Eight track and cassette tapes were introduced in the 1960s.
Development of vinyl.
For audiophiles everywhere it remains the singular most impressive format of recording and reproducing music.
Generally unsaturated polyester resins including conventional vinyl resins shrink when cured and can.
The major period for vinyl was from the inception of the vinyl lp in 1948 to 1988 when cds outsold records for the first time.
By the mid 1980s more cassettes than vinyl records were sold.
Because vinyl records can become scratched warped and dirty other formats slowly took over.
The groove usually starts near the periphery and ends near the center of the disc.
Development of low shrinkage vinyl resin.
During and after world war ii when shellac supplies were extremely limited some 78 rpm records were pressed in vinyl instead of shellac wax particularly the six minute 12 30 cm 78 rpm records produced by v disc for distribution to us troops in world war ii.
As a range of unsaturated polyester resins vinyl ester resins have higher activity and faster curing reaction resulting in a larger curing shrinkage rate after curing of the vinyl ester resin.
Beginning in 1939 columbia records continued development of this technology.
Beginning in 1939 columbia records continued development of this technology.
Vinyl had the advantage of lower surface noise level than shellac and was more durable.
At first the discs were commonly made from shellac with earlier records having a fine abrasive.
A phonograph record also known as a gramophone record especially in british english or simply a record is an analog sound storage medium in the form of a flat disc with an inscribed modulated spiral groove.