Overhead handling: Head’s up for productivity
Square footage is expensive and always at a premium in every facility—whether the application is manufacturing, storage or distribution. For that reason, companies are looking overhead for movement of increased productivity, enhanced ergonomics and more efficient handling of goods in single item and pallet load quantities.
Whether in e-commerce or omni-channel fulfillment of individual items, bulk transport of pallet loads without forklifts, or discrete vertical lifting of work-in-process, the latest developments overhead technologies are maximizing both space and handling flexibility.
Pouch sorters ideal for e-commerce, omni-channel fulfillment
Pouch (or pocket) sorters consist of hanging carriers (also called shuttles or backbones, depending on the supplier) that travel on rollers—powered with a combination of electricity and gravity—on rail, and an individual pouch that hangs beneath each carrier.
Because they are soft and flexible, each pouch can handle single units in a variety of shapes and sizes and weighing up to 22.5 pounds. That makes pouch sorters ideal for e-commerce and omni-channel retail fulfillment applications, says Barry Evans, vice president of sales at WRH Global Americas.
“Each pouch is individually identified by bar code or RFID tag and individually controlled to be conveyed into different buffer loops or storage lanes as needed,” Evans says.
Unlike belt conveyor that uses a lot of floor space, the pouch sorters travel overhead in installations customized to maximize building cube. Multiple loops can be constructed on different planes; the only limiting factors being the height of the building and the distance from the bottom of the pouch to the top of the rail, Evans adds. “Facilities are looking at this solution as a means to avoid a footprint expansion.”
Pouch sorters are offshoots of overhead garment-on-hanger (GOH) systems that move and transfer items of apparel packaged for direct-to-store replenishment or e-commerce orders. The pouches themselves were initially introduced as a means to handle items difficult to handle on traditional flat processing systems, such as belts, purses or shoes, explains Krish Nathan, CEO of SDI Systems. “In omni-channel retail operations, we see potential for both systems to be implemented together; the time to consider a pouch system is when you have a bigger variety of products than just garment-on-hanger.”
Additionally, the pouch sorters are fast. “They’re high-speed, handling up to 10,000 pouches per hour,” Nathan says, adding that the sorters are integrated with sophisticated software that uses algorithms to determine which items belong to an e-commerce or store replenishment order. “The software routes the appropriate pouches to packers on the floor.”
Further, pouch sorters allow for dynamic product buffering and waveless picking, says Joseph Harris, director of engineering at KNAPP Logistics Automation. “You can decouple picking and packing with this system,” he says. “We install pouch sorters with multiple induction points located at strategic points throughout a facility, including on each level of every pick module, to minimize the need for personnel to travel throughout the facility.”
Induction into the pouches can be either semi- or fully automated, with the pouches opened automatically and the scanning and insertion of each item done by either a person or a machine. Packing sequence parameters can be specified such as building an individual parcel to place heavier items on the bottom and lighter items on top, or for store aisle replenishment.
“These systems deliver parallel processing of order picking, sorting and packing, which shortens order cycle times drastically,” Harris adds. “With wave picking, it might take up to three hours to get an order through your system; with the flexibility of individual item control from pouch sorters and their software, it’s more like 15 to 20 minutes. Certain orders can be prioritized as needed or order cut-off times can be extended, for example.”
As an operation’s needs grow, the system itself can be expanded with the addition of more carriers and pouches. “It’s a very modular system with a low cost of entry, so they can be scaled up easily within an existing operation,” Harris adds, noting that systems can either be designed as a retrofit that complements current technologies or in greenfield construction of a new facility.
Additionally, notes Evans, the carriers have applications beyond distribution. Because they can be outfitted with different tooling—such as clips, trays or totes—they can be used in manufacturing as well. For moving larger items, two carriers can be combined on a single hanger mechanism to transport loads up to 40 pounds.
