When rolled, aluminium is first passed through a hot rolling mill and then transferred to a cold rolling mill.

Hot rolling mills

Before rolling, the aluminium is an ingot of up to 600mm thick. This ingot is heated to around 500°C and passed several times through the hot rolling mill. The thickness of the metal is gradually reduced to around 6mm. This thinner aluminium is then coiled and transported to the cold rolling mill for further processing.

Cold rolling mills

There are several types of cold rolling mill, and they produce various types of rolled product, with thicknesses as low as 0.05mm.

In general the type of product depends on the alloy used, the rolling deformation and thermal treatment used in the process as well as careful adjustments to the mechanics and chemistry of the process. Rolling mills are controlled by very precise mechanisms and measuring systems.

Rolled products

Rolled products can be divided into foil, sheet and plate.

Foil is less than 0.2 mm thick and is used mainly in the packaging industry for foil containers and wrapping. Foil is also used for electrical applications, building insulation and in the printing industry.

Sheet is between 0.2 mm and 6mm in thickness and has a wide variety of uses in the construction industry including aluminium siding and roofing. Sheet is also used extensively in transport applications such as automobile body panels, airframes and the hulls of boats.

Plate is any rolled product over 6mm in thickness. It also is found in a number of applications including airframes, military vehicles and structural components in bridges and buildings.

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