The Tomra Sorting Recycling division of Norway-based Tomra Group says its sensor-based plastic flake sorting technology is helping customers achieve “unparalleled recovery and purity rates of polyethylene (PE) and polypropylene (PP), both of which are polyolefins (PO).” Previously, Tomra says, its flake sorting systems mainly focused on polyethylene terephthalate (PET).
The company says its new InnoSort Flake device and its AutoSort Flake machine can perform flake sorting as the final stage in a bottle sorting process that “takes place once the infeed material has been shredded, screened, washed and dried.”
“Tomra is deeply committed to advancing the circular economy, and our new technology will open new doors to continue leading the resource revolution,” says Carlos Manchado Atienza, regional director Americas for TOMRA Sorting Recycling. “For years, the industry only looked for high-purity PET recycling, but now TOMRA has demonstrated that even recycled PO can be made to the quality of virgin material.”
Previously, InnoSort Flake offered a total width of either 39.4 or 59.1 inches (1 or 1.5 meters) and was designed solely for PET flake sorting, according to the firm. The new InnoSort Flake is 78.7 inches (2 meters) wide and uses Tomra’s Near Infrared (NIR) Flying Beam PO-specific and Dual Full-Color Camera technology to deliver higher throughput.
Tomra calls Flying Beam the only NIR technology on the market that offers automatic continuous signal correction to deliver the most stable and reliable sorting performance, along with the lowest maintenance and energy consumption.
The NIR sensor technology allows PO flakes to be sorted by material and color, and the PO-specific sensor used in the Flying Beam works in unison with the dual, full-color camera technology to gather suitable spectral information to accurately sort PP and PE flakes as small as 0.079 inches (2 millimeters), says Tomra.
Using a front and rear camera setup allows InnoSort Flake to see the color of each flake and identify the details such as prints or ink, according to the firm. The unit purifies both the PE stream and the PP stream by identifying and removing unwanted polymer contamination and color impurities. “Any left-over contaminants are removed, resulting in unparalleled purity levels that meet both the standards demanded by current industry legislation and end customers,” states Tomra.
In high-end applications such as bottle-to-bottle recycling, where contamination of the infeed material is low but quality requirements are high, Tomra Sorting Recycling says AutoSort Flake can detect material, color and metal to achieve both extremely high purity and stable throughput.
“With the use of polyolefins continuing to rise – the global polyolefins market is predicted to reach close to $4 billion by 2027 – sorting polyolefins will become an increasingly important realm of plastics recycling,” says Valerio Sama, head of product management at Tomra Sorting Recycling. “We need to be able to increase the purity and yield of recycled plastics to a level where the material is suitable for re-use in food packaging, and we also need to bring that material back into the loop as part of a circular economy model.”
Continues Sama, “PE and PP are both polyolefins and, if mixed up together, they negatively impact the recycling process. Separating PE and PP is a complex challenge even for sensor-based sorting technology, but we set out to develop a new NIR sensor specifically for this application. With the launch of our new InnoSort Flake, our customers can further rely on us as a ‘one-stop shop’ for all their bottle and flake sorting needs.”
William Zeng, InnoSort Flake product manager at TOMRA Sorting Recycling, adds: “Even if the flakes have a different color on each side, they can be sorted as required. The unit’s highly flexible modular design allows for up to four chutes to work independently from each other, and the 2-meter (78.7-inch) width allows for multiple sorting steps to be applied on the same machine and at the same time, such as re-sorting (sorting a second time) and recovery. It’s a very exciting development in plastics recycling.”
Valerio says another resin is already being targeted by the firm’s researchers. “Our focus remains on continual improvements to our sensor-based sorting performance – driving higher capacity, higher efficiency and lower loss rates. We’re currently looking into developing a solution for PVC [polyvinyl chloride] sorting and look forward to sharing more details about this project in due course.”