PVDC vs. EVOH: Which Offers Better Barrier Performance in Real Cold Chain Conditions?

Among high-barrier packaging materials, polyvinylidene chloride (PVDC) and ethylene vinyl alcohol copolymer (EVOH) are two of the most widely used options in global food packaging. Both materials are known for their strong oxygen barrier properties and are commonly used in cold chain food packaging.

Under these real-world conditions, the barrier stability and environmental adaptability of PVDC and EVOH can differ significantly. These differences often become the key factors when food processors and exporters select packaging materials.

EVOH is widely recognized for its excellent oxygen barrier performance in dry environments. Its molecular structure contains highly polar hydroxyl groups that form strong hydrogen bonds within and between polymer chains. This tight molecular packing results in extremely low free volume, which greatly limits oxygen transmission.

Under dry conditions, EVOH can achieve an oxygen transmission rate as low as 0.1 cc·20μm/m²·day·atm, making it one of the most effective oxygen barrier plastics available. Additionally, the ethylene content in EVOH can be adjusted between 27–48 mol%, allowing manufacturers to balance barrier performance with processing flexibility. Because of these characteristics, EVOH is often selected for packaging applications where low humidity conditions are maintained.

PVDC, by contrast, is known for its balanced and comprehensive barrier performance. Its molecular structure has high symmetry and crystallinity, while the chlorine atoms provide strong hydrophobic characteristics. As a result, PVDC does not form hydrogen bonds with water molecules, making it difficult for both oxygen and water vapor to diffuse through the material.

Laboratory tests show that PVDC can achieve oxygen transmission rates below 1 cc·20μm/m²·day·atm, placing it among the top-tier high-barrier packaging materials. In addition to oxygen barrier performance, PVDC film also offers excellent moisture barrier and aroma barrier properties, along with strong resistance to oil, acids, alkalis, and puncture damage.

These combined properties make PVDC one of the few materials capable of delivering simultaneous oxygen, moisture, and odor protection, which is especially valuable for fresh meat and seafood packaging.

The barrier properties of EVOH are closely related to the hydroxyl groups in its molecular structure. While these groups contribute to strong oxygen barrier performance, they are also highly hydrophilic. This means EVOH is particularly sensitive to humidity.

To reduce moisture exposure, EVOH is often placed within multilayer packaging structures, typically sandwiched between outer layers such as polyethylene (PE) or polypropylene (PP), which provide moisture resistance. This design can help limit moisture penetration under stable conditions.

However, real cold chain logistics introduce additional variables, including:

• Temperature and humidity fluctuations during transportation
• Minor packaging seal defects
• Micro-gaps between multilayer film layers
• Condensation or frost forming inside packages
• Salt spray exposure during long-distance maritime shipping

Over time, these factors can allow small amounts of moisture to reach the EVOH layer. Once moisture is absorbed, the barrier performance of EVOH can gradually decrease, which may affect its long-term stability in high-humidity cold chain environments.

PVDC film behaves very differently under the same conditions. Because its molecular structure does not contain hydrophilic groups, the material is largely unaffected by environmental humidity.

This hydrophobic structure allows PVDC to maintain stable barrier performance even in high-humidity and low-temperature environments typical of cold chain logistics.

Whether exposed to condensation during refrigerated transport, high humidity during storage, or salt spray during overseas shipping, PVDC continues to provide consistent oxygen and moisture barrier protection. This stability helps prevent oxygen penetration, moisture migration, and odor transfer, which are key factors in food oxidation and spoilage.

Another advantage is that PVDC barrier film maintains its barrier performance at low temperatures, including the typical cold chain range of 0–4°C. The molecular structure remains stable, ensuring that oxygen and moisture barrier properties remain consistent during refrigeration. This helps slow microbial growth and supports the preservation of product freshness, flavor, and texture.

In practice, PVDC and EVOH are not direct competitors, but rather materials that serve different roles depending on product type, logistics conditions, and market positioning.

Across global cold chain packaging markets, PVDC bag is widely used in mainstream fresh food packaging and export-oriented cold chain logistics, while EVOH is more commonly applied in dry food packaging or specialized high-end applications where humidity is easier to control.

In the Chinese market, PVDC has become a mainstream packaging material for cold chain meat products. Major meat processors such as Shuanghui Group and Yurun Group widely use PVDC-based packaging films for chilled meat, sausages, and braised meat products. The strong barrier performance helps extend shelf life and reduce product return rates.

EVOH, meanwhile, is more commonly used for processed dry foods, nuts, and seasoning products, where humidity levels are lower and its dry-state oxygen barrier performance can be fully utilized.

A newer development in packaging technology is the PVDC–EVOH multilayer composite structure, which combines the advantages of both materials. EVOH provides strong oxygen barrier performance in dry conditions, while PVDC ensures stable barrier protection under humid conditions.

This combination is increasingly used in premium ready-to-cook foods and high-end fresh products, such as premium steaks and ready-to-eat seafood. However, due to higher material costs, these advanced structures are currently applied mainly in niche high-end markets.