What Are Aluminum Discs and How Are They Made?Daniel Franklin | August 06, 2018
Aluminum discs or circles in various sizes and thicknesses are commonly used to manufacture products, as well as more creative uses. Products manufactured with aluminum circles include capacitors, medical tubes and kitchen wear, as well as beverage cans.
The circles are often drawn with presses into various sizes. Capacitors use small cans, whereas an aluminum kitchen pot would be much lager. The size and thickness of the circle are matched for the desired size and thickness of the finished product. Because aluminum is quite malleable, it makes it easier to draw to the final shape than other metals. Aluminum does not rust like steel, but it does oxidize and is often coated to prevent this.
In other cases the aluminum oxide may be desirable. With capacitors it acts as a thin electrical insulator, for example. In some cases aluminum circles are used in their original circular shape to make pet and key tags. Instead of being drawn, these circles are engraved or have lettering stamped into them. Large, thick discs are another type used for different products. These are cut with computer numerical controlled (CNC) equipment or forged into shapes such as gears or supports. In addition to these mentioned uses, there are many other applications of aluminum circles as they lend themselves to further manufacturing or use as-is.
The production process starts with raw aluminum, which is melted and mixed in various ratios with other metals, or kept pure and cast. Eventually this is rolled into aluminum sheets which are coiled onto spools. In some cases the sheets are cut into smaller coils for processing but are sometimes used as a full sheet. These aluminum sheets are passed through a blanking machine that cuts out circles from the roll of material. The discs are then stacked for finishing.
The cut out circles are annealed, softening the edge that was cut, as the blanking process has a tendency to harden the edge. Annealing is a process of heating and cooling in which the metal is cooled slowly to remove the internal stresses. After the circles have been cut and annealed, there is remaining scrap from the sheet, which is recycled back into the process as raw material. Cut discs are stacked, packaged and sold to various factories to make many of the above-mentioned products. Large users of aluminum circles may choose to purchase aluminum sheet and perform the blanking process themselves. This has a cost advantage of purchasing sheets, but requires additional material handling to deal with the scrap, since the scrap needs to be shipped back to an aluminum processing company. Additionally, the machine maintenance and space adds cost to the process, which needs to be considered when deciding to purchase discs or perform the process in-house.
While aluminum discs themselves are not complicated, the resultant products and production often requires some thought.