Aluminium Foil
Developed more than 100 years ago, aluminium foil is a very thin aluminium sheet, with a gauge below 200 µm, down to 4 µm. It is an efficient material that can be used in many different applications, including food, beverage, and pharmaceutical packaging, as well as for technical applications such as for cable wraps, heat exchangers and Li-lon batteries.
In 2020, 6 million tons of aluminum foil market was being generated across the globe. China is now the largest producer of aluminum foil in the world with 54% of the total capacity, followed by Europe (14%), North America (12%), Japan, and India.
Packaging, including for food, beverage, and pharma, dominates the global aluminum foil market and amounts to 60% of the total demand. The other 40% is used for technical applications such as heat exchangers (automotive and building), insulation, cable wraps, and batteries. However, the demand for aluminum foil for batteries is growing significantly.
• Aluminium foil properties:
- Absolute barrier protection: Aluminium foil is an absolute barrier to light, oxygen, gases, moisture, bacteria and provides a high level of protection, preservation, and conservation of products for long periods of time without the need for refrigeration.
- Net saver of resources: Thanks to it providing absolute barrier protection, being lightweight, and having infinite recycling possibilities, used in food and beverage applications, aluminium foil actually saves more resources than it needs for its production.
- Recycling: As a material, aluminium is infinitely recyclable and can be recycled without losing its properties or quality. Indeed, remelting aluminium foil only requires 5% of the energy needed to produce primary aluminium.
- Mechanical Properties: Aluminium foil is malleable, foldable, formable and can be used for wrapping without losing any of its barrier properties. Moreover, depending on its thickness, alloy, or temper, aluminium foil can be moulded into any shape.
- Hygiene: After annealing at a high temperature at the end of the production process, aluminium foil is completely sterile and safe to use with most foods. However, in most other applications, it is typically laminated with another material.
- Printing qualities: Aluminium foil, whether with a bright or matte finish, is compatible with all printing technologies.
- Conductivity: Aluminium foil has an excellent thermal and electrical conductivity and is ideal for heat-sealing or high-precision and ultra-sonic sealing.
- Lightweight: Aluminium is a very light metal with a density 2.7g/cm3 - one third that of steel, and, therefore, can minimize both the weight and waste of product packaging and help you to save resources during product transportation.
• Aluminium foil production:
Aluminium is one of the most abundant elements in the earth’s crust. Indeed, it is a very popular metal due to its unique properties; infinite recyclability, superior corrosion resistance, absolute barrier protection, high heat conduction, and a very high strength-to-weight ratio.
Aluminium is used in many innovative industries, including the automotive and aerospace industries, and for a range of applications, including product packaging.
Aluminium production begins with bauxite mining, which is refined into alumina (aluminium oxide), and then converted into aluminium through electrolytic reduction. As aluminium is infinitely recyclable, recycled materials such as aluminium foil are then introduced into the production process in order to protect the environment.
Recycled aluminium foil which has exactly the same properties and specifications of the primary metal, is melted in a melting furnace (using only 5% of the energy needed to produce primary aluminium).
Aluminium foil can then be produced using either the ‘DC Process’ or the ‘CC Process.’ With current technology and equipment, both of these processes are viable, and both produce good quality thin aluminium foil.
For the DC Process, the aluminium foil is produced by first rolling heated aluminium ingots (hot rolling) down to coils with gauges of 2 to 4mm. These are then cold rolled by several passes to create the required foil gauge.
For the CC Process, the molten metal is converted directly (using continuous casting) into coils with gauges of 5-6mm. These coils are then coil rolled into coils with the final foil gauge.
When the foil has reached its final gauge, the coils are slitted into final widths and coil sizes, before being annealed in a special furnace. For many of the foil’s applications, the annealing of the foil is a critical step.
Indeed, annealing removes all organic waste from the foil and ensures it is absolutely clean for any future contact with food. It also creates the final mechanical properties for optimised running.
• Aluminium Foil Markets:
One of the largest applications of aluminium foil is flexible packaging which includes aseptic beverage cartons, confectionary, bakery and other oven cooked products, coffee, tea and chocolate drinks, tobacco products, and pharmaceutical packaging.
Other large applications of aluminium foil include aluminium foil containers and household foil for home cooking or food storage. Aluminium foil is also widely used in commercial kitchens in restaurants, hospitals, schools, and canteens.
Besides these food, beverage, and pharmaceutical applications, aluminium foil is used in many technical applications. For example, aluminium foil is used in heat exchanges in cars and trucks and for insulation and cable wrapping in the construction industry.
Aluminium foil is also used in Li-Ion batteries, the demand for which has increased significantly in recent years due to the huge growth in popularity of electrical cars.