The technical indicators of filter paper can be mainly divided into two aspects, one is the filter characteristics of filter paper, and the other is the physical characteristics. Filtration characteristics include air permeability, maximum aperture, and average aperture. Physical properties include quantification, thickness, stiffness, break resistance, resin content, etc.

First, the relationship between the physical characteristics of filter paper and the performance of filter
Step 1 Quantify
Quantitative in the filter is mainly manifested in the weight and price of the filter. For the filter, its filtration area is certain. Under a certain filter area, the larger the quantity, the heavier the filter paper and the heavier the filter. Because the filter paper accounts for a relatively high proportion of the cost of the filter, the filter cost is larger.

Step 2: Thickness
The corrugated canister filter, the thickness of the filter paper, can limit the maximum filter area of the filter.

3. Stiffness and break resistance, indicating the deformation resistance, pressure difference resistance, high stiffness and high break resistance of filter paper, can show that the durability of the filter is good, but the stiffness is too high and it is easy to become brittle, and the filter is easy to damage.

4. Resin content
Filter paper added resin, is to increase the stiffness of the filter paper, and filter paper processing in the shape, depending on the use of different, generally between 10 to 30%. The resin content is too high, and the resin easily blocks the pore structure of the filter paper.

Second, the relationship between the filter characteristics of the filter paper and the filter performance
1. Permeability of filter paper
Air permeability is a comprehensive reflection of filter paper performance and is the primary consideration in filter design. It is closely related to the filter's flow resistance characteristics, filtration efficiency, original resistance, life and other performance indicators, the greater the permeability of the filter paper, the smaller the flow resistance, the smaller the original resistance, and vice versa. There is opposite qualitative relationship between permeability and flow resistance.
Air permeability is also an indicator of the moisture resistance of filter paper. The larger the permeability of the filter paper, the easier it is to absorb moisture, and the filter paper becomes longer after absorbing moisture. The processing size is not stable, affecting mass production. The processing performance is poor. In severe cases, the quality is degraded. When the end cap is damp before bonding, the filter paper length is 2 ~ 4mm, which affects the height control of the filter element. After bonding, the filter paper is moistened, the filter grain is distorted, and the quality of the filter element is seriously affected.

2. Maximum aperture, average aperture
The maximum aperture and average aperture can be measured using the bubble method, and the maximum aperture is the aperture calculated from the pressure at the first bubble point. The average aperture is the aperture calculated from the bubble point pressure. According to this principle, the maximum and average aperture values of eAO can be taken into account. Bubble point test is used to judge the integrity of the filter. The accuracy of filter can be approximated according to the size of average aperture and maximum aperture. The average aperture is closely related to the filtration efficiency of the filter, and the smaller the average aperture, the higher the filtration efficiency.