The phrase “electromagnetic levitation conveyor” might conjure up images of a futuristic factory with floating production lines. But reality isn’t far from science fiction in this case.

Unlike conventional conveyors, which are driven by belts or chains, the Alpha-Lite system uses electromagnetic force for propulsion, indexing, queuing, and position sensing. The conveyor is a non-contact system. It uses rollers as guide, but there is no physical motor. Products are placed on pallets. A magnetic coil generates a magnetic force which interacts with permanent magnets on each pallet. As a result, pallet speed is easily controlled and the pallet can move bi-directionally with programmable acceleration or deceleration. The system is software-controlled. Each pallet has a unique ID address, so the control software can sense and avoid collisions.

Singapore-based PSB Technologieswww.psb-technologies.com Systems and Automation Centre (SAC) is using the conveyor in its customized high-precision, high-speed automation systems. “We are targeting the medical device industry for first applications. The flexibility and capability to precisely control individual pallets without vibration is suitable for applications such as contact lens production, syringes, or disposable kits. The conveyor is also a clean system, with few moving parts. It doesn’t generate many particles compared to standard systems,” says SAC vice president Yew Sang Chin.

According to Meng Kwang Han, PSB Technologies’ general manager, SAC first saw the conveyor technology at the Assembly Technology Expo Show in Chicago in 2007. “We had an existing automation project with bottlenecks. This technology offered a solution, so we immediately got in touch with the U.S.-based supplier,” he says.

PSB Technologies then tapped one of the Singapore government’s public-private partnership programs to integrate the conveyor into its automation products. “We received a grant from the Innovation Development Scheme, administered by Singapore’s Economic Development Board,” says Han. “Its function is to encourage Singapore-registered business entities to develop innovative products, processes, and applications. The grant helped defray our labor and material costs as well as the cost to engage an overseas consultant to help train our staff on the technology.”

Under the two companies' agreement, the supplier provides magnetic modules and PSB Technologies designs and configures the conveyor. The supplier provides collision-avoidance firmware and PSB Technologies develops the control software that provides the conveyor's on-demand, on-the-fly, bi-directional, and variable-speed capabilities.

As with any technology, the system has tradeoffs. The upfront investment is typically 30% higher than the cost of a traditional conveyor system, says Han. However, operating and maintenance costs are lower, so the ROI is typically five years or less. Lack of moving parts reduces downtime, cuts the need for inventory, and, ultimately, results in a longer lifecycle. The magnetic system needs more space between stations than a conventional system. However, it can run in both directions, so the conveyor can branch and split in ways that are impossible with a conventional conveyor.

Submitted by Susan Mucha, President, Powell-Mucha Consulting Inc.