What is the working principle of the oil press?

Oil press working principle:

When the oil press is running, the processed oilseeds enter the pressing chamber from the hopper. The pressing screw rotates to push the seeds into the pressing chamber for extraction. As the seeds move through the pressing chamber of the oil press, the high pressure in the chamber creates significant friction resistance between the seeds and the pressing screw, and between the seeds and the pressing chamber, causing friction between the seed particles and resulting in relative movement.

Additionally, since the root diameter of the pressing screw gradually thickens and the pitch gradually reduces, when the pressing screw rotates, the thread forces the seeds to push forward and flip outward. At the same time, the material layer close to the surface of the pressing screw thread also rotates with the pressing shaft. Consequently, each seed particle in the pressing chamber does not move at the same speed or in the same direction, but there is relative movement between the particles. The heat generated by friction meets the heat required for the oil pressing process, which helps to promote the thermal denaturation of protein in the seeds, destroy the colloid, increase plasticity, and reduce viscosity, making it easier for oil to precipitate. This process increases the oil output rate of the oil press, allowing the oil to be squeezed out from the material and flow out through the gaps between the pressing bars and the strips.