Robots and vision-based quality system provide overall efficiency of 99.7%.
Fruit pies on the belt conveyor will be inspected and packaged by the Sigpack system. Source: Sigpack Systems.
The Bama Companies, 2004 recipient of the Malcolm Baldrige National Quality Award, has been making handheld turnovers and pies for more than 40 years. Recently, it installed an 18-robot system with a vision-based quality system to package pies as they arrived from processing.
Several potential suppliers were evaluated for this automation project. “Bama chose to partner with Sigpack due to the flexibility the robot system offered, by picking the pies directly from the main belt and placing them into the cases,” says Bama’s Vice President of Engineering Randy Roark. “Others were suggesting row distribution solutions, which involved multiple steps and greater complexity. Sigpack streamlined the process.”
Challenges in the project included a frozen product and its chilled environment, a high production rate, complex product inspection and a cinnamon topping. Production efficiency, quality control and sanitation were key considerations. “A test at Bama showed it required six people for a proper visual inspection of the product,” says Roark. “Prior to the design phase of the project, Sigpack Systems conducted lab tests, with actual frozen product, to review Bama’s inspection criteria, as well as to confirm the pick reliability of the gripping tool.”
The line, which runs at 1,400 pies per minute, incorporates a state-of-the-art vision quality control system, which ensures that only products of exact quality are accepted from the process equipment before being placed into cases.
The frozen fruit pies exit the Bama freezer in rows of 20. After a series of belt turns, the products enter the packaging room, where temperatures and humidity are controlled. The rows of pies are separated via spreader belts and proceed under an overhead camera, which examines the entire product flow.
Nine Model XR31 Delta robots are positioned on opposite sides of the main packaging belt. This layout facilitates complete pick coverage, reduces overlap and limits excess robot movement. The design also allows for easy operator and maintenance access to each robot within the system. The robots use a custom-designed vacuum picker to gently pick and place pies into the cases, which move in a counter-flow direction to the main belt. The system is also equipped with special filters to assist with the collection and removal of excess cinnamon dust. “The line speed was previously dictated by available staff. ” Roark notes. “Now, the robots are always ready to perform and we can maintain a more consistent line speed and production flow. The added benefit is reduced product variability.”
The vision system acquires a detailed image of the product carpet at the beginning of the line. Every single apple pie is then evaluated for acceptability, including minimum and maximum length and width tolerances, partial products, and overlapping or connected products. Additionally, the number, shape and position of the slits in the surface of the pies are checked, as well as the quality of the topping. The positions of all acceptable products are communicated to every robot. Each robot detects the exact position of the good products with its own vision system and picks, based upon a sophisticated strategy, the best product for the cycle. Advantages of this centralized quality control compared to an individual control in each robot cell are more reliable operation through easier calibration and safer retrace ability of bad products.
For more information, Tom Pecht, 920-662-1258, firstname.lastname@example.org.