Highly flexible system meets all project goals and requirements. System consists of two robot palletizing cells; each serves two product filling lines. System meets required cycle time, palletizing six bags per minute (24 bags per minute total). Depending on bag size and orientation, each robot picks one, two or three bags at a time, with each cycle averaging approximately 10 seconds per pick and place. Robots provide improved productivity, reliable production, and tighter, more uniform and stable pallet loads. Robots significantly decrease need for direct labor, while improving safety by reducing injuries.
Project Challenges
- Fully automated palletizing line to reduce direct labor costs and improve safety by reducing lifting and repetitive motion injuries.
- Improve productivity, and create more consistent and stable loads.
- Palletize bagged product from four production lines with a maximum throughput of six bags per minute per line (24 bags per minute total).
- Palletize filled valve paper bags (polylined) of product that typically weigh approximately 22.7 kg (50 lbs), but occasionally can weigh up to 25 kg (55 lbs).
- Handle a variety of bag sizes and dimensions. Filled bags range from 558.8 mm L x 393.7 mm W x 165.1 mm H (22" L x 15.5" W x 6.5" H) to 863.6 mm L x 482.6 mm W x 190.5 mm H (34" L x 19" W x 7.5" H).
- Stack bags onto standard 1,219.2 mm L x 1,016 mm W (48"L x 40" W) wooden pallets into loads that are typically 10 layers high, but occasionally may be 12 layers high. Accommodate partial loads and maximize unit loads, as required.
Motoman Robotics Solution
Motoman Robotics provided a custom EPL300 palletizing system, including:
- (2) Motoman EPL300 “Expert Palletizing” robots with NX100 controllers. Each robot has robot base riser and custom base plate. Each serves two (customer-provided) infeed conveyors.
- (2) Custom end-of-arm tooling – fork-style grippers capable of handling one, two or three bags at a time, depending on product size and orientation.
- Cell guarding package that meets ANSI/RIA R15.06-1999 safety standard. Includes 3.66-m (12') H woven-wire perimeter safety fence; three access gates with positive-break safety switches; self-muting light grid at shuttle-car drop off to stretch-wrapper infeed; and two light curtains (one across the back of each palletizing cell).
- NOTE: Customer supplied bag accumulation conveyors, bag centering conveyors, bag orientation conveyors, bag pick zone conveyors, and load build pallet conveyors (two of each per cell), and was also responsible for electrical controls, including remote PLC used to control the conveyors. Customer was also responsible for shuttle-car delivery of an empty pallet with slip sheet to each of the four pallet build stations and removal of full pallets, pallet dispenser, slip sheet rack, etc. One cell was fully integrated, set-up and run-off at Motoman and the second cell was functionally run-off.
Fixtures/Tooling Details
Motoman Robotics provided two sets of custom end-of-arm tooling consisting of fork-style grippers. Gripper combs fit between the conveyor rollers to lift bags, then retract during load building. A bag hold-down device keeps bags in place during robot motion. Grippers are capable of lifting two bags. Depending on product bag size and orientation, grippers pick single bags, two bags oriented long-ways (end-to-end) or three bags wide (side-by-side). Robot grippers do not handle slip sheets or pallets.
Ref: ACS-086