Acoustic Revive RD-3 CD/SACD/DVD/BD Disc Demagnetizer

Firstly, it is thought that ferrous ingredients contained in the printing ink of the label side of the disc is one of the causes of discs becoming magnetized. For example, iron oxide is used for red, yellow or brown ink, cobalt is used for blue or green ink and nickel is used for silver ink. These materials, iron, cobalt and nickel, are called ferromagnetic substances, and they are relatively easy to magnetize.

Second, problems are caused by the aluminum used for the recording side of the CD. Currently, the JIS (Japanese Industrial Standard) states that the purity of the aluminum used must be at least 99.0 %. The other 1 % contains ferromagnetic substance such as iron, nickel and cobalt. Aluminum is a weak magnetic material, so it is easily influenced by magnetism.

CD players contain magnetic substances, when a disc is played, the rotation of the mechanism, magnet and motor generates a flux which quickly causes discs to become magnetized.