Product Focus: Reactive Dyes
Achieve Brilliant Colors with Exceptional Fastness
The modern textile coloration field recognizes reactive dyes as fundamental technology because they deliver intense coloration along with outstanding fastness properties and strong molecular bonds to both natural and synthetic fibers. Alfa Chemistry provides an extensive range of superior reactive dyes designed for precise dyeing methods and environmentally compliant manufacturing across various industrial sectors. Whether you're seeking vibrant hues, robust wet fastness, or sustainable solutions, we deliver engineered colorants that meet the most stringent requirements in global textile manufacturing.
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What Are Reactive Dyes?
Reactive dyes are a class of water-soluble dyes that form covalent bonds with hydroxyl or amino groups on textile substrates—most commonly cellulose fibers (e.g., cotton) and protein fibers (e.g., wool, silk). Structurally, reactive dyes consist of a chromophore (color-bearing group), a solubilizing group, a bridging unit, and one or more reactive groups such as triazine or vinyl sulfone. These reactive groups chemically link the dye molecule to the fiber, creating exceptional durability and wash-fastness.
What Is the Basic Structure of Reactive Dyes?
Chromophore (Color-Imparting Group)
At the core of every reactive dye molecule lies a chromophore, responsible for absorbing specific wavelengths of light and thereby generating color. The chromophore is often further fine-tuned with electron-donating or withdrawing substituents to modulate hue, brightness, and lightfastness.
Common chromophores include:
- Azo groups (-N=N-)
Predominant in red, orange, and yellow shades.
- Anthraquinone groups
Provide vivid blues and violets with high tinctorial strength.
- Phthalocyanine groups
Often used in turquoise and deep green shades due to their extended conjugation.
Reactive Moiety (Covalent Linkage Site)
This is the defining feature of reactive dyes, enabling them to chemically bond with hydroxyl (-OH) or amino (-NH2) groups on the fiber. The reactive moiety determines the dye's reactivity, fixation mechanism, and required application conditions. Key types include:
- Monochlorotriazine (MCT)
Moderate reactivity; requires alkaline conditions and elevated temperature (~80°C).
- Dichlorotriazine (DCT)
Higher reactivity at lower temperatures (~40 - 60°C); widely used in cold pad-batch dyeing.
- Vinyl Sulfone (VS)
Forms highly stable ether bonds under alkaline conditions; suitable for exhaust and pad-batch dyeing.
- Mixed Bifunctional Systems
Combine different reactive groups to balance fixation efficiency, pH flexibility, and fastness (e.g., MCT-VS).
Solubilizing Groups
To facilitate aqueous application and fiber penetration, reactive dyes are typically modified with hydrophilic substituents. These groups also reduce dye-dye interaction, leading to better reproducibility and application uniformity.
such as:
- Sulfonic acid groups (-SO3H)
Improve water solubility and promote dye exhaustion and leveling.
- Carboxylic acid groups (-COOH)
Further enhance water dispersibility and help control dye aggregation.
Key Characteristics of Reactive Dyes
Chemical Reactivity
Reactive dyes demonstrate their characteristic feature by forming covalent bonds with fiber substrates, which leads to durable color retention.
Superior Fastness
The covalent attachment of dyes to fabrics results in outstanding durability against washing and exposure to light and sweat.
Vibrant Color Range
Reactive dyes deliver a wide range of brilliant colors with high chroma, which encompasses primary colors alongside fluorescent shades.
Good Solubility
Water solubility enables the dye to penetrate materials evenly and produce consistent colors.
Fiber Versatility
These materials work well with cotton, rayon, silk, wool, nylon and other fibers, which makes them essential throughout the textile industry.
What Reactive Dyes Do We Offer?
To address diverse industrial needs, Alfa Chemistry provides a comprehensive range of disperse dyes, including:
Reactive Cold Dyes
Optimized for low-temperature dyeing processes (30~60°C), reactive cold dyes exhibit high reactivity with cellulosic fibers under mild alkaline conditions. They are ideal for cold pad-batch dyeing, ensuring good penetration, evenness, and fixation on lightweight and delicate fabrics.
