Methods for obtaining natural colorants from plant material (e.g., tobacco material) and for using such natural colorants to dye various substrates are provided. Natural colorants are obtained using particular enzymes and particular conditions (e.g., time, temperature, and pH profiles). Such colorants can be used to dye substrates, for example, using conventional dyeing techniques or using unique in situ methods.

Methods for obtaining natural colorants from plant material (e.g., tobacco material) and for using such natural colorants to dye various substrates are provided. Natural colorants are obtained using particular enzymes and particular conditions (e.g., time, temperature, and pH profiles). Such colorants can be used to dye substrates, for example, using conventional dyeing techniques or using unique in situ methods.

A process for leather production from a raw animal hide includes the steps of pre-soaking, soaking, unhairing and liming, re-liming, deliming and bating, pickling and tanning, degreasing, re-tanning, neutralizing, dyeing and fatliquoring, and washing the processed hide. Waste liquid is collected from at least one of the foregoing steps is recycled to at least one of the foregoing steps. The collected waste liquid can be recycled to the same step, to a different step, or to two of more steps in the process.

[Problem] To provide a novel method for manufacturing synthetic leather that is colored using dye.

[Solution] A method for manufacturing synthetic leather having an outer surface layer on a base fabric, said method comprising the steps of: (i) coating a releasable base material with an outer surface layer composition containing a polyurethane resin and at least one dye selected from natural dyes and chemical dyes, and drying the coating to form an outer surface layer; and (ii) layering the outer surface layer over a base fabric.

[Problem] To provide a novel method for manufacturing synthetic leather that is colored using dye.

[Solution] A method for manufacturing synthetic leather having an outer surface layer on a base fabric, said method comprising the steps of: (i) coating a releasable base material with an outer surface layer composition containing a polyurethane resin and at least one dye selected from natural dyes and chemical dyes, and drying the coating to form an outer surface layer; and (ii) layering the outer surface layer over a base fabric.

The present disclosure relates to a natural dyeing method using shouliang yam rhizome, and more particularly to a natural dyeing method using shouliang yam rhizome, which prevents the discoloration of a naturally dyed fabric, is harmless to the human body, and exhibits excellent color development, excellent antibacterial activity, excellent deodorization, and excellent dyeing fastness such as friction fastness and light fastness.

The present disclosure relates to a natural dyeing method using shouliang yam rhizome, and more particularly to a natural dyeing method using shouliang yam rhizome, which prevents the discoloration of a naturally dyed fabric, is harmless to the human body, and exhibits excellent color development, excellent antibacterial activity, excellent deodorization, and excellent dyeing fastness such as friction fastness and light fastness.

The present disclosure relates to a natural dyeing method using fermented persimmon juice, and more particularly to a natural dyeing method using fermented persimmon juice, which prevents the discoloration of a naturally dyed fabric, is harmless to the human body, and exhibits excellent color development, excellent antibacterial activity, excellent deodorization, and excellent dyeing fastness such as friction fastness and light fastness.

The present disclosure relates to a natural dyeing method using fermented persimmon juice, and more particularly to a natural dyeing method using fermented persimmon juice, which prevents the discoloration of a naturally dyed fabric, is harmless to the human body, and exhibits excellent color development, excellent antibacterial activity, excellent deodorization, and excellent dyeing fastness such as friction fastness and light fastness.

A dyeing method includes immersing a fiber into a dye for dyeing the fiber, in which the dye includes indigo and indirubin, and the indigo and the indirubin have a weight ratio of 20:1 to 80:1. The indigo in the dye has a concentration of 0.1% o.w.f. to 5% o.w.f. The dyed fiber may simultaneously have high luminance, high color saturation, high strength of colorization, and sufficient colorfastness.