Dairy

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. 

Traditionally lids were embossed to ensure reliable handling on the lidding machine; today they can also be supplied without embossing. The separation characteristic is provided by a pattern of ‘dots’, messages or logo designs printed on the inner sealing side.

Opaque lids for dairy product containers can help to extend shelf life by protecting the sensitive contents from direct exposure to the strong fluorescent lighting in refrigerated supermarket display cabinets.

An alufoil closure completely eliminates spoilage due to exposure to the atmosphere and deterioration during storage.

Where a total barrier is required, as in the case of processed cheese products, aluminium foil provides ideal protection and attractive portion presentation. The ‘dead-fold’ nature of the foil, even when laminated to a paper substrate, gives full control during and after the wrapping process. With processed (sterilised) cheese portions, the foil is edge-sealed and an easy open tear tape can be built into the portion packaging to facilitate opening.

Attractive alufoil packs continue to attract consumer attention in the cool cabinet. For many well-known brands the bright foil packaging is an intrinsic part of the product. As well as prolonging the shelf life of the cheese by protecting it from drying out or the effects of light and odours, the decorated alufoil laminate maintains the brand presence until the last portion has been used.

Alufoil cheese packaging is not only available as a wrapper. An example of an alufoil container application is the packaging of spreadable cheeses by Tine, a Norwegian dairy product manufacturer. The company chose a range of specially designed and decorated aluminium containers with attractively printed alufoil peel-off lids and plastic covers.

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.

Developments in the design of butter and fat wrappers have included the introduction of tough puncture resistant and even ‘ice proof’ laminates. The freeze and thaw resistant butter wrapper overcomes the problem of moisture condensation which can sometimes cause delamination when a traditional foil/paper wrapper is thawed.

For heat-processed dessert products the alufoil container has several advantages. The entire pack is opaque. No deterioration due to UV light ispossible. The conductivity of the alufoil allows rapid heating, minimum processing time and rapid cooling. The decorative potential of the container is high. In the case of the smoothwalled container format, pre-distorted printing allows for excellent graphics on the shaped dish. In a similar way to yoghurt or cream, lids can be decorated and either embossed with a pattern or entirely smooth.