View Full Product ListReactive HE Dyes (High Exhaustion Dyes)
HE dyes are engineered for maximum dye uptake and fixation efficiency, especially in exhaust dyeing systems. Their molecular design ensures low hydrolysis, making them suitable for high-speed and resource-saving dyeing processes.
View Full Product ListReactive Hot Dyes
These dyes require elevated dyeing temperatures (80~90°C) for activation and fixation, providing excellent build-up, penetration, and leveling on various substrates. They are widely used in exhaust and continuous dyeing of cellulosic fabrics.
View Full Product ListReactive ME Dyes (Medium Energy Dyes)
ME dyes offer a balanced profile between cold and hot dyes, enabling efficient dyeing at moderate temperatures (60~70°C). They are suited for systems requiring energy efficiency without compromising on fixation or fastness.
View Full Product ListReactive Vinyl Sulphone Base Dyes
These dyes contain vinyl sulphone (VS) as the reactive moiety, capable of forming stable covalent ether bonds with cellulose under alkaline conditions. Vinyl sulphone dyes are known for their superior wash fastness and chemical stability.
View Full Product ListReactive Printing Dyes
Specially formulated for screen and digital printing on cotton and viscose, these dyes exhibit excellent print definition, color clarity, and reproducibility. They are designed for compatibility with various print paste formulations and steaming processes.
View Full Product ListOther Reactive Printing Dyes
This category includes specialty reactive dyes used for niche printing techniques or performance-critical applications, such as discharge printing, rapid steaming, or multi-fiber blends. Custom formulations are available upon request.
View Full Product List
Reactive Cold Dyes
Reactive HE Dyes (High Exhaustion Dyes)
Reactive Hot Dyes
Reactive ME Dyes (Medium Energy Dyes)
Reactive Vinyl Sulphone Base Dyes
Reactive Printing Dyes
Other Reactive Printing Dyes
*Please use the links above to find a product that meets your
requirements.
*If the product you need is not listed here, we can provide it for you through custom
synthesis.
Explore Our Full Range of Reactive Dyes – Request Samples Today!
Customers Often Look For
Discover our most sought-after reactive dyes, engineered for exceptional fixation, vivid color yield, and robust wash fastness - optimized to meet the demanding needs of textile dyeing, printing, and industrial coloration with precision and reliability.
| Catalog Number | Product Name | Color Index | Categories | Price |
|---|---|---|---|---|
| DYE-REA-0001 | Reactive Red M5B | Reactive Red 2 | Reactive Cold Dyes | Inquiry |
| DYE-REA-0006 | Reactive Gol. Yellow MR | Reactive Yellow 44 | Reactive Cold Dyes | Inquiry |
| DYE-REA-0010 | Reactive Yellow M8G | Reactive Yellow 86 | Reactive Cold Dyes | Inquiry |
| DYE-REA-0032 | Reactive Green HE4B | Reactive Green 19 | Reactive HE Dyes | Inquiry |
| DYE-REA-0035 | Reactive Navy Blue HER | Reactive Blue 171 | Reactive HE Dyes | Inquiry |
| DYE-REA-0047 | Reactive Purple H3R | Reactive Violet 1 | Reactive Hot Dyes | Inquiry |
| DYE-REA-0049 | Reactive Blue H5R | Reactive Blue 13 | Reactive Hot Dyes | Inquiry |
| DYE-REA-0061 | Reactive Green ME4GL | Reactive ME Dyes | Inquiry | |
| DYE-REA-0064 | Reactive Jet Black HFGR | Reactive ME Dyes | Inquiry | |
| DYE-REA-0067 | Reactive Blue BF | Reactive Blue 222 | Reactive ME Dyes | Inquiry |
| DYE-REA-0108 | Reactive Red P8B | Reactive Red 13 | Reactive Printing Dyes | Inquiry |
| DYE-REA-0109 | Reactive Megenta PB | Reactive Violet 26 | Reactive Printing Dyes | Inquiry |
What Are Reactive Dyes Used for?
