Ethylene-vinyl alcohol (EVOH) is one of the most well-known flexible thermoplastic oxygen barrier materials used today. It is needed for refrigerated food. It is also suitable for shelf-stable foods, where oxygen reduces packaging quality and shortens shelf life. The majority of thermoplastic barrier materials used in rigid or semi-rigid food containers are EVOH.
Its moisture sensitivity is limited in lid film used in rigid trays. These trays used for packaging thermally processed shelf-stable food low acid foods. The ongoing use of other oxygen barrier technologies, such as polyvinylidene chloride and aluminum foil, is rampant. Food processing technology innovations provide growth opportunities.
As the food industry developed, so did the packaging needed to keep up with the demand and expectations. Food products were becoming more competitive and technical, with longer shelf lives required. The EVOH laminates were introduced worldwide. It is because they became more important than ever for packaging to provide the best protection and aesthetics.
In this article, let’s find out why EVOH is leverage when using it in packaging.
What is EVOH Film?
EVOH is an adaptable, entirely transparent, lustrous thermoplastic copolymer. It stands for ethylene-vinyl alcohol copolymer (EVOH). This material has an excellent flex-break obstruction. It offers excellent resistance to hydrocarbons, oils, and natural solvents. EVOH is known for having some of the best gas obstruction protection from gases like oxygen, nitrogen, and carbon dioxide. This makes it particularly suitable for packaging nourishment and drugs. Besides, we can use it for packaging beauty care products and other transient objects. Because of this, the EVOH films market is gaining traction in the food packaging industry.
EVOH is thought to have unrivaled obstruction properties. When compared to other standard packaging solutions, EVOH stands out. Yet, when exposed to dampness, EVOH loses its excellent gas-obstruction properties. It doesn’t end here, technology comes in and helps for preservation.
The global EVOH films for the packaging market are increasing. Based on these features, we can use them among various food product manufacturers worldwide.
Why We Use EVOH?
The polar hydroxyl groups cause strong inter-and intramolecular bonding. It is present in the vinyl alcohol unit that is attributed to EVOH’s excellent barrier properties. These hydroxyl groups are also responsible for moisture sensitivity. It is because water is readily absorbed due to the polymer’s hydrophilic nature.
- High barrier property
EVOH provides an excellent oxygen barrier to protect valuable food ingredients. It also ensures that packaged contents remain fresh throughout the entire supply chain. It includes the assurance during prolonged storage. It also reduces and eliminates the need for added preservatives. Besides, it gives food packaged under a modified atmosphere a longer shelf life without loss of quality.
It can be printed with high-quality and eye-catching graphics. It is leverage to give the buyer an extra incentive to purchase for graphics purposes.
Manufactures can process EVOH economically and efficiently. It allows thickness reduction. It was resulting in more economical structures and reducing the impact on the environment.
- Excellent transparency and high gloss
EVOH provides an excellent oxygen barrier as well as superior transparency. It ensures that the food retains its flavor and color for an extended period of time. PackagingBest delivers a good and even layer distribution even under deep forming conditions. We make sure to make an ideal for thermoformed packaging applications. Besides, EVOH has a high gloss and low haze that produce exceptional clarity. The use of EVOH on a package’s outer surface provides an excellent glow for improved package appearance.
- Antistatic Properties
EVOH is a strongly antistatic polymer. It prevents dust from adhering to the package when used as a surface layer. It is very advantageous to use, especially when you are in the food industry.
- Ethylene Content
Understanding the excellent barrier properties of EVOH requires an understanding of its structure. EVOH is made up of monomer units of ethylene and vinyl alcohol. The hydroxyl groups cause the inter-and intra-molecular bonding. Vinyl alcohol units are responsible for the different gas barrier properties. But these units are also known to be soluble in water to be very difficult to synthesize. So, ethylene units have excellent water resistance. The addition of both monomer units results in a processable thermoplastic copolymer. It produces good gas barrier properties, but it is also water sensitive.
