Filter cloths are indispensable for filtration work, but there are various types depending on the material and weaving method, and it is necessary to select the most suitable one according to the purpose and conditions of use. This article describes the types and characteristics of filtration cloths.
What is a filter cloth?
A filter cloth is a cloth used to separate liquids and gasses mixed with impurities discharged from factories and workplaces. Filtration has been practiced since ancient times. In recent years, various types of filter cloths have appeared on the market, such as those with high friction resistance, chemical resistance, heat resistance, and abrasion resistance, and those that can process large quantities of filtration.
Types of yarn
Filter cloths differ not only by fiber material, but also by the type of use. The following are three types of yarn fiber.
These fibers tend to feel less resistance but have a density that does not allow particulate matter to pass through. They are useful in a variety of situations, but they have a tendency to be fluffy and clogged, and they do not release cake discharge well.
Long fibers have a smooth surface without fluffiness and are characterized by good cake release. Most of them have higher strength than staple fibers, but they also have higher resistance, which is one advantage and disadvantage.
The surface is smooth and the cake is well detached, but there are some disadvantages such as the inability to filter fine particles on its own.
Types of weave
There are several types of weaving methods used for filter cloth, and the three most common are plain weave, twill weave, and satin weave. In addition, diverse types have emerged by weaving using multiple fibers and controlling the coarseness of the weave.
This is a robust weave with a flat surface, and the cloth grain is often tight, making it easy to use as filter cloth for high-pressure applications.
This weave has a diagonal pattern on the surface and is characterized by its flexibility. It can be made into thick, high-density filtration cloth and is used in a variety of situations, making it a common filtration cloth.
Compared to the other two weaves, this is a smoother and denser filter cloth.
Features by material
Synthetic fibers currently used for filter cloth include polypropylene, polyamide (nylon), and polyester.
Polypropylene has high chemical resistance and can be used in both acidic and alkaline environments. However, its heat resistance is not very high, and it should be used between room temperature and 90°C.
This material has strong resistance to alkalinity. It is also highly resistant to abrasion and can be used stably. However, it is weak against acids, especially inorganic acids.
This material boasts high heat resistance and can be used from room temperature to about 130°C. It is acid-resistant and has high resistance to elongation. It is resistant to acids and resists elongation, but be aware that it is weak against alkalinity.
In addition to these materials, vinylon and cotton are also used for filtration cloth in some cases. Efficient filtration can be achieved by selecting the material with the right characteristics.
There are so many types of filter cloths on the market today that it is difficult to know which one is right for what purpose. The performance varies greatly depending on the type of yarn, weave, and material, so it is important to learn the characteristics of each type so that you can choose the filter cloth that best meets your needs.