Reactive dyes are extensively employed across numerous industrial and commercial sectors:
Apparel & Fashion Textiles: T-shirts, jeans, dresses, scarves, socks, and more.
Home Textiles: Bed linens, towels, curtains, upholstery fabrics.
Industrial Textiles: Automotive seat covers, technical fabrics, and workwear.
Digital & Screen Printing: Suitable for both traditional printing methods and modern inkjet systems.
Other Industries: Also used in cosmetics, paper, leather, and specialty polymers where fiber-binding dyes are required.
What Is Reactive Dyeing Process?
Reactive dyeing comprises several well-defined stages for optimal fixation and uniformity:
Adsorption
The dye is absorbed onto the fiber surface under controlled temperature and electrolyte concentration.
Exhaustion
Gradual migration of dye into the fiber with the aid of salts like sodium sulfate or Glauber's salt.
Fixation
Addition of alkali (e.g., sodium carbonate) activates the fiber and dye for covalent bond formation.
Washing-Off
Removal of unfixed or hydrolyzed dye molecules to enhance fastness and avoid staining.
Services That Fit Your Needs
Alfa Chemistry delivers personalized reactive dye development solutions for unique applications. Our R&D team will work collaboratively to develop solutions for custom shades and functional additives like UV-blocking and antimicrobial treatments, which can easily integrate into your manufacturing process. Services include:
- Development of triazine reactive dyes
- Development of pyrimidine reactive dyes
- Development of vinylsulfone-based reactive dyes
- Development of phosphonic acid-based reactive dyes
Curious About Our Success Stories?
The following case studies demonstrate how our products have led to significant technological breakthroughs and economic benefits in real-world applications.
Case 1: Medium to large cotton mill in India purchases Reactive Red M5B (CI: Reactive Red 2) for reactive dyeing line modification
Background:
A cotton yarn and fabric dyeing company in Gujarat, India, planned to upgrade its reactive dyeing system to improve colorfastness and reduce wastewater load.
Product Sourced: DYE-REA-0001 Reactive Red M5B (Reactive Red 2)
Application Notes:
The customer was using this product in an intermittent roll and cold stack dyeing process with the goal of improving uniformity and colorfastness of the red dye while reducing the wash load associated with dye hydrolysis.
Alfa Chemistry provided a high purity M5B sample for pre-testing. The technical team recommended adjusting the salt concentration and alkali addition sequence to improve dye pick-up. After the test, the dyed fabrics showed an improvement of one grade in wash fastness (from grade 3 to grade 4). The customer highly recognized the dispersion and batch-to-batch consistency of the dyes, and subsequently signed an annual purchase agreement.
Case 2: A European outdoor sports brand specified Reactive Blue HERD (CI: Reactive Blue 160) for functional cotton fabrics.
Customer Background:
A German sustainable apparel brand focuses on environmentally friendly sportswear and seeks a blue colorant with high sunlight fastness and washing resistance for use in cotton-polyester composite functional fabrics.
Product: DYE-REA-0037 Reactive Blue HERD (Reactive Blue 160)
Application Note:
This blue dye is used for the dyeing of blends containing 20% polyester and 80% combed cotton and is subjected to a sunlight fastness test. Alfa Chemistry offers a detailed guide to the application of HERD dyestuffs as well as recommendations for pre-treatment. Dyeing was carried out using a mild high salt gradient method to ensure blue color saturation and to prevent problems with polyester segregation. The finished fabric passed the lightfastness test at level 5 or higher, meeting the requirements of their outdoor performance textile product line. Satisfied with the environmental data, the customer expanded the scope of cooperation to three blue color gradients.
Case 3: Home textile factory in East China chooses Reactive Red ME4BL (CI: Reactive Red 195) to develop new reactive printed bedding products
Background:
A home textile company with an annual production capacity of 20 million meters of bedding fabrics plans to develop a new print pattern with "coral red" as the main color.
