EVOH or PVDC? How to Choose the Right High-Barrier Packaging Material

For packaging engineers, material selection is often a process of balancing multiple factors. When high-barrier packaging is required, PVDC and Evoh almost always appear on the shortlist.

Both materials have their advantages, but choosing the wrong one can result in insufficient shelf life, uncontrolled packaging costs, or even large-scale quality problems during distribution.

1. Oxygen Barrier: EVOH Leads in Dry Conditions, While PVDC Performs Better at High Humidity

Oxygen barrier performance is one of the core requirements of high-barrier packaging.

Under standard dry conditions, the oxygen transmission rate (OTR) of EVOH can be as low as 0.5–3 cm³/(m²·24 h·atm), making it one of the most effective oxygen barrier layers currently available for commercial packaging applications.

However, EVOH's oxygen-barrier advantage comes with one critical prerequisite: the environment must remain dry.

EVOH contains a large number of hydroxyl groups in its molecular chains. These hydroxyl groups can form hydrogen bonds with water molecules. The effect of water on EVOH goes beyond simple adsorption. Absorbed water acts as a Plasticizer, reducing the cohesive energy density between polymer chains and increasing chain mobility, which allows oxygen molecules to permeate more easily.

PVDC behaves quite differently. Its molecular structure is relatively symmetrical, while the chlorine atoms have hydrophobic characteristics and do not readily form hydrogen bonds with water molecules. As a result, its oxygen barrier performance is much less sensitive to changes in environmental humidity.

Experimental data provide a clear comparison: at relative humidities between 0% and 70% RH, EVOH generally provides better oxygen barrier performance than PVDC. Once relative humidity exceeds 70%, however, EVOH's oxygen barrier performance decreases rapidly and can become inferior to PVDC.

At 80% RH, PVDC has been reported to provide approximately three times better oxygen barrier performance than EVOH. At 100% RH, this advantage increases to approximately 13 times.

This difference can be decisive in real-world applications. Take meat packaging as an example. The ambient relative humidity may be around 60–70%, while the relative humidity inside the meat package can reach 95–100%. The relative humidity at the packaging material interface is therefore generally above 70%. For this reason, PVDC can offer a significant practical advantage over EVOH in meat packaging applications.

2. Moisture Barrier: An Area Where PVDC Has a Clear Advantage

If EVOH and PVDC each have their own strengths in oxygen barrier performance, PVDC has a much more pronounced advantage when it comes to moisture barrier performance.

EVOH's weakness against moisture is also related to the hydroxyl groups in its molecular structure. These hydrophilic groups affect not only oxygen barrier performance but also the material's ability to block water vapor.

Research has indicated that, when achieving the same level of water-vapor barrier performance as PVDC, EVOH can be one of the least efficient options.

For packaging applications where moisture protection is essential—such as dry foods, pharmaceutical blister packaging, and electronic component packaging—PVDC's moisture-barrier performance can be difficult to replace.

For products such as fruits and vegetables that require a certain degree of moisture or gas exchange, however, EVOH's relatively higher moisture permeability may actually become an advantage.

3. Temperature Resistance: Distinguish Between Coatings and Laminated Film Structures

When evaluating temperature resistance, it is important to distinguish between PVDC-coated films and PVDC laminated composite films.

For PVDC-coated films, such as KOP and KPET, the barrier performance of the PVDC coating may decrease under high-temperature retort conditions above 121°C, meaning that these coated structures are not suitable for high-temperature retort processing.

PVDC laminated composite films are different. They provide excellent barrier properties, as well as resistance to oil, chemicals, and retort processing. Their operating temperature range can extend from approximately -18°C to 135°C.

PVDC laminated films produced using a solvent-free lamination process can withstand retort processing at 121°C for 40 minutes. Under these conditions, the inside and outside of the packaging bag remain free from deformation, the heat-sealed areas do not crack, the layers do not delaminate, and mechanical strength and barrier performance remain stable.

When used for meat products and subjected to high-temperature retort processing at 121°C for 30 minutes, the resulting package can achieve a shelf life of more than six months at room temperature.

