ISO 22553-13:2021 PDF

Overview

ISO 22553-13:2021 specifies a laboratory method to determine the re-solving (redissolution) behaviour of electro-deposition coatings (e-coat). The standard is intended for electro-deposition coatings used in automotive and other industrial applications such as chillers, consumer goods, radiators, aerospace and agricultural equipment. The method evaluates whether deposited e-coat films are prone to dissolve back into the coating bath or ultrafiltrate during processing and rinsing.

Why this matters: re-solving behaviour affects coating uniformity, film thickness, surface defects and overall process yield. ISO 22553-13 provides a repeatable procedure for quality control and formulation assessment.

Key Topics

• Scope and terms: Defines redissolution and ultrafiltration/ultrafiltrate as used in electro-deposition coating testing.
• Principle: Two pretreated conductive panels are coated in a laboratory deposition cell, exposed to the parent coating and to ultrafiltrate under controlled conditions, then cured and evaluated for changes in dry-film thickness and surface defects.
• Apparatus and tolerances:
  • Laboratory deposition tank with recirculation and DC supply.
  • Thickness gauge with maximum permitted error of 0.1 µm.
  • Oven capable of maintaining specified bake temperatures within ±2 °C (to 150 °C) or ±3.5 °C (150–200 °C).
  • Thermometer (±0.1 °C) and stopwatch (±1 s).
• Test panels: Electroconductive panels pretreated per ISO 1514, approx. 190 × 105 × 0.75 mm.
• Procedure highlights:
  • Homogenize bath and set deposition voltage/time to achieve nominal dry-film thickness.
  • After deposition and rinse, immerse portions of the coated panel sequentially in the e-coat bath and in the ultrafiltrate with agitation for defined periods without applied voltage, then rinse and cure.
  • Measure dry-film thickness at three points per zone and perform visual inspection for surface defects (stripes, dissolution effects).
• Evaluation: Record mean dry-film thickness per zone and rate surface change intensity using the ISO 4628-1 scale (0–5).

Applications

• Routine quality control of e-coat formulations and process parameters in automotive and industrial coating lines.
• Comparative testing during R&D to assess susceptibility to re-solving when using ultrafiltration or rinse processes.
• Supporting supplier qualification and audits where coating stability and resistance to bath or ultrafiltrate exposure are critical.