Introduction
Switching between different types of ink — for example, from black MEK ink to white pigmented ink, or from MEK to ethanol-based ink — is a common need in industrial printing. However, improper flushing can lead to serious issues such as chemical reactions, nozzle clogs, or inconsistent prints.
This article walks you through how to safely flush and convert your printer when changing inks, whether it’s a CIJ, TIJ, or DOD system.
1. Why Flushing Is Important When Switching Inks
Each ink formulation has unique chemical properties — including solvent base, resins, colorants, and conductivity. Mixing incompatible inks can result in:
- Thick sludge or gel formation
- Filter blockages or pump overload
- Jetting instability or distorted characters
- Shortened printhead and nozzle life
Flushing the system is mandatory before any ink change.
2. When You Must Flush the Printer
- Switching from MEK to ethanol or acetone
- Switching between dye and pigment inks
- Switching to UV or security inks
- Returning rental equipment or sending for servicing
3. What You Need for Flushing
✔ Compatible flushing solvent (typically same base as old ink)
✔ Flush bottles with clean nozzles
✔ Waste container for old ink/solvent
✔ Clean cloth and gloves (safety first)
4. Step-by-Step: How to Flush a CIJ Printer
- **Stop the printer** and disable ink stream
- **Drain the ink tank** completely
- **Add flushing solvent** (e.g., Cheef C-V901)
- Run the printer in flush mode (usually accessible in service settings)
- Repeat flushing **2–3 times** until the fluid runs clear
- Install the new ink and **prime the ink line**
- Print test samples to ensure proper ink flow
5. Flushing Guidelines by Ink Type
| Current Ink | New Ink | Recommended Flush |
|---|---|---|
| MEK-based black | MEK-based white | MEK-compatible flush (e.g., C-V901) |
| MEK black | Ethanol black | Flush with MEK first, then ethanol flush |
| Pigmented ink | Dye ink | Flush multiple cycles, clean filter and printhead |
| UV ink | Regular ink | Flush with compatible UV ink cleaner |
6. TIJ Ink Cartridge Flushing Tips
Thermal inkjet cartridges (e.g., HP-based) are single-use, so flushing typically applies to the printhead or manifold system in bulk TIJ installations:
- Remove the old cartridge
- Wipe the printhead with a lint-free cloth and cleaning solvent
- Allow the system to dry before inserting a new cartridge
7. Cheef Flushing Solutions
Cheef-brand flushes are available for all major printer brands and ink types:
| Cheef Code | Flush Type | Application |
|---|---|---|
| C-V901 | MEK Flush | Most CIJ MEK inks (Videojet, Domino, Linx) |
| C-ETH901 | Ethanol Flush | For switching to ethanol ink |
| C-TIJCLEAN | TIJ Cleaner | Printhead wipe and recovery |
8. Safety and Environmental Notes
- Wear gloves and eye protection when flushing
- Use in a well-ventilated area
- Dispose of used ink and flush according to local DG regulations
Conclusion
Flushing your printer before switching ink types isn’t optional — it’s essential for maintaining print quality, protecting your equipment, and avoiding costly downtime. Whether you’re changing colors, solvents, or applications, Cheef flushing solutions make the process simple, safe, and effective. Visit ChinaCIJInk.com to explore compatible cleaners and get expert flushing advice for your printer model.