The barrier properties of EVOH are also attributed to the polymer’s intrinsic high degree of crystallinity. Crystals domains are usually dispersed in an amorphous matrix. It is to reflect the semi-crystalline structure. The polymer’s barrier properties are also affected by the size and distribution of the crystals. When the ethylene content is less than 40 mol%, the crystals are monoclinic, similar to those found in Poly Vinyl Alcohol (PVOH). When the ethylene content is high (over 80 mol%), the crystals have an orthorhombic structure. It is similar to PE (polyethylene). Intermediate compositions exhibit a mixture of both structures and have a low level of crystallinity.
Another factor that influences barrier performance is the thickness of the EVOH layer. EVOH is typically used as a thin barrier layer in multilayer structures. The thickness is varying depending on the application. An EVOH layer of a few micrometers, typically less than 10 µm, is adequate as a food packaging barrier.
Thermoforming has a significant effect on the material’s thickness distribution. The film material is softened with heat. It is molded by mechanical stretching and pressure in this process. Its thickness distribution and surface area of the final packaging are determined by the corners’ drawing depth and angle. Yet, this effect can be mitigated in part. It is because the film’s stretching can affect the orientation of the polymer chains. In which may be drawn closer together. As a result, chain mobility in amorphous zones can be limited. It makes it more difficult for oxygen molecules to pass through. It is resulting in lower oxygen permeability.
Ethylene-vinyl alcohol copolymers are a class of thermoplastic polymers. It is used in various industries, including food packaging. The main advantage of EVOH films for packaging applications is their excellent barrier to gases. It includes oxygen, carbon dioxide, and so on and organic vapors such as food aroma. To protect oxygen-sensitive goods, EVOH is used in multilayer structures. These are used in bags, trays, cups, bottles, squeezable tubes, or jars. EVOH films also can be used for rigid packaging of entrees, edible oils, and juice. We can also use it in cosmetics, pharmaceuticals, heating pipes, and automotive plastic fuel tanks.
On top of that, we can utilize it in condiment packaging and toothpaste packaging. We can use it in flexible packaging. EVOH is suitable in processed meats, red meat, cereal, pesticides, and agrichemical. The hydrophilic nature of EVOH must be considered in package design. It is to reduce water uptake and polymer swelling during thermal treatment processes such as retorting.
Environmental Benefits of EVOH
The best way to minimize environmental impact is to reduce both product and packaging waste. PackagingBest can help by providing a valuable function. Without diminishing the overall amount of packaging is an assurance from us. It saves money by conserving resources, increasing productivity, and avoiding waste.
- Reducing waste
Throughout a product’s life cycle, PackagingBest helps to conserve resources and reduce waste. The best way to minimize environmental impact is to reduce waste. On top of that, we avoid the loss of all resources invested in producing and distributing fresh food.
- Less Packaging, More Function
When EVOH is used in packaging, our product’s layers of only a few microns allow for the use of fewer resources while still providing a useful barrier function. Optimized portion size and lightweight aid in storage, transport, and display effectiveness. Extended freshness and quality protection help to reduce waste and conserve resources.
- Resist Organic Solvents and Oils
EVOH is resistant to oils and organic solvents. They are ideal for packaging oily goods, edible oils, and mineral oils. It is also used in industrial chemicals and organic solvents.
- Weather Resistance
EVOH has a high degree of weatherability. Even though exposed to sunlight, the polymer preserves its color and does not turn yellow or opaque. Mechanical characteristics changes are minimal, indicating a high resistance to weather effects overall.
Flexible packaging must meet several standards set by food manufacturers. They want their goods to stay fresh for as long as possible. The packaging should keep oxygen and odors. It also should retain aromas and protective modified atmospheres. A pleasing appearance, including excellent transparency, is essential for increasing shelf appeal. It provides an additional incentive to potential customers. Packaging can also be lightweight while still being strong enough to retain all of its valuable properties during transport and handling. In terms of packaging, we are here for your customized packaging. Please contact us for more information.