The two unit operations not only use mechanically very similar machines. Innovation attempts a range of operational combinations. Puffing is a heat treatment process, while steaming/tempering is a prerequisite for effective oil extraction. Therefore, the idea of combining these two unit operations is self-evident. It started with the installation of a small device on "full-fat" oil products (mainly soybean and cottonseed meal) as animal feed, using an extruder for moist heat treatment to reduce anti-nutritional factors.

Unfortunately, as explained earlier, expanding high oil content oils is not very efficient or requires special geometry of the screw shaft and large amounts of electrical energy. However, once these initial issues were resolved, the system was characterized by a very simple setup, good oil production efficiency, high oil press output and low energy consumption. The flash evaporation of material moisture during the discharge of the extruder requires a good ventilation system to avoid excessive condensation in the downstream conveyor or screw press.

The advantages and benefits of combining puffing with screw pressing are obvious, but the reverse order has been applied and can still be seen in some places. The main motivation for this process solution is that the extruder can produce granular materials with a certain structure and stability. In the case of poor screw pressing (pre-pressing) performance, after the cake with high oil content enters the solvent leaching system, the excess powder leads to poor solvent permeability and high residual oil content in the cake. Extruders for pressed press cake are designed to improve the structural strength of the press cake. Early press-expanding was tested in multi-oil plant plants where extruders were already available for soybean processing. The overall success of this combination of process machines is limited because additional electrical power needs to be installed, (ii) the additional heat generated by the extruder must be removed by the cake dryer and cooler, and the amount of cooling air must be handled to reduce dust and odor emissions. If there is no extruder, it is necessary to invest in upstream equipment for billet preparation and pressing to produce a suitable pre-pressed cake that does not require any additional processing before solvent leaching.