Acid Dyes: Superior Coloration Technology for Polyamide and Wool Fibers
In the textile industry, acid dyes have an indispensable place, especially in the dyeing of protein or synthetic polyamide-based fibers such as polyamide (nylon), wool, and silk. Taking their name from the acidic environment they require during application, these dyestuffs create permanent and vivid colors by establishing strong bonds with the amino groups in the fiber structure.
Developed to meet the needs of the sector, Priocid Dyestuffs increase the production efficiency of dyehouses with the solutions they offer in critical parameters such as leveling, fastness, and trichromy compatibility.
Working Principle of Acid Dyes: Ionic Bonding
The dyeing mechanism of acid dyes is based on a chemical attraction force.
- Ionic Bond: In an acidic environment (low pH), amino groups on wool or nylon fibers become positively (+) charged. Water-soluble acid dyes are anionic (-) in structure. These opposite charges attract each other, and an ionic bond is formed.
- Penetration: Dye molecules penetrate into the fiber, ensuring coloration both on the surface and in the core.
Product Classification and Properties (Priocid)
Acid dyes are divided into different classes according to their molecular sizes and binding strengths to the fiber. This classification is critical for selecting the right dye according to the final end-use of the product to be dyed (e.g., is it carpet, swimwear, or a coat?).
1. Leveling Dyes: Priocid E Series
- Structure: They are small-molecule dyes.
- Properties: Their movement capability (migration) within the fiber is very high. This minimizes the risk of uneven dyeing (unlevelness) and provides excellent leveling.
- Usage Area: They are preferred in dyeing light and medium shades, in carpet yarns, and in fabrics where levelness is crucial. Their wet fastness properties are lower compared to milling dyes.
2. Half-Milling and Milling Dyes: Priocid A and Priocid S Series
- Structure: They are medium and large-molecule dyes.
- Properties: They establish stronger bonds with the fiber (Van der Waals forces are effective in addition to ionic bonds).
- Advantages: Washing and perspiration fastness properties are higher compared to the Priocid E series. Since they are resistant to the "Milling" (felting) process, they are frequently used in woolen fabrics.
- Usage: Medium and dark shades, apparel fabrics.
3. Metal-Complex Dyes: Priocid NHF and M Series
- Structure: Contains metal within the dye molecule within ecological limits.
- Properties: It is the group with the highest light and wet fastness. Since the molecular structure is very large, it is difficult for it to leave the fiber.
- Usage: Automotive upholstery, outdoor textiles, and medium-dark colored products requiring very high durability.
Special Solutions for Perfect Trichromy: Priocid NHF and M Series
One of the biggest challenges in dyeing processes is ensuring that the three primary colors (Yellow, Red, Blue) used to match the color are absorbed at the same speed and harmony. This harmony is called "Trichromy."
- Priocid NHF: Solves "combination incompatibility," one of the biggest problems encountered in polyamide dyeing. In nylon/lycra blends requiring high fastness, it prevents shade differences by ensuring simultaneous fixation of dyes.
- Priocid M: It is the dyestuff group that gives the highest fastness in polyamide dyeing.
Which Acid Dye Group Should You Choose?
| Feature | Priocid E (Leveling) | Priocid A / S (Milling) | Priocid NHF / M |
| Molecule Size | Small | Medium / Large | Very Large |
| Leveling | Excellent | Good | Medium |
| Washing Fastness | Low/Medium | High | Very High |
| Light Fastness | Good | Good | Excellent |
| Brightness | Very Bright | Bright | Duller |