Technology guide
Piezo Inkjet (DOD) Coding
Piezo drop-on-demand (DOD) inkjet fires ink only where the code needs it, using a printhead that flexes to push out each drop. In coding, it's best known for tall, high-resolution case codes: logos, text and shipping barcodes printed straight onto corrugated cases.
How it works
In a piezo printhead, each nozzle has a piezoelectric element that changes shape when a voltage is applied. That flex creates a pressure pulse that pushes out a drop of ink, only when a drop is needed (drop-on-demand). Rows of nozzles build the code as the case moves past.
Because piezo doesn't heat the ink, it can run a wider range of inks than thermal inkjet, including thicker and pigmented inks, and some systems use inks that set as soon as they touch the case. Many piezo case coders feed from a bulk ink supply rather than a sealed cartridge.
Piezo, valve-jet and thermal inkjet case coders
Three inkjet methods show up on case-coding lines:
- Piezo: tall codes at high resolution, often from bulk ink. The choice when the code has to be several inches tall and sharp.
- Valve-jet (large-character): small valves release ink to print big, lower-resolution dot-matrix characters. Simple outer-case text where looks matter less.
- Thermal inkjet: high-resolution codes up to 1" in a single pass, or 2" with stitched heads, from sealed cartridges with little scheduled maintenance. The 160 mL XL cartridge holds 4× the ink of a standard one, for long case-coding runs.
Start with the code height and the look you need.
Case & carton coding →Best for
- Tall, high-resolution codes, logos and barcodes on outer cases
- Replacing pre-printed boxes or labels with direct-to-case printing
- Shipping and GS1 barcodes on corrugated cases
- A wide range of inks, including pigmented inks
Considerations
- Often a bulk ink system rather than sealed cartridges; ask about the maintenance routine
- Size the system to the code height you really need
- Ink choice is tied to the printhead; check it against your substrate
How it