Inert barrier technology: ultra-thin layer of silicon dioxide extends shelf life

  • Technology applied to plastic cups for the first time
  • Ultra-thin layer of silicon dioxide
  • Barrier coating & plastic form a “covalent bond”

There are a number of techniques that can be used to help extend the shelf life of foods. In the dairy industry, for example, ultra-high-temperature processing and the addition of preservatives are popular options. Consumers have shown themselves to be more and more skeptical of both of these approaches. At the same time, however, they are demanding a long shelf life in order to limit food spoilage. With its inert barrier technology, Greiner Packaging International is addressing these demands.

An ultra-thin layer of silicon dioxide

Inert barrier technology takes advantage of the very good properties of the chemical compound silicon oxide. An extremely thin layer of this material is applied to the inside of plastic cups. The technical conversion is done in the form of a plasma deposition process. The plastic cups are placed in a chamber, which is then placed under vacuum. An electrode inside the chamber then generates a plasma from injected oxygen and silicon-containing gas. This results in the application of a coating to the cups. The barrier coating and the plastic form what is called a “covalent bond”.

20 times higher oxygen barrier than uncoated PP cups

The silicon oxide layer is chemically inert and sharply reduces oxygen and moisture permeability. It increases the oxygen barrier by a factor of 20 compared to uncoated plastic PP cups. Compared to PS packaging, it is even by a factor of 30. Inert barrier technology ensures aroma protection and retains the smell and taste of the contents. It is not sensitive to fluctuations in temperature and humidity, and is also flexible and well-suited for pasteurization and sterilization. Inert barrier technology prevents the so-called ‘retort shock’ (a drop in barrier effectiveness). This increases the shelf life for foods without the addition of preservatives.

Coated packaging considered as monomaterials

The silicon oxide layer applied using inert barrier technology is around 500 times thinner than a human hair. It weighs practically nothing, and therefore has no impact on the packaging weight. Coated packaging has been declared monomaterials and can simply be ground up and recycled.


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