Oil Expeller is also known as screw oil press. Continuous screw pressing can deal with almost all kinds of oilseeds and nuts (soybean, cotton seed, copra, rice bran, palm kernel). 
Oil pressing line usually including oil pre-treatment and oil pressing two parts. Different oil seeds materials for oil pressing plants are pre-treatment in different ways, which usually includes cleaning, de-stoning, cracking, cooking, faking before going through the expander/expeller. Next is the Mechanical Oil Pressing process. The cake is sent to the extractor/press/expeller for pressing oil, then flitered via vibrating sieve or filter press to get clean & clear crude oil.
Mechanical Oil Pressing Types
● Pre-pressing:
Pre-pressing is a technique used where oilseeds are subjected to a preliminary pressing to remove some of the oil content, leaving behind a cake that can be further processed to extract the remaining oil. The resulting oil from pre-pressing is usually of good quality and has a higher yield. 70% of the oil will be extracted, the oil residual in cake is around 15-18%
● Cold Pressing:
Keep the temperature between 60 and 70℃ in order to prevent the protein denaturation.Cold Pressing produces oil that retains more of its natural flavor and nutrition. However, the yield of oil from cold pressing is usually lower compared to other methods.

● Hydraulic Pressing:

Hydraulic pressing is wildely used in sesame, walnut, avocado, coconut and other oilseeds extracting oil. Specially designed in a compact structure for domestic and small oil mill use; offers pure and high-quality edible oil.