Views: 0 Author: Site Editor Publish Time: 2026-07-31 Origin: Site
I. Product Overview: Providing Excellent Color Fastness for Protein and Polyamide Fibers
In the textile dyeing and printing industry, acid dyes are the preferred choice for dyeing protein fibers such as wool and silk, as well as polyamide fibers like nylon, due to their bright colors and complete shade range. However, the binding force between acid dyes and these fibers is often insufficient under wet processing conditions such as conventional washing and soaping, leading to easy fading and staining, which seriously affects the final quality of the fabric.
To address this industry pain point, Zhejiang Kefeng Silicone Co., Ltd., leveraging its profound R&D strength in textile auxiliaries, has launched the Fixing Agent for Acid Dyes. This product is specifically used for the after-treatment of fabrics dyed or printed with acid dyes. By forming a firm "bridge" between the fiber and dye molecules, it significantly improves various wet fastness properties of the dyed fabric, making it a key auxiliary for ensuring the quality of high-grade textiles such as nylon and wool.
II. Product Performance and Mechanism of Action
This fixing agent is a high-molecular-weight aromatic sulfonate condensate, belonging to the anionic type of auxiliary. Its excellent fixing effect is derived from the following scientific mechanisms:
Ionic Bonding Action: Under acidic fixing conditions (pH 4-5), the amino groups (-NH₂) on nylon and wool fibers are protonated, forming positively charged cationic sites (-NH₃⁺). The fixing agent molecules, due to their anionic nature, preferentially undergo strong electrostatic binding with these cationic sites, firmly "locking" themselves onto the fiber surface.
Formation of a Protective Film: The macromolecules of the fixing agent deposit on the fiber surface, forming a dense, network-like protective film. This film effectively seals the pores on the fiber surface, reducing the water solubility of the dye molecules. This greatly hinders the diffusion and desorption of the already fixed dyes from the fiber interior into the aqueous solution during washing.
Synergistic Enhancement: The aromatic ring structures in the fixing agent can interact with the conjugated systems in the dye molecules through intermolecular forces such as van der Waals forces, further enhancing the fixing effect.
III. Core Advantages and Value Proposition
This product has been specifically optimized to overcome the shortcomings of traditional acid fixing agents, such as susceptibility to fixing spots, negative impact on fabric hand feel, and poor compatibility with leveling agents. It offers the following outstanding advantages:
Significantly Improved Various Fastness Properties: After treatment with this agent, the wash fastness, soaping fastness, perspiration fastness, and rubbing fastness of nylon and wool fabrics are all notably enhanced, meeting or exceeding international standard requirements.
Excellent Process Stability: The product exhibits outstanding stability against acids, hard water, and electrolytes. The fixing bath is less prone to precipitation or aggregation, effectively preventing the formation of fixing spots. Furthermore, it demonstrates good compatibility with non-ionic or weakly cationic leveling agents remaining on the fiber, ensuring uniform and consistent fixing results.
Good Hand Feel and Environmental Characteristics: This agent has minimal impact on the hand feel of the treated fabric, avoiding the stiffness and roughness often associated with traditional fixing agents. The product is environmentally friendly, free from APEO, NPEO, formaldehyde, and other harmful substances.
Excellent Anti-Staining Function: During the soaping process of printed fabrics, this product effectively prevents the white ground from being re-stained by acid dyes, ensuring the clarity of the print pattern and the purity of the whiteness.
IV. Application Process
This product is suitable for two main fixing processes: the exhaust method and the pad method.
Exhaust Method (Recommended Process) :
Dosage: Typically 1.0% - 5.0% (o.w.f) , depending on the shade depth.
Liquor Ratio: 1:10 ~ 1:15
pH Value: Adjust to 4.0 - 5.0 with acetic acid.
Temperature: 70 - 85℃
Time: 20 - 30 minutes
Pad Method:
Dosage: 20 - 50 g/L (Suitable for continuous dyeing and fixing processes, such as for nylon webbing).
Temperature: 70 - 85℃
V. Conclusion
Kefeng's Acid Dye Fixing Agent is a finishing auxiliary specifically engineered for fibers like nylon and wool. Through its unique anionic high-molecular-weight condensate, it constructs a robust "protective layer" between the fiber and the dye, effectively solving the common industry problem of poor wet fastness of acid dyes. While significantly enhancing the color fastness grade of textiles and ensuring process stability, it simultaneously maintains a good fabric hand feel and meets environmental requirements. For dyeing and printing enterprises seeking high-quality dyeing results and a reliable production process, this product stands as a trustworthy auxiliary choice.
