Overview
EN ISO 8130-15:2023 - Coating powders, Part 15: Rheology specifies standardized methods to determine the rheological behaviour of coating powders both as particulate materials and in their molten state. The standard supports reproducible evaluation of powder fluidization, apparent viscosity, cohesion, deaeration and melt rheology to inform production, processing and quality control of powder coatings.
Key topics and technical requirements
- Scope: Methods for measuring rheological behaviour of powder coatings in particulate (fluidized bed) and molten forms.
- Apparatus: Requires a rotational rheometer compliant with ISO 3219-2, a cylindrical measurement cell (min. Ø50 mm, height 100 mm), rectangular stirrer (min. 10 × 30 mm), mass flow controller (0.05–5 L/min), pressure transducer and disposable plate-plate geometry for melt tests.
- Sampling: Representative sampling per ISO 15528; recommended minimum sample volume ~80 ml for particulate tests.
- Powder tests:
- Fluidization measurements (unstirred and stirred modes) by varying air flow (example procedure: decrease from 5 L/min → 0 then increase to 5 L/min) to identify incipient and full fluidization.
- Fluidized bed rheology across rotational speeds (typical range 0.1 to 1 200 min⁻¹; shear rates 0.02 s⁻¹ to 320 s⁻¹) to calculate apparent viscosity analogous to non‑Newtonian fluids.
- Deaeration: standard procedure includes fluidizing at 5 L/min for 5 min at 8 min⁻¹, then stopping airflow and recording pressure response.
- Cohesion strength: measures internal particle bonding as an index of flowability.
- Melt tests: Use a heated plate-plate rheometer (ISO 3219-2) to determine melt viscosity, gel point and polymerization-related behaviour; recommended plate diameter ≥25 mm and sample preparation guidance (e.g., compress particulate fill before melting).
- Results & reporting: Procedures for expression of results, precision and required test report information are included.
Applications and users
EN ISO 8130-15:2023 is practical for:
- Powder coating manufacturers optimizing formulations for sprayability, fluidization and cure behaviour.
- Process engineers tuning fluidized bed, pneumatic conveying and spraying systems.
- Quality control laboratories implementing standardized QC tests for lot release and stability checks.
- R&D and material scientists studying melt flow, gel-point and particle interactions to improve reuse and recycling of powders.
Practical benefits include improved process reproducibility, troubleshooting of flow problems, and data for specifying powders by rheological performance.
Related standards
Keywords: EN ISO 8130-15:2023, coating powders, powder rheology, melt rheology, fluidized bed, apparent viscosity, powder coatings, quality control.
