Air-powered productivity
Air-powered productivity by Carl Kirkland Ever experienced equipment failure because your old-fashioned piston air compressor took an unscheduled break? Magor Mold swears by rotary vane compressors, and knows how to keep them on the clock.
June 1, 2008
Air-powered productivity by Carl Kirkland Ever experienced equipment failure because your old-fashioned piston air compressor took an unscheduled break? Magor Mold swears by rotary vane compressors, and knows how to keep them on the clock.
Magor Mold specializes in servicing and building high-cavitation, hot runner molds for medical disposables. |
Any equipment failures we experienced usually occurred because of compressed air problems,” says Hans Hermann, purchasing manager at Magor Mold (San Dimas, CA). “We may have been planning on running our equipment lights out ... overnight. But when one of our technicians comes in to set up a new job and there’s a failure, he has to restart and finish the job from the night before. So we’d be behind, behind as much as a day, and that’s a huge expense.”
But it’s an expense Magor Mold hasn’t had to pay for about five years now, since switching from piston driven air compressors to rotary vane compressors from Italy’s Mattei Compressors Ltd., supplied by their local distributor, Lans Company Inc. (Glendora, CA).
In a rotary vane compressor, the blades are guided in slots and held outward by centrifugal force. A thin film of oil between the blades and the stator wall forms a seal. A single vane between the delivery and intake ports prevents air escaping from high to low pressure.
A large volume of oil injected into the stator lubricates the moving parts and cools the air during compression, and it also seals the clearances between the rotor, stator, and end covers. Along the surface where the rotor touches the stator, the oil, pushed by the air pressure, slips into the gap between the compressor’s delivery ports and the adjacent blade, sealing it.
“The rotary vane design is much more efficient than our old piston compressors,” Hermann says. “Piston compressors go up to a pressure, shut off, let the tanks go down, and then the compressor starts again until the tanks go back up. So, if you want to keep your shop pressure at 120 psi, your piston compressor has to run from 150 to 130, and you regulate the shop to 120. What’s great about the rotaries is that they’ll run constantly at 125 psi, and you don’t need to have regulated air in the shop. Every 2 psi lower equates to a one percent savings in power consumption.”
He adds that the rotary vane compressors either can run continuously at full pressure, or automatically, internally cycling. When his compressor controls sense a pressure drop, for example when a machine goes down, it automatically shuts the compressor off.
Lights-out reliability
If you’re a regular IMM reader, you may recall Magor Mold. It’s a 40-year-old moldmaking company specializing in servicing, engineering, and building hot runner, multicavity tooling for tight-tolerance medical disposables and assemblies. It also supplies molds for molding LSR (Click here for an initial report). On average, the mold technicians at Magor Mold have anywhere from 30 to 35 years in the business.
The company was purchased by Wolfgang Buehler, Magor’s president, in 1988. Buehler also was instrumental in launching a medical parts molder, Apec (Baldwin Park, CA), which recently has grown into multinational status by launching Apec Asia in Shenzhen, China.
Efficient Mattei rotary vane air compressors help keep Magor Mold running 24/7. |
Magor Mold runs highly automated high-speed CNC equipment from suppliers that include Charmilles and Mitsubishi under the 24-ft-high ceiling in its 30,000 ft2, air-conditioned facility.
“We depend on having compressed air systems that are very consistent, very reliable,” says Hermann. “We have machines that require a high volume of air 24/7, because we do a lot of lights-out manufacturing. So, to get that reliability, we’re very willing to invest in the right compressor system.”
Magor Mold started out with a 30-hp model Mattei air compressor that it purchased in 2002. As the company grew and added machinery, there were concerns that the Mattei’s service requirements could interfere with the company’s production schedules. So he contacted his distributor.
“We told Lans that we wanted a backup compressor to minimize downtime. They’d been providing us with a diesel-powered unit for backup, but if you’re going to schedule maintenance around the availability of your vendor’s backup compressor, that may not have always fit into our production schedule, and that could put us at risk of a failure.”
So, Magor Mold purchased a second 30-hp Mattei compressor. If its primary compressor requires servicing, it simply switches over to the auxiliary unit without missing a beat. Service calls have no affect on its production schedules.
Regardless, to preclude the need for service calls, Hermann says Magor Mold is very conscientious about preventive maintenance. It pays particular attention to keeping contaminants like moisture and oil out of its air compressors.
“The pneumatics of our machines would foul and deteriorate pretty quickly if we didn’t use preventive measures,” he says. All the air is run through a moisture collection tank that’s drained every day. The air’s also routed through an air drier.”
Although the Mattei compressors reportedly have very little oil carry-over, Magor Mold also runs its shop air through an oil-removal filter, just in case.
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