ISO 6272-1:2011

Overview - ISO 6272-1:2011 (Paints and varnishes - Falling-weight test, large-area indenter)

ISO 6272-1:2011 specifies a laboratory method to evaluate the impact resistance / rapid-deformation resistance of a dry paint or varnish film when a falling weight with a 20 mm diameter spherical indenter deforms the coating and substrate. The method is intended to determine whether coatings crack or peel under rapid deformation and can be used either as a pass/fail compliance test or as a classification test to find the minimum mass/height that causes failure.

Key topics and technical requirements

• Apparatus: falling-weight assembly with guide tube, die (ring with inner diameter 27 ±0.3 mm), clamping sleeve, stops to limit indentation and a ×10 magnifier for inspection.
• Indenter and masses: spherical-segment head of (20 ± 0.3) mm diameter; typical weights 1 000 ±10 g or 2 000 ±20 g; additional masses may be added up to 4 kg for classification tests.
• Guide tube tolerance: clearance between guide tube inner diameter and weight outer diameter (0.7 ±0.2) mm to ensure accurate, low-friction guidance.
• Test panels and coating: panels planar and ≥0.25 mm thick; prepare and coat panels per ISO 1514 and manufacturer instructions; film thickness measured per ISO 2808 and must not deviate by more than 10% from the agreed value.
• Conditioning and environment: condition panels at (23 ±2) °C and (50 ±5) % RH for at least 16 h; begin testing immediately and complete within 30 minutes after removal from conditioning; record test temperature and relative humidity.
• Procedures:
  • Pass/fail: one specified mass and drop height; five impacts at different positions - coating acceptable if at least 4 of 5 show no cracking/peeling.
  • Classification: increase drop height in 25 mm increments (and/or mass) to determine the first failure height; test adjacent heights to establish the end point.
• Reporting: include product ID, reference to ISO 6272-1:2011, substrate prep, application and drying details, film thickness, mass/height used, orientation (coated face up/down), stops used, environmental conditions, results and any deviations.

Applications and users

ISO 6272-1 is used for:

• Quality control and batch acceptance of industrial and decorative coatings
• R&D and formulation optimization for impact/rapid-deformation resistance
• Specification compliance for coatings on metal and other substrates
• Comparative classification of coating systems

Typical users: paint and varnish manufacturers, independent test laboratories, specifiers, procurement teams, OEMs and coating formulators.

Related standards

• ISO 6272-2 (Falling-weight test, small-area indenter)
• ISO 1513, ISO 1514, ISO 2808, ISO 3270, ISO 13076, ISO 15528 (normative references for sample prep, panels, thickness measurement, conditioning, lighting and sampling)

Keywords: ISO 6272-1, falling-weight test, impact resistance, paints and varnishes, large-area indenter, rapid-deformation test, coating testing, 20-mm indenter.