The temperature resistance of EVOH depends on its ethylene content and structural design. EVOH-based films can be used for aseptic packaging and retort pouches. In multilayer coextruded structures, EVOH serves as the intermediate barrier layer and is protected by polyolefin layers on both sides.EVOH coextruded films using PP as the inner and outer layers can also withstand retort processing at 121°C for 30 minutes.

It is important to note that the heat resistance of a multilayer coextruded film depends on the resin with the lowest temperature resistance among the outer layer, inner layer, and tie-layer materials.

For example, EVA can generally only be used below 80°C. Therefore, a multilayer coextruded film containing EVA as a tie layer cannot be used continuously above 80°C.

Consequently, when selecting PVDC or EVOH coextruded films for retort applications, the thermal stability of the entire film structure must be evaluated rather than focusing solely on the barrier layer itself.

4. Material Selection Logic: Make the Decision Based on Product Characteristics

Based on the comparison above, the selection between PVDC and EVOH can generally follow the logic below.

5. Frequently Asked Questions

Question 1: If a Product Requires High-Temperature Sterilization at 121°C, Should I Choose PVDC or EVOH?

Both can be used in retort packaging, but the specific material structure must be distinguished.

PVDC laminated composite film, rather than PVDC-coated film, can withstand high-temperature sterilization at 121°C for 40 minutes. After this treatment, the packaged product can achieve a shelf life of more than six months at room temperature.

EVOH-based films are also suitable for retort pouches. EVOH coextruded films using PP as the inner and outer layers can withstand 121°C for 30 minutes of retort processing.

The key is to evaluate the thermal stability of the entire film structure. The temperature resistance of a multilayer coextruded film is determined by its least heat-resistant layer.

Question 2: Will the Chlorine Content of PVDC Affect Export Markets from an Environmental Perspective?

The recyclability of chlorinated PVDC materials has been a focus of industry discussion.

In March 2025, Syensqo demonstrated that multilayer food packaging containing PVDC as the barrier layer could be mechanically recycled effectively within a standard PE waste stream. The recycled material could then be used for injection-molded products without the need for additional stabilizers.

This development has substantially improved the recycling prospects of PVDC.

For products intended for the EU market, manufacturers should pay close attention to the PFAS limits under the PPWR and confirm the compliance documentation for additives and adhesives used in the coating system with their suppliers.

Question 3: EVOH Performance Decreases in High-Humidity Environments. Is There a Way to Compensate for This?

Several technical approaches can be used to reduce EVOH's sensitivity to humidity.

The most common approach is multilayer coextrusion, in which EVOH is positioned as the intermediate barrier layer and protected on both sides by polyolefins such as PE or PP to limit moisture exposure.

In addition, adding a recycling compatibilizer, such as Mitsubishi Chemical's Soaresin™, to the EVOH formulation can increase the allowable EVOH content in the PE recycling stream from 5 wt% to 10 wt%, while improving recycling compatibility of the multilayer structure.

However, these solutions also increase process complexity and cost, so they need to be evaluated as part of the overall packaging design.

If the humidity of the product's distribution environment genuinely cannot be controlled below 70% RH, PVDC may be a more practical option.

Conclusion

There is no absolute winner between PVDC and EVOH. The key is whether the material matches the characteristics of the product and its distribution environment.

If the product is exposed to high humidity during distribution, has a high moisture content, requires both oxygen and moisture barriers, or must withstand 121°C high-temperature retort processing, PVDC may provide a more suitable material solution.

If the environment is dry and controllable, extremely high oxygen barrier performance is required, and recycling compliance is also an important consideration, EVOH may be more appropriate.

When selecting a high-barrier packaging material, it is recommended to evaluate the target shelf life, temperature and humidity conditions throughout distribution, regulatory requirements in the target market—particularly PFAS limits and recycling compliance—and the overall packaging cost budget as key decision factors.

Where necessary, the feasibility of the material structure should be verified through actual storage and transportation testing before finalizing the packaging solution.