Filtration refers to an operation for separating and trapping particulate matter dispersed in a gas or a liquid, and the filter material is a substance for performing the above operations, and most of them are textiles. For example, when making tofu, separating the soybean milk from the bean residue, the beanbag cloth used is a filter cloth; for another example, the screen separating the coarse sand from the fine sand when building the house also belongs to this category. In a broader sense, textiles used in the fields of gas/solid separation, liquid/solid separation, gas/liquid separation, solid/solid separation, liquid/liquid separation, and gas/gas separation are called textiles for separation.
It is widely used in the food, electronics, pharmaceutical and chemical industries. For example, pre-filtration of high-purity water used in electronics, microelectronics, and semiconductor industries; filtration of purified water, mineral water, fruit juice, tea beverages, health drinks, and filtration of white wine, wine, beer, rice wine, and other fruit wines in the food industry. Granules, syrups, juice concentrates, and corn syrup filtration.
Nowadays, both in industrial production and in life, higher requirements are imposed on filtration and separation, and some requirements are usually beyond our imagination. For example, in hemodialysis of kidney patients, separating normal blood from impurities in the blood and trapping up to 10 microns of dust from the high-temperature gases emitted by coal-fired boilers are difficult operations. This requires special fibers and textiles for separation and filtration.
Filtration is also very important in our daily lives. For example, the air supply system installed in a large building must first filter the air before sending it to the interior. In this regard, there are internationally uniform standards and there are certain requirements for the corresponding textile filter materials. Automotive air filters, fuel filters, and oil filters have filters that are textile materials for filtration. The material of this filter element looks like a paper, but in fact, they are wet-laid nonwovens. Of course, these textile materials have been post-treated.
For filtration under certain special environmental conditions, such as the filtration of coal-fired boiler high-temperature flue gas and waste incineration gas, special fibers are used to make the filter material in order to achieve the environmental protection requirements for filtration. The application of these high-performance fiber filters has become a core technology and key equipment in some high-tech fields.
