Overview
EN ISO 8130-8:2021 - "Coating powders - Part 8: Assessment of the storage stability of thermosetting powders" specifies a standardized method to estimate the storage stability of thermosetting coating powders. Adopted by CEN (as EN ISO 8130-8:2021) and published as ISO 8130-8:2021, the document defines how to simulate storage conditions, measure changes in the powder’s physical state and chemical reactivity, and assess the powder’s capacity to form a satisfactory final coating after storage.
Key topics and technical requirements
- Principle: Subject the powder to defined artificial storage (temperature and time) and evaluate changes in flowability, agglomeration, caking, chemical reactivity and final coating performance.
- Storage conditions: Typical test temperatures specified include (30 ± 0.5) °C or (40 ± 0.5) °C; samples can also be stored in sealed water baths if protected from moisture.
- Chemical reactivity: Initial and final gel time measurements are made in accordance with ISO 8130-6 to quantify changes in curing behaviour.
- Physical stability: Observe and record changes in ability to flow, tendency to agglomerate or cake; compression at container bottom can be simulated using standard loads (100 ± 1 g).
- Apparatus: Air‑circulating oven, glass test tubes (≈200 mm × 40 mm), stoppers, test-tube stand, standard loads, aluminium-foil discs and precision balance.
- Coating preparation and evaluation: Apply powder to agreed test panels (default: solvent-degreased steel panels per ISO 1514 or pretreated aluminium) at a film thickness of (50 ± 10) µm (or as agreed). Condition coated panels at (23 ± 2) °C and (50 ± 5) % RH for 24 h, then inspect visually and perform any agreed tests (gloss, film thickness, impact resistance).
- Reporting and interpretation: Results express changes in appearance, gel time and coating properties. The standard notes that different ageing mechanisms (physical vs chemical) may not correlate directly; results give an indication of storage performance, not absolute lifetime.
Applications and users
- Manufacturers of powder coatings and formulators validating product shelf life and packaging.
- Quality control and R&D laboratories conducting storage testing and stability screening.
- Specifiers, procurement and compliance teams assessing supplier claims of storage stability.
- Certification bodies and test houses requiring standardized procedures for comparative evaluation.
Related standards
EN ISO 8130-8:2021 is essential reading for anyone involved in ensuring reliable performance of thermosetting powder coatings after storage and transport. Keywords: EN ISO 8130-8, ISO 8130-8:2021, storage stability, thermosetting coating powders, powder coatings, gel time, storage testing.
