Compared with other dyes, vat dyes possess a series of remarkable characteristics, which make them widely used to solve various fastness-related problems. Let’s take a detailed look:

Vat dyes cover a complete color spectrum from yellow to black, ranging from bright hues to ordinary tones. Their most prominent feature is that intermediate shades account for the majority. Most of these intermediate shades are single-component dyes with excellent dyeing reproducibility, especially in green, olive green, flesh tone, brown and grey color series.

For instance, reactive green dyes are generally compounded with yellow and turquoise reactive dyes. It requires strict process control during dyeing to match reactive dyes with different dyeing properties well. By contrast, vat dyes include multiple single-structure green varieties. They can not only meet diverse application demands but also deliver far better dyeing reproducibility than reactive dyes.

There is an increasingly stringent requirement for composite fastness based on light fastness on cotton fabrics, such as perspiration-light fastness, perspiration-light-washing fastness, and perspiration-light-rubbing fastness, especially for pale shades.

Vat dyes outperform other cotton dyes in these properties, making them highly suitable for dyeing and printing workwear, summer garments, sportswear, overcoats, curtains, furniture covers and other textile products.

Vat dyes feature superior chlorine fastness compared with reactive dyes, whether tested in 20ppm chlorine water or 500ppm chlorine solution. Additionally, they have excellent washing fastness.

Therefore, vat dyes are ideal for textiles requiring chlorine disinfection and high wash resistance, including fabrics, bedding, covers, bed sheets and garments used in hotels and hospitals. Their advantages are even more prominent for products that need repeated washing. They are also perfectly suited for dyeing and printing textiles demanding top-grade wet fastness, such as fabrics base-dyed with reactive dyes and discharge-printed with vat dyes.

In Europe, America and other regions, strong detergents are widely adopted to save washing water — new-type detergents prepared by adding Tetraacetylethylenediamine (TAED) into peroxides, or high-dose detergents combined with warm water washing. Vat dyes maintain sufficient fastness under such washing conditions.

Vat dyes show minimal shade change after conventional resin finishing. They also maintain excellent stability against newly developed functional finishing processes that alter fiber properties, such as shape memory finishing, dimensional stabilization finishing, deodorant finishing and antibacterial finishing. Moreover, fabrics dyed with vat dyes have more stable aging performance than those dyed with reactive dyes.

One-bath union dyeing of blended fabrics like polyester/cotton, nylon/cotton and vinylon/cotton is gaining growing popularity in the printing and dyeing industry. Vat dyes have excellent union dyeing properties, applicable to one-bath continuous dyeing, printing and exhaust dyeing of such blended fabrics.

The dyed fabrics can be made into school uniforms, various work uniforms, breathable overcoats and special textiles, especially military uniforms and combat suits such as camouflage uniforms, with outstanding comprehensive fastness and special properties like infrared resistance.

This property of vat dyes enables their application in manufacturing high-grade textiles with reactive dye base dyeing and vat dye discharge printing, ground-free dyeing of polyester/cotton knitted fabrics by jet dyeing machine, package yarn pre-dyeing of polyester/cotton blends, and high-fastness printing and dyeing of polyester/cotton blends via the URS process.

Fabrics dyed with vat dyes can present natural plant tones and European-style styling based on rustic color tones. For example, fabrics base-dyed with indigo and direct-printed with vat dyes can be processed by stone washing, bleaching and other treatments to produce textiles with extremely vivid, clear and natural plant-like hues.

In summary, vat dyes have a host of distinctive advantages over other cotton dyes, particularly in fastness performance. Hence, vat dyes remain a category of cotton dyes worthy of great attention and extensive application.