Decolorization method of polyester fabric
A decolorization method of a polyester fabric, including the following steps, is provided. A first extraction treatment is performed on the polyester fabric using a recycled solvent, so that a first portion of a dye in the polyester fabric moves into the recycled solvent. A first filtering treatment is performed on the recycled solvent and the polyester fabric to obtain a treated polyester fabric. A second extraction treatment is performed on the treated polyester fabric using a fresh solvent, so that a second portion of the dye in the treated polyester fabric moves into the fresh solvent. A second filtering treatment is performed to obtain a decolored polyester fabric and the recycled solvent.
1 . A decolorization method of a polyester fabric, comprising:
performing a first extraction treatment on the polyester fabric using a recycled solvent, so that a first portion of a dye in the polyester fabric moves into the recycled solvent;
performing a first filtering treatment on the recycled solvent and the polyester fabric to obtain a treated polyester fabric;
performing a second extraction treatment on the treated polyester fabric using a fresh solvent, so that that a second portion of the dye in the treated polyester fabric moves into the fresh solvent; and
performing a second filtering treatment to obtain a decolored polyester fabric and the recycled solvent, wherein the recycled solvent comprises fresh solvent and 0.1 wt. % to 10 wt. % dye, based on a total weight of the recycled solvent.
2 . The decolorization method according to claim 1 , wherein in the first extraction treatment, a weight ratio of the recycled solvent to the polyester fabric is 4:1 to 50:1.
3 . The decolorization method according to claim 1 , wherein a weight ratio of the fresh solvent to the treated polyester fabric is 4:1 to 50:1.
4 . The decolorization method according to claim 1 , wherein the fresh solvent comprises an aromatic hydrocarbon solvent, an alcohol ether solvent, an alcohol solvent, or an amide solvent.
5 . The decolorization method according to claim 1 , wherein the fresh solvent comprises benzene, toluene, xylene, propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, butanol, pentanol, hexanol, dimethylformamide, dimethylacetamide, or a combination thereof.
6 . The decolorization method according to claim 1 , wherein based on a total weight of the dye, a total amount of the first portion and the second portion removed is 90 wt % to 99.9 wt %.
7 . The decolorization method according to claim 1 , wherein a CIELAB color definition of the decolored polyester fabric has L value of above 80, a value of −3.0 to +3.0, and b value of −6.0 to +6.0.
8 . The decolorization method according to claim 1 , further comprising repeatedly performing a cycle of the first extraction treatment and the first filtering treatment 1 to 7 times before the second extraction treatment.
9 . The decolorization method according to claim 1 , further comprising repeatedly performing a cycle of the second extraction treatment and the second filtering treatment 1 to 3 times after the second filtering treatment.