摘要:
The method for concentrating a fluoropolymer in a fluoropolymer aqueous dispersion includes a step for preparing a fluoropolymer aqueous dispersion, and a step for filtering the fluoropolymer aqueous dispersion in a polymer membrane. The polymer membrane oscillates during the filtration. The method for concentrating a water-soluble, fluorine-containing emulsifier in an aqueous solution containing the water-soluble, fluorine-containing emulsifier includes a step for preparing an aqueous solution containing a water-soluble, fluorine-containing emulsifier, and a step for filtering the aqueous containing the water-soluble, fluorine-containing emulsifier in a polymer membrane. The polymer membrane oscillates during both the filtration steps.