Coating

Knife-Over-Roll Coating Add-on Weight Calculator

The gap is not the film and the film is not the add-on. Two conversions sit between the setting on the machine and the weight the customer pays for.

Knife Setting
mm
×

Fraction of the gap that leaves as wet film; measure it on your own line.

mPa·s
Coating Formulation
g/cm³
%
Line Running
m/min
m

Dry Add-on Weight

— g/m²

Solids remaining on the cloth after drying

Film & Line

Wet Film Thickness
— mm
Wet Add-on Weight
— g/m²
Shear Rate Under the Knife
— 1/s
Shear Stress
— kPa
Wet Coating Consumption
— kg/h
Dry Solids Laid Down
— kg/h

Shear stress is Newtonian here. Most coating pastes are shear-thinning, so the real stress at speed is lower than this and the gap factor drifts with it — treat the stress as a comparison between settings, not an absolute.

Knife-Over-Roll Coating Add-on Weight Calculator — free, with the formula and a worked example, at Textile School.