Defoaming
Foam is stabilised by surfactants in the bubble wall. A defoamer droplet enters the wall, spreads, thins it and breaks the bubble, releasing the air before the film dries.
Home / Additive guide
The additive guide.
A practical reference for paint and ink technologists: what each family does, how to select and add it, and the terms you’ll meet on a data sheet.
Mechanisms
Three effects behind most coating defects.
Wetting and dispersing
Wetting displaces air from the pigment surface. Dispersing groups then anchor to the particle and keep it apart from its neighbours, electrostatically in water and sterically in solvent.
Surface control
Uneven surface tension pulls a wet film into craters and orange peel. Surface additives concentrate at the film surface and level it out, improving wetting, flow and slip.
Eight families
What each family does.
The same families appear in water-borne and solvent-borne systems, with chemistries tuned to each.
Selection
Choosing the right grade.
In the lab
How to run a ladder study.
- Fix the control
Make one batch without the additive under test.
- Build the ladder
Add the grade at three or four levels across the recommended range.
- Test like the real process
High-speed stirring for foam, roller or spray for micro-foam, drawdowns for levelling.
- Measure
Density loss, grind, colour strength, gloss, craters, viscosity and settling.
- Check side effects
Craters, haze, recoatability and water sensitivity, then re-test after heat-ageing.
- Choose the lowest level that works
Overdosing costs money and can create new defects.
Glossary
Terms on a data sheet.
- PVC
- Pigment volume concentration: the volume share of pigment and extender in the dry film. High-PVC paints foam and settle differently from glossy low-PVC paints.
- APEO-free
- Contains no alkylphenol ethoxylates, surfactants restricted in many markets.
- VOC-free
- Contributes no volatile organic compounds to the formulation.
- Amine-neutral
- Suitable for systems neutralised with amines without side reactions or odour issues.
- Micro-foam
- Fine entrapped air that becomes pinholes and haze in the dry film.
- Flocculation
- Dispersed pigment re-clumping, causing weak colour, floating and low gloss.
- Mill-base
- The concentrated pigment, dispersant and binder grind before let-down.
- Polarity (solvent-borne)
- Non-polar, medium-polar and polar systems need different additive chemistries; our tags show where each grade fits.
- Thixotropy
- Viscosity that drops under shear and recovers at rest, so paint brushes easily yet resists sag.
- Solids
- The non-volatile share of an additive as supplied, important for dose calculation.
Technical support