Pressing information-bearing thermoplastic discs under HF heating - using pref. silicone rubber forming plates of low dielectric loss

摘要

The thermoplastic discs may bear picture or sound signals. They are pressed, using high-frequency heating. The press's forming plates, which bear the new information pattern, are made of a plastic, pref. (silicon) rubber, of low dielectric loss, while the discs are made of a plastic of high dielectric loss. When previous information is erased, the HF current is continued until it has passed its mas. and is again reducing.