1) Product Description:
Aluminium foil (or aluminum foil), often referred to with the misnomer tin foil, is aluminium prepared in thin metal leaves
with a thickness less than 0.2 mm (7.9 mils);Thinner gauges down to 6 micrometres (0.24 mils) are also commonly used.
In the United States, foils are commonly gauged in thousandths of an inch or mils.Standard household foil is typically
0.016 mm (0.63 mils) thick, and heavy duty household foil is typically 0.024 mm (0.94 mils).The foil is pliable, and can
be readily bent or wrapped around objects.Thin foils are fragile and are sometimes laminated to other materials such as
plastics or paper to make them more useful.Aluminium foil supplanted tin foil in the mid 20th century.
2) Manufacture:
Aluminium foil is produced by rolling sheet ingots cast from molten billet aluminium, then re-rolling on sheet and foil rolling
mills to the desired thickness, or by continuously casting and cold rolling.To maintain a constant thickness in aluminium foil
production, beta radiation is passed through the foil to a sensor on the other side.If the intensity becomes too high, then
the rollers adjust, increasing the thickness.If the intensities become too low and the foil has become too thick, the rollers
apply more pressure, causing the foil to be made thinner.
The continuous casting method is much less energy intensive and has become the preferred process.For thicknesses
below 0.025 mm (1 mil), two layers are usually put together for the final pass and afterwards separated which produces
foil with one bright side and one matte side.The two sides in contact with each other are matte and the exterior sides
become bright;This is done to reduce tearing, increase production rates, control thickness, and get around the need
for a smaller diameter roller.[9]
Some lubrication is needed during the rolling stages;Otherwise, the foil surface can become marked with a herringbone
pattern.These lubricants are sprayed on the foil surface before passing through the mill rolls.Kerosene based lubricants
are commonly used, although oils approved for food contact must be used for foil intended for food packaging.
Aluminium becomes work hardened during the cold rolling process and is annealed for most purposes.The rolls of foil
are heated until the degree of softness is reached, which may be up to 340°C (644 °F) for 12 hours.During this heating,
the lubricating oils are burned off, leaving a dry surface.Lubricant oils may not be completely burnt off for hard temper
rolls, which can make subsequent coating or printing more difficult.
The rolls of aluminium foil are then slit on slitter rewinding machines into smaller rolls.Roll slitting and rewinding is an
essential part of the finishing process.

3)Properties:
Aluminium foils thicker than 25 µm (1 mil) are impermeable to oxygen and water.Foils thinner than this become slightly
permeable due to minute pinholes caused by the production process.
Aluminium foil has a shiny side and a matte side.The shiny side is produced when the aluminium is rolled during the final
pass.It is difficult to produce rollers with a gap fine enough to cope with the foil gauge, therefore, for the final pass, two
sheets are rolled at the same time, doubling the thickness of the gauge at entry to the rollers.When the sheets are later
separated, the inside surface is dull, and the outside surface is shiny.This difference in the finish has led to the perception
that favouring a side has an effect when cooking.While many believe (wrongly) that the different properties keep heat out
when wrapped with the shiny finish facing out, and keep heat in with the shiny finish facing inwards, the actual difference
is imperceptible without instrumentation.Increased reflectivity decreases both absorption and emission of radiation.Foil may
have a non-stick coating on only one side.The reflectivity of bright aluminium foil is 88% while dull embossed foil is about 80%.

4)Applications:
Packaging
Insulation
Electromagnetic shielding
Cooking
Art and decoration
Geochemical sampling
Ribbon microphones

5)Aluminum Foil Product Range: