Cost-effective, high-barrier, recyclable pe/clay composite films for sustainable packaging
A recyclable PE-based composite film using ionic liquid-exfoliated clay technology to deliver high oxygen barrier performance, replacing EVOH and multilayer structures. Targets food packaging applications with a cost-effective, single-material solution at TRL-4, ready for extrusion blow molding scale-up with industry partners.
Overview
This solution addresses a critical challenge in food packaging: the need for high-barrier flexible films that are also fully recyclable. Current packaging relies on multilayer structures containing non-recyclable barrier polymers such as EVOH, PET, Nylon-6, and EVOH copolymers, which complicate recycling and increase costs. The proposed technology uses polyethylene (PE) combined with an ionic liquid (IL)/clay composite to deliver oxygen barrier performance comparable to these specialty polymers while remaining 100% recyclable within existing PE streams.
The technology is designed for cost-effective replacement of EVOH and other multilayer barrier films. By exfoliating clay directly within the PE matrix using RoCo's proprietary non-halide, non-toxic ionic liquid technology, the resulting composite achieves significantly improved oxygen transmission rate (OTR) performance. Initial compression-molded samples have demonstrated an OTR of 28 cc-mil/100in²/day at clay/IL loadings of just 5,000 ppm, indicating strong barrier enhancement at low additive levels.
Technical specifications
Key features:
- Exfoliated clay in HDPE matrix confirmed by XRD and EDX analysis, enabling uniform dispersion and barrier performance
- Ionic liquid processing technology that is non-halide and non-toxic, providing a safer and more sustainable alternative to conventional clay compatibilizers
- Low additive loading (5,000 ppm clay/IL) achieving meaningful OTR reduction, preserving PE's inherent water vapor transmission rate (WVTR) advantages
- Single-material recyclability enabling the film to be processed within standard PE recycling streams
- Rheological characterization confirming processability of IL/clay/PE composites for extrusion and blow molding operations
- Extrusion-validated at 10 kg scale, demonstrating compatibility with industrial processing equipment
Processing pathway: Compression molding has been used to generate initial films and OTR data. Extrusion blow molding is expected to further align the exfoliated clay platelets within the PE matrix, potentially yielding additional improvements in barrier performance beyond the current compression-molded results.
Technology readiness level
The technology is currently at TRL-4 (component validation in a laboratory environment). Key validation completed to date includes:
- Exfoliation of clay in HDPE matrix confirmed via XRD and EDX
- Compression-molded films produced with measured OTR of 28 cc-mil/100in²/day
- Multiple extrusion experiments demonstrating scalable processing at 10 kg levels
- Rheological property testing of IL/clay/PE composites
- Headspace GC/FID analysis performed on composite materials
Planned next-stage validation activities:
- Benchmarking OTR performance against current state-of-the-art barrier films
- Producing three PE/clay composite variants at various loadings at 20 kg scale
- Partner-led extrusion blow molding trials to evaluate clay alignment effects
- Short-term and long-term OTR testing, including humidity exposure
- Headspace GC/FID testing
- Pilot-scale production and technology transfer to manufacturing partners
About Liquid Ion Solutions LLC (DBA RoCo)
RoCo, officially known as Liquid Ion Solutions, LLC, is an advanced materials company based in Pittsburgh, Pennsylvania, that specializes in the design, synthesis, and application of ionic liquids. Founded in 2014, the company utilizes these versatile compounds—often described as tunable liquid salts—as environmentally friendly alternatives to hazardous solvents for diverse industrial uses, including energy storage, polymer processing, and functional materials. Their technical capabilities are supported by in-house synthesis, rigorous testing, and a distribution partnership with IoLiTec, enabling them to provide both custom-engineered solutions and a commercial portfolio of ionic liquid products. The firm’s research and development efforts are frequently conducted in collaboration with academic institutions and supported by public funding from agencies such as the U.S. Department of Energy, NASA, and the USAF.
RoCo applies its chemical expertise to address complex global environmental challenges, specifically focusing on the circular economy and sustainable manufacturing. Key innovations include the development of ionic compatibilizers that facilitate the upcycling of plastics, such as polypropylene, by overcoming traditional mechanical property limitations. Furthermore, the company is engaged in CarbonTech initiatives, including the development of water-lean solvents for carbon capture and utilization, as well as research into recyclable, high-barrier packaging films and polyurethane waste reclamation. By providing consulting, feasibility studies, and cutting-edge materials technologies, RoCo helps corporate partners and industrial clients integrate sustainable, performance-driven solutions into their operations across sectors like packaging, clean energy, and waste management.
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