Overview
EN ISO 22553-9:2021 (ISO 22553-9:2020) defines a laboratory method to determine the volatile-matter content (stoving loss) of electro-deposition coatings (e-coats) during stoving. The standard is applicable to e-coats used in the automotive sector and other industrial products (chillers, radiators, consumer goods, aerospace, agriculture). It specifies test panels, apparatus, a repeatable procedure and the calculation for reporting stoving loss as a mass fraction (percent).
Key topics and technical requirements
- Scope and purpose: Measure the mass loss of an e-coat during thermal curing (stoving) to quantify volatile content and reaction-related loss.
- Test principle: Determine non-volatile matter after stoving; calculate stoving loss as (mass loss after stoving / mass of applied e-coat) × 100.
- Apparatus & accuracy:
- Laboratory deposition system with tank recirculation and DC supply
- Analytical balance (accuracy 0.0001 g)
- Oven capable of holding specified object temperature (±2 °C up to 150 °C; ±3.5 °C between 150–200 °C)
- Thermometer (0.1 °C), timer, ammeter
- Test panels: Electrically conductive, pre-treated panels per ISO 1514, approximately 190 mm × 105 mm × 0.75 mm.
- Procedure:
- Deposit e-coat in a controlled laboratory bath (temperature typically 25–35 °C)
- Rinse, pre-dry (≈110 °C for ~60 min), weigh, then stove at the agreed object temperature and time
- Carry out each determination in triplicate (mean or median may be used)
- Evaluation & reporting:
- Calculate stoving loss (%) from measured masses
- Test report must include product ID, tank voltage/temperature, application and stoving times/temperatures, results, deviations and anomalies
- Precision: No precision data is currently available in the document.
Practical applications and users
This standard is intended for:
- Coating formulators evaluating solvent/volatile behavior during cure
- Automotive and industrial QA/QC labs verifying e-coat specifications
- R&D teams optimizing bake schedules and cure chemistry
- Third‑party testing organizations and certification bodies
Understanding stoving loss helps optimize cure cycles, ensure regulatory compliance for VOC/volatile content, and improve coating performance and cost-efficiency.
Related standards
- ISO 22553-1 - Vocabulary for electro-deposition coatings
- ISO 1514 - Standard panels for testing
- ISO 4618 - Terms and definitions (paints and varnishes)
- ISO 23321 - Demineralized water for industrial applications
Keywords: EN ISO 22553-9:2021, ISO 22553-9, e-coat stoving loss, electro-deposition coatings, volatile-matter content, stoving test method, paints and varnishes.
