| 摘要 |
In a mixing tank (12), a TAC is dissolved to a solvent so as to be swollen. Thus a mixture (25) is obtained, and fed to a heating device (15) by driving a pump (26). The heating device (15) heats the mixture (25), such that the solid content in the mixture may be dissolved. The mixture (25) is fed out as a dope (27) from the heating device (15) to a cooling device (16). The dope (27) is cooled down by the cooling device (16) to a surface temperature of a cooling drum (42) onto which the dope (27) is to be cast. Thus impurities containing hemicellulose and the like are precipitated, and the dope (27) is filtrated such that the impurities may be trapped. The dope (27) is cast onto the cooling device (16) while the precipitation of the impurities is prevented after the casting. |
