Ink Droplet Deviation in CIJ Printing: Causes and Fixes

In Continuous Inkjet (CIJ) printers, precise ink droplet trajectory is essential for clean, accurate characters. When droplet deviation occurs, it can lead to distorted prints, overlapping text, or unreadable codes. This article explores the key reasons behind ink path deviation and offers actionable solutions to restore alignment.

What Is Droplet Deviation?

• It refers to ink droplets not following their intended flight path
• Can result in skewed, blurry, or incomplete characters
• Usually caused by problems in charging, deflection, or environmental factors

Common Symptoms

• ⚠️ Curved or offset characters
• ⚠️ Vertical or horizontal shifting in text
• ⚠️ Misalignment between lines or lines overlapping
• ⚠️ Inconsistent code spacing during continuous printing

Main Causes and Solutions

1. Misaligned Deflection Plates

• Cause: Electrodes out of position or covered in ink residue
• Fix:
  • Clean deflection plates using approved solvent and lint-free cloth
  • Recalibrate plate spacing in maintenance menu if supported

2. Improper Charge Voltage

• Cause: Voltage too high or low causes droplets to be deflected too far or too little
• Fix:
  • Run automatic droplet calibration or adjust charge settings manually
  • Ensure ink is within correct viscosity range for accurate charging

3. Electrostatic or Magnetic Interference

• Cause: External electrical fields distort droplet path
• Fix:
  • Ensure printer is grounded properly
  • Avoid running cables or power lines near the print zone
  • Use anti-static bars or shields if necessary

4. Dirty or Mispositioned Nozzle

• Cause: Dried ink or a slightly tilted nozzle changes droplet angle
• Fix:
  • Flush nozzle regularly
  • Inspect nozzle alignment with calibration tools or laser guide

5. Ink Stream Instability

• Cause: Ink pressure fluctuations or air bubbles in the system
• Fix:
  • Check and regulate pump pressure
  • Bleed ink lines to remove bubbles
  • Replace ink filters if partially clogged

Best Practices for Preventing Droplet Deviation

• ✅ Perform droplet alignment weekly or after changing ink
• ✅ Keep deflection plates clean and free of residue
• ✅ Maintain stable ambient temperature and humidity
• ✅ Check charge electrode regularly for wear or damage

FAQs

• Can I run the printer if the characters are slightly off? Not recommended—deviation worsens over time and leads to unreadable codes
• Do I need special tools to check alignment? Some models offer digital auto-tuning; others require manual scope adjustment

Conclusion

Ink droplet deviation is a critical issue in CIJ printing, but one that’s usually fixable with proper maintenance and calibration. A stable ink stream, clean deflection system, and correct charge voltage are the pillars of accurate droplet control. For alignment kits, technical assistance, or part replacement, contact Cheef Inkjet at sales@cheef.cn.