Understanding Ink Conductivity in CIJ Printers
In Continuous Inkjet (CIJ) printing, ink conductivity plays a crucial role in ensuring accurate drop formation and proper charging of ink droplets. It is one of the key physical parameters monitored in real-time during printer operation. If the conductivity drifts out of range, print quality and printer reliability can be seriously affected.
What Is Ink Conductivity?
Conductivity refers to the ink’s ability to conduct electricity, typically measured in microsiemens per centimeter (µS/cm). In CIJ systems, this electrical property is vital for forming and charging individual ink droplets so they can be deflected toward the substrate or recirculated.
Why Conductivity Matters in CIJ Printing
1. Precise Drop Charging
CIJ printers use electrostatic fields to charge individual ink droplets. If conductivity is too low or too high, the charge may not be properly applied, leading to deflection errors or missing prints.
2. Stable Jetting and Drop Formation
Conductivity affects the ink’s behavior in the nozzle and charging tunnel. Poor conductivity can destabilize the ink stream, causing inconsistent droplet spacing or satellite droplets.
3. Ink System Monitoring
CIJ printers continuously monitor conductivity through sensors. If the value drifts from the target range, the printer automatically adds makeup fluid or stops printing to protect components.
Typical Conductivity Ranges
Each ink formulation has a specific recommended conductivity range, often between:
- Standard CIJ Ink: 500–2000 µS/cm
- Pigmented CIJ Ink: 800–2500 µS/cm
- Fast-Dry Solvent Ink: 1000–3000 µS/cm
*Note: These values vary by ink brand and printer model. Always consult your ink’s technical data sheet (TDS).
How Conductivity Is Controlled
- Makeup Fluid Addition: CIJ systems dilute ink using makeup to adjust both viscosity and conductivity.
- Solvent Balance: Loss of volatile components through evaporation causes conductivity to rise. Makeup restores balance.
- Temperature Compensation: Advanced systems auto-correct readings for temperature changes, which affect conductivity readings.
Common Causes of Conductivity Issues
- Evaporation from open ink tanks or during idle time
- Wrong makeup fluid added (wrong composition)
- Expired ink losing chemical balance
- Contaminants (dust, water, incompatible chemicals)
Tips for Maintaining Correct Conductivity
- Use only manufacturer-recommended ink and makeup fluid.
- Seal ink tanks and printer enclosures to reduce solvent evaporation.
- Schedule regular ink system cleaning to prevent build-up or contamination.
- Monitor sensor readings and calibrate conductivity sensors periodically.
FAQs
- Can I adjust conductivity manually? No. Always let the printer control conductivity by adding makeup fluid. Manual adjustments can damage the system or void warranties.
- What happens if conductivity goes out of range? You may experience missing characters, deflection errors, or charging failures. Most printers will trigger a fault and stop printing.
Conclusion
Ink conductivity is fundamental to the operation of CIJ printers. Properly controlled conductivity ensures accurate drop charging, consistent print quality, and printer reliability. Monitoring this parameter and using correct fluids will keep your system running smoothly. Need help diagnosing conductivity issues? Contact Cheef Inkjet today at sales@cheef.cn!
