Filter Fabric Types & Characteristics

What is filter fabric? Filter fabric is a filtering medium woven from natural or synthetic fibers. The materials of filter fabric include natural fibers such as cotton, hemp, wool, silk, etc.; Synthetic fibers include polypropylene, polyester, nylon, vinylon, etc., among which polyester and polypropylene are the most commonly used. In a broader sense, filter fabric materials also include various inorganic fibers, such as glass fiber, metal fibers, asbestos fibers, etc. Here, our products mainly focus on synthetic fibers. Filter fabric is widely used in industries such as pharmaceuticals, chemicals, dyes, steel, construction, iron smelting, ceramics, cement, geology, and mining. It is used for filtering air, dust, liquids, etc. Filter fabric is divided into two types based on manufacturing methods: woven filter fabric and non-woven filter fabric.

Filter Fabric Types

Woven Filter Fabric

Woven filter fabric is made by interlacing woven fibers in a certain pattern. Woven filter fabric is primarily produced using a loom through steps such as spinning, sizing, warping, threading, weaving, setting, and calendering. The main types are plain weave, twill weave, and satin weave. Plain weave fabric has many interlacing points and poor breathability; Satin weave fabrics have the fewest interlacing points, good breathability, a smooth surface, and are relatively easy to clean. Twill weave fabrics have a smooth surface, are relatively easy to clean, and have high strength, combining the advantages of strength and good dust collection.

Non-Woven Filter Fabric

Non-woven filter fabric is commonly referred to as non-woven fabric. It does not go through the usual spinning and weaving processes but directly forms a web of fibers. It is called fabric because it has the appearance and some properties of cloth. The production processes and procedures include: dry-laid web formation (needle punching, hydroentanglement, stitch bonding, thermal bonding, chemical bonding); spunbond method; melt blown process; electrospinning; wet-laid web formation, etc. Non-woven fabric breaks through the traditional textile principles and features a short process flow, fast production speed, high output, low cost, wide application, and diverse sources of raw materials.

Non-Woven Fabric Filtration Mechanism

Most of the theories related to non-woven fabrics are based on the in-depth filtration effect. It is much more complex than simple screening or sieving. For particle capture, in-depth filtration and separation theories are more relevant than other mechanisms. At this time, inertial effect, interception effect, diffusion effect, electrostatic effect, and gravitational effect occur, thereby capturing dust particles.

Non-Woven Fabric Category

According to their use, they can be divided into exhaust non-woven fabric and intake non-woven fabric.

Exhaust Non-Woven Fabric

Exhaust non-woven fabric. Common materials include ordinary fiber types such as polyester fiber, polyamide fiber, polyolefin fiber, polyvinyl chloride fiber, polyacrylonitrile fiber, conductive fiber, and high-performance fiber types such as polytetrafluoroethylene fiber, polyphenylene sulfide fiber, Teflon fiber, Nomex fiber, and polyimide fiber. The main production processes are needle punching and hydroentanglement. Surface treatment methods include heat setting, singeing, calendering, impregnation, coating, and other treatments. Mainly used in dust filter bags and dust filter cartridges.

Dust collector filter bag

Dust collector filter cartridge

Common Types of Exhaust Non-Woven Fabric

Intake Non-Woven Fabric

Common materials for intake non-woven fabric include polypropylene fiber, polyacrylonitrile fiber, polyester fiber, polyvinyl alcohol fiber, polyvinyl chloride fiber, polytetrafluoroethylene fiber, bicomponent fibers, and multicomponent fibers. The production process and treatment of intake non-woven fabric are more complex and detailed compared to exhaust non-woven fabric. It not only includes various binders, additives, and fibers as raw materials but also involves many web-forming technologies and process flows. Its application range is wide, including primary, medium, and high-efficiency filters, automotive air filters, cabin air filters, household air purifiers, and other fields.

Intake Non-Woven Fabric Classification