“For example, in Europe, we have a customer using the system with a clip in a completely automated process, transferring empty tubes from a single forming machine to a series of multiple filling machines where they are filled with caulk,” he says. “Because the machine that makes the tubes is faster than the machine that fills the tubes, the system is used for buffering in between at a ratio of 3:1.”
Electrified monorails move full palletloads, large products overhead
When it comes to moving full palletloads of product across a long distance within a facility—and at speeds that can keep up with a high-production, high-capacity operation—overhead electrified monorails are ideal says Richard Goelz, regional account manager at Eisenmann Corp.
“Compared to other types of conveyor, such as roller or belt, the electrified monorail can run at speeds upward of 600 feet per minute and move as many as 400 pallets per hour,” he explains. “When you’re going a long distance, it minimizes the amount of work-in-process being moved around and opens up access to areas that would otherwise be blocked by floor-based conveyance systems.”
Within distribution centers, the systems are more common in Europe but are starting to make inroads into North America. That’s because—when moving pallets long distances—the overall cost to install, maintain and run the system is lower than a conventional pallet conveyor.
“There are fewer moving parts and motors, both of which contribute to easier maintenance and longer lifespan of the equipment,” Goelz says, adding that with the advent of inductively powered, no-contact carriers that eliminate contact shoes, brushes and bus bars for power transmission, there is no longer any maintenance associated with powering the carriers.
Electrified monorail can also directly interface with stacker cranes in an automated storage and retrieval system (AS/RS) as a point of transfer for pallets entering and exiting the system. Further, because the system is always connected to power, it supports powered devices that flexibly accommodate a variety of manufacturing processes. These might include lifts, turntables or conveyor for worker ergonomics.
“An appliance manufacturer integrated a lift into their carrier to raise or lower the product to the ideal level for the worker assembling or inspecting it,” he explains. “They’re also common in automotive assembly, rotating an entire vehicle during the robotic application of paint or sealant.”
Other features include safety bumpers or photo-eyes on the carriers to determine if an obstacle intersects the monorail’s travel path, then trigger the system to slow down or stop. “If people are working around the system, we add safety barriers because of their high operating speeds,” he adds.
Wire rope hoists for low-clearance applications give greater load control
As more frequent up-and-down movement of lower weight, discrete loads in low-headroom applications grows, a new type of wire rope hoist offers features that address both concerns.
“Generally speaking, wire rope hoists have a much higher capacity range than an electric chain hoist. Our products go from a half ton to 60 tons, but roughly 50% of the wire rope hoists sold are for the 5- to 10-ton load handling market,” says Paul Smielecki, marketing manager at Columbus McKinnon, noting that most operations are moving lighter loads more frequently. “As the capacities go higher, the frequency of use decreases.”
In addition to a design that allows it to raise and lower loads in tight spaces, the company’s new Load King LT hoist incorporates variable frequency drives in lieu of contact-based control. “The drives give the operator more flexibility in controlling the load than contact controls,” he says. “The difference is similar to flicking a light switch on and off versus turning a dimmer knob.”
That increased control allows for smooth acceleration and deceleration, plus controlled speed for gentler handling of the load, creating a safer environment. Also, the variable frequency drive control minimizes wear on the hoist’s key components—including the brakes—for longer lifespan, less maintenance and lower total cost of ownership. “There’s also much greater precision in positioning,” adds John Vander Linden, global product manager at Columbus McKinnon. “All these benefits are drawing greater interest in variable frequency drive hoist technologies throughout manufacturing and materials handling operations.”
Going forward, Smielecki says, hoists will be outfitted with smart technologies that enable them to wirelessly communicate their status and other information to a centralized reporting system.
“Facilities managers will be able to use these details for scheduling of preventive maintenance, as well as to monitor the number of daily lifts, starts and stops to determine usage patterns,” he says. “We have that monitoring technology today; what’s currently in development is the ability to transmit that hoist data wirelessly. But it’s coming.”
Companies mentioned in this article
• Columbus McKinnon
• Eisenmann Corp.
• KNAPP Logistics Automation
• SDI Systems
• WRH Global Americas