The dyeing process can be roughly divided into three stages:
Adsorption is the process by which the dye attaches to the surface of the fiber; the dye is adsorbed by the fiber in solution due to intermolecular forces and electrostatic attraction between ions.
B. Diffusing and penetreating
After adsorption, the dye needs to enter the inside of the fiber and remain inside; under certain conditions, the adsorbed dye diffuses and penetrates from the surface of the fiber into the fiber, and enters the amorphous region of the fiber, until the dye, the surface of the fiber, and the dye inside the fiber The concentration reaches equilibrium.
This is a key process of good dyeing fastness; the dye entering the amorphous region of the fiber is linked to the fiber macromolecule by chemical force (ionic bond or covalent bond) intermolecular attraction (van der Waals force) and hydrogen bond to obtain a certain degree Fastness of bonding.
In actual dyeing, the above three stages cannot be clearly distinguished. Different dyes, different fibers, different dyeing processes, the dyeing process is also different.