Milk, cream and yoghurts packaged in sterile cartons makes it possible to preserve their intrinsic properties, without refrigeration, due to a very thin layer of aluminium foil. These long-life packs are impervious to light, odour and gases, while at the same time providing a crucial barrier to light and oxygen and the preservation of essential vitamins. Such aseptic cartons are lightweight and designed for efficient transportation, storage and on-shelf display. Most importantly, without the need for refrigeration due to the alufoil layer, considerable savings in energy resources along the supply chain can be achieved.
The compatibility of aluminium foil with heat-seal lacquers, coupled with the metal’s excellent heat conductivity and stability, makes it the ideal material for capping and heat-sealing of all types of plastic milk containers. Whether the milk is fresh, aseptically filled or sterilised in the container, the foil/coating combination can be designed to meet the demands of processing and distribution. A foil diaphragm solves the problem of achieving a reliable screw-top closure for blow-moulded milk bottles. This is heat-sealed to the bottle opening using induction heating. Only the metal foil becomes heated by a high frequency electro-magnetic field which is applied after filling and capping. Although reliably sealed, the foil can be peeled away cleanly thanks to coatings that combine seal strength with peelability.