Importance and measurement of minimum film‐forming temperature

The minimum film forming temperature (MFFT) has been described as “the minimum temperature at which a waterborne synthetic latex or emulsion will coalesce when laid on a substrate as a thin film”. If there are no pigments present, such materials will form a smooth, clear, transparent film when dried at temperatures above their MFFT. At temperatures below their MFFT, drying will result in a white, powdery, cracked film. For effective use, it is therefore important that paints and coatings based on emulsions are applied only to surfaces with a temperature above that of their MFFT. This is usually derived by the manufacturer and printed on the side of the tin.