4 bolt oil expeller

An expeller press is a machine that squeezes oil through a cavity, using continuous pressure and friction. Expeller pressing extracts about 87 to 95% of the oil out of the seed, so some oil is left over after the pressing process is completed. Expeller-pressed oil is commonly refined using this same process.The original oil expeller press was invented in the late 1800s by Anderson International's founder, Valerius D. Anderson. This patented mechanical screw press design was a radical departure from hydraulic presses used at the time.