What is Barrier in Food Packaging? Extension Shelf Life with EVOH and PA Layers

One of the biggest causes of deterioration of food products is oxygen and moisture, which leaks inside the packaging. The concept of "Barrier" is fully activated at this point: the packaging means how much the film does not pass gas, moisture, light and flavor. The higher the barrier, the shelf life of the product is so long.

Barrier Types

• Oxygen Barrier: It delays the pain of fats and microbial deterioration. EVOH and polyamide stand out in this regard.
• Water steam (nem) barrier: Prevents drying or moistening of the product. Polyethylene (PE) and polypropylene (PP) are strong moisture barrier.
• Aroma Barrier: Prevents the loss of smell in products such as coffee, spices and chocolate, or the intake of smell from outside.
• Light Barrier: It is provided with metalized or opaque structures; it protects light-sensitive products.

Why is EVOH Layer Important?

EVOH (ethylene vinyl alcohol copolymer) is one of the polymers that provide the highest oxygen barrier known. Generally placed between PE or PET layers because it is sensitive to moisture alone. Thus, both high oxygen barrier and good moisture protection are achieved. PE-EVOH-PE and PET+EVO Home Widely used in structures, modified atmosphere packaging (MAP).

Polyamide (PA) Layer

Polyamide provides both medium-high-level gas barrier and provides excellent mechanical strength (punching and puncture resistance). PA/PE and PA/EVOH/ Home Home structures form the basis of thermoform and vacuum applications.

How Much Layer Movies Work?

Modern food packaging is made of a single material, each of which consists of layers that are undertaken as a different task. Typical structure:

• Outer layer: printing surface and mechanical protection
• Medium layer(s): barrier (EVOH, PA) and adhesive (tie layer)
• Inner layer: heat source (sealing) layer, usually PE

GKK Foil designs these layers with coextrusion and lamination technologies according to the requirement of your food product.

Select the Right Barrier Level

No maximum barrier required for each product. High humidity barrier for dry bread is enough; high oxygen barrier is critical for fresh meat and cheese. High barrier from the back can improve both cost and make the recycling difficult. Therefore, the choice of barriers should be performed by observing the balance of product-life–cost.

To determine the structure of barrier suitable to your product Contact GKK Foil.