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How Aluminum Foil Is Made

2016-10-18

Aluminum foil is inexpensive, durable, non-toxic, and greaseproof. In addition, it resists chemical attack and provides excellent electrical and non-magnetic shielding.

Shipments (in 1991) of aluminum foil totaled 913 million pounds, with packaging representing seventy-five percent of the aluminum foil market. Aluminum foil's popularity as a packaging material is due to its excellent impermeability to water vapor and gases.

Aluminum foil is produced by rolling aluminum slabs cast from molten aluminum in a rolling mill to the desired thickness. To maintain a constant thickness, a technician monitors the rolling mill sensors to ensure the pressure on the slab is correct. Sensors are able to tell the technician if the pressure is too great or not enough and then the technician can adjust the rollers to apply more or less pressure. It is then coiled and sent to the cold rolling mill. To avoid breakage because of the thinness, the foil is doubled in the cold rolling mill and the rolled to the desired thickness. Aluminum foil provides a complete barrier to light, oxygen, moisture and bacteria. For this reason, foil is used extensively in food and pharmaceutical packaging. It is also used to make aseptic packaging that enables storage of perishable goods without refrigeration.

Aluminum foil was so vital to the defense effort that families were encouraged to save strips of foil. In many towns, the collected foil balls could be exchanged for free entry to a movie theater.

It is used to manufacture thermal insulation for the construction industry, fin stock for air conditioners, electrical coils for transformers, capacitors for radios and televisions, insulation for storage tanks, decorative products, and containers and packaging. The popularity of aluminum foil for so many applications is due to several major advantages, one of the foremost being that the raw materials necessary for its manufacture are plentiful.