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New Equipment Means Cleaner Return Sand, and Cleaner, Larger Castings

Dec. 11, 2008
Bentonville Casting's expansion increased the sizes of its castings, and its need for rotary cleaning equipment.

Arkansas’s Bentonville Casting Co. has grown as a business since it invested in a Didion rotary media drum 17 years ago, and the sizes of its castings have increased, too. It was that pattern of expansion that helped the iron foundry recognize it needed a new system for cleaning the larger castings it now produces.

The 54-year-old jobbing foundry, in Bentonville, AR, produces gray and ductile iron castings as small as a few pounds and as large as 550 lb., from flaskless automatic green-sand molding, cope-and-drag molding, and chemically bonded sand molding. It bought its first Didion ( machine, a rotary sand casting separator, in 1977. In 1991, it bought and installed a Didion MD-50 rotary media drum. “Over the years we have been very pleased with the quality of the equipment, the low maintenance requirements, the performance / significant savings, and the great customer service we receive from Didion International,” explains Bentonville Casting president Chris Hines.

Now, Bentonville Casting has replaced the MD-50 machine with a new, model MD-80 Mark 5 rotary media drum. Hines explains: “The benefits we realized from the MD-80 Mark 5 machine are that we can now run larger castings that were too big for the MD-50, and we have less new sand additions, as the machine double screens the sand to ‘minus 3/8’.”

Hines adds that the rotary drum makes sand quality better because of its core sand and tramp metal discharge option, and that the castings are protected better than in the previous machine, because of the larger size of the media bed.

“I immediately noticed how much more robust the machine was and the number of improvements that Didion had made over the older machine,” offers Bob Jaskie, who manager Bentonville Casting’s molding and melting operations.

Among the benefits of Bentonville Castings’ new rotary drum is a contoured configuration that suits its line of larger castings.

“We already appreciated the savings and how little maintenance the older model MD-50 required, getting over 10 years life out of the liners,” says Jaskie, “so when we saw the new style, thicker interlock liners we were really impressed. The new contoured configuration proved to be better for our larger castings. We use to have to manually knock out the cores from the castings produced on our cope-and-drag line, and now it is done automatically in the MD-80 Mark 5.”

Jaskie says the foundry’s return sand now is “fluffy and more consistent. The core butts, tramp metal, and debris are automatically and continuously purged from our sand, which improves our casting quality. We also now have cleaner castings with less flash going into the finishing department, as well as cleaner returns going back for remelt.”

Hines says Bentonville Casting is committed to continuous improvement efforts, and says his company is “always thinking and looking for ways to make our foundry operations more efficient.

“This recent installation is a great example of our commitment to our customers that we are continually reinvesting and modernizing our plant,” he concludes.