Product: DYE-REA-0054 Reactive Red ME4BL (Reactive Red 195)
Application Notes:
Reactive Red 195 has excellent colorfastness and high concentration of coloring power when used in the combination of coating and reactive printing processes, which require bright color, high fastness, non-migration, and resistance to perspiration. Reactive Red 195 has excellent colorfastness and a high concentration of coloring power. After blending, this dye can be used with printing paste, and its fastness can be maintained above grade 4 after fixing at high temperature. Customer feedback is that the color brightness and luster are better than similar domestic dyes, especially in large-volume printing with high batch stability. It has been used in many new patterns and become the main series of colorants for spring and summer of 2024.
Case 4: A Southeast Asian garment processing company purchased Reactive Yellow GR (CI: Reactive Yellow 15) for T-shirt basic dyeing.
Customer background:
A large-scale export garment processing factory in Southeast Asia focuses on OEM orders in the European and American markets, and its regular T-shirt products need to be matched with reactive dyestuffs for color mixing in small batches.
Product: DYE-REA-0079 - Reactive Yellow GR (Reactive Yellow 15)
Application Note:
For cotton T-shirt dip-dyeing and continuous pad-dyeing, the color tone required is between "lemon yellow" and "light bean yellow" with good repeatability and environmental compliance. Alfa Chemistry recommends this GR series of dyes and provides small samples for customers in conjunction with the color-matching database. Alfa Chemistry recommends this GR series of dyes and provides the customer with small sample ratios in conjunction with the color matching database. The dyed product achieved a fastness level of 4+ in both wet and dry rubbing tests. After the first use, the customer moved to regular purchasing and then expanded to other basic color shades.
Customer Reviews
What Our Customers Ask
What types of fibers are reactive dyes suitable for dyeing?
Reactive dyes are mainly used for natural fibers (e.g. cotton, linen, silk), regenerated cellulose (e.g. viscose, tencel) and some protein fibers (e.g. wool). The affinity and reaction conditions of different series of dyestuffs for each type of fiber are different; please refer to the product technical data sheet for details.
How can I choose the right reactive dyestuff for my process?
The selection should be based on the dyeing method (e.g., cold stacking, continuous pad dyeing, intermittent dyeing), the type of fibers to be dyed, the need for weathering/washing/sunlight fastness, the intensity of the color, and the environmental requirements. Our technical team can provide advice on dyeing prescription design to help customers optimize their formulations.
What is the dye pick-up rate and color fixation rate of the dyestuff?
Different dye structures have different dyeing and fixing rates. For example, Reactive Red M5B has a dyeing rate of more than 75% and a color fixation rate of more than 70%, depending on process parameters such as pH, salt concentration, temperature and type of fixative.
What are the storage conditions and expiration date of reactive dyes?
A6: We recommend storing the dyes in a cool and dry place under sealed conditions, away from direct sunlight and high humidity. Under normal storage conditions, the shelf life of powdered dyes is 24 months, and liquid dyes are recommended to be used up within 12 months.
Is it possible to provide samples for sampling and testing?
Yes, we can provide samples in small packages (usually 25g~100g) for customers' color matching experiments, fastness test and process verification. For sample requests, please contact sales or fill out the online form.
Do the products support customized color or chromatic formula?
Yes, we provide customized services, including non-standard color codes, targeted development of specific dyeing performance, and low-salt dye design. We have a complete color-matching database and a high-throughput dye synthesis platform to respond quickly to customer needs.
Does it support technical support service? Who can I consult if I have dyeing problems?
We have a team of experienced application engineers to provide one-on-one dyeing technical guidance, problem analysis, process optimization and quality traceability support to our global customers. You can contact us by email, phone or online customer service channels.
Can reactive dyes be used for digital inkjet printing?
Yes, some high-purity reactive dyestuffs (e.g. Reactive Blue HERD) can be used in the formulation of textile inkjet printing inks, but they need to undergo special treatments (e.g. fineness regulation, solubility optimization, etc.). We recommend consulting us for specialized dye solutions based on equipment model and printhead type.
