EN ISO 8780-2:1995 PDF

Overview

EN ISO 8780-2:1995 titled "Pigments and extenders - Methods of dispersion for assessment of dispersion characteristics - Part 2: Dispersion using an oscillatory shaking machine" is an internationally recognized standard developed by CEN. It specifies a method for dispersing pigments and extenders utilizing an oscillatory shaking machine, primarily intended for quality control testing. This method is adapted to low-viscosity mill bases that enable free movement of grinding spheres and is used with an agreed low-viscosity binder system.

The standard forms part of a series under ISO 8780, which addresses various dispersion methods to assess pigment dispersion characteristics effectively. EN ISO 8780-2 offers a controlled, reliable technique essential in pigment and extender testing for the paints and coatings industry.

Key Topics

• Scope and Applicability The method is suitable for preparing dispersions of samples in pigment quality control. It applies only to low-viscosity mill bases, not suitable for optimizing mill base formulations for alternative dispersing techniques.

• Equipment and Materials

  • Oscillatory shaking machine with a specified stroke rate of 680-690 reciprocations per minute and shaking amplitude of 16 mm.
  • Holder designed for multiple mill base containers, maintaining consistent positioning for repeatability.
  • Uniform containers (e.g., 250 ml glass or polyethylene bottles) to ensure consistent volume and conditions.
  • Grinding spheres with carefully controlled diameter (~3 mm ± 0.5 mm) and density (~2.6 g/cm³ ± 0.2 g/cm³) to guarantee reproducible dispersion.

• Mill Base and Binder System Uses an agreed low-viscosity binder system. The pigment concentration is adjusted according to binder demand:

  • Low binder demand: pigment > 40%
  • Medium binder demand: pigment 10%-40%
  • High binder demand: pigment