Aluminum disc
Encyclopedia
An aluminium disc is a disk made out of aluminium
and is used as a transcription disc in magnetic recording media, specifically early radio
recordings. Aluminium discs are also used in hard disk
(as "platters"), shock tube
s, and other manufacturing processes.
Originally, aluminum disc recordings were produced by scratching an imprint directly onto the aluminum surface. Such recordings were very durable, but could not be re-recorded. In 1934, the Pyral
Company in France
, and the Presto Corporation in the United States
, independently created the acetate disc
by applying a layer of lacquer
onto the aluminum disc. This made re-recording possible, but over the years some recordings have been lost due to the acetate drying up and flaking off.
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
and is used as a transcription disc in magnetic recording media, specifically early radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
recordings. Aluminium discs are also used in hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
(as "platters"), shock tube
Shock tube
For the pyrotechnic initiator, see Shock tube detonatorThe shock tube is an instrument used to replicate and direct blast waves at a sensor or a model in order to simulate actual explosions and their effects, usually on a smaller scale...
s, and other manufacturing processes.
Originally, aluminum disc recordings were produced by scratching an imprint directly onto the aluminum surface. Such recordings were very durable, but could not be re-recorded. In 1934, the Pyral
Pyral
Pyral SAS is a manufacturer of magnetic recording media products, based in Avranches, France. As of 2004, it is an independent company.Prior to 2004, it was part of EMTEC, BASF, and Rhône-Poulenc....
Company in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, and the Presto Corporation in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, independently created the acetate disc
Acetate disc
An acetate disc, also known as a test acetate, dubplate , lacquer , transcription disc or instantaneous disc...
by applying a layer of lacquer
Lacquer
In a general sense, lacquer is a somewhat imprecise term for a clear or coloured varnish that dries by solvent evaporation and often a curing process as well that produces a hard, durable finish, in any sheen level from ultra matte to high gloss and that can be further polished as required...
onto the aluminum disc. This made re-recording possible, but over the years some recordings have been lost due to the acetate drying up and flaking off.