How EVOH Co-Extrusion Films Are Driving Innovation in Flexible Packaging
As the global flexible packaging industry experiences a shift toward higher performance and greater sustainability, EVOH (ethylene-vinyl alcohol copolymer) co-extrusion films are emerging as a pivotal material in advancing packaging technology. According to Smithers’ latest research, the global high-barrier flexible packaging market is projected to reach $28.5 billion in 2024, with EVOH-based multilayer films growing at an annual rate exceeding 6.8%.
1.Technology Advancements: Raising the Benchmark for Packaging Performance
1.1 Exceptional Gas Barrier Performance
EVOH is redefining packaging standards with its outstanding Gas Barrier Properties. With oxygen transmission rates as low as 1 ml/(m²·24h·0.1MPa) under ASTM D3985, it meets stringent FDA requirements for medical packaging.
In a typical 7-layer co-extruded structure—PE/TIE/PA/EVOH/PA/TIE/PE—EVOH acts as the central barrier layer. This symmetrical configuration provides dual-layer protection, lowering oxygen permeability by more than 60% compared to conventional 5-layer films. In high-temperature retort pouches for ready meals, such barrier performance can extend shelf life by up to 50%.
1.2 Multilayer Structural Innovation
Advanced multilayer designs help maintain EVOH polymer’s performance even in high-humidity conditions. By adopting a PA/EVOH/PA symmetrical arrangement, the structure combines barrier integrity with moisture resistance. The outer PA layers serve as a shield, maintaining water vapor transmission rates (WVTR) below 0.1 g/(m²·24h). This surpasses the performance of PVDC-based films, making EVOH plastic suitable for moisture-sensitive applications like frozen seafood.
2.Application Development: Expanding Across Sectors
2.1 Food Packaging
For retort packaging, structures like PA/TIE/PP/TIE/PA/TIE/PP can endure 121°C sterilization, making them ideal for bone-in meats and marinated products.
In coffee packaging, PE/TIE/PA/TIE/PA/TIE/PE films with nitrogen or CO₂ flushing preserve over 95% of aroma compounds.
2.2 Medical Packaging
EVOH co-extrusion films support safer pharmaceutical solutions. Multi-layer infusion bags (PE/TIE/PA/EVOH/PA/TIE/PE) offer controlled transparency and are free of extractables, providing a safer, shatter-resistant alternative to glass containers.
2.3 Bioreactor Film Materials
Mitsubishi Chemical’s EVOH-based 7-layer films have achieved ISO 10993 biocompatibility certification and are widely used in single-use bioreactor bags. In 2024, the company’s “X-layer” technology reached ±2% thickness precision across 9 layers, enabling ultra-thin, high-barrier films for medical use.
3.Sustainability: Advancing Environmental and Economic Performance
3.1 Cleaner Production Methods
EVOH co-extrusion is inherently solvent-free, eliminating the use of benzene-based compounds. This aligns with both FDA and EU food contact regulations and avoids common issues like adhesive migration. Compared with dry lamination, co-extrusion cuts production costs by up to 30%.
3.2 Improved Recyclability
Recent developments have enhanced EVOH material’s compatibility with circular economy goals. New-generation films can incorporate post-consumer recycled (PCR) resins. For instance, a PA/PE 7-layer film developed by a major plastics firm contains over 90% PE, meeting EU recyclability thresholds with a recovery rate of 85%, and is CE certified. This structure supports global anti-plastic initiatives and enables high-barrier films that are easier to recycle.
4.Frequently Asked Questions
Q: How does EVOH perform in high-temperature, high-humidity environments?
A: Modern EVOH films use protective layer designs—such as PA/EVOH/PA—to maintain stable barrier performance in humid or thermally demanding settings.
Q: What makes EVOH co-extrusion films more sustainable?
A: These films support solvent-free processing, mono-material designs, and integration with PCR resins. A full-PE construction enables more than 85% recyclability without compromising protection.
Q: Are EVOH co-extrusion films cost-effective?
A: Despite a higher material cost, EVOH film can reduce total cost of ownership by extending shelf life, lowering damage rates, and improving packaging efficiency. One food manufacturer reported a 20% boost in line speed and a drop in defect rate from 8% to 2%.
EVOH co-extrusion films are at the forefront of innovation in flexible packaging. Their unique combination of gas barrier excellence, environmental compliance, and multi-sector versatility positions them as a leading material in the transition toward high-performance, sustainable packaging. As multilayer technologies evolve and circular economy standards tighten, EVOH will remain central to the next generation of flexible packaging solutions.