The difference between the squeezing method and the leaching method is that the squeezing method directly separates the oil from the oil by physical pressure, and the whole process does not involve any chemical additives, thus ensuring the safety, hygiene, pollution-free and natural nutrition of the product.

In the leaching method, solvent oil (No.6 light gasoline) is used to process oil raw materials through "six-removal" process (degreasing, degumming, dehydration, deodorization and deacidification), which is one of the reasons why the price of leached oil is generally lower than that of pressed oil. Obviously, from the perspective of pursuing natural health, oil extraction is more in line with people's consumption psychology.

The earliest method of oil extraction was squeezing, and hydraulic squeezing was used about two centuries ago. Due to the high labor intensity and slow processing speed of hydraulic press, continuous or physical extraction methods have been developed recently, including French screw press and Anderson screw press.

These devices are effective for high oil content (30% ~ 50%) such as corn germ and sunflower seeds, but not very effective for low oil content (2 1%) such as soybeans. Press or screw press can be used before solvent leaching and combined with solvent leaching technology.