|Pigments for Textile Printing (www.qualitron.net)|
When a positively charged cationic pre-treat is added to the fiber a magnetic bond is formed. The process is complete when a cationic binder is added to "lock" the pigment into place.In pigment dyeing no actual chemical reaction takes place between the dye and the fabric.
The pigment dyeing process is generally a three step process such as:
1.Cationisation of the Fabric
Pigment dyeing is an electrical process whereby the goods to be dyed are given an electrical charge opposite that of the pigment. When the pigment is added to the bath, the opposite electrical charges attract each other, much like the north and the south poles of two magnets. Because of the electrical nature of the process.
A typical recipe for cationizing Step
- Cationic Imparting Agent
- Acetic Acid for pH control
2.Pigment Exhaustion on the Fabric
The pigments are first mixed with water and a dispersing agent that imparts an anionic charge to the pigments. This solution is added gradually to the dyeing machine. The temperature of the bath is slowly increased and the machine is held at the dyeing temperature for up to 20 minutes. The fabric is held at an elevated temperature to increase the adsorption of the pigments.
A typical recipe for this step
|A Process flow diagram for pigment Garment dyeing process|
- Its applicable to a wide range of textiles and wide gamut of colors available. Some brilliant fluorescent pigments are available for special applications and fashion items.
- The process of pigment dyeing can also be relatively cheap.
- The process chemicals are less toxic , environmentally friendly and least polluting.
- The color fades with the repeated use , just like denims.
- Color fading could be a problem if not desired, and can only be kept intact with further chemical treatments.
- The abrasion resistance and hand could be unsatisfactory depending upon the pigment, binder and softener used.
- Dark and deep shades are better produced with other dyestuffs rather than pigments.