ISO 19403 Paints and Varnishes - Wettability

The “ISO 19403 Paints and varnishes - Wettability” standard, developed by the International Standards Organization (ISO), consists of a series of standards and mainly specifies the following optical test methods:

• Measurement of contact angle
• Determination of the surface free energy of a solid surface, including polar and dispersive fractions
• Determination of surface tension of liquids, including polar and dispersive fractions
• Checking the measurement setup with reference materials

This set of standards can be applied for the characterization of substrates, coatings, and coating materials. Applicability may be limited to fluids with non-Newtonian rheology.

This set of standards consists of the following sub-standards under the same title:

• ISO 19403-1 Part 1: Vocabulary and general principles. This standard describes general terms and definitions for wettability. Some general principles are included in the annex of the standard (Annex A). This standard is intended to be used in conjunction with ISO 4618 Paints and varnishes - Terms and definitions.
• ISO 19403-2 Part 2: Determination of the surface free energy of solid surfaces by measuring the contact angle. This standard describes a test method for determining the surface free energy of a solid surface by measuring the contact angle. This method is applicable for the characterization of substrates and coatings. For the determination of the surface free energy of polymers and coatings, a method according to Owens, Wendt, Rabel and Kaelble or a method according to Wu is preferably used. Morphological and chemical homogeneity has an influence on the measurement results. The procedures specified in this standard are based on the state of the art using the penumbral drop projection method. Other methods are not excluded. The measurement of the contact angle in powders is not part of this standard.
• ISO 19403-3 Part 3: Determination of surface tension of liquids using the pendant drop method. This standard describes a test method for measuring the surface tension of liquids by an optical method using pendant drops. The method is applicable for the characterization of liquid coating materials. The applicability may be limited to liquids with non-Newtonian rheology. Other methods for determining surface tension are used, for example, EN 14370 Surfactants - Determination of surface tension" or ISO 1409 Plastics/rubber - Polymer dispersions and rubber lattices (natural and synthetic) - Determination of surface tension".
• ISO 19403-4 Part 4: Determination of the polar and dispersive fractions of the surface tension of liquids from an interfacial tension. This standard describes a test method for determining the polar and dispersive fractions of the surface tension of liquids by optical methods. This method is applicable for the characterization of liquid coating materials, in particular when drying effects occur during the measurement. Applicability may be limited to liquids with non-Newtonian rheology. This standard assumes that, in addition to knowledge of the surface tension of the liquid to be tested, at least one suitable reference liquid is known.
• ISO 19403-5 Part 5: Determination of the polar and dispersive fractions of the surface tension of liquids from measurements of contact angles on a solid having only a dispersive contribution to the surface energy. This standard describes a test method for determining the polar and dispersive fractions of the surface tension of liquids by optical methods. This method is applicable for the characterization of liquid coating materials. Applicability may be limited to liquids with non-Newtonian rheology. This standard assumes that the surface tension of the liquid to be tested and the surface free energy of dispersive reference solids are known.
• ISO 19403-6 Part 6: Measurement of dynamic contact angle. This standard describes a method for measuring the dynamic contact angle by an optical method. By this method the advance and retreat angles are determined. By means of this defined measurement, the wetting and non-wetting properties can be characterized. In addition, conclusions can be drawn about the morphological and chemical homogeneity of the interfaces.
• ISO 19403-7 Part 7: Measurement of the contact angle on an inclined platform (roll-off angle). This standard describes a method for the dynamic measurement of the roll-off angle of a liquid drop on a solid surface. From this dynamic measurement, the advance and retreat angles of the rolling drop can also be determined. The roll angle plays a role, for example, in the assessment of easy-to-clean or non-stick surfaces.

Among the numerous tests, measurements, analyses and evaluation studies carried out for businesses in various sectors, our organization also provides testing services defined in the “ISO 19403 Paints and varnishes - Wettability” standard with its trained and expert staff and advanced technological equipment.