Overview
EN ISO 2812-5:2018 - Paints and varnishes: Determination of resistance to liquids - Part 5: Temperature‑gradient oven method - specifies a laboratory procedure to evaluate how individual-layer or multi-layer coating systems resist exposure to liquids or paste-like products. The method uses a temperature-gradient oven to apply a controlled thermal gradient beneath coated test panels while droplets of test substances are applied, enabling assessment of coating degradation and, if necessary, damage to the substrate.
Key topics and technical requirements
- Test principle: apply droplets of the test substance to a coated panel, expose the panel in a temperature-gradient oven, then assess effects.
- Gradient oven: must generate a linear temperature gradient along the panel and limit transverse variation (maximum gradient over the panel width ≤ 2.5 °C). Heat is applied from the bottom for homogeneous transfer.
- Typical test settings (as specified unless otherwise agreed):
- Oven gradient: 35 °C to 80 °C, with a linear increase of 1 °C per 1 cm along the panel.
- Exposure time: 30 minutes.
- Droplet volume: 25 µL to 100 µL (use a metering pipette).
- Test panel dimensions: nominally 560 mm × 100 mm, substrate thickness 0.7–1.0 mm (steel unless agreed otherwise).
- Conditioning: panels conditioned for at least 16 h at (23 ± 2) °C and (50 ± 5)% RH (ISO 3270).
- Measurements and evaluation: determine dry film thickness (ISO 2808), assess visual effects (reference to ISO 13076 for lighting and visual procedure), and wipe/clean panel after exposure before assessment.
- Limitations: temperature and humidity strongly influence results; any deviations must be agreed and reported.
Applications and practical value
- Useful for coating manufacturers, test laboratories, R&D teams, quality control, specifiers, and certification bodies who need to:
- Screen liquid resistance of paints, varnishes and coating systems.
- Compare formulations or curing regimes under a controlled thermal gradient.
- Evaluate potential substrate damage after exposure to chemicals, oils, cleaners or paste-like products.
- Support product data sheets, conformity testing, and durability assessments.
Who should use this standard
- Laboratories performing standardized coating tests.
- Formulation chemists and product developers evaluating chemical resistance.
- Quality assurance personnel and spec writers needing reproducible, comparable test data.
- Certification and regulatory bodies assessing performance claims.
Related standards
- ISO 1513, ISO 1514, ISO 2808, ISO 3270, ISO 4618, ISO 13076, ISO 15528 - referenced for sample preparation, panel preparation, film thickness, conditioning, terminology, lighting/visual assessment and sampling.
Keywords: EN ISO 2812-5:2018, temperature-gradient oven, resistance to liquids, paints and varnishes, coating durability, liquid resistance test, gradient oven method.
