Filtration technology has been used in production in ancient China, and paper made from plant fibers was already available in 200 BC. In 105 AD, Cai Lun improved the papermaking method. In the process of making paper, he swayed plant fiber pulp on a dense bamboo curtain. The water is filtered through the gap of the bamboo curtain, and a thin layer of wet pulp is left on the surface of the bamboo curtain. After drying, it becomes paper.
The earliest filtration was mostly gravity filtration. Later, pressure filtration was used to increase the filtration speed, and vacuum filtration appeared again. The rotary drum vacuum filter invented in the early 20th century realized the continuous operation of filtration. Since then, various types of continuous filters have appeared one after another. Intermittently operated filters (such as plate and frame pressure filters, etc.) have been developed because they can be automated, and the filtering area is getting larger and larger. In order to obtain filter residues with low moisture content, mechanically pressed filters have been developed.