Hardness: filter paper will become wet during filtration. Some experimental procedures of long-term filtration should consider the use of stronger filter paper after wet water.
Filtration efficiency: filtration efficiency is affected by the density and size of seepage holes on the filter paper. High efficiency filter paper filter speed is fast, and the resolution is high.
Capacity: solid particles accumulated during filtration may block the holes in the filter paper. Therefore, the more dense the seepage holes are, the higher the capacity is, and the more allowed filtration.
Suitability: some filter papers are made by special procedures, such as nitrogen-free filter paper, which is used in laboratory medicine to determine blood nitrogen content.
Note that the filter paper cannot filter zinc chloride, otherwise the filter paper will be corroded and damaged by zinc chloride
