EN ISO 787-16:1995 PDF

Overview

EN ISO 787-16:1995 is an international standard developed by CEN that specifies general methods for testing pigments and extenders. This part, titled "Determination of relative tinting strength (or equivalent colouring value) and colour on reduction of coloured pigments - Visual comparison method," outlines a procedure to measure and compare the tinting strength and color of pigments when mixed with white pigments. The method described relies on visual comparison and is supported by sample preparation under defined conditions with an automatic muller, ensuring consistent and reproducible results.

The standard is essential for quality control and product specification in various industries that utilize pigments, such as paints, coatings, and plastics. It helps in assessing the coloring power and color quality of pigments under standardized test conditions.

Key Topics

• Test Procedure: The test involves four main parts:

  • Determining dispersion conditions for colored pigments and the ratio with white pigments.
  • Preparing dispersions using an automatic muller with specified force, number of revolutions, and binder ratios.
  • Mixing colored pigment dispersions with white pigment pastes in known ratios.
  • Visual comparison of strength and undertone between the test and reference pigment pastes.

• Materials and Apparatus:

  • Use of specific binders such as alkyd resin or urethane-modified linseed oil for dispersing pigments.
  • White pigment paste composition typically includes titanium dioxide, binder, and additives.
  • Essential equipment includes an automatic muller with ground glass plates, palette knives, glass panels, and film applicators.

• Preparation and Dispersion:

  • Pigments are carefully dispersed to achieve a fine particle size (