Overview
EN ISO 22553-13:2021 (Corrected version 2021-11) specifies a laboratory method to determine the re-solving behaviour of electro-deposition coatings (e-coats). Adopted by CEN, this part of the ISO 22553 series applies to cathodic and anodic electro-deposition coatings used in the automotive sector and other industrial applications (chiller units, consumer products, radiators, aerospace, agriculture). The method evaluates whether freshly deposited film dissolves again in the bath or during rinsing (including ultrafiltrate exposure).
Key topics and requirements
- Scope and terms: Defines re-solving, ultrafiltration (UF) and ultrafiltrate; references ISO 4618 and ISO 22553-1 terminology.
- Principle: Coat electrically conductive test panels in a laboratory deposition system, expose parts of the coated surface to the original e-coat bath and to the ultrafiltrate, then cure and assess film thickness and surface defects.
- Apparatus: Laboratory deposition tank with circulation and DC supply, film thickness gauge (max permissible error 0.1 µm), oven (stoving temperature control ±2 °C up to 150 °C), thermometer and timer.
- Test panels: Conductive panels with pre-treatment per ISO 1514; dimensions ~190 × 105 × 0.75 mm.
- Procedure highlights:
- Homogenize bath (visible circulation) and set bath temperature (product-specific; typically 25–35 °C).
- Deposit to nominal dry film thickness using appropriate voltage/time.
- Sequential immersion: expose 2/3 then 1/3 of a panel to the e-coat bath (no voltage) for 10 min each, rinse; repeat on another panel using ultrafiltrate.
- Cure/stove panels at the specified object temperature (typically 100–180 °C).
- Measure dry film thickness at three points per area and calculate mean.
- Evaluation: Visual inspection for surface defects and rating of intensity (0–5) following ISO 4628-1:2016; report mean thicknesses and descriptive findings.
- Other: Single determination is standard; no precision data provided in the document.
Applications and users
This standard is intended for:
- Coating formulators and R&D labs assessing re-solving risk during bath circulation and rinsing.
- Quality control teams in automotive OEMs and Tier suppliers verifying e-coat robustness.
- Industrial coaters and testing laboratories for acceptance testing of cathodic/anodic e-coat systems.
- Suppliers of ultrafiltration systems and process engineers optimizing rinsing and bath maintenance.
Practical benefits include early detection of formulation or process issues that could lead to film defects, improved bath management, and clearer acceptance criteria for suppliers and manufacturers.
Related standards
- ISO 1514 - Standard panels for testing
- ISO 2808 - Determination of film thickness
- ISO 4618 - Terms and definitions for paints and varnishes
- ISO 4628-1 - Evaluation of degradation (designation system)
- ISO 22553-1 - E-coat vocabulary
- ISO 23321 - Demineralized water for industrial applications
Keywords: EN ISO 22553-13:2021, electro-deposition coatings, re-solving behaviour, e-coat, ultrafiltrate, film thickness, stoving, automotive coatings.
