ISO 22553-6:2019

Overview

ISO 22553-6:2019 specifies a standardized laboratory method to identify and evaluate entry marks (immersion streaks) that can occur during electro-deposition (e-coat) processes. The standard describes how to reproduce immersion conditions, prepare test panels, control deposition parameters and assess visible marks and dry-film thickness. It is applicable to electro-deposition coatings used in the automotive sector and other industrial applications (chillers, radiators, consumer products, aerospace, agriculture).

Key topics and technical requirements

• Objective: Detect and characterize entry marks that form parallel to the bath surface when a workpiece is immersed under applied electric potential (cathodic or anodic e-coat).
• Principle: Wet one half of a conductive test panel with demineralized water, immediately energize and immerse under controlled deposition conditions, then evaluate the coated panel after rinsing and stoving.
• Apparatus and materials: laboratory deposition system with tank recirculation and DC supply, conveyor unit with controlled speed, film-thickness gauge (≤0.1 µm error), oven, thermometer, demineralized water per ISO 23321.
• Test panel: Electrically conductive panel with pretreatment per ISO 1514; typical size ~190 × 105 × 0.75 mm.
• Mandatory deposition parameters (example values from the standard):
  • Tank temperature: 29 °C to 35 °C
  • Immersion voltage: 40 V below breakaway voltage
  • Stirrer speed: 500 min⁻¹
  • Immersion speed: 1 cm/s; immersion angle 90°; depth 14 cm
  • Coating duration: 2 min
  • Anode/cathode relation and other geometry specified
• Evaluation:
  • Visual assessment on dry and wetted halves using a 0–5 marking scale (0 = no visible marks, 5 = severe marks).
  • Dry-film thickness measured at three points on each half per ISO 2808.
• Reproducibility: Perform determinations in duplicate; include specified test-report elements (tank voltage, temperature, stoving, film thickness, visual scores, deviations, anomalies, date).

Applications and users

• Who uses it: coating labs, quality control teams, OEMs (automotive, aerospace), e-coat suppliers, R&D and process engineers, failure analysis teams.
• Practical uses:
  • Baseline and acceptance testing for e-coat suppliers and purchasers.
  • Process troubleshooting to identify immersion-related defects.
  • Comparative evaluation of formulations, pretreatments or equipment settings.
  • Supplier qualification and production control in automotive and industrial coating lines.

Related standards

• ISO 1514 - standard panels for testing
• ISO 2808 - determination of film thickness
• ISO 4618 - terms and definitions
• ISO 22553-1 - electro-deposition vocabulary
• ISO 23321 - demineralized water for industrial applications

Keywords: ISO 22553-6:2019, electro-deposition coatings, entry marks, e-coat, immersion marks, cathodic e-coat, test method, film thickness, automotive coating testing.