Naphthalene sulfonate formaldehyde condensates (SNF, Dispersant NNO) are dispersants. In the paper and board sector they are used where fine particles have to stay evenly dispersed in water: pigment and filler slurries, dye dispersions, and the gypsum core of paper-faced plasterboard. They are not sizing or wet-strength agents.
Where They Are Used
| Application | Role | Grade usually tested |
|---|---|---|
| Pigment and filler slurries for coatings | Keeps calcium carbonate, clay or pigment dispersed at high solids | Dispersant grade (NNO) |
| Paper dyeing | Disperses dye particles for even shade | Dispersant grade (NNO) |
| Plasterboard (gypsum wallboard) | Lowers the water needed for the gypsum slurry, so less water has to be dried off | SNF powder grade |
What They Do Not Do
- They do not size paper or make it water-resistant; that is done by sizing agents.
- They are not wet- or dry-strength resins.
- Lignosulfonates are also used as low-cost dispersants in some of these applications.
How to Test
- Measure slurry viscosity at your target solids with and without the dispersant.
- Check stability over storage time and at process temperature.
- Check foam and compatibility with other additives.
- For plasterboard, measure slurry flow, setting and board density.
Plasterboard additives are covered on plasterboard and gypsum board additives; dye-dispersant grades on Dispersant NNO. SNF grades: SNF product page.
Frequently Asked Questions
Is naphthalene sulfonate used in paper making?
Yes, as a dispersant for pigment and filler slurries and dyes, and in the gypsum core of plasterboard. It is not a sizing or strength agent.
Does SNF make paper waterproof?
No. Water resistance comes from sizing agents. SNF only keeps particles dispersed.
Which grade is used for plasterboard?
SNF powder grades are tested as gypsum slurry water reducers; the dose is set by slurry trials.
