Abstract: Rubber-molding presses, which are closed manually upon installation of pieces of rubber compound, are opened automatically by a system which continuously calculates and recalculates the correct cure time and is actuated when the calculated cure time equals the elapsed cure time. An interval timer starts running from the time of mold closure, and the temperature within the mold cavity is measured often, typically every ten seconds. The temperature is fed to a computer which also is given access to the time-temperature cure data for the compound being molded, and the computer calculates and recalculates every time the data as to temperature is presented, until the total picture of time and temperature presents to the computer the time at which the material is fully cured. Then the computer signals for automatic opening of the mold press.