The origin of aluminium foil can be traced back to early 1900s when a popular candy brand was first packaged in aluminium foil in 1913. To this day, the candies are still being used with aluminium foil packaging. The uses of foil have grown manifold over the past 100 years and its growing use in different sectors and industries are constantly improving the products as well as our lives.
Approximately 75% of aluminium foil is used for packaging of foods, cosmetics, and chemical products, and 25% is used for industrial applications (e.g., thermal insulation, electrical cables, and electronics). Aluminium foil manufacturers commonly use pure aluminium. In recent years it has become popular to add a variety of aluminium alloys engineered to add strength and reduce the thickness of the aluminium foil. Based on the application, foils can be differentiated into the following types –
- Packaging: Aluminium foil is mostly used for packaging as it is highly malleable: it can be easily converted to thin sheets and folded, rolled or packed. It acts as a total barrier to light and oxygen, odours and flavours, moistness, and germs, and so it is used broadly in food and pharmaceutical packaging, including long-life packs for drinks and dairy goods, which allows storing without refrigeration. Aluminium foil containers and trays are used as bakeware.
- Laminated foil is used for packaging things like cigarettes and pharmaceutical items. It helps to savor the freshness of these products and give them a longer shelf life.
- Self-Adhesive foil has one specific side that will stick to the container you wish to cover. This is great for packaging lunch or dinner.
- Insulation: Aluminium foil is widely used for radiation shield (barrier and reflectivity), heat exchangers (heat conduction) and cable liners (barrier and electrical conductivity).
- Electromagnetic shielding: The shielding effectiveness of aluminium foil depends upon the type of incident field (electric, magnetic, or plane wave), the thickness of the foil, and the frequency (which determines the skin depth).
- Cooking: Aluminium foil is also used for barbecuing delicate foods,such as mushrooms and vegetables.
- Art & Decoration: Heavier foils made of aluminium are used for art, decoration, and crafts, especially in bright metallic colours. Metallic aluminium, normally silvery in colour, can be made to take on other colours through anodisation. Anodising creates an oxide layer on the aluminium surface that can accept coloured dyes or metallic salts, depending on the process used. In this way, aluminium is used to create an inexpensive gold foil that actually contains no gold, and many other bright metallic colours. These foils are sometimes used in distinctive packaging.
- Geochemical Sampling: Foil is used by organic/petroleum geochemists for protecting rock samples taken from the fields and in the labs where the sample is subject to biomarker analysis.
- Ribbon Microphones: The material used in many ribbon microphones is aluminium leaf, or "imitation silver leaf", as it is sometimes called. This is pure aluminium and is around 0.6 to 2.0 micrometres thick.