Colour Fixative: The Various Applications in the Textile Industry

In the textile industry, reactive dyes are widely used due to their bright and vibrant coloration. However, the presence of water-soluble groups in these dyes often leads to poor wet fastness, resulting in fading and staining during washing. This not only affects the appearance and color integrity of dyed fabrics but may also cause dye transfer onto white or differently colored textiles, leading to staining or cross-dyeing issues. To address this problem, the industry has introduced the use of colour fixative—an auxiliary chemical designed to improve various aspects of dye fastness. Through fixative treatment, the colorfastness of textiles is significantly enhanced, ensuring long-lasting dye performance.

A colour fixative is a compound that promotes stronger bonding between dye molecules and textile fibers. Its core function is to improve the wash and water fastness of dyed fabrics, ensuring they retain their vibrant colors even after repeated laundering, without fading or dye transfer. Importantly, the use of colour fixative must comply with formaldehyde-free standards to ensure the fabric's environmental friendliness—an essential consideration for modern, eco-conscious consumers.

Properties and Applications of Colour Fixative

As an essential compound in the textile field, the colour fixative plays a critical role through its unique performance. It enhances the binding of dye molecules to fibers, significantly improving both wash and water fastness. This ensures that even after multiple washes, the textile maintains its original brightness without fading or staining. Moreover, compliance with formaldehyde-free regulations ensures that treated fabrics meet environmental and health standards.

• Strong fixing capability, effectively enhancing colorfastness performance.

  
  

• Compatible with a wide range of dyes, with minimal impact on color tone.

  
  

• Excellent affinity with fibers, enabling high absorption efficiency during application.

  
  

• Maintains consistent shade with no noticeable color change after treatment.

  
  

• Improves wet fastness without negatively affecting other fastness metrics, such as light fastness.

  
  

• Does not affect the hand feel or mechanical strength of the fabric.

  
  

Multi-functional Roles of Colour Fixative

The versatile functions of the colour fixative are reflected in several aspects:

Formation of Insoluble Pigment Complexes

The fixative reacts with the dye's water-soluble groups, forming insoluble color lakes on the fabric surface. This blocks dye solubility in water, thereby significantly enhancing wet fastness. However, this method can sometimes lead to slight changes in color shade or reduced light fastness.

Film-forming Mechanism

The fixative can form a reticulated film on the fabric surface, physically trapping the dye and preventing it from being washed off.

Cross-linking Reactions

The reactive groups in the fixative molecule may chemically bond with functional groups on both the dye and the cellulose fiber (such as hydroxyl groups), forming strong covalent bonds. This enhances dye fixation at the molecular level.

Molecular Attraction

Intermolecular forces between the fixative and fiber surfaces also contribute to its binding strength, further improving dye fastness