TECHNOLOGY | ODOUR REDUCTION


Above: UK compounder Luxus has developed odour-extrac- tion technology


“We found that lower temperatures, higher rpm, and a double vacuum plus water injection yielded recyclates of the lowest odour in our experiments,” reported the IKV researchers. “We further investi- gated Kreyenborg’s IR-heat treatment in compari- son to traditional heat storage with the aim of reducing the amount of VOC with high molecular weight. In film extrusion, we aimed again for lower temperatures and added yet another degassing step. Currently, we are analysing the deodourisa- tion and film extrusion samples.”


Auto interior VOCs Aimplas, the Plastics Technology Centre in Spain, has been leading an initiative called H2


Odor to


reduce odours in polyolefin PCR for use in vehicle interiors. The project is using water-based decon- tamination and deodourisation technologies from Fych Technologies to minimise VOCs. “The automotive industry is one of the most demanding sectors, but also one of the most strategic for applying advanced recycling solu- tions,” said Juan Alfonso Naranjo, researcher in Sustainable and Future Mobility at Aimplas, in a post on the organisation’s website. “With this project, we want to offer a sustainable and viable alternative that contributes to the fulfilment of the new European objectives.” The project is funded by the Valencian Institute


of Competitiveness and Innovation (IVACE+i) and European Regional Development Funds. UK-based technical plastics recycling and compounding company Luxus supplies the global auto industry, including recycled grades for auto interior trims. The company recently tackled the problem of odour in post-consumer waste under a grant funded by the Industrial Energy Efficiency Accelerator, in partnership with the UK’s University of Lincoln. The Odour Control Accelerator project wrapped up in 2024 and resulted in an odour-


26 COMPOUNDING WORLD | July 2026


extraction technology that can be integrated into the extrusion process for recycled PP. “One of the main aims for this project was to develop a system that can target as many of the identified critical odour species as possible,” said Natalie Stones, Laboratory and Technical Manager at Luxus. “Odour in recycled polymers, especially those with high post-consumer waste content, is often due to the presence of VOCs, contaminants, and residuals from prior use (eg, food, chemicals, or packaging materials). These odours can make the recycled polymers less desirable for high-value applications. Common sources of VOCs in recycled plastics include alkanes, ketones, aldehydes, and carboxylic acids, often originating from degrada- tion during use or improper disposal, residual additives, or other contaminants from packaging or consumer goods.”


One challenge for solving odour problems is


that odour perception is subjective. A well-rounded assessment combines instrumental, quantitative analysis with sensory measurements from human panellists, Stones said. Another challenge is that many of the VOCs and SVOCs that cause odour can be present in low concentrations. “Isolated compounds can have a large contribu- tion to the overall odour but may be below their limit of detection threshold when analysed, so remain unidentified,” she explained. “Synergistic effects of VOCs also add to the complexity of the analysis of odour causing compounds, as they may produce a stronger or characteristically different odour when combined.” The Luxus proprietary technology uses high


pressure and dispersion to remove VOCs during compounding. The company designed a special- ised barrel section and extruder configuration to maximise melt surface area, said Stones. A post- conditioning deodourising unit was also installed downstream of the extruder. The polymer com- pound is pneumatically conveyed to the top of this conditioning column, and a counter-current airflow draws air through the descending polymer. “A high residence time allows for the circulating air to encapsulate any airborne VOCs to migrate from the polymer into the airstream. Sensors and controls ensure the process remains consistent and so all material is uniform,” she said. “The Luxus project demonstrated that effective


odour reduction in recycled polypropylene requires an approach that goes beyond conven- tional odour scavengers. By combining in-line VOC extraction during extrusion with post-conditioning deodourisation, the technology significantly reduced odour intensity and improved material


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IMAGE: LUXUS


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