Industry challenges
Water-based coatings and inks often struggle with pigment and filler settling, storage separation, and the trade-off between sag resistance and levelling. In high-solids or highly filled systems, simply raising the dosage of conventional thickeners can push high-shear viscosity too high and hurt application; different resins, salts, pH and surfactants also change stability.
What nanocellulose does
CNF forms a three-dimensional fibre network through its high aspect ratio, raising low-shear viscosity, yield stress and thixotropic recovery to suspend pigments and fillers and reduce settling and sagging. CNC is better suited to nano-reinforcement, interface tuning or coating densification. Carboxyl, hydroxyl or hydrophobic surface groups can be matched to different continuous phases.
Recommended grade
Recommended: carboxylated cellulose nanofibrils (C-CNF).
Why: this scenario needs a rheological network plus stable dispersion in water. The long fibres of CNF form a percolating network more easily than CNC, and carboxylation gives good water dispersibility at suitable pH and ionic strength, making it the better choice for suspension, anti-settling and thixotropy control in water-based systems.
Alternatives
If the system is ion-sensitive or you want to avoid high surface charge, try hydroxyl CNF. If the focus shifts from thickening and suspension to film reinforcement, surface properties or nanocomposites, evaluate CNC. Non-aqueous or low-polarity systems should start with hydrophobically modified CNF/CNC rather than a standard water-dispersed CNF.
Trial suggestions
Based on total formulation solids, start with a blank plus 0.10%, 0.25% and 0.50% dosage levels. Pre-disperse the nanocellulose thoroughly, add it slowly after the pigments and fillers have been dispersed, then proceed to let-down. Compare storage settling, viscosity curve, thixotropic recovery, levelling, sag resistance and film properties.
Common issues
- Lumps after addition: check local concentration, addition rate and pre-dispersion.
- Viscosity rises too fast: lower the dosage and avoid adding everything at once.
- Flocculation in high-salt systems: check how electrolytes and pH affect the double-layer stability of C-CNF.
- Rough or dull film: check fibre dispersion scale and compatibility with the resin.
Note
These suggestions are for nanocellulose material selection and preliminary trials only, not fixed formulations, final process parameters or regulatory conclusions. Results depend on product type, surface groups, solids content, dispersion state, dosing method, and on the system's pH, ionic strength, resin/polymer/protein type, pigments, fillers and other additives. Run a blank and a dosage gradient to confirm the grade and process conditions for your own system. For food, cosmetic, medical and food-contact uses, confirm regulations, purity, testing and market access separately for the target market.
