From grocery store checkout lanes and ski lifts to moving sidewalks and airport baggage systems, conveyors are part and parcel of modern life. Within industrial automation, conveyor systems are also indispensable for moving goods around warehouses, keeping assembly lines humming, loading and unloading trucks and ships, and facilitating a myriad of other material handling chores. Since 1905, when Richard Sutcliffe first fashioned conveyor belts for use in coalmines, conveyors have become a mainstay in mining operations worldwide. Here we explore some modern conveying applications, as well as several new products used in conveyors and their support systems.
Innovative conveyor spurs stick pack success
Just as bottled water sales in the U.S. have increased dramatically over the past 10 years, so too have single-serve powdered drink products that consumers mix directly into their water bottles. T.H.E.M. (Technical Help in Engineering and Marketing), Marlton, N.J., is a leading stick packager for food, beverage, and healthcare companies around the world. However, filling thousands of stick packs per day is no easy task, which is why the company turned to Dorner Manufacturing Corp., Hartland, Wis., and Yeaman Machine Technologies Inc., Elk Grove Village, Ill., to design a new stick-packaging machine. Although stick packs have been widely used in Asia and Europe since the 1970s, they didn't catch on in the U.S. until the late 1990s when a well-known food manufacturer introduced a grab-and-go yogurt product in a tube.
T.H.E.M. was in prime position to help launch the stick pack in 1996, when it became the exclusive U.S. partner of Sanko Stick Packaging, a Japan-based company at the forefront of stick-packaging equipment. Since then, T.H.E.M. has filled millions of stick packs for several global brands containing everything from sugar and baby formula to artificial sweeteners and flavored drink mixes.
To help improve efficiency, the company looked at adding two new vertical cartoners from Yeaman Machine. In other stick-packaging lines, T.H.E.M. employees would count up to 20 sticks at a time and pack them into a box on a moving cartoner. This process often required more than 20 employees to huddle around the cartoner picking, counting, and packing sticks. Another problem is that this type of cartoning line requires significant change-part tooling and downtime to switch between different carton sizes.
“My thought was to separate the picking and counting of sticks from loading them into the carton,” recalls Brian Stock, vice president of sales and marketing for Yeaman Machine. “Our idea, with the help of a Dorner LPZ-series conveyor, was to count sticks and place the grouped counts between cleats on the conveyor. The LPZ then transports grouped sticks to operators around the cartoner's load area, where these workers simply pick up the grouped counts and load them into the carton. This design maintains the same production rate, but with fewer employees, faster change-over times, and a smaller initial capital investment due to the reduction in tooling costs.”
Each system features a 25-ft LPZ conveyor attached to a CVC-600/1200 vertical hand load cartoner from Yeaman Machine. The first 20 ft of the conveyor are on floor level to allow up to eight employees to preload 10 stick packs and place them on the conveyor. To keep each bundle separate, the conveyor is outfitted with a 2-in. cleated urethane belt. Bundles are then moved on the conveyor up a 15° angle to the loading area, where up to six employees package them into boxes.
Pillow blocks allow easy, cheesy conveying
Preparing cheese for grocery store shelves involves many steps, one of which includes slicing large blocks of cheese into smaller portions. Often, this repackaging occurs at automated grocery distribution plants. In one such application, pillow blocks from igus Inc., East Providence, R.I., are used on a cutting machine's input guidance mechanism to center hunks of cheese weighing as much as 187 lb — and ensure that wheels and chunks are sliced properly.
The arms of the centralizing unit are mounted on the pillow blocks and then guided smoothly up from beneath a conveyor. The guides can act as potential bacteria traps, and are inaccessible for maintenance — so they are subjected to severe washdowns. Fortunately, the maintenance-free DryLin pillow blocks are water and chemical resistant, will not corrode, and have virtually no cavities in which food can lodge. For more information, visit www.igus.com.
Conveying solutions online
Common motor requirements for conveyor systems include low vibration, precise stopping, environment resistance, suitable acceleration/deceleration capabilities, and position retention. Various motors are used for high-precision feed and digital control, but dust-resistant, watertight ac motors are suitable when environmental elements are a factor. To view several conveyor systems in action, check out the nifty animations and motor choices featured at Oriental Motor's website, www.orientalmotor.com/applications/index.html.
Kinder, gentler conveying
A new module lifts and lowers crushable packages and cartons more gently than wedge conveyors. Made by Bosch Rexroth Corp., Buchanan, Mich., the modules work with the company's VarioFlow Modular Conveyor Systems. The new elevators and lowerators combine non-marring flocked chain with soft overhead rollers for gentle upward or downward product transport through vertical curves, including those with steep angles. For more information, visit www.boschrexroth-us.com.
Vector duty motor conveys efficiency
The newly released TENV Vector Duty Motor line from WEG Electric Corp., Suwanee, Ga., is designed to deliver a 1,000:1 constant torque, even over a wide speed range. The efficient, inverter-duty motors are suited to conveyors, cranes and hoists, extruders, and more. Special features include numerous mounting configurations, thermistors, a space heater, IP56, 65, and 66 ratings, tropicalized internal painting, special shaft seals, encoder, and brake. For more information, visit www.weg.net.
Ball transfer units handle heavy loads
J.W. Winco Inc., New Berlin, Wis., now makes a series of GN 509 steel and stainless ball transfer units. These metric-sized components are typically used on conveyor tracks, to enable linear or rotary movement of heavy loads. Three versions are available; all are RoHS compliant. Transfer units have a load capacity of 500 to 2,000 N, depending on size and type. For more information, visit www.jwwinco.com.