A new barrier solution for UHT milk packaging

| Preform developements | Société Générale des Techniques, SGT France | Rezé

Specialists in the manufacture of preforms in polyethylene terephthalate (PET), Société Générale des Techniques launched a range of preforms onto the market specially designed to package UHT milk. One year after becoming available, the preforms have already been adopted by the dairy industry.

In fact, SGT has developed a range of monolayer PET preforms with the same qualities as multilayer PET. The innovation rests in the formulation of the resin which provides the PET with new properties, including a total barrier to light. Opaque, hermetically-sealed and therefore a barrier to UV, this new range is now adapted to packaging photosensitive liquids such as milk. 

Fully recyclable, the mono-layer preforms do not require any specific technology for blow moulding and can be customised. They also offer a maximum level of hygiene and safety during aseptic filling and guarantee long-term milk conservation. 

Once blow moulded, the bottle remains perfectly sealed, even without a cap and may be stored horizontally in the fridge. 

Based on this first observation, SGT continued testing and has rolled out this barrier solution to its full 38 mm neck range, which currently represents over 25 different preform models with contents between 250 ml and 2 L. 

Bottle weight has also been studied and reduced. In comparison with a one-litre PEHD bottle which currently weights 29 g, the SGT version only weights 24 g and may be reduced further, providing 20% savings on raw materials. 

Environmentally-friendly, economical and easy to produce in large quantities, the monolayer preform dedicated to milk is a winning solution. While some companies are still testing it, others have already bought it and are marketing it. One thing is sure, this new barrier solution has convinced dairy sector experts of the utility of the plastic packaging.