Picking and sorting materials by hand at a recycling center generally is a dirty and dangerous job. Officials at construction and demolition (C&D) materials recycler and hauler Recon Services say the company is improving efficiency and safety with the addition in April of a ZenRobotics sorting line at its 973 Materials facility in Del Valle, Texas.
Recon operates Recon Recycling, a concrete crushing operation; 973 Materials, a concrete, asphalt and brick recycler; hauling company Recon Services; and CD Metal Recycling. It employs 70 people. Recon is one of 20 U.S. companies validated by the Recycling Certification Institute, Sacramento, California, to recycle C&D materials.
The facility is the first in the U.S. to install the technology, which automates the sorting of a wide range of materials, including a variety of plastics, such as the rigid polyvinyl chloride (PVC) used in construction applications.
Recon worked with Westminster, Colorado-based Plexus Recycling Technologies, which distributes the ZenRobotics equipment line for Helsinki-based ZenRobotics Ltd.
Recon Services learned about Zen- Robotics at a trade show last year. The recycler, led by owner Walter Biel, had plans to build a new line and decided the robotic option was a perfect fit. Assuming it operates 16 hours per day, Recon could save about $4.5 million in labor costs over the course of the lease, Biel says.
“It’s a situation of being more efficient,” says Will Hancock, vice president of operations for Plexus. “And it’s really hard to try and keep good [worker] health in a job that no one wants. With the robots, [Biel] can run 24 hours, seven days a week. There’s no holiday time; there’s nothing of that nature, so now he’s able to run longer, process more material, get purer streams of material as well.”
The robotic sorting line comes in three models: ZRR1, ZRR2 and ZRR3, with the number designating the number of arms.
Recon is leasing a ZRR2; Hancock says a two-arm system is typical. The robots can discriminate between and pick any number of materials; but, because they operate in an area of just 6.5 feet by 6.5 feet, they are limited in the number of bins they can fill.
“You could do a hundred different applications, and it all depends on what your bin spacing is,” he says.
At the Recon plant, the robots pick 12 different kinds of materials.
The ZenRobotics units can separate large objects weighing up to 45 pounds. Their smart grippers open from 0.75 inch to 25 inches, allowing them to sort objects of various sizes and shapes.
With the Recon setup, the robots can separate plastics based on polymer, color, shape and size. “We can actually send cleaner batches to the system and make optical sorting much more efficient,” Hancock says.
Biel says all his employees are on board with the move, and he’s looking at the displacement of human pickers as an opportunity to provide these employees with better jobs. “We’re not laying anybody off,” he says. “We’re really enhancing our system to let our existing employees work safer and give them some different opportunities to be put in a different place on our site to be more productive.”
Hancock says in a best-case scenario, humans can make 800 picks an hour, but that rate gradually declines as the day wears on and fatigue sets in. The robots pick at a consistent rate of 2,000 items per hour.
Recon bought additional equipment for its 973 Materials facility—a density separator and a triple-deck finger screen—from Canadian firm Sparta Manufacturing, Notre-Dame, New Brunswick.
Plexus is leasing the equipment to Recon for five years; the purchase price of a ZRR2 is about $1 million. A lease is preferable because the technology is constantly changing, Hancock says.
He says once the new robotic operation is running, Plexus will work to teach the robots. “We say, ‘This is wood, we don’t want to pick this; this is steel, this is PVC, this is rigid plastics, these are nonrecyclables,’ things of that nature.” Then the robots are taught to pull contamination out of the pile.
How much will the robotics improve Recon’s recycling capability? “We’re hoping it’s going to double what we’re doing right now,” Biel says.
The robots also will be able to separate some items Recon Services didn’t pull before the installation, such as different grades of plastic. They can do that because each of the arms can pull six different fractions (of the waste stream). Typically, workers are picking one fraction. “Most of our plastic goes to the landfill,” he says. “Now, we would just change the robots, train them to pick whatever plastic we want and let them do it. So, it could give us some opportunity that could expand our operations.”
Hancock says the robots consume relatively little electricity—as little as 10 to 20 kilowatts per hour for the entire system.
The Plexus vice president emphasizes that the company’s goal isn’t to replace existing plastic recycling systems that represent a large investment. “We are just able to provide a much cleaner stream to those recyclers where they run 97 percent PET (polyethylene terephthalate), that’s only going to make their offices that much more efficient.”
Biel says, “It’s definitely going to improve our business. It’s a decision that we made and are very excited about moving forward with, with no hesitation at all.”