Levelling, substrate wetting, slip — the additives you only see on the finished film.
Most film defects arise at the interface: craters from local contamination, orange peel from excessive surface tension, poor wetting on critical substrates. Surface additives lower the surface tension of the coating and level out local differences before the film sets.
Silicone and acrylate chemistries behave differently here — above all in recoatability, the most common source of complaints in multi-layer build-ups. Besides levelling, this class also sets the surface itself: slip, scratch resistance and anti-blocking. Optimising both at once is rarely possible; which effect takes priority is something we clarify from the application.
What matters when choosing
Decide the trade-off: levelling, substrate wetting or surface slip
Is recoatability required? It rules out several types
Silicone or acrylate based
Also check foam stabilisation — many surface additives stabilise foam
Test critical substrates (plastics, aged coatings, contaminated surfaces) beforehand
Selection guide at a glance
Type
Main effect
Typical dosage
Watch out for
Silicone based (polyether siloxane)
Levelling, slip, substrate wetting
0.1–0.5 %
Check recoatability depending on modification
Acrylate based
Levelling without slip
0.1–1.0 %
Recoatable; some grades stabilise foam
Substrate wetting additives
Critical substrates, crater prevention
0.1–0.5 %
Surface tension drops — also check foam
Slip / anti-scratch grades
Mechanical surface resistance
0.1–0.5 %
In multi-coat systems test intercoat adhesion
Guide values for initial orientation — our assessment as a distributor. The manufacturer's technical data sheet and trials in your own system are decisive.
Trade names in our range
Extract from our product database. Click a name — Coaty will explain the product to you.
Technical data sheets and free samples come directly from us — no detour via the manufacturer. Prices on request.
