Reactive dyed
Also known as: Reactive dyeing
Dyeing process in which the dye forms a covalent chemical bond with the cellulose fibre.
Description
Reactive dyed refers to textiles whose colour has been produced by reactive dyes. These dyes carry a reactive anchor group (mono- or dichlorotriazine, vinyl sulphone) that under alkaline conditions bonds covalently to the hydroxyl groups of cellulose. The result is a durable, chemically anchored colour with high wash, rub and light fastness. Reactive dyeing is today the dominant dyeing technology for cotton and other cellulose fibres (viscose, modal, lyocell).
The process typically runs at 40-60 degrees (with cold dye even lower), with alkali (soda) added to activate the reaction and salt to increase dye affinity. After the reaction phase the fabric is thoroughly rinsed to remove hydrolysed (unbound) dye. Yields range from 60-90 percent depending on dye and process; the rest burdens the wastewater.
Advantages: high wash fastness (grade 4-5 by ISO 105-C06), brilliant shades, wide colour range. Drawbacks: high salt load in wastewater (60-100 g salt per litre), residual dye needs complex treatment. Modern approaches use low-salt reactive dyes such as Avitera SE (Huntsman) that halve water and salt use.
Properties
| Process | Covalent dye-cellulose bond |
|---|---|
| Result | Brilliant, deep colours |
| Colour fastness | Very high (wash and rub grade 4-5) |
Related product categories
Sources & references
2- Wikipedia: Reaktivfarbstoff Wikipedia — Freie Enzyklopädie https://de.wikipedia.org/wiki/Reaktivfarbstoff
- Huntsman Avitera SE huntsman.com https://www.huntsman.com/products/textile-effects
