ISO 19403-5:2024

Overview

ISO 19403-5:2024 is an international standard published by ISO that outlines a test method for determining the polar and dispersive fractions of the surface tension of liquids. Using optical contact angle measurements on a solid surface with only a disperse contribution to its surface energy, this standard plays an essential role in the characterization of paints, varnishes, and other liquid coating materials. The method described can be applied to a wide range of liquid coatings; however, certain restrictions may apply when testing liquids exhibiting non-Newtonian flow behavior.

This document is part of the comprehensive ISO 19403 series on wettability and supports quality control, product development, and research in industries relying on surface tension characterization.

Key Topics

• Surface Tension Measurement: Specifies methods to measure both the polar and dispersive components of a liquid’s surface tension through optical assessment of contact angles.
• Reference Solids: Describes the use of homogeneous, dispersive solids (such as PTFE or paraffin) as reference surfaces, ensuring accurate determinations by minimizing polar contributions.
• Contact Angle Analysis: Details the measurement of contact angles between the test liquid and the reference solid, both by static and dynamic optical methods, enhancing reproducibility and accuracy.
• Calculation Methods: Incorporates the Owens-Wendt-Rabel-Kaelble (OWRK) and Wu methodologies for separating polar and dispersive fractions based on contact angle data.
• Reporting Requirements: Outlines essential information for comprehensive test reporting, including details on the sample, procedure, calculation methods, and observed deviations or uncertainties.

Applications

Industrial Coating Characterization

• Paints and Varnishes: Enables precise formulation adjustment by characterizing how coatings interact with different substrates, improving adhesion, durability, and application properties.
• Quality Assurance: Offers a standardized approach to validate product consistency in manufacturing environments by regularly testing surface tension parameters of liquid coatings.
• Research and Development: Supports the optimization of new coatings, adhesives, inks, and other surface-active products through detailed analysis of wetting behavior.
• Material Compatibility: Assists in determining surface compatibility, aiding in substrate selection or pre-treatment techniques to achieve optimal performance.

Broader Industrial Impact

• Polymers and Plastics: Useful in industries focused on polymeric materials, where wetting and adhesion are critical to product performance.
• Surface Treatment: Plays a role in the development of cleaning, priming, or activation processes for improved coating outcomes.
• Environmental and Regulatory Compliance: Provides the framework for demonstrating conformity with industry and regulatory requirements surrounding material performance and safety.

Related Standards

Organizations working with ISO 19403-5:2024 may also reference the following related international standards:

• ISO 19403-1: Paints and varnishes - Wettability - Part 1: Vocabulary and general principles
• ISO 19403-2: Paints and varnishes - Wettability - Part 2: Determination of the surface free energy of solid surfaces by measuring the contact angle
• ISO 19403-3: Paints and varnishes - Wettability - Part 3: Determination of the surface tension of liquids using the pendant drop method
• ISO 1409: Plastics/rubber - Polymer dispersions and rubber latices - Determination of surface tension
• EN 14370: Surface active agents - Determination of surface tension
• ISO 3219-1: Rheology - Vocabulary and symbols for rotational and oscillatory rheometry (noting restrictions for non-Newtonian liquids)
• ISO 15528: Sampling methods for paints, varnishes, and raw materials

By following ISO 19403-5:2024, organizations can enhance product quality, ensure consistency, and support innovation in surface coatings through scientifically rigorous, internationally recognized methods for the measurement of the polar and dispersive components of surface tension.