Brief introduction of filter cloth air permeability tester

There are many types of industrial filter cloths, which are roughly divided into polypropylene filter cloths, dust filter bags, monofilament filter cloths, non-woven filter cloths, filter press filter cloths, mesh bags, high temperature filter cloths, polyester filter cloths according to different materials and uses. Filter cloth, industrial cloth series, etc. Synthetic fibers mainly include polypropylene, polyester, nylon, vinylon, etc. Among them, polyester and polypropylene are the most commonly used, mainly for solid-liquid separation. The broad industrial filter cloth also includes woven meshes of various metal materials such as stainless steel wire, nickel wire, brass Silk. Material: polyester, polypropylene, nylon, vinylon, aramid, glass fiber, cotton, glass fiber, basalt fiber. Weaving method: plain weave, twill weave and satin weave, non-woven needle punching. Features and performance: high precision, strong load, acid resistance, alkali resistance, temperature resistance, wear resistance, rich in special filtration performance.

Specifications: 5 mesh-2300 mesh, air permeability 10-21m/s When the dust particles are below 0.2μm, the Brownian motion such as thermal motion of gas molecules is generated Polyester Monofilament ya  due to the extremely fine dust, which increases the contact chance between the dust and the filter cloth. The dust is trapped. This diffusion effect is opposite to the inertia effect, which increases with the decrease of the filtered gas velocity and increases with the decrease of the dust particle size. Taking glass fiber as an example, the finer the fiber, the higher the dust removal efficiency (see table).

However, the pressure loss of the thin fiber diameter is larger than that of the thick fiber, and the smaller the corrosion resistance, the worse the corrosion resistance. The application of filter cloth is more and more extensive, and the development will be more rapid. The breathability of non-woven filter materials will be the focus of our research. In "Fiber and Textile Testing Technology": The so-called fabric breathability refers to the performance of the fabric through air under the condition of a pressure difference on both sides of the fabric. It is customary to express the air permeability, that is, the volume of air flowing through the unit area of the fabric in unit time under the specified pressure difference on both sides of the fabric, the unit is L/(m2·s).

In ISO 9237-1995, the definition adopted is: Air permeability, the velocity of air flow vertically through the sample under the conditions of specified test area, pressure drop and time. In GB/T 5453-1997, the definition adopted is: air permeability, the performance of air through fabrics. Expressed as the rate at which the airflow passes vertically through the sample under the specified test area, pressure drop and time conditions. Air permeability directly affects the flow resistance of the finished filter cloth.

There are various methods for measuring the air permeability index in the world, but the basic method is the same, that is, the resistance when a certain flow of clean gas passes through a certain area of filter material. The difference is that some specify the resistance value, measure the flow rate, and some specify the flow rate value, measure the resistance size, and the specified value or the area passing through the filter material is also different. Therefore, the test of the air permeability of the filter material must be specifically tested in combination with the final use of the product and relevant standards. The air permeability of the filter cloth is required to be under a certain area and a certain pressure (20mm water column).