ISO 22553-12:2020

Overview

ISO 22553-12:2020 - Paints and varnishes - Electro-deposition coatings - Part 12: Sedimentation on horizontal areas - specifies a laboratory test method to assess sedimentation of electro-deposition (e-coat) coating materials on horizontal surfaces. The method is intended for automotive applications and other industrial uses (e.g., chiller units, radiators, consumer products, aerospace, agriculture) where sedimentation on horizontal areas can affect appearance and performance.

Key topics and technical requirements

• Test principle: Immerse an L-shaped test panel in an e-coat bath, deposit the coating under controlled conditions, oven-dry/cure, then visually evaluate the formerly horizontal surface for sedimentation defects (stripes, inclusions, etc.).
• Specimen: Phosphated L-panel, folded to (90 ± 5)°, horizontal surface width (70 ± 5) mm.
• Apparatus and materials: laboratory deposition tank with recirculation and DC supply, agitation (mixing impeller ≥ 50 mm), thickness gauge (max error 0.1 µm), thermometer (±0.1 °C), stopwatch, oven with specified temperature stability.
• Bath control: Homogenize the e-coat bath (example mixing speed ~500 min⁻¹), maintain bath temperature to product requirements (note: document recommends ±0.5 °C control during deposition; typical range 25–35 °C).
• Deposition parameters: Select voltage and deposition time to achieve the nominal expected dry film thickness; increase to application voltage and hold for selected time.
• Post-deposition: Rinse panels with demineralized water per ISO 23321 to remove excess, then dry/cure per product specifications.
• Evaluation: Visual inspection of the horizontal face using the ISO 4628-1 classification scale (0–5: no change to very marked change). Measure final dry film thickness using ISO 2808 methods.
• Reproducibility: The standard specifies a single determination; no fidelity data are provided in the document.
• Reporting: Test report must include product ID, reference to ISO 22553-12:2020, bath voltage and temperature, application times, curing conditions, dry film thickness and measurement method, ISO 4628-1 result, deviations, anomalies, and test date.

Applications and users

• Primary users: E-coat formulators, automotive OEM and supplier quality teams, independent coating test laboratories, R&D teams, and specification writers.
• Practical value: Detects and quantifies sedimentation-related appearance defects on horizontal areas of components, supports product development, quality control, and batch acceptance for parts sensitive to horizontal deposition (radiators, chilled equipment, consumer enclosures, aerospace components).

Related standards

• ISO 2808 - film thickness measurement methods
• ISO 4618 and ISO 22553-1 - terminology for paints and e-coat vocabulary
• ISO 23321 - demineralized water specification for paint testing
• ISO 4628-1 - classification of appearance changes (visual rating 0–5)

Keywords: ISO 22553-12:2020, electro-deposition coatings, e-coat sedimentation test, L-panel, horizontal surface sedimentation, automotive coating test, film thickness, ISO 2808, ISO 4628-1.