What Is EVOH? A Comprehensive Guide

Ethylene vinyl alcohol, otherwise known as EVOH, is a flexible copolymer known for its excellent barrier properties. Its ability to block gases, fuels, chemicals, and aromas has made it increasingly popular across the packaging industry. EVOH helps maintain product freshness and protection throughout storage and transport, making it a reliable choice for sensitive applications.

Yes, ethylene vinyl alcohol is a type of thermoplastic polymer, meaning it can be heated, melted, and reshaped without affecting its chemical properties. This makes it easy to process and form into different types of packaging formats. The EVOH polymer has qualities that make it great for packaging because it’s naturally clear, flexible, and glossy, giving it a clean appearance while still delivering strong protection.

In packaging, the ethylene vinyl alcohol copolymer is commonly used in multilayer structures, where it sits between the outer plastic walls of the container. Many designs also include a layer of regrind material, which is typically placed between the virgin plastic layers. A thin layer of adhesive is placed between the EVOH layer and the outer wall, helping to bond the surrounding materials.

EVOH is commonly layered with materials such as high-density polyethylene (HDPE) and polypropylene (PP) to create strong, reliable packaging. Because of its ability to protect products from gases, chemicals, and odors, EVOH is most frequently used in pharmaceutical, chemical, automotive, and agricultural industries.

Ethylene vinyl alcohol offers several benefits that make it a great material for various packaging applications.

• Barrier Properties: The EVOH barrier provides excellent protection against oxygen, gases, and aromas. This helps maintain product quality and prevents contamination.
• Shelf Life: Because EVOH can block oxygen so effectively, it can extend the shelf life of sensitive products.
• Versatility: EVOH can be used in packaging for food, cosmetics, pharmaceuticals, agricultural products, and more.
• Durability: When combined with other plastic materials, EVOH adds strength and stability to packaging.
• Sustainability: EVOH is recyclable, and its strong barrier performance can reduce the need for additional, thick layers of plastic.

Both fluorination and ethylene vinyl alcohol are used to create barrier properties in plastic containers, but they differ in environmental impact, cost, and application. EVOH offers great oxygen & gas barrier properties and is generally more easily recyclable. On the other hand, fluorination provides better solvent resistance and is more cost-effective for aggressive chemicals.

While ethylene vinyl alcohol offers various benefits, there are a few key considerations to keep in mind. Because it has such high moisture sensitivity, EVOH must be placed between other materials to maintain its performance. Although it is recyclable, its multilayer structure can complicate the recycling process for the other materials involved. EVOH can also underperform in certain high-pressure or high-temperature environments, so it’s important to consider whether it aligns with the type of applications you may be using it for.