Overview
ISO 7784-2:2023 - Paints and varnishes - Determination of resistance to abrasion - Part 2 describes a laboratory method to measure the abrasion resistance of protective and decorative coatings using abrasive rubber wheels acting on a rotating test specimen. The test quantifies coating wear by measuring mass loss after a defined number of rotation cycles, providing reproducible data for product development, quality control and specification compliance.
Key topics and technical requirements
- Test principle: Two loaded, freely rotatable abrasive rubber wheels press eccentrically onto a rotating specimen, producing a ring-shaped wear zone; abrasion is assessed by mass loss.
- Apparatus: Turntable abrasion tester with:
- Turntable speed of (60 ± 2) min⁻¹.
- Eccentric offset of (19.05 ± 0.3) mm between wheel axis and specimen axis.
- Suction device to remove abrasive dust (distance (3 ± 1) mm).
- Abrasive wheels:
- Axial bore (16.0 ± 0.1) mm; diameter (48.4 ± 4.0) mm (usable down to 44.4 mm); thickness (12.7 ± 0.2) mm.
- Elastomer hardness and abrasive grain size/type to be agreed (Shore A or IRHD referenced).
- Wheels dressed for 50 cycles before testing and re-dressed every 500 cycles using P150 abrasive-paper disc (FEPA 43‑1).
- Test loads: Apparatus baseline ~2.5 N per wheel; additional weights provide test loads around 4.9 N and 9.8 N per wheel (per agreement).
- Specimens and conditioning:
- Minimum specimen size 100 × 100 mm, fixed on the turntable (central hole).
- Dry film thickness determined per ISO 2808.
- Condition at (23 ± 2) °C and (50 ± 5) % RH for at least 16 h (unless agreed otherwise).
- Procedure and evaluation:
- Weigh specimens to 0.1 mg before and after test; perform tests in triplicate.
- Report individual mass losses and mean mass loss in milligrams.
- Precision: No precision data currently available in the standard.
Applications and users
ISO 7784-2 is used for:
- Coating formulators and R&D teams comparing abrasive durability of paint/varnish systems.
- Quality control laboratories verifying batch-to-batch consistency and compliance with specifications.
- Third-party testing houses and certification bodies issuing performance data for procurement or tendering.
- Specifiers and end-users (automotive, industrial, flooring, protective coatings) who require quantitative abrasion data for material selection.
Practical uses include product benchmarking, failure investigation, validating coating improvements and supporting technical datasheets and performance claims.
Related standards
- ISO 7784 series: Part 1 (abrasive paper on rubber wheel) and Part 3 (abrasive paper on metal wheel, linear reciprocation) - compare methods and select the most appropriate abrasion test.
- Normative references used in ISO 7784-2: ISO 1514, ISO 2808, ISO 3270, ISO 4618, ISO 48-4/48-5, and FEPA Standard 43‑1.
Keywords: ISO 7784-2, abrasion resistance testing, paints and varnishes, abrasive rubber wheels, turntable abrasion tester, coating wear, film thickness, conditioning.
Open preview (PDF)Paints and varnishes — Determination of resistance to abrasion — Part 2: Method with abrasive rubber wheels and rotating test specimen