Dyeing method of polyvinyl alcohol (PVA) film using supercritical fluid

摘要

A method for dyeing a polyvinyl alcohol-based film is provided to reduce the use amount of dyes, the amount of waste dyes, and the amount of wastewater, thereby suppressing the pollution of environment due to a dyeing process. A polyvinyl alcohol-based film is dyed by inputting the polyvinyl alcohol-based film and dyes dissolved in solvent into a reactor bath, and increasing an inner temperature and an inner pressure of the reactor bath to a supercritical fluid environment. The solvent is one selected from a group consisting of water, ethylene glycol, glycerol, dimethyl sulfoxide, formamide, and dimethyl formamide, or a mixture thereof. Further, 0.1-1.0 wt.% of the dyes are used based on 100 wt.% of the organic solvent.