ISO 3233-1:2019

Overview

ISO 3233-1:2019 - Paints and varnishes - Determination of percentage volume of non-volatile matter - Part 1 specifies a laboratory method to determine the non-volatile matter by volume (NVV) and the practical dry‑film density of coatings. The method uses a coated test panel (disc or plate) and the Archimedes’ principle (weighing in air and in an immersion liquid) to measure the volume of a dried coating for any agreed temperature and drying/curing period. ISO 3233-1:2019 is the preferred method for air‑drying materials and is not applicable when the critical pigment volume concentration (CPVC) is exceeded.

Key topics and technical requirements

• Principle: Determine dry coating mass and displaced fluid volume by weighing the coated receptacle in air and immersion liquid; compute dry‑film density and NVV.
• Outputs: Practical dry‑film density (ρp), non‑volatile matter by volume (NVV), and derived spreading rate (coverage per unit volume at a specified dry thickness).
• Apparatus & reagents: analytical balance (0.1 mg), receptacles (discs ~60 mm or plates ~75×120 mm), hooks/cradles, beaker/immersion liquid (typically distilled water), desiccator, forced‑ventilation air oven.
• Procedure essentials:
  • Apply sample to panel by dipping, brushing or applicator; perform determinations in triplicate.
  • Dry/ cure under specified temperature/time (see Annex A for examples); a minimum coated mass on plate is required (25 mg added in this edition).
  • Compute NVV from the ratio of liquid coating density to dry‑film density.
• Scope limits: Designed for measurements immediately after application; use for non‑air‑drying or highly reactive systems has not been fully validated. Not suitable above CPVC due to film porosity.
• Normative references: ISO 1513, ISO 2811 (density methods), ISO 4618 (terms), ISO 15528 (sampling).

Applications and users

• Quality control and R&D in paint and varnish manufacturing
• Coating formulators validating formulation solids and coverage
• Independent testing laboratories and certification bodies verifying spreading rate and NVV
• Specifiers and procurement teams assessing coating performance and material economy
• Regulatory or compliance testing where standardized NVV measurement is required

Related standards

• ISO 3233 series (other parts)
• ISO 1513 - sample preparation
• ISO 2811 - density determination
• ISO 4618 - terminology
• ISO 15528 - sampling

Keywords: ISO 3233-1:2019, non-volatile matter by volume, NVV, dry-film density, Archimedes’ principle, paint testing, spreading rate, air-drying coatings, coating density.