Relentless competition and an influx of off-shore castings has hurt the U.S. and Canadian foundry industries, according to Arnie Bloomquist, president of foundry-equipment manufacturer IMF North America, Muskegon, Mich. These producers are further hampered by outdated equipment and inefficient processes that require substantial manpower and material-handling equipment, he says.
To survive, manufacturers are forced to find creative ways to cut costs and increase productivity. The good news, Bloomquist says, “Those that have taken risks and invested in automation see it positively affects the bottom line.”
One example he cites is Martinsville, Illinoisbased Rowe Foundry (www.rowefoundry.com), where a substantial investment in automated machinery boosted production 150%. The foundry makes gray-iron castings for construction, heavyequipment, machine-tool, and agricultural uses.
A key addition was the Fast Loop System from IMF, Luino, Italy (www.imf.it), that automates the moldmaking process. Modular equipment and Allen-Bradley PLCs let the company tailor the system to meet specific production needs.
Fast Loop starts with a pattern-management system using RSView software from Rockwell Automation, Milwaukee (www.rockwell.com), that facilitates pattern storage and retrieval. A computer database stores production specifications for each pattern. It is said to handle even short runs with little downtime.
An operator directs the mixer head via joystick to fill pattern boxes with sand. These get compacted on a vibrating table. Compaction time and vibration frequency are set for each pattern according to mold qualities, and a robotic strickling tool removes excess material. Molds then move to curing stations, taking advantage of the latest chemical binders that harden quickly, then to a rollover/stripping machine that separates the sand mold and pattern. Patterns are reused or returned to storage, while the molds head to the painting line.
There, tip-up machines let operators efficiently apply a zircon spray coating that improves the casting-finish. A steel-slat conveyor carries the molds through a drying oven and, after setting cores, automated handling equipment precisely closes the mold halves to ensure accurate parting-line fit-up.
Conveyors transport the finished molds to the pouring area where they are filled with molten metal and, when cool, a shakeout system separates the castings. Manipulators recover the castings for finishing operations while the sand goes to a reclamation plant for subsequent reuse.
Production rates with the Fast Loop System range from 8 to 30 molds/hr depending on size, which can range from 800 800 100 mm to 1,800 3,400 680 mm.
It produces up to 15 molds/hr at Rowe. As a result, the company has seen a significant improvement in casting through-put and lower scrap rates, according to Glenn Kuehnel, the foundry manager. In addition, the new system has shortened lead-times, improved customer service, and reduced labor costs by approximately 50%.