5. Air permeability
Air permeability is a comprehensive reflection of filter paper performance and is the primary consideration in filter design. It is closely related to the flow resistance, the filtration efficiency, the original resistance, the ash storage capacity (service life), etc. The greater the permeability of the filter paper, the smaller the flow resistance and the smaller the original resistance, and vice versa.
Air permeability is also an indicator of the moisture resistance of filter paper. The larger the air permeability, the easier it is to absorb moisture. The filter paper becomes longer after moisture absorption. The processing size is unstable, which affects mass production. In severe cases, the quality is degraded.
6. Maximum pore size, average pore size
The maximum pore size and average pore size can be measured by the bubble method, and the maximum is the pore diameter derived from the first bubble point pressure, the average is calculated from the bubble point pressure. According to this principle, the values of the maximum and the average pore size can be referred to.
The bubble point test is used to judge the integrity of the filter. The accuracy of the filter can be approximated based on the average and the maximum pore size. The average pore size is closely related to the filtration efficiency, and the smaller the average pore size, the higher the filtration efficiency.
Based on the technical indicators of filter paper, the last three chapters have analyzed the relationship between filter paper index and filter performance, as well as the impact on the design and manufacture of filters.
There are many kinds of filter materials, and the filter paper has a large proportion in the filter material industry with excellent performance and a reasonable price. The filter with filter paper as the filter medium is closely related to the performance index of the filter paper. The indicators of the filter paper interact with each other and are related to each other.
They are reflected in the performance parameters of the filter and are not a single corresponding relationship. Instead, several index parameters of the filter paper jointly determine the performance of the filter. For example, the life of the filter is determined by several parameters such as air permeability, thickness, surface density, and average pore size. Therefore, only by comprehensively understanding the relationship between the filter paper index and the filter performance, can we design and manufacture high-quality filters suitable for different occasions to meet different needs.