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.
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.
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 u
sed, 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.
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%.
Applications:
Packaging
Insulation
Electromagnetic shielding
Cooking
Art and decoration
Geochemical sampling
Ribbon microphones
Aluminum Foil Product Range:
| Product |
Alloy |
Temper |
Thickness
mm |
Width
mm |
Coil I.D
mm |
Coil O.D
mm |
Aluminium Foil
|
1235 |
H18 H26
H24 O |
0.00635~0.2 |
90 to 1520 |
75/150/500 |
200 to 1700 |
| 8011 |
H18 H26
H24 O |
0.00635~0.2 |
90 to 1520 |
75/150/500 |
200 to 1700 |
| 8006 |
H18 H26
H24 O |
0.00635~0.2 |
90 to 1520 |
75/150/500 |
200 to 1700 |
| 1060/1100 |
H18 H26
H24 O |
0.00635~0.2 |
90 to 1520 |
75/150/500 |
200 to 1700 |
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