ISO 8130-3:2021

Overview

ISO 8130-3:2021 - "Coating powders - Part 3: Determination of density by liquid displacement pycnometer" - specifies a laboratory method to determine the density of coating powders using a liquid-displacement pycnometer. The method measures the mass and volume of a test portion wetted by a selected displacement liquid that does not swell or dissolve the powder. Results are calculated and reported at (23 ± 1) °C.

Key topics and technical requirements

• Method principle: Density determined by liquid displacement in a pycnometer (mass and displaced volume).
• Apparatus and materials:
  • Pycnometer complying with ISO 2811-1.
  • Vacuum pump (for bubble removal).
  • Balance (200 g capacity, 1 mg readability).
  • Displacement liquid: aliphatic hydrocarbon(s) free of aromatics, boiling point 80 °C–140 °C; must not interact with sample.
  • Water (ISO 3696 grade 3), freshly boiled and cooled (used for calibration and when appropriate).
• Conditions and sampling:
  • Test temperature: (23 ± 1) °C; relative humidity: (50 ± 5) %.
  • Sampling per ISO 15528 to obtain representative test portions.
• Procedure essentials:
  • Duplicate determinations required.
  • Determine density of displacement liquid by pycnometer filled with liquid and with water (water density at 23 °C taken as 0.998 g/cm3).
  • Introduce powder wetted by displacement liquid, remove entrapped air (vacuum if needed), fill to mark and weigh.
  • If duplicate results differ by > 2 %, repeat tests.
  • Report mean value to nearest 0.01 g/cm3.
• Reporting: Include sample ID, reference to ISO 8130-3:2021, pycnometer type/volume, displacement liquid type/grade, sample mass, individual and mean results, deviations from the method and anomalies, and test date.
• Notes: The 2021 edition updated references (ISO 2811-1), removed acetone for cleaning, changed filling order, and set the acceptable inter-result difference as a percentage. No precision data are provided in the standard.

Applications and users

• Who uses it:
  • Coatings manufacturers and quality control laboratories.
  • R&D teams developing powder coatings and formulators assessing raw materials.
  • Test labs performing conformity checks and suppliers verifying product specifications.
• Practical uses:
  • Verifying batch-to-batch consistency of powder coating density.
  • Calculating coverage, formulation control and material properties where density is a key parameter.
  • Supporting product datasheets and regulatory or contractual quality requirements.

Related standards

• ISO 2811-1 - Pycnometer method for paints and varnishes (pycnometer specification).
• ISO 1183-1 - Density methods for plastics (used for powders with density < 1.00 g/cm3 by agreement).
• ISO 3696 - Water for analytical laboratory use (grade 3 specification).
• ISO 15528 - Sampling of paints, varnishes and raw materials.
• ISO 8130-14 - Vocabulary for coating powders.

Keywords: ISO 8130-3, coating powders, density determination, liquid displacement pycnometer, pycnometer method, displacement liquid, powder coating QC.