Once the particles melt, surface tension pulls the film flat until rising viscosity and the start of crosslinking stop it. Flow is measured by the inclined plate test, where a pressed pellet melts and runs down a tilted plate and the length of the run is recorded. Good flow and leveling give a glassy, smooth finish; poor flow gives orange peel. Too much flow thins edges and can sag.
This lot has no flow, it's gelling before it levels, so everything looks like an orange.
Also heard as
- flow and leveling
- flow-out
- inclined plate flow
Related terms
Gel time
How many seconds a powder takes at a set temperature to go from melted to a rubbery gel that no longer flows.
Orange peel
A dimpled surface texture like the skin of an orange, the most common appearance complaint on powder.
Film build
The thickness of the cured coating, usually given in mils or microns.
Ramp
The heat-up time a part needs in the oven before it reaches cure temperature and the cure clock starts.