Overview

This part of ISO 3233 specifies a simple practical method for calculating the non-volatile matter by volume, NVV, of a coating material from the non-volatile-matter content, NV, the density of the coating material, and the density of the solvents. Using the non-volatile matter by volume results and the density obtained in accordance with this part of ISO 3233, it is possible to calculate the theoretical spreading rate of a coating material. This part of ISO 3233 is not applicable to coating materials which exceed the critical pigment volume concentration (CPVC). This method is used to determine the volume of the dry coating obtainable using a coating material by calculation of the percentage volume of non-volatile matter. The value obtained by this method might not be the same as that measured or calculated by adding together the masses and volumes of the raw materials in a formulation. The volume occupied by a combination of resin and solvent might be the same as, greater than, or less than the combined volume of the separate components, since contraction or expansion of resin and the solvent can occur. A second factor affecting the volume of a dry coating is the degree to which the spaces between pigment particles are filled with binder. A third factor is the use of volatile components in reactive systems that, by their reaction, change into non-volatile film-building materials; that is, amines and reactive solvents in high-build two-component coating materials. Above and close to the critical pigment volume concentration, the volume of a dry paint film is greater than the theoretical volume, due to an increase in unfilled voids between pigment particles. The porosity of the film means that this method is unsuitable. Other methods for determination of the percentage volume of non-volatile matter are described in ISO 3233-1 and ISO 3233-2. The method described in this part of ISO 3233 is a quick method which needs only the results of the non-volatile matter and the density of the coating material and the density of the solvents for the calculation. The precision of the method depends mainly on the determination of the non-volatile matter content and the unknown densities. But the precision of the combination of measurements and calculation is better than the precision of pure calculation methods with no measurements. The simple practical method is often used in the automotive industry, especially for commercial vehicles. The committee responsible for this standard is NA 002-00-07 AA "Allgemeine Prüfverfahren für Beschichtungsstoffe und Beschichtungen" ("General test methods for coating materials and coatings") at DIN Standards Committee Coatings and Coating Materials (NAB).

Document: references other documents

Responsible national committee

NA 002-00-07 AA - General test methods for coating materials and coatings  

Responsible european committee

CEN/TC 139 - Paints and varnishes