Polyurethane foam, a key global plastic product, is widely used across various industries. However, addressing the challenge of waste recycling remains a critical issue for the polyurethane sector. The EU-funded PUReSmart project has brought together nine partners from six countries to explore innovative methods and technical solutions to tackle this problem.
The project has recently concluded, presenting a groundbreaking recycling solution for PU foam scrap. This advancement significantly enhances recycling efficiency and outcomes, with the potential to revolutionize traditional mattress manufacturing and recycling systems.
Intelligent Sorting Technology Facilitates Waste Separation
While the polyurethane industry has long prioritized recycling, effective solutions for managing discarded mattresses were scarce until a few years ago. Approximately 60% of such waste was landfilled, with the remainder incinerated. Through collaborative efforts, particularly by integrating smart mechanical recycling with chemical decomposition technology, PUReSmart has developed an innovative process for chemically breaking down polyurethane waste, achieving complete recovery of flexible foam. This advancement supports the industry’s carbon reduction goals, aligning development with environmental objectives.
Funded by the EU Horizon 2020 research and innovation program, the PUReSmart project received €6 million over four years. Its primary goal was to recycle over 90% of polyurethane waste, transforming it into new and reusable products.
From its inception, the project aimed to shift the conventional production-use-disposal model toward a circular economy framework. PUReSmart proposed starting the recycling process with solid mechanical sorting, facilitating subsequent chemical decomposition. The project then focused on advancing smart sorting technologies to classify various polyurethane foams by material type and reduce them to their fundamental chemical components.
This strategy proved effective. Redwave, a PUReSmart partner, introduced a solution using near-infrared (NIR) sensors for detecting and sorting polyurethane waste more accurately. While NIR spectroscopy is widely applied to sort thermoplastics like PET and PE, this marks its first application in polyurethane foam separation.
Redwave has developed reliable solutions for identifying and classifying 20–30 different types of polyurethane, including MDI-based foams, traditional foams, high-resilience foams, and foams containing flame retardants or other additives. Efforts are ongoing to upgrade waste sorting systems, simplifying downstream chemical decomposition processes.
Accelerating Chemical Decomposition Technology Development
In tandem with refining early-stage sorting, PUReSmart has advanced chemical decomposition technologies and industrial-scale trials. Recently, Recticel Engineered Foams, a project partner, conducted experiments using recycled polyols and isocyanates sourced from Covestro’s Leverkusen pilot plant in Germany to manufacture new polyurethane foams.
Unlike other chemical processes for recycling polyurethane foam, this method does not rely on polyols derived from fossil resources. Instead, ethylene glycol and an additive are combined with pre-sorted foam waste. During chemical decomposition, the foam breaks down into high-purity polyols and toluenediamine (TDA, a precursor to TDI) with excellent yields. These recovered materials can then be reprocessed to produce new flexible polyurethane foams as needed.
