Common types of equipment for expressing juice or oils are the tank press and the cage press.
The tank press is used for fruit juice production and consists of a horizontal cylinder which is divided internally by a membrane. During an automatically controlled pressing cycle of 1.5 h, fruit pulp is fed into one side of the membrane and compressed air is applied to the opposite side. Juice flows out through channels and, when pressing is completed, the tank is rotated to loosen and discharge the press residue. High yields of good-quality juice are obtained by the gentle increase in pressure at capacities ranging from 3600 kg to 25 000 kg.
In the cage press, up to 2 t of fruit pulp or oilseed flour is placed into a vertical perforated or slatted cage, either loose or in cloth bags depending on the nature of the material. In larger presses, ribbed layer plates are used to reduce the thickness of the pulp or flour bed. The pressure is gradually increased on the top plate by an hydraulic system or motor-driven screw thread and liquid is collected at the base of the press.