Overview
ISO 7784-3:2022 specifies a laboratory test method for determining the abrasion resistance of coatings using a rigid, abrasive-paper covered wheel that acts on a linearly reciprocating test specimen. It is Part 3 of the ISO 7784 series and is intended for coatings where a loaded, non‑rotating wheel with abrasive paper repeatedly abrades a specimen that moves back and forth.
Key topics and technical requirements
- Test principle: A rigid wheel covered with abrasive paper is pressed against the coating while the specimen reciprocates over a 30 mm stroke. After each double stroke the wheel is rotated slightly so a fresh portion of abrasive contacts the surface.
- Apparatus: Typical wheel diameter 50 mm, abrasive strip 12.0 ± 0.2 mm wide. Device must apply and control test load between 0.98 N and at least 6.9 N with ±0.05 N accuracy and an adjustable counter for double strokes.
- Abrasive media: Recommended P180 silicon carbide abrasive paper (ISO 6344-2). Strip length typically ~158 mm (longer if cut at 45°).
- Kinematics and speed: Relative movement set to (40 ± 2) double strokes per minute. Wheel advance mechanism to bring fresh abrasive into contact (maximum 400 double strokes per advance).
- Specimens and preparation: Plane panels, minimum 30 × 50 mm (typical 50 × 50 × 1–5 mm), prepared per ISO 1514. Film thickness measured per ISO 2808.
- Conditioning and environment: Condition specimens at (23 ± 2) °C and (50 ± 5) % RH for at least 16 h (ISO 3270). Testing also normally performed at 23 ± 2 °C with humidity recorded.
- Procedure details: Includes pre‑test steps (evaluate loss in mass at 10, 30, 50, 100 double strokes), possible adjustment of load or abrasive grain by agreement, and triplicate determinations.
- Evaluation: Abrasion quantified by loss in mass measured to 0.1 mg resolution; precision and repeatability/reproducibility clauses are included in the standard.
Applications and users
ISO 7784-3:2022 is used by:
- Coating manufacturers for product development and comparative screening of abrasion resistance.
- Independent testing laboratories performing standardized quality and compliance tests.
- R&D teams optimizing formulations for wear resistance (automotive, industrial, protective coatings).
- Procurement, specification writers, and certification bodies requiring reproducible abrasion data for material selection.
Practical benefits include reproducible, comparable abrasion data for performance claims, quality control, and benchmarking coatings under controlled lab conditions.
Related standards
- ISO 7784 series (other abrasive-wheel methods)
- ISO 1514 (standard panels for testing)
- ISO 2808 (film-thickness determination)
- ISO 3270 (conditioning and test environment)
- ISO 4618 (terms and definitions)
- ISO 6344-2 (abrasive paper grain specification)
Keywords: ISO 7784-3:2022, abrasion resistance test, paints and varnishes, abrasive-paper covered wheel, linearly reciprocating specimen, P180 silicon carbide, film thickness, coating abrasion.
Open preview (PDF)Paints and varnishes — Determination of resistance to abrasion — Part 3: Method with abrasive-paper covered wheel and linearly reciprocating test specimen