Anti-fog film

Applications of anti-fog film

Anti-fog films are used in many different areas. For example, they are applied in ski goggles, safety goggles, and other types of eyewear to prevent lenses from fogging up. Windows or mirrors in rooms with strong temperature fluctuations can also be protected against condensation with anti-fog film. Vehicle windows can likewise be safeguarded from fogging. Anti-fog films are especially widespread in the packaging industry, particularly in food packaging.

Anti-fog film for food packaging

Packaged food often contains moisture or at least residual humidity. To prevent this remaining moisture from condensing on the packaging film or on a viewing window in cardboard packaging when outside temperatures allow it physically, a film with anti-fog properties is required. This feature ensures that the moisture forming inside the packaging does not appear as droplets on the film packaging or the viewing window. Customers maintain a clear view of the packaged products, the goods look more appealing, and the products are protected from damage caused by condensed moisture. For fresh products such as fruit and vegetables, as well as meat, sausage, and cheese, the use of anti-fog film is therefore particularly important.

Types of anti-fog film in the food sector

• Cling films with an anti-fog effect are used for packaging fresh foods such as meat, fish, or fruit. They ensure a clear and attractive view of the product.
• Viewing windows for cardboard packaging play an important role in the food sector, as cardboard packaging is considered environmentally friendly. Here, it is especially important that the viewing windows provide an unobstructed view of the product through an anti-fog effect.
• Lidding films with an anti-fog coating are used as covers for fresh food trays and containers. They prevent the cover from fogging up and also ensure an appealing presentation.
• Vacuum packaging and shrink films with an anti-fog effect for vacuum-packed foods such as cheese or processed meats ensure that the product does not fog up from the inside during storage and remains clearly visible.

Materials used for anti-fog films

Anti-fog films are usually made from polycarbonate (PC), polyethylene terephthalate (PET), or acrylic. These films are equipped with a special coating that prevents fogging. However, there are also materials that have natural anti-fog properties. These include, for example, films made from CDA (cellulose diacetate).

The anti-fog film optimont® AF

With optimont® AF, Bleher Folientechnik offers an anti-fog film made from BO-PET material. One side of this film is equipped with an anti-fog surface, while the other side features improved adhesion. This makes the film versatile in use and suitable for printing. The underlying BO-PET material provides excellent heat resistance, dimensional stability, high mechanical durability, and resistance to a wide range of chemicals.

The anti-fog film optimont® CDA

CDA is made from cellulose and is therefore a film produced from renewable raw materials. optimont® CDA is crystal clear, food-safe, certified compostable, and features a natural anti-fog effect. CDA film is scratch-resistant, has a high surface tension, and is suitable for viewing windows in packaging, window lamination and back bonding, as well as print lamination.

Environmental friendliness of anti-fog film

With optimont® CDA, there is an anti-fog film made from a renewable raw material that is certified compostable according to several certification methods. This film therefore provides an alternative to anti-fog films based on petrochemical raw materials. However, optimont® CDA is not as mechanically durable as competing materials, especially BO-PET. Wherever packaging requires not only an attractive, fog-free presentation but also high mechanical strength, anti-fog films made from petrochemical raw materials remain the preferred solution for now.

Advantages of anti-fog film

• Attractive product presentation

Fogged packaging appears unattractive and unhygienic to customers.

• Improved shelf life

Anti-fog films provide better moisture regulation inside packaging. This can extend the shelf life of products, as they are not damaged by condensed water.

• Wide range of applications

Anti-fog film is suitable for various packaging methods: viewing windows in cardboard packaging, full film packaging, vacuum packaging, and lidding film.

• Temperature resistance

High-quality anti-fog films can also be used at low temperatures, enabling their application in cooling systems and refrigerated display cases. Disadvantages of anti-fog films

• The coating can be affected by strong temperature fluctuations.
• Aggressive cleaning agents may reduce or eliminate the anti-fog effect.
• Anti-fog treatment is cost-intensive, which impacts the overall cost of packaging.
• Not all anti-fog films are suitable for every type of food. Selecting the right film requires expertise and experience.