Last Updated: 2026-09-17
Production lines that stop for coding cost thousands per hour. What is continuous inkjet printing? It is a non-contact printing method where a printhead projects a continuous stream of ink droplets, charges selected droplets, and deflects them onto a surface to form text and codes at high speed.
Overview
Continuous inkjet printing, commonly called CIJ, is one of the most widely used coding technologies in industrial packaging. The printhead projects a steady ink stream, breaks it into individual droplets, and directs each droplet to a precise position on the product. Ink that is not used returns to the reservoir for recirculation.
CIJ systems operate without touching the substrate, which makes them suitable for fragile, wet, or irregular surfaces. The technology is recognized under ISO 9001 quality frameworks and documented as a standard inkjet printing method.
Because the printhead never contacts the substrate, CIJ can mark products immediately after filling or sealing, while surfaces are still wet or warm. This capability reduces the need for secondary handling stations between packaging and coding steps.
How It Works
The CIJ printing process follows a closed-loop ink circuit:
| Component | Function |
|---|---|
| Ink reservoir | Stores ink and make-up fluid at controlled viscosity |
| Pump | Pressurizes ink through the printhead nozzle |
| Charge electrode | Assigns an electrical charge to each droplet at breakoff |
| Deflection plates | Create an electric field that steers charged droplets |
| Gutter | Catches unused droplets and returns them to the reservoir |
The nozzle diameter typically measures 40 to 70 microns. A piezoelectric crystal vibrates at high frequency to create uniform droplet breakoff. Make-up fluid replenishes solvents that evaporate during operation, keeping ink viscosity within the correct range for consistent print quality.
Advantages
CIJ printing offers several benefits for production environments:
- Prints on plastic, glass, metal, and curved surfaces without contact
- Operates at line speeds up to 5 meters per second
- Recirculates unused ink, reducing waste during long runs
- Handles solvent-based inks for fast drying on non-porous materials
The printhead design allows coding on moving products at full line speed. Make-up fluid management keeps the nozzle clear, reducing clogs that cause unplanned downtime on food and pharmaceutical lines.
The SHICAI Approach
SHICAI designs CIJ printers for production lines that require reliable coding without frequent intervention. Our printheads feature simplified nozzle pathways that reduce cleaning time. The make-up fluid delivery system adjusts viscosity in real time based on temperature and operating hours. Every system is built to ISO 9001 quality management requirements for regulated packaging environments.
Related Questions
- What is continuous inkjet printing used for?
- Continuous inkjet printing is used for date codes, lot numbers, and batch identifiers on food packaging, beverage cans, and pharmaceutical products. It handles high-speed lines where contact printing would create bottlenecks.
- How does CIJ differ from thermal inkjet?
- CIJ uses a continuous stream of charged droplets and recirculates unused ink. Thermal inkjet heats ink in a chamber to eject droplets on demand, which suits smaller batch operations.
Next Steps
- Read our CIJ printer working guide for a step-by-step breakdown of the process.
- Want to confirm CIJ fits your substrate? Send us a sample for free testing with no commitment.
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