AppliedProduct selection and comparison are drawn from the owner-authorized Coating Additives Handbook. Verify current TDS/SDS and performance in the intended formulation before use.
Technical challenge
Waterborne or fast-applied coatings retract on low-energy, waxy or insufficiently cleaned substrates.
Product selection
Candidates are organized by a supplied technical handbook and the individual published TDS where available. These are starting points for trials, not confirmed equivalents or universal dosage recommendations. Grades without a SITI TDS page are not treated as formally published product profiles.
| Grade / evidence | Relevant system | Selection considerations |
|---|---|---|
| KOBOND 3503 ↗Published TDS profile · handbook slide 45Products category ↗ | Waterborne coatings and printing inks | Modified acetylenic-diol wetting agent for rapid substrate wetting; assess dynamic wetting and foam. |
| KOBOND 3504 ↗Published TDS profile · handbook slide 45Products category ↗ | Waterborne coatings and printing inks | Polyether-modified acetylenic-diol option; compare spreading and recoatability on the actual substrate. |
| ADDSiL 3006Handbook grade; TDS page unavailable · handbook slide 45Products category ↗ | Silicone substrate wetting | Handbook silicone wetting example; check surface tension, compatibility and cratering in trials. |
Substrate-wetting technology comparison
The table reproduces product-selection directions from the owner-authorized handbook. Listed grades are screening candidates, not interchangeable products or a claim that every grade has a published SITI TDS. Confirm current documentation and the complete formulation.
| Technology | Handbook-listed grades | Selection consideration |
|---|---|---|
| Acetylenic diol | KOBOND-3501, 3503, 3504, 3505, 3506, 3507 | Rapid dynamic wetting; selected grades may have lower foam tendency. Test at the actual coating speed. |
| Silicone substrate wetting | ADDSiL-3002, 3006, 3014, 3015, 3020, 3027 | Low-energy substrate spreading; check foam, compatibility, slip and recoating. |
| Fluorinated wetting | KOBOND-3901, 3902, 3903, 3905, 3906 | Strong surface/interfacial tension reduction on difficult oily or waxy surfaces; verify current product and regulatory data. |
Handbook slides 45
The coating–substrate interface
A liquid coating must contact and spread over the substrate before it can form a continuous film. Poor wetting may appear as beading, crawling, edge retraction, incomplete coverage or local adhesion failure. Low-energy polyolefins, waxy surfaces, release-agent residues and contaminated metal deserve special attention. The liquid's surface tension, the solid's surface free energy and their interfacial interactions all contribute. A smaller contact angle often indicates improved spreading for a specified liquid–solid pair, but no single angle is a universal pass/fail rule.
Static versus dynamic surface tension
Equilibrium surface tension describes an interface after surface-active molecules have had time to arrange. Dynamic surface tension describes a newly formed interface before that equilibrium is reached. Rapid spraying, roll coating, gravure printing and fast-drying waterborne systems may create fresh interfaces faster than an additive can migrate. A good equilibrium value can therefore coexist with poor wetting during the actual process. Evaluate both the target substrate and the relevant application speed.
Waterborne systems and formulation balance
Waterborne coatings often need more help to wet low-energy surfaces. A substrate wetting agent may be added during let-down or final adjustment, but its addition point and dose should follow the grade's TDS and formulation trials. Verify spreading together with foam generation, cratering, adhesion, appearance and recoatability. The aim is adequate contact with the substrate while preserving the rest of the coating system, not the lowest possible surface-tension number.
Formulation guidance
- Test the actual cleaned or pretreated substrate, including edge and recess coverage.
- Measure or compare wetting at the process speed where the defect occurs.
- Check foam, adhesion and recoatability after any wetting-agent adjustment.
Troubleshooting
- Beading or edge withdrawal
- Test the actual cleaned substrate and compare dynamic wetting at the application speed.
- Wetting improves but foam rises
- Rebalance wetting and foam control, then verify adhesion and recoatability.