摘要 |
After a melt-processable fluorine-containing copolymer is heated and molten, the copolymer is reheatd in a closed apparatus under a non-static condition at a temperature of, for example, 130 DEG C to the melting point of the fluorine-containing polymer, whereby a content of volatile materials in the copolymer is reduced to 30 % or less of an initial content of volatile materials. Thereby, the content of volatile materials in the melt-processable fluorine-containing copolymer, which has been once molten, can be effectively decreased without using a large apparatus while avoiding the contamination of the copolymer with foreign particles. |