Sodium lignosulphonate is one of the main dispersants in the dye industry. It is used to grind and standardise disperse and vat dyes, and to keep dye and pigment particles from re-agglomerating in powders, granules and liquid concentrates. Our Dye & Pigment Dispersant Grade (GAC-DP) is a high-purity sodium lignosulfonate made for this use.
What It Does for Dyes
- Grinding aid: during wet or dry milling it reduces particle friction and helps reach a fine particle size.
- Dispersant: its sulfonic and carboxylic groups adsorb on dye particles and give them a negative charge, so they repel each other.
- Standardising filler: it is blended into dye powder to set strength and improve wetting and redispersion when the dyer makes up the bath.
Dye & Pigment Dispersant Grade Data
| Item | GAC-DP (typical) |
|---|---|
| Appearance | Brown powder |
| Water-insoluble matter | 0.5% max |
| Calcium & magnesium | 0.5% max |
| Core material | Same specification as the Dispersant Grade (GAC-NaLS-Dispersant-P): 95% min dry matter, 70% min lignosulphonate |
| Starting dosage | 2 – 8% of dye or pigment solids; start at 3 – 5% in first trials |
| Addition point | During wet grinding, or dry-blended before standardisation; pre-dissolving in water helps in wet mills |
Where It Is Used
| Application | Role |
|---|---|
| Disperse, reactive and vat dye powders | Dispersant and standardising agent |
| Pigment concentrates | Grinding aid and dispersant |
| Water-based printing inks | Pigment dispersant |
| Seed-treatment colourants | Disperses the colourant in agrochemical formulations |
Checks Before Switching Dispersant
- Grind the dye with your current dispersant and with GAC-DP at two dosages.
- Compare particle fineness, dispersion in the dye bath and colour strength.
- For disperse dyes used at high temperature, run a heat stability test; method in dispersant heat stability test.
- Lignosulfonates are brown; check that shade is not affected in light colours.
How lignosulfonate compares with naphthalene dispersants: NNO vs MF vs lignosulfonate. Textile use: sodium lignosulfonate in the textile industry.
Frequently Asked Questions
Why is sodium lignosulphonate used in dyes?
As a grinding aid, dispersant and standardising filler. It keeps dye particles fine and separated, so the dye disperses evenly in the bath.
What dosage is used in dye formulations?
The GAC-DP TDS gives 2 – 8% of dye or pigment solids, starting at 3 – 5% in first trials.
Which dyes is it used with?
Mainly disperse and vat dyes, and also reactive dye powders, pigment concentrates and water-based inks.
Does it affect dye shade?
It is brown, so check shade in light colours. Purer, low-colour grades reduce the effect.
