Overview
EN ISO 23900-1:2018 (ISO 23900-1:2015) is the general introduction to the ISO 23900 series on pigments and extenders - methods for dispersion and assessment of dispersibility in plastics. This part explains the scope, terminology and the relationship between the individual test methods used to evaluate pigment/extender performance in polymer matrices. It sets out the purpose of the test procedures: to enable comparison between similar pigments (for example, a test sample versus a reference) and to provide an indication of relative dispersibility under practical conditions when test conditions and plastics are appropriately chosen.
Key Topics and Requirements
- Terminology and definitions: clear definitions for key terms such as dispersibility, ease of dispersion, aggregate and agglomerate that underpin consistent interpretation of results.
- Preliminary agreements: parties must agree on the plastics material, method of dispersion and assessment method prior to testing because these choices substantially affect results.
- Methods of dispersion and assessment: overview of practical procedures used in the series, including:
- Two-roll milling for PVC (detailed temperatures and steps referenced in ISO 23900-2) - dispersion at ~160 °C then shearing at ~130 °C to measure increase in colour strength.
- Two-roll milling for polyethylene for black/colour pigments and for white pigments (ISO 23900-3 and ISO 23900-4).
- Filter pressure value test (ISO 23900-5) measuring pressure increase when extruding pigmented polymer through a filter pack.
- Film test (ISO 23900-6) assessing agglomerate size and frequency in films.
- Precision: statements on precision are provided in the subsequent parts of the series and are influenced by chosen plastics and dispersion methods.
Applications and Users
- Practical applications: evaluation of pigment/extender performance for coloration, quality control, product development and supplier comparison in plastics manufacturing and compounding.
- Typical users:
- Pigment and extender manufacturers
- Plastics compounders and processors
- Quality assurance / R&D laboratories
- Colour technologists assessing colouristic properties and dispersion stability
- Benefits: standardized comparison of dispersibility, improved formulation decisions, reduced risk of dispersion-related defects (streaking, poor colour strength, filtration issues).
Related Standards
Keywords: EN ISO 23900-1:2018, pigments and extenders, dispersibility, methods of dispersion, two-roll milling, filter pressure value, film test, colouristic properties, pigment dispersibility.
