Back Ionisation
A condition, which may occur during electrostatic application of powder coating where excessive build up of charged powder particles limits further powder to be deposited onto the substrate. A pockmarking pattern usually occurs on the powder surface.
Bell
Electrostatic spray device whose applicator is bell shaped. Centrifugal force throws the powder off its edge into a fine pattern. The charged particles are then attracted to the work surface.
Binder
The portion of the powder formulation that forms the primary strength of the film. It binds pigments and additives into a solid film and to the substrate.
Blast Cleaning
Removal of surface contamination and corrosion products by use of air and mechanical abrasives (also referred to as sand or shot blasting).
Blistering Bubbles
formed under the cured powder film, usually caused by the expansion of trapped air, moisture or corrosion.
Blooming
A hazy appearance on the surface of a coating.
Bridging
The ability of a finish to cover cracks, voids or small gaps without a break in the film.
BTU British Thermal Unit
The amount of heat required raising the temperature of 1 pound of water by 1 0F.
Bulk Density
Mass per unit of volume in powder form, including the air trapped between the particles.