ASTM D5965

Density of Coating Powders

Applicability: ASTM D5965 applies to thermosetting and thermoplastic coating powders used in electrostatic spray and fluidized-bed powder coating processes, including epoxy, polyester, polyurethane, hybrid, and acrylic powder formulations. The standard encompasses three test methods: Method A using a liquid pycnometer, Method B using a helium gas pycnometer, and Method C using a liquid pycnometer with a surfactant; each method is applicable depending on the powder reactivity with water or organic solvents used as the displacement medium.

Purpose: ASTM D5965 determines the specific gravity of coating powders by measuring the mass of a known volume of the powder material through either liquid displacement or helium gas pycnometry, providing the ratio of powder density to water density at a reference temperature. Specific gravity is a fundamental formulation parameter used to calculate theoretical spreading rate and coverage per unit mass, compare the cost-effectiveness of competing coating powder formulations, and verify lot-to-lot consistency during quality control testing by powder coating manufacturers and industrial applicators.