ALD nanolaminate moisture barrier coating for bio-based food packaging films
Atomic layer deposition process applying chemically bonded, conformal nanolaminate moisture barriers (~20nm thick) onto bio-based films for dry food packaging. Achieves up to 99.5% reduction in water vapor transfer rate on flexible substrates, with barrier properties maintained after rolling and package formation.
Overview
This solution applies atomic layer deposition (ALD) to deposit a chemically bonded, highly conformal nanolaminate moisture barrier onto bio-based packaging films. The resulting barrier layer is on the order of 20 nanometers thick and becomes an integral part of the substrate, maintaining its barrier performance after package formation. The technology addresses a key challenge in sustainable packaging: delivering effective moisture protection on flexible bio-based films without adding significant weight or material. By enabling durable, uniform barriers on environmentally friendly substrates, the approach supports the development of dry food packaging with reduced reliance on conventional petroleum-based multilayer films.
Technical specifications
Key features:
- ALD-based conformal coating applied to flexible bio-based films, including hard-to-coat surfaces
- Nanolaminate material stacks using TiO2, Al2O3, and TiO2/Al2O3 combinations
- Sub-nanometer growth control enabling precise barrier layer thickness (~20 nm)
- Low process temperatures compatible with temperature-sensitive polymer substrates
- Substrate pretreatment options (cleaning and pre-treatment procedures) agreed with the sponsor
- Durable barrier performance maintained after repeated rolling to less than 1-inch diameter
- Validated barrier performance on polyester films achieving water vapor transfer rate as low as 0.2 g/(m2day) and oxygen transfer rate as low as 0.3 cc/(m2day), representing up to 99.5% reduction versus untreated substrate
Technology readiness level
The ALD barrier coating process has been demonstrated on polyester films with two-orders-of-magnitude improvement in water vapor barrier performance and confirmed durability after mechanical handling. This project represents a one-year proof-of-concept effort to adapt and validate the process on sponsor-supplied bio-based films (~3 inches x 3 inches), exploring process conditions such as temperature, deposition thickness, and reactant exposure times. Samples will be returned to the sponsor for barrier property evaluation, with complementary access to a Permatran-W instrument for internal testing. Process scaling to large sample sizes and high-throughput production is beyond the scope of this initial effort but represents a clear pathway toward commercial deployment.
About North Carolina State University
North Carolina State University is a large, comprehensive public land‑grant research university in Raleigh. Its on‑campus research and technology park co‑locates corporate R&D groups, government partners, and faculty labs, enabling shared facilities, prototyping, and agile contracting. Located in North Carolina’s Research Triangle, partners tap a dense regional ecosystem while engaging through a statewide extension network and a mature co‑op program that deliver field deployment and workforce pipelines. Multiple pilot and demonstration facilities support scale‑up and validation toward pre‑commercial readiness. Research is supported by competitive funding from major federal agencies, including NSF, USDA, DOE, and DOD, and a dedicated technology transfer office with clear IP pathways helps accelerate commercialization.
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