Expeller is the key equipment of screw-press process, which 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). Below is the clarification of mechanical oil extracting:

• Single Pressing: Also called full pressing. The oil could be extracted as much as possible. The oil residual in cake is around 5-7%
• Prepressing: 70% of the oil will be extracted, the oil residual in cake is around 15-18%
• Heat Pressing: Cook the oil seeds before pressing in order to be extracted more oil
• Cold Pressing: Keep the temperature between 60 and 70℃ in order to prevent the protein denaturation.

Advantages of Screw Oil Pressing:The mainly advantages of screw pressing type oil extraction plant by means of oil expeller is better adaptability, flexible production, high quality of the oil, light color, pure flavor, simple technology, few supporting equipment.

Mechanical Oil Pressing Types :

• Single Pressing (Full Pressing): Generally applied in small oil pressing plant. The key equipment is expeller by means of mechanical extraction. Double pressing is available for high oil content seeds, so that to achieve higher output.
• Pre-pressing: It belongs to mechanically oil extraction. It is mostly applied in large scale oil processing projects to process high oil-content oilseeds. Use screw oil mill machine (expeller) for pre-pressing to get initial oil. Then pre-pressed oil cakes will go through solvent extraction process.
• Hot Pressing: It means the oil plant includes cooking process. Hot oil pressing utilizes heat and mechanical pressure to extract oil from seeds and nuts. It is featured of high yield of oil recovery.
• Cold Pressing: Mechanically separating oil from raw materials through crushing and pressing. This oil pressing type uses only the application of pressure, without heat and any chemicals.
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  Soybean Oil Pressing
  
  Sunflower Seeds Oil Pressing
  
  Peanut Oil Pressing
  
  Sesame Oil Pressing
  
  Corn Oil Pressing
  
  Castor Oil Pressing
  
  Canola Oil pressing
  
  Cottonseed Oil Pressing