Plastic packaging with durable barrier properties

Plastic packaging with durable barrier properties
Ever since the advent of food packaging, food preservation has been a factor which has had a significant influence on the development of new forms of packaging.

The breakthrough for innovative packaging was made long ago with the arrival of plastic – but to its relatively high gas permeability, this material is not suitable for preserving food over very long periods. However, another breakthrough has successfully been made thanks to the multi-layer barrier compound.

The changing lifestyle of many consumers in terms of smaller packaging sizes, ready meals and frozen food is driving the innovation for new forms of packaging. Extending the shelf life of foodstuffs is a top priority here. The use of thinner and lighter materials means that there is growing demand for functional plastic packaging with barrier properties that must be improved constantly.

Furthermore, legal specifications and the objectives of the food processing industry with regard to extending shelf life have played a part in the establishment of defined barrier properties in packaging. Additional demands to provide greater hygiene and protection against external agents have prompted the packaging industry to develop new solution concepts. Netstal and its Business Unit PAC have assumed a leading role in this regard by meeting these demands with an innovative and patented system.

The three partner companies Netstal-Maschinen AG and Glaroform AG from Switzerland and Ilsemann Automation from Germany are working together to replace existing packaging and their barrier properties with plastic compound solutions that are of high quality, environmentally-friendly and cost-efficient to produce as well as reclosable. A replacement was also developed as a multi-layer barrier compound.

The innovation of the multi-layer barrier compound

What is innovative about this new packaging solution is a barrier foil which is positioned between injected layers of plastic. Firstly, a preformed barrier foil which is similar to the finished container and made from metal or plastic of low permeability is inserted into the mould.

Secondly, the first plastic layer is injected into the outer side of the container followed by a second plastic layer onto the barrier foil on the inner side. The specific structure of the multi-layer barrier compound is such that the barrier foil is protected against damage from the outside without coming into contact with the packaged product.

An additional benefit is that in-mould labelling can be used together this packaging.
The same process also lends itself to the production of the accompanying covers. Another innovation of the multi-layer barrier compound is that there is no “retort shock” upon sterilisation of foodstuffs in the autoclave. The term “retort shock” refers to the weakening of barrier properties in packaging during the sterilisation process due to the water absorption of the plastic. Within the scope of joint development, the first step made was to build and test a pre-series prototype system.

The packaging produced using this system meets practical standards and trials can be now carried out in the food processing industry. The system will be developed further with our partners in the packaging and food processing industries.

Advantages of the process
1.alternative to tins currently in use
2.flexible design
3.optimal market presentation possible thanks to IML
4.comparable shelf life to tins
5. improved quality using injection moulding/in-mould labelling
- reproducible, dimensionally stable
- stackable and hygienic/clean
- product is reclosable
- easy to open
- reduced risk of injury compared to tins
- no damage to bulk materials
- no crevice corrosion, no “tinny taste”
- optimal sealability with oil on the area to be sealed

6. inner layer safe for all filling products such as meat, vegetables, brine, oil, sauces, coffee, tea, medicinal products, paints, lacquers
7. use of recyclate in outer layer possible
8. reduced ecological taxes (classed as composite packaging)

With the multi-layer barrier compound, partner companies Netstal, Glaroform and Ilsemann have heralded a new generation of plastic packaging. Thanks to their many years of experience and extensive expertise in the packaging sector, the three companies have successfully developed a viable replacement for glass and metal packaging.