PTFE membrane filter material is composed of a microporous, extremely smooth and hydrophobic PTFE filter membrane and different substrates (such as needle felt or woven fabrics). type of filter material.
Whether considering the production cost or air flux, the prepared polytetrafluoroethylene filter membrane should have high porosity and the thickness should be as thin as possible.
The thickness of the prepared expanded polytetrafluoroethylene film is only 3~10μm, and the porosity is large.
Therefore, the mechanical strength such as tensile resistance of the film is relatively poor, and corresponding supporting materials must be provided before it can be truly used.
The selection principles of supporting materials are: ① high porosity, low filtration resistance, which will not cause too much filtration resistance to the composite filter material; ② good mechanical properties; ③ the scope of application is equivalent to the requirements of the actual industrial system. That is to say, it can withstand normal temperature, medium temperature, and high temperature respectively, and the chemical stability requirements such as pH must also be adapted to the actual system; ④ The price is low and easy to purchase.
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