With large scale disruption to recycling collections, sorting facilities and secondary material markets across the world, TOMRA Sorting Recycling has published an article looking at how Plant design automation and technology advancements lead to increased purity rates while requiring fewer manual sorters…

The rapidly evolving effects from the novel coronavirus, COVID-19, the global pandemic has governments and companies enacting unprecedented measures to protect the lives and livelihoods of the populace. Emergency social distancing and quarantine orders to flatten the curve of transmission rates have been enacted globally.

Students are remotely learning as schools close to stem the spread of the virus. The “non-essential” workforce is recommended, ordered in some cases, to stay from home, using technology to work remotely. Meanwhile, some essential services workers are receiving increases to their hourly rates as hazard pay.

Recycling industry feels the pinch
Deemed essential services in many countries, the waste and recycling industries face virus-related impacts, as collection services and practices are being altered to protect workers. Receiving recyclable materials has a high rate of interaction with the public, and the recycling process often involves close worker interaction.

As a result, many locations around the world have temporarily halted collection of a portion or all recyclable materials. In the United States, Michigan and South Carolina facilities have halted the collection of recycle materials placed kerbside, turning to landfill instead. In the United Kingdom, where recycling centres are not considered “essential,” some councils have reduced bin collection services, while others have closed recycling entirely to prevent close contact among people and possibly spreading the virus.

To mitigate the inherent risks associated with coronavirus, the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) has issued the general safe practices guidelines of frequent handwashing with soap and water, use of hand sanitizer, avoid touching the face with unwashed hands and avoid close contact with those who are sick.

At the time of writing, OHSA recommended that waste agencies handle solid waste with potential or known COVID-19 contamination like any other non-contaminated waste – use typical engineering and administration controls, safe work practices and personal protective equipment (PPE), such as puncture-resistant gloves and face and eye protection, to prevent worker exposure to the waste and recycle materials managed.

To minimise worker interaction, recycling companies are adjusting business practices, such as moving to staggered waste collection shifts, to prevent virus exposure. Manual sorter repositioning and staggered breaks have been implemented for social distancing. Where sorter repositioning is not possible, temporary barriers between workers are being placed where advance safety.

Strain on supply
Consumer buying and recycling habits in Europe have seen a spike in virgin PET demand, combined with decrease return rates, taxing the recycled polyethylene terephthalate (rPET) market, the most widely recycled plastic in Europe. French recycling operations anticipate reduced collection rates for polyethylene and polypropylene as well, at a time when the market typically sees the start of peak season for rPET and recycled polyolefins.

A vast majority of U.S. states with bill deposit programs have suspended enforcement, limiting the returns of aluminium cans as well as glass and plastic bottles. Other states have stopped drop-off programs at recycling facilities and reduced facility operating hour reductions to combat the virus.

Automation and technology advances
It is said that necessity is the mother of invention. In times of social and business disruptions, people find ways to overcome the challenge. We are seeing this play out with the coronavirus pandemic. Displaced students are learning virtually, quarantined citizens are finding virtual ways to stay connected and “nonessential” workers are keeping business running through work-at-home initiatives. 

The waste and recycling industries face the compounded issue of material and labour shortage trends for the foreseeable future. Recycling operations must make the most with the material they receive, with fewer workers. “Advancements have been made in sorting circuit automation at both front and back ends, which have helped recycling operations decrease the number of manual sorters while increasing material purity,” mentions Fabrizio Radice, Head of Global Sales and Marketing TOMRA Sorting Recycling.

China National Sword in 2017 started the innovation engine for plant builders and manufacturers of equipment used at MRFs and metal recycling yards. Before National Sword, recycled product with up to 10% impurities was acceptable. After, impurity content of no more than 0.05% was mandated, and other countries eventually followed China’s lead.

“The industry has grown from material recovery to recycled product refining,” says Eric Thurston, Sales Manager Metals for TOMRA Sorting Recycling. “Companies want the sorting circuit to do the majority of the work, so they can redirect manual sorters to better utilise the talents.”

Equipment automation is helping to deliver better separation of mixed materials at the front end of the recycling circuit. The expanded use of more advanced front-end screening and separating equipment is helping to better classify paper, containers, glass and metals, based on size, colour, density and ballistic properties. “The better the separation at the front end, the more efficient the back-end sorting will be, and the fewer manual sorters will be required,” comments Thurston.

On the circuit’s back end, where material is sorted into final products, significant improvements in equipment technologies are helping to reduce the number of manual sorters required for final product quality. Newer laser technologies introduced over the last three years make it possible to remove more impurities from metal and paper products. Sensor improvements now enable optical sorters to pick out fine molecular differences in PET and paper materials to get a cleaner product sort.

“By taking a systems-thinking approach to the entire circuit and upgrading both the front and back ends,” says Nick Doyle, Recycling Area Sales Manager, West North America for TOMRA Sorting Recycling, “we are helping MRF operators significantly decrease their manual sorter count, in some cases by 50% or more. This is not only beneficial in current times with the coronavirus pandemic, it better utilises worker talents and saves operators substantial sums of money annually.”

Digital trends
Today, more of the recycling circuit’s components can be networked together to further advance efficiencies. Sorting machines can capture operating data, such as when the circuit is running, duration, output and service alerts that can be accessed remotely via an Internet connection. This allows managers to employ fact-based decision making about the equipment and circuit, improve operating efficiency and increase sorting accuracy.

More available data combined with significantly improved computing capabilities has expanded the use of artificial intelligence (AI) in sorting equipment to help recycling operations solve much more complex sorting problems than in the past. Robotic sorters and sensor-based sorting equipment are now integrated with advanced machine learning capabilities to recognise patterns in the waste stream and make a smarter sort. Doyle suggests that operators consider pairing advanced optical reducing sorters with robots using AI to help boost quality, while the need of manual sorters.

As a final consideration as to whether a circuit should be upgraded to improve sorting accuracy, Doyle offers, “If it hasn’t been upgraded within the last three years, it may not be as efficient as possible, and a company might be using more manual sorters than necessary. Investing in the circuit now, when volume and labour availability are down, can help to reduce the impact on the business and pay dividends when the business rebounds to pre-pandemic levels.”