This standard specifies the test method for determining two critical thermal properties of acrylic-based polymer dispersions used for waterproofing: Minimum Film Forming Temperature (MFFT) and White Point. MFFT is the lowest temperature at which the liquid material can properly cure into a continuous, effective waterproofing film.
Acrylic-based Polymer waterproofing Materials - Methods of Test, Part 2: Determination of Coarse Particles
Quick Reference Values
Typical MFFT Apparatus Temperature Range-5°C to +75°C
Specified Wet Film Thickness for Test75 ± 5 microns
Definition of MFFTThe lowest temperature at which a latex will uniformly coalesce when laid on a substrate as a thin film.
Definition of White PointThe temperature at which a dried film of the polymer dispersion turns white or opaque upon cooling.
Dry Air Flow Rate over Film2-4 litres/minute
Key Formulas
Coarse Particles (%) = (m1 / m) x 100 — where m1 is mass of residue and m is mass of sample.
Practical Notes
The MFFT value is crucial for determining the safe application temperature range for a waterproofing product; applying it below the MFFT will lead to film defects and failure.
This test is primarily used by manufacturers for quality control and by testing laboratories for product certification, not typically performed on-site.
Results from this test directly inform the Technical Data Sheet (TDS) and application guidelines for waterproofing materials, especially regarding use in different climates.