Packaging changes constantly, so packing machines must be sufficiently flexible and versatile to output myriad wrappings — plus operate at high speeds and accuracy. Even slight errors can disrupt a manufacturing line and waste materials, particularly at the end of a process. Here we review two examples of electromechanical motors replacing pneumatics in these designs.
Consider one case packer that puts pillow bags into corrugated cartons or reusable plastic cartons (RPCs) at up to 80 1-lb bags per min., but includes zero pneumatics. Instead, all motion on the multi-axis SD55 Case Packer from Impax Automation, Bakersfield, Calif., is servo driven — for precise motion and accommodation of various bag dimensions and carton sizes with minimal changeover (whether for a standard bag-size change using preprogrammed recipes, or a new product.)
Transmitting motor power and aiding in precise motion control is a right-angle nickel-plated HG+ gearbox from Wittenstein Inc., Bartlett, Ill. In fact, the original HG+ gearbox was the first hypoid gear reducer developed for high-speed applications; now it's applied in a variety of designs, including the SD55 Case Packer and associated carton handling and indexing systems.
Meanwhile, the SD55 frame incorporates control hardware, electrical, and communication cabling into structural elements in a compact 5-ft2 footprint. Enclosures feature sloped tops to shed moisture away from costly electrical gear.
Kicking pneumatics to the curb
Servomotors are replacing certain pneumatics in other food-specific cartoner applications as well. Packaging these items into cartons takes finesse, and even small details can become major manufacturing obstacles. For example, some cartoning applications require that the endflaps of each carton are opened at exactly the right time. To this end, some machines use flap kickers — fingerlike devices that deflect carton flaps outward to ensure that product is smoothly loaded into containers.
One designer is Kliklok-Woodman, a manufacturer of food-packaging technology with operations in Decatur, Ga. The company's engineers recently developed a new iteration of their CELOX Endload Cartoner, which sits at the end of a production line and fills cartons with packaged foods, and then seals them at up to 325 cartons per min. The design includes a servo-driven flap kicker, to keep up with the fast pace; the original used a flap kicker powered by a pneumatic cylinder, which wore down quickly when used at high speeds.
The engineers used integrated software to design the flap kicker, with digital modeling and simulation to help size motion components to energy consumption, speed, and throughput requirements.
“The flap kicker's motion is solely dependent upon the size of the particular carton and the size of its flaps,” says Florin Bruda, Kliklok-Woodman mechanical engineer. “So I plugged in specific end-user requirements and quickly tested different servomotor sizes to find the right one, avoiding the need to test each option on a physical machine.”
Kliklok-Woodman engineers chose an Allen-Bradley B310P MP-Series Food Grade (MPF) servomotor because it can withstand high-pressure caustic washdowns and is more reliable than a pneumatic cylinder.
For details on the alpha HG+ gearbox, visit wittenstein-us.com. View Impax Automation videos of the SD55 in action at impaxautomation.com. For more information on the flap kicker application, visit rockwellautomation.com.