Robot picks smaller 8-38 lb cases individually, and palletizes them at a line rate of 10 per minute (600 per hour). Robot picks tall, narrow 20-lb cases two at a time and palletizes them at a rate of 20 per minute (1,200 per hour). Robot system reliably performs back-breaking palletizing job that people did not want to do. Employee turnover is reduced, employee satisfaction is increased, and injuries are significantly reduced. Palletizing robot enabled plant to increase production. As a result, unit cost decreased and company was able to hire more workers for processing line. System changeover is quick and easy; operator simply selects different robot program using robot teach pendant and the system is ready to run the next batch.
Project Challenges
- Reduce high employee turnover due to high-volume manual palletizing and also reduce lifting and repetitive motion injuries.
- Increase productivity and reliability, while producing consistent loads.
- Palletize sealed cardboard cases containing 18 different types of product onto wooden pallets at a rate of up to 12,000 cases per day. Pallet layers contain 10-21 cases, depending on the product and stacking patterns vary. Products are batch run and only one type of product goes on a pallet. Cases weigh up to 44.1 kg (20 lbs) each.
- Accommodate seven different sizes of cardboard cases, with dimensions ranging from 171.5-320.7 mm W x 311.2-431.8 mm L x 146.1-254 mm H (6.8"-12.6" W x 12.3"-17" L x 5.8"-10" H).
Motoman Robotics Solution
Motoman Robotics provided a custom SP100X palletizing system, including:
- Four-axis Motoman SPX100X robot with XRC 2001 controller.
- Robot base riser.
- Custom end-of-arm tooling, consisting of a multi-function single-zone vacuum gripper with a pneumatically actuated side plate.
- Single-lane powered infeed conveyor with sensors to indicate case presence and proper location.
- OMRON Zen programmable logic controller (to run conveyor photo eyes, gate system, and operator pushbutton stations).
- (2) Pallet stations.
- (2) Operator stations (one at each pallet station).
- Cell safeguarding package, including woven wire safety fence, and light curtains to protect personnel from entering the robot’s work envelope during operation.
Fixtures/Tooling Details
Custom-designed multi-function gripper uses a single-zone vacuum gripper along with a pneumatically actuated mechanical side plate to securely grip and transfer the cases, regardless of their size or weight. The robot gripper picks the smaller, lighter cases that weigh 3.6-17.2 kg (8-38 lbs) each individually, and palletizes them at a line rate of 10 per minute (600 per hour). The robot palletizes the tall, narrow 9.1-kg (20-lb) cases that each contain two 4-liter/1-gallon jars two at a time. Design uses both vacuum and side plate grippers to ensure that the robot will never drop a case, preventing breakage of the jars of pickled food product inside the cases.
Ref: ACS-081