Sodium lignosulfonate comes from the paper industry: it is made from the lignin dissolved during sulfite pulping. Its uses back in the industry are narrower than often claimed. It is not a bleaching or whitening agent; bleaching removes lignin, and lignosulfonate is lignin.
From Pulp Mill to Product
In sulfite pulping, wood chips are cooked in a sulfite liquor. Lignin becomes water-soluble lignosulfonate and is washed out of the pulp. The spent liquor is then purified, concentrated and dried to make sodium lignosulfonate. Step-by-step: sodium lignosulfonate manufacturing process.
Uses in the Paper and Board Industry
| Use | What it does | Source |
|---|---|---|
| Fiberboard binder | Binder component in fiberboard resin formulations | Grade One and Liquid Grade One TDS |
| Dust control at mills and yards | Binds dust on unpaved roads and wood-yard surfaces | Grade One and Dust Control TDS |
| Pellet and briquette binder | Binds fine particles into pellets and briquettes | Grade One TDS (binder for powdered and granular materials) |
For board binders, results depend on resin chemistry, furnish, moisture and press conditions, so production trials are needed. The chemistry behind these uses is covered on lignosulfonate.com: sodium lignosulfonate in the paper industry.
What It Is Not Used For
- Bleaching or whitening paper: lignosulfonate is dark and is itself a form of lignin.
- Removing lignin from wood: that is done by the sulfite cooking liquor, not by lignosulfonate.
Frequently Asked Questions
Is sodium lignosulfonate made from paper industry waste?
Yes. It is made from the spent liquor of sulfite pulping, a by-product of pulp production.
Is sodium lignosulfonate used to bleach paper?
No. It is a dark, lignin-based material. Bleaching removes lignin from pulp.
How is it used in fiberboard?
As a binder component in resin formulations, as listed in the Grade One TDS. Production trials are needed for each board line.
Which grade suits paper-industry uses?
Grade One or Liquid Grade One for binders, and the Dust Control Grade for mill roads and yards.
