Summer 2023 Newsletter

Volume 10, Issue 1

These are the Main Technological Solutions Available in Canada for Carton Sorting

As many material recovery facilities (MRFs) across the country prepare to meet the new requirements of producer responsibility organizations (PROs) as part of the various provincial extended producer responsibility (EPR) programs, we thought it would be interesting to provide an overview of the main technological solutions currently available in Canada that can be applied to carton sorting. We asked five leading equipment manufacturers present in the Canadian market—Bulk Handling Systems (BHS), Machinex, PellencST, Sherbrooke OEM and TOMRA Recycling Sorting—to describe their offerings.

The champion of carton sorting

The most popular piece of equipment for sorting cartons is undoubtedly the optical sorter. All five equipment manufacturers consulted offer at least one model. In a nutshell, these sorters use spectrometry to analyze the unique light signature produced by each material. When objects they have been programmed to recognize enter them, such as cartons, they activate precise air blasts that project these objects along conveyors to redirect them to other streams of the sorting chain. They do this at an unprecedented speed that can exceed several hundred objects per minute.

Of course, each model of optical sorter has its own set of strengths that their manufacturer emphasizes. TOMRA Recycling Sorting puts the focus, for example, on the fact that its air nozzles are fast enough to eject 1,200 objects per metre of sorting width per minute. As for Machinex, one of the main advantages of its sorter is its generous access to internal mechanisms for easy maintenance. Bulk Handling Systems mentions, among other things, the ability to incorporate its sorters into a compact, autonomous patented system that includes a recovery circuit for containers, including cartons. For its part, PellencST points to its “Future Proof” guarantee, which is said to ensure that the machines can incorporate the company’s future innovations related to the Industrial Internet of Things, digital watermarks and artificial intelligence. Lastly, Sherbrooke OEM is banking on the ability of its sorters to combine hyperspectral imaging, near-infrared (NIR) and artificial intelligence to achieve nearly 100% recognition rates.

Optical sorter models Mistral+ CONNECT from PellencST, EAGLE VIZION from Sherbrooke OEM, AUTOSORT from TOMRA Recycling Sorting, MACH Hyspec from Machinex and NRT from Bulk Handling Systems (BHS).

Clearly, there is a trend towards the inclusion of artificial intelligence in optical sorters, with the majority of manufacturers indicating that they make use of it in one way or another. In particular, these new features could help the machines better distinguish containers and packaging made with food-grade fibres and resins from objects that resemble them but are not suitable for food contact. This could then pave the way for the use of recycled fibres in cartons.

According to PellencST, optical sorters make “carton sorting one of the easiest separations to achieve in a MRF.” Sherbrooke OEM goes so far as to say that, from its point of view, optical sorting would even be “the only justifiable solution for carton sorting.” For those considering adding a new sorter to their existing facility, TOMRA suggests placing it at the end of the line where the majority of cartons tend to end up and where installation would be the least disruptive to operations. Although the volume of cartons in MRFs is significant, it is still relatively lower than many other materials, such as plastic containers. For this reason, carton recognition on these machines is frequently combined with that of other materials in order to leverage the optical sorter’s full potential.

Robots in support

In addition to optical sorters, two of the five equipment manufacturers surveyed, Bulk Handling Systems and Machinex, offer robots equipped with artificial intelligence that can also be used for the purposes we are interested in. It should be noted that there are also firms that specialize solely in these sorting robots, such as AMP Robotics and Waste Robotics, which we also interviewed for an article in the summer of 2021.

Because they are slower than optical sorters (e.g., 70 picks per minute), robots would be best suited for complementary use or when the quantities to be processed are smaller. They can be used for quality control; for example, to remove contaminants from the final stream of cartons or retrieve cartons that were not detected upstream and still find themselves in the waste stream.

Being more compact, robots can also be suitable for facilities that do not have the space to accommodate an optical sorter. We are told that robots can easily be installed on a manual sorting line without requiring prolonged shutdowns, allowing existing centres to add automated sorting for certain materials, such as cartons. Like optical sorters, they can be programmed to simultaneously recognize other types of objects in addition to cartons to make them more cost-effective.

Although cartons can very well be sorted manually in smaller centres or on streams where their quantity is relatively small, the technological solutions found on the market can be essential to increasing sorting quality and overcoming labour shortages. MRFs, whether new or existing, now have a wide selection of high-performance solutions from which they can choose those that best suit their needs and budget.

SamurAI sorting robots from Machinex and Max-AI from Bulk Handling Systems (BHS)