Record press

It is essentially a hydraulic press fitted with thin nickel stampers which are negative impressions of a master disc.

[2] The process of compression molding forces the hot vinyl to fill the grooves in the stampers, and take the form of the finished record.

In the mid-1960s, Emory Cook developed a system of record forming wherein the mold pressure was replaced by a vacuum.

In this technique, the mold cavity was evacuated and vinyl was introduced in micro-particle form.

A small pressing plant in Hollywood also employed a similar system which they maintained fused the particles more evenly throughout the disc thickness calling their product polymax.