How should I choose a screw oil press? From its operating principle to practical applications, I'll guide you step by step to identify the most suitable oil press. Follow my method, and next time you shop for oil press equipment, you'll be like a seasoned industry expert, choosing the machine that best suits your needs in under three minutes.
What is an automatic screw oil press?
When many people first enter the edible oil processing industry, their first impression is the vast variety of oil presses on the market. Some oil presses appear smooth to operate, but in practice, they often lack efficiency, especially in small and medium-sized oil presses.
A screw oil press is a compact machine that continuously extracts oil using a rotating screw. It is widely used to extract edible oil from over 20 oilseed crops, including palm, peanuts, soybeans, coconuts, walnuts, almonds, sunflower seeds, rapeseed, sesame, castor seeds, and flax seeds.
Seeds are drawn in through an inlet and pressed into the press chamber by the screw. The working principle of a screw oil press is simple yet highly efficient, so understanding its mechanism is crucial to understanding why it remains a staple in most oil extraction applications.
Working Principle and Key Features
The automatic screw oil press machine works by forcing oilseed into a barrel, where the screw rotates, pushing the oilseed forward.
The screw's motion exerts pressure on the chamber, forcing the seed cells to break apart and squeeze the oil out of small holes in the barrel, rupturing the cells in the process (similar to squeezing toothpaste). The solid byproduct, or oil cake, can be discharged through various outlets, allowing the oil extraction process to continue.
Many screw oil presses are equipped with temperature control systems, allowing operators to easily preheat the oilseed and maintain this temperature throughout the extraction process, achieving optimal oil yield without compromising oil quality. (For hot extraction, a roaster is recommended to preheat the oilseed to the desired temperature and moisture content, depending on the crop type.)
By adjusting the screw speed and applied pressure, it is possible to balance oil yield and cake quality. This oil press is designed to operate continuously 24 hours a day, processing 50-800 kg of raw material per hour, depending on the machine model and crop type.
One of the greatest advantages of the screw oil press is its wide range of crop applications. It can equally utilize over 20 oilseed crops, including palm fruit, peanuts, soybeans, sunflower seeds, rapeseed, and sesame.
Multi-stage pressing also increases oil yield compared to hydraulic oil presses, as hydraulic presses allow for reprocessing of the virgin meal to yield even more oil.
However, the crude oil from the automatic screw oil press machine typically contains high levels of impurities and phospholipids, resulting in a dark yellow-brown color and requiring filtration before use.
The screw oil press's extremely high daily output, high flexibility, and excellent oil yield have made it a flagship model for many commercial edible oil mills worldwide.
The screw oil press offers high stability, uninterrupted operation, and strong versatility, making it suitable for extracting most oilseeds.
Its optional multi-stage pressing and temperature control functions help improve oil recovery, making it the first choice for most edible oil manufacturers.
