When PE Packaging Is Not Enough: EVOH Barrier Solutions for Sunscreen and Liquid Foundation
The sunscreen and liquid foundation markets are becoming increasingly demanding—not only in terms of formula performance, but also in packaging compatibility.
Modern beauty formulas often contain complex combinations of oils, UV filters, pigments, fragrances, film-forming agents, and volatile ingredients. As formulas become lighter, longer-lasting, and more sensorial, packaging is expected to do more than simply hold the product.
For certain formulations, a conventional single-layer PE bottle may not provide enough protection during long-term storage or compatibility testing. This is where EVOH multi-layer packaging becomes especially relevant.
Why Sunscreen Formulas Can Be More Sensitive to Packaging
Sunscreen products are often formulated with multiple oil-soluble UV filters, emollients, fragrances, and other functional ingredients.
Depending on the formulation, some of these ingredients can be sensitive to oxygen, light, or long-term exposure to the surrounding environment. During storage, brands may need to monitor several changes, including:
- formula discoloration;
- odor changes;
- weight loss;
- viscosity changes;
- ingredient migration;
- changes in overall formula stability.
For this reason, packaging selection for sunscreen products is not only about bottle shape or dispensing performance. The barrier performance of the packaging material can also become an important part of formula protection.
Liquid Foundation Has Similar Packaging Challenges
Liquid foundation formulations are also becoming more sophisticated. Today’s foundations often focus on properties such as:
- long wear;
- lightweight texture;
- quick drying;
- smooth spreading;
- strong film formation;
- high pigment stability.
To achieve these effects, formulas may contain volatile ingredients, oils, silicones, fragrances, and different types of film-forming materials. Some oils and fragrance-related ingredients may gradually oxidize when exposed to oxygen, while some volatile or low-molecular-weight ingredients may slowly migrate through packaging materials.
The result is not always visible leakage. In many cases, the bottle may still look perfectly normal while the formula gradually experiences changes in weight, fragrance, texture, or composition.
That is why packaging compatibility testing is particularly important for sunscreen and foundation products.
Why Single-Layer PE May Not Be Enough
PE is widely used in cosmetic packaging because it offers good flexibility, chemical resistance, processing stability, and cost efficiency. For many formulas, a single-layer PE bottle works very well. However, PE is not considered a high-barrier material. For formulations that contain ingredients sensitive to oxygen, fragrance loss, or migration, a single-layer PE structure may not provide sufficient protection.
This can become more noticeable during:
- high-temperature testing;
- accelerated aging;
- long-term storage;
- compatibility testing.
In these cases, brands may need to consider packaging with a stronger barrier structure.
What Is EVOH?
EVOH stands for Ethylene Vinyl Alcohol Copolymer. In cosmetic packaging, EVOH is mainly used as a barrier layer. Its role is to help reduce the transmission of oxygen and certain volatile or organic substances through the bottle wall.
Instead of using EVOH as the entire bottle material, it is usually incorporated as one thin functional layer inside a multi-layer structure. This allows the packaging to combine the advantages of different materials. PE can provide moisture resistance, flexibility, and structural protection, while EVOH provides the main oxygen and migration barrier. The result is a packaging structure that offers better formula protection than standard single-layer PE.
Why EVOH Is Useful for Sunscreen and Foundation Packaging
For sunscreen and liquid foundation products, EVOH packaging can provide several practical benefits.
Improved Oxygen Barrier
Reducing oxygen transmission can help protect formulas containing oxidation-sensitive oils, fragrances, and other ingredients. This is particularly valuable for formulas designed for longer shelf life.
Better Protection Against Ingredient Migration
Certain fragrance components, volatile ingredients, or organic substances may gradually migrate through conventional plastic packaging. An EVOH barrier layer can help reduce this transfer.
Better Formula Stability
By improving the barrier between the formula and the external environment, EVOH packaging can help maintain the original balance of the formulation for longer periods. This can support better stability in color, fragrance, viscosity, and overall product performance.
EVOH Is Part of a Multi-Layer System
EVOH performs best when it is used as part of a properly designed multi-layer structure. It is normally placed between other plastic layers rather than directly exposed as the main external layer.
A simple way to understand the structure is:
Outer layer: structural protection and moisture resistance
Middle barrier layer: EVOH
Inner layer: formula contact and chemical resistance
Depending on the required barrier performance and manufacturing design, EVOH bottles can be produced in different layer structures. The most common options include 3-layer, 5-layer, and 6-layer bottles.
3-Layer EVOH Bottle
A simplified 3-layer structure can be understood as:
PE / Barrier Layer / PE
The outer and inner PE layers provide protection and structural performance, while the middle layer improves barrier properties. Compared with single-layer PE, a 3-layer structure provides an additional level of formula protection while keeping the overall structure relatively simple.
It can be considered for products that need improved barrier performance without requiring a highly complex packaging structure.
5-Layer EVOH Bottle
A typical 5-layer structure is:
PE / Tie / EVOH / Tie / PE
Each layer has a different purpose.
- The outer PE layer provides structural protection and supports surface decoration.
- The first tie layer helps connect PE with EVOH.
- The EVOH layer provides the main oxygen and migration barrier.
- The second tie layer connects the EVOH layer to the inner PE layer.
- The inner PE layer provides direct contact with the cosmetic formula.
This is one of the most commonly used structures for high-barrier plastic bottles. For sunscreen, foundation, skincare, and other sensitive formulas, the 5-layer structure provides a strong balance between barrier performance, manufacturing stability, and packaging flexibility.
6-Layer EVOH Bottle
A 6-layer structure can add an additional functional layer.
A typical structure may be:
Outer PE / Regrind Layer / Tie / EVOH / Tie / Inner PE
The additional layer can be used to optimize material distribution or improve production efficiency.
For brands looking at both barrier performance and material efficiency, this type of structure provides greater flexibility in packaging development. The exact layer design can also be adjusted according to the formula, bottle shape, wall thickness, and required barrier level.
Why Different Layer Structures Require Different Equipment
Producing a multi-layer EVOH bottle is very different from producing a standard single-layer PE bottle. Each material must be accurately distributed into the required layer during the extrusion and blow-molding process. Different layer structures therefore require different production configurations.
For example, 3-layer, 5-layer, and 6-layer bottles require different combinations of:
- extrusion systems;
- material feeding systems;
- co-extrusion die heads;
- layer control systems;
- processing parameters.
The mold and production setup must also be matched to the bottle design and the selected layer structure. This is why multi-layer barrier packaging requires both suitable machinery and experience in material processing. It is not simply a matter of adding EVOH into an existing PE bottle.
Choosing the Right EVOH Structure
More layers do not automatically mean better packaging. The right structure depends on the actual formulation. A relatively stable formula may only require a simpler barrier structure. A more sensitive sunscreen or foundation formula may require stronger oxygen or migration protection. The development process should therefore consider:
Formula → Compatibility Test → Barrier Requirement → Layer Structure → Bottle Design → Production Validation
This approach helps avoid unnecessary over-engineering while still providing sufficient protection for sensitive formulas.
Choebe Multi-Layer EVOH Packaging Capability
At Choebe, we understand that barrier packaging needs to be developed together with the formula.
Different products have different requirements, and a single packaging structure cannot solve every compatibility challenge.
Choebe is equipped with production capabilities for:
3-layer EVOH bottles
5-layer EVOH bottles
6-layer EVOH bottles
Each structure is supported by the corresponding production equipment and manufacturing setup. This allows us to evaluate different packaging solutions based on the customer's formula requirements, barrier targets, bottle design, and intended market positioning. Beyond production, Choebe can also support customers from packaging concept and mold development through testing, decoration, and mass production.
For sunscreen and foundation brands, this means packaging can be considered as part of the formula protection strategy from the early stages of product development. The goal is not simply to create a more complex bottle. The goal is to create the right barrier structure for the right formula.
For beauty brands developing sensitive, high-performance, or premium formulations, EVOH multi-layer packaging provides another option for improving long-term product protection while maintaining the flexibility and design possibilities of plastic packaging.