-
chased together with its matching furnace or separately and then used with existing melting equip- ment. This can be cost effective, but limitations exist. “Quite often people are look- ing to use an existing furnace, but frequently the furnace isn’t deep enough to take the pump,” Brown said. “Without modifying the fur- nace, it may not be possible. Then you have the added cost of a new furnace, which makes it harder to justify.”
Barriers and Doors Te pouring process does not
have to be automated at the same time as the molding line in a cast- ing facility, although it does help. “Automation is the driving
force,” Brown said. “If a foundry is automating the line, it doesn’t make sense to have an automated mold- ing line and then have pouring be the limiting factor.” If a metalcasting operation is updating its production by adding a new automatic molding machine, it might be a good time to consider automating pouring at the same time while funds are available. Job shops in particular might want to keep autopouring in mind when
36 | MODERN CASTING February 2015
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