Innovative ideas for efficient plastics recycling

Few raw materials are as complex as secondary materials for recycling. After all, customers can never be completely sure of the composition of the material flows. Plastic recycling also still has problems with fluctuating demand. Maximum efficiency is therefore required to compete with Virgin Material. An overview of new impulses for the circular economy of plastics.

Written by Marius Schaub

Various used packaging made of HDPE — New technologies make it possible to automatically detect whether packaging such as HDPE bottles have been in contact with food during the use phase.

Plastics that are no longer needed go into recycling – that should be clear to everyone. Unfortunately, however, the collection of used plastic products and packaging does not lead to the creation of secondary material. There are many reasons for this. In particular, sorting plastics by type is still a major problem for the recycling industry.

Machine and plant manufacturers are therefore continuously working on removing obstacles. New technologies make it possible, for example, to identify packaging that has been in contact with food, to sort black plastics by type and to continuously increase general process efficiency. This is particularly important for the competitiveness of secondary plastics, as recycled material always competes with virgin material. This year, several suppliers have presented innovations for improving plastics recycling.

More performance and efficiency in extrusion and compounding

Plastics recycling as a growth market: Coperion has decades of experience in the production of plastics, but has long focused exclusively on the production of virgin material. The company’s entry into equipment for manufacturers of secondary materials benefits from its accumulated process knowledge. Whether extruding and compounding, pelletizing or feeding – many processing steps in the preparation of used plastics are similar to the production of virgin material. The supplier’s extrusion technology with twin-screw extruders is at the heart of its offering for recyclers. Compared to designs with a single screw, the torque and throughput are higher. High energy efficiency also increases the efficiency of the overall process.

The focus on recycling processes not only leads to adjustments and optimizations, but also to new developments. A filtration compounder enables filtration and compounding in a single production step. The integrated mode of operation removes contaminants from the melt, which can then be compounded with reinforcing or filling materials. In addition to a leaner system design, this machine is also designed to significantly reduce energy consumption while increasing the quality of the compounds.

Interior view of a technical center with a multi-story plant for the processing of plastic waste — In November 2024, Coperion opened a new technical center dedicated entirely to the processing of plastic waste.

In November 2024, Coperion also demonstrated its commitment to the recycling of plastics with a new building. At the company site in Weingarten, the manufacturer opened a new technical center, the “Recycling Innovation Center”. Focused entirely on plastics recycling processes, customers can send their material flows through all the necessary process steps and put the systems through their paces.

Safely identify plastics with food contact

Before used plastics can be processed and turned into secondary material, they have to be sorted. The purer the material flow, the higher the quality of the final product. Mixed collections in particular often contain contaminants. Tomra has long been a specialist in sorting a wide variety of material flows – in addition to solutions for the food industry, mining and the textile industry, it also offers solutions for recycling.

With the help of Artificial Intelligence (AI), the manufacturer is now addressing a sorting requirement that is particularly difficult to fulfill: distinguishing between used plastics with and without food contact. This is crucial for processing, as hygiene concerns and strict regulations make the treatment of food waste during recycling a major challenge. Gain Next is the technology that aims to change this. It builds on Tomra’s autosort sorting systems and consists of optical waste sensors that complement traditional near-infrared (NIR), visual spectrometry and other sensors.

The supplier quotes purity levels of over 95 percent for packaging applications in various customers’ plants – and promises recyclers new sources of income if they are able to process and market more material flows than before by using the advanced sorting technology.

A man operates a laptop that displays graphs of operating data from a sorting plant for plastics recycling — Collected operating data provides the basis for evaluating and optimizing system operation.

Clearly identify black plastic fractions

Steinert is also a well-known supplier of sorting technology. The company has grown up with systems for metals, but also offers solutions for glass recycling and the mining industry. Steinert develops particularly sophisticated machines for plastic waste such as that from municipal waste collections. The new Unisort Finealyse+ system combines NIR and hyperspectral imaging (HSI) to offer both a particularly high spatial and spectral resolution. According to the supplier, this is particularly beneficial for sorting plastic flakes.

In the past, Steinert has already solved a challenge that has long been a headache for plastics recyclers: the detection of black plastics. This is because one disadvantage of NIR sorting is that plastic colored with carbon black does not reflect enough infrared light to enable detection. The technology is used in Unisort Black and Unisort Blackeye systems and helps users to detect more material and give it a second life.

Process intelligence for more flexibility, performance and efficiency

Netzsch is well-known to users in the pump, shredding system and grinder industries. With Sens Xpert, the company has expanded its expertise in 2022 to include process intelligence, from which processing companies in the plastics industry should benefit. To this end, the subsidiary combines real-time material data from tools with modern machine learning software to analyze material behavior.

Production efficiency can be increased by up to 30 percent, they say – for example by quickly detecting deviations in material and process parameters, which enables early adjustments to be made and rejects to be avoided.

On the way to a circular economy for plastics

Plastic recycling is no longer an exception, but a long-established practice that keeps enormous quantities of material in circulation and thus reduces the environmental and climate impact of plastics. However, there is still a lot to be done before the move away from a linear economy becomes a reality worldwide and for all material flows. Technology providers that increase and expand the efficiency and performance spectrum of solutions for sorting and processing used plastics play an important role in ensuring that this path can be pursued.

Author

Marius Schaub