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Application of Transparent AlOx-PET High Barrier Film in Food Packaging

AlOx-PET film is a common high-barrier material, which has been widely used in composite films for food packaging. It is produced by depositing a transparent aluminum oxide (AlOx) layer on the surface of a BOPET film substrate through physical vapor deposition (PVD). This material boasts excellent barrier properties, good thermal stability, high strength, and stable chemical properties. 

Common high-barrier materials can be divided into two categories: transparent and non-transparent. Transparent high-barrier materials mainly include EVOH co-extruded films, nylon films, coated films, and vacuum-deposited films. Non-transparent high-barrier materials include aluminum foil and aluminum-coated films.

Among transparent vacuum-deposited films, there are aluminum oxide films (aluminum trioxide) and silicon oxide films (silicon dioxide). Silicon oxide (such as SiOx-PET) films are favored in high-end product packaging due to their excellent barrier properties, environmental friendliness, and other comprehensive advantages. However, their production cost is relatively higher than other products. In contrast, AlOx-PET films (aluminum oxide films) have a distinct advantage in manufacturing cost, making them more widely used in product packaging. Typically, their oxygen transmission rate (OTR) is ＜2ml/(m²·24h, 23℃ 0%RH), and water vapor transmission rate (WVTR) is ＜2g/(m²·24h, 38℃ 90%RH). Such excellent barrier performance greatly maintains product freshness, enhances product safety, extends product shelf life, and prevents products from deteriorating easily. AlOx-PET films possess the following characteristics and comparative advantages:

- High transparency, relatively environmentally friendly, microwaveable, and detectable by metal detectors when used as food packaging.

- Superior barrier properties compared to K-films (PVDC-coated films).

- Strong stability with minimal impact from ambient temperature and humidity, which is significantly better than EVOH co-extruded films, PVA-coated films, and PVDC-coated films.

- As a printing substrate, the vacuum-deposited layer has a high corona value, ensuring excellent ink adhesion.

- After special treatment, it exhibits outstanding heat resistance and can be used for boiled and retorted products.

There are certain differences between printing-grade and laminating-grade films. For example, commonly used nylon films: printing-grade ones are usually synchronously stretched with single-sided corona treatment, while laminating-grade ones can be asynchronously stretched with double-sided corona treatment. For PET films: printing-grade ones generally undergo single-sided corona treatment in the middle section, while laminating-grade ones feature double-sided corona treatment or single-sided corona treatment with a coating on the other side.

When AlOx-PET film is used as a printing substrate, a protective coating is applied on its surface. This coating can reduce damage to the vacuum-deposited layer caused by film bending, creasing, and friction during machine operation, thereby maintaining excellent barrier properties. For retort printing-grade AlOx-PET films, in addition to the surface protective coating, a primer coating process is also required to enhance the high-temperature adhesion of the vacuum-deposited layer. However, when used as ordinary laminating-grade material, AlOx-PET film usually does not have a surface protective coating to save costs. These differences remind users to be aware of distinguishing between printing-grade and laminating-grade films and avoid various problems caused by mixed use.

- Widely used as a barrier layer in the packaging of food products such as meat, cooked food, biscuits, candies, dried fruits, tea, coffee, chocolate, dehydrated food, pet food, and seafood, etc.

- Replaces K (PVDC)-coated films, significantly improving product barrier properties, reducing environmental pollution caused by PVDC, and enabling boiling and retorting. It also provides better packaging transparency without yellowing.

- Replaces BOPA, EVOH, and co-extruded films, achieving substantial cost reduction, significantly improved product barrier performance, and better adaptability.

- Replaces SiOx films, greatly lowering costs while offering softer handfeel, better transparency, improved processability, and more environmentally friendly recycling.

- Replaces aluminum foil, providing higher lamination strength, lower cost, transparency, microwaveability, and detectability by metal detectors.

- Replaces ordinary aluminum-coated films, delivering better barrier properties, higher lamination strength, transparency, microwaveability, and detectability by metal detectors.

AlOx-PET/CPP (PE);
AlOx-PET/PA/CPP (PE);
BOPP (PET)/AlOx-PET/CPP (PE);
AlOx-PET/PA/RCPP;
PA/AlOx-PET/RCPP;
AlOx-PET/RCPP;
PET/AlOx-PET/RCPP, etc.

If you have any questions or needs about AlOx-PET high barrier packaging, please feel free to contact us via [email protected].