Mark Passarell, superintendent of Greenbridge’s Evergreen recycling division, has a hard time taking his eyes off the plant’s new recycling robots used to sort plastic bottles for recycling. Why? Because the six robots from AMP Robotics, with their long arms and suction cup grippers, are not only super fast, they’re also super accurate. Passarell has one word to describe them:
The robots’ pick rate is determined by the flow rate of material running through the processing line and the accuracy of picks. See Evergreen’s robots in action here.
Like most recyclers, Evergreen had relied on manual sorting since opening in 1998. But as volumes have grown—Evergreen collects and processes more than one billion post-consumer PET bottles a year—manual sorting no longer made sense.
“Sorting is the most tedious job we have at Evergreen. The shifts are 12 hours long. The work is repetitious and full of mundane repititious work Our people were really good picking 30 to 40 bottles per minute but it’s hard to keep that up,” he explains. “When the robots were installed, we cross-trained our team members and moved them to other jobs in the plant.”
There’s another reason parent company Greenbridge needed to “amp up” recycling with robotics. In May, Evergreen is breaking ground on a major expansion. The company is adding a third rPET manufacturing line, increasing annual capacity of food-grade rPET pellet and flake to 80 million pounds a year. The added sorting capacity of the robots will support Evergreen’s need for more PET bottles to recycle into rPET for new packaging.
Hand-in-Glove: PET recycling and rPET manufacturing
Anticipating the expansion of its rPET manufacturing capacity, Greenbridge began exploring the idea of adding robotics at Evergreen in early 2020 to expand its recycling capacity. Accelerating sorting would enable more PET recycling. AMP Robotics, a Colorado-based company and pioneer in artificial intelligence (AI), robotics, and infrastructure for the waste industry, was selected as the vendor-partner for Evergreen’s robots.
“AMP Robotics had a history on the front-end sorting bottles from trash. What we were asking them to do was more specific: pull clear PET bottles from a mixed stream of bottles. That’s a more challenging process,” Passarell says.
AMP was up to Evergreen’s challenge, leveraging its experience in artificial intelligence to teach the robots to recognize clear bottles from green or opaque bottles. During the development process, a team from Evergreen traveled to the AMP facility to conduct preliminary testing. This included running actual waste stream from Evergreen through the AMP robotics. Test results led to important adjustments.
The custom-built equipment was installed at Evergreen in November 2020, five in the final sort area and the sixth in the trash sort area as the final chance to pick good bottles. The AMP-Evergreen team worked around the clock to install and test the robots. Since then, AMP has met with Evergreen on a weekly basis to continue to make enhancements to the robots.
Passarell says the robots are revolutionizing Evergreen’s recycling process by making bottle sorting faster and more accurate. “The net result is we’re getting more PET bottle picks from the trash stream. We want to recover all we can.”
In addition to PET, AMP’s AI-powered robotics also precisely identify and capture plastics including HDPE, LDPE, polypropylene, and polystyrene, sorting by color, clarity and opacity. AMP robots also recognize different form factors such as lids, tubs, clamshells, cups, and more. The technology can be applied to cardboard, paper, cans, cartons, and many other containers and packaging types reclaimed for raw material processing.