The high level of air filter material mainly includes the following aspects: 1 high filtration efficiency; 2 small air flow resistance; 3 high mechanical strength; 4 uniformity; 5 meet special requirements of waterproof, fireproof and mildew resistant. The following is a description of the characteristics of the high-efficiency air filter glass fiber filter material by the North filter:
Worldwide, fiberglass air filtration materials still dominate the high efficiency air filtration market. Comprehensive analysis of the current world's advanced glass fiber filter materials, most have the following characteristics.
1. Structure of multi-component glass fiber
In order to improve the filtration performance of the filter material and change the pore state of the single-component glass fiber paper, a plurality of glass fibers of different linear densities are generally used to prepare the filter paper. Due to the use of multi-component glass fiber, the prepared filter paper not only has high gap ratio, but also has reasonable geometric structure and pore size distribution, and can exert the structural effect and shielding effect of the filter material, thereby high filtration efficiency and low airflow resistance. The tensile strength has also been greatly improved.
2, high efficiency, low resistance
In recent years, research and development of high efficiency air filtration materials has been rapid. HEPA filter paper was once the most efficient filter paper, and ULPA filter paper is now the most efficient filter paper. The filtration efficiency of ULPA filter paper to 0.12um particles can reach 99.99999%.
At a gas flow rate of 0.32 L/(cm 2 • min), the gas flow resistance is also controlled below 600 Pa. It is estimated that in the near future, a new generation of filter materials with higher efficiency and lower resistance will also be developed and applied.
3. High mechanical strength
High-efficiency air filter materials have high mechanical strength requirements, and the difference in longitudinal and transverse strength is as small as possible. Giving the filter material a sufficiently large tensile strength and stiffness is essential to improve the stability of the filter material during production, transportation, storage and use. The high-strength filter material is folded to produce a filter device that maintains the stiffness of the filter layer to form a good airflow path and has a strong impact resistance, while increasing the effective filtration area, improving and improving the filter equipment. Filtering performance is therefore of practical importance. However, the glass fiber is very soft and has a small bonding force. Therefore, it is necessary to use a reinforcing agent for the glass fiber filter paper to have high mechanical strength.
For a long time, filter materials at home and abroad have generally been enhanced with cross-linking agents and resin-based binders. By the reaction of the crosslinking agent with the linear resin, the groups in the glass fiber, and the reaction of the crosslinking agent itself, the linear resin structure is changed into a network-like macromolecular resin structure, thereby further improving the mechanical strength of the filter material and reducing The difference in strength between the vertical and horizontal directions.
4, good process performance
In order to increase the effective filtration area of the filter material and reduce the airflow resistance, the filter material is generally folded into a corrugated shape. Therefore, the filter material should have good process performance, that is, good flexibility and high folding resistance. Filter materials with poor process performance tend to be damaged once folded, resulting in reduced product yield, low work efficiency, increased cost, and affecting the overall performance of the filter.
5, waterproof, fireproof, mildew and other special properties
In some special occasions such as military and nuclear industries, the filter material should also have special properties such as waterproof, fireproof and mildew resistant. Otherwise, under the conditions of humidity, high temperature or open flame, the structure of the filter material will be destroyed, seriously affecting or even losing its filtration performance, or becoming a breeding ground for bacteria such as mold. Therefore, it is very important to impart good waterproof, fireproof, and mildew resistance to the filter material.
Compared with the world's advanced air filtration materials, China's domestically produced filter materials can reach or exceed their level in terms of filtration efficiency, tensile strength and other technical indicators, but there are still some gaps in the overall, mainly reflected in the filter materials. Uniformity is not good, process performance is generally poor, and research on special properties such as waterproofing, fireproofing, and mildew resistance is not systematic and in-depth. This has largely restricted the development level of filter equipment in China, which is an urgent problem to be solved in China.