ISO 9117-6:2012

Overview

ISO 9117-6:2012 is an internationally recognized standard published by the International Organization for Standardization (ISO). Titled Paints and Varnishes – Drying tests – Part 6: Print-free test, this standard specifies a practical, empirical method to evaluate the resistance of paint, varnish, or related coatings to imprinting. The test uses a nylon (polyamide) gauze under a controlled force for a set duration to determine if the coating surface resists marking after drying.

This standard provides a straightforward way to assess the print-free drying state, either as a pass/fail evaluation after a specific drying period or through repeated measurements to identify the time required to reach a print-free surface condition. ISO 9117-6 helps manufacturers and quality control laboratories reliably gauge coating drying performance, which is critical for product durability and aesthetics.

Key Topics

• Print-free test method: Using a polyamide gauze square pressed onto the coating surface with a rubber disc and specified weights to apply defined pressure (5.2 kPa, 13.2 kPa, or 26.3 kPa).
• Drying time determination: Measuring the time required for the coating to become resistant to visual marking, either by a single pass/fail test or by repeated tests at intervals.
• Sample preparation: Guidelines for using standardized test panels (glass, polished steel, tinplate, or aluminum) and applying coatings per ISO 1514 and ISO 1513.
• Test conditions: Specified ambient temperature (23 ± 2 °C) and humidity (50 ± 5 %) for air drying, with provisions for stoving and ageing of heat-cured coatings.
• Test apparatus: Details on gauze specifications, rubber discs, calibrated weights, and timing instruments.
• Reporting requirements: Comprehensive test reporting instructions covering sample details, preparation methods, drying conditions, gauze type, applied force, test results, and any deviations or anomalies observed.

Applications

ISO 9117-6:2012 is essential for industries involved in manufacturing and testing paint and varnish products, including:

• Quality control and assurance of coatings to ensure adequate drying and resistance to surface marking.
• Product development for comparing drying properties of new formulations or additives.
• Process validation in production environments where drying conditions must be optimized.
• Performance benchmarking to meet contractual specifications or regulatory requirements.
• Failure analysis where insufficient drying causes defects or surface flaws impacting coating durability and appearance.

This method is valuable for paints, varnishes, lacquers, and other related surface treatments used in automotive, industrial, architectural, and consumer goods sectors.

Related Standards

ISO 9117-6 is part of a broader series dedicated to drying tests for paints and varnishes. Related parts include:

• ISO 9117-1: Determination of drying through to the core and overall drying time.
• ISO 9117-2: Pressure test for stackability of coatings.
• ISO 9117-3: Surface drying using glass beads.
• ISO 9117-4: Drying test using a mechanical recorder.
• ISO 9117-5: Modified Bandow-Wolff test.

Additionally, the standard references related ISO documents for sampling, sample preparation, and measurement techniques critical to ensuring consistent and reliable test results:

• ISO 1513: Paints and varnishes – Examination and preparation of samples for testing.
• ISO 1514: Paints and varnishes – Standard panels for testing.
• ISO 2808: Paints and varnishes – Determination of film thickness.
• ISO 15528: Paints, varnishes, and related materials – Sampling.
• ISO 48: Rubber vulcanized or thermoplastic – Hardness measurement.
• ISO 3270: Conditions for conditioning and testing paints and varnishes.

Summary

ISO 9117-6:2012 provides a practical, standardized method to assess paint and varnish coatings’ resistance to imprinting, which is a critical indicator of drying status and surface integrity. The method combines simplicity with reliable repeatability under defined conditions, supporting quality control, research, and production across multiple industries. By conforming to this standard, manufacturers and testing labs ensure consistent drying performance, aiding in the development and evaluation of high-quality coating products.

Keywords: ISO 9117-6, paint drying test, varnish drying test, print-free test, coating resistance, polyamide gauze test, drying time measurement, paint quality control, drying assessment standard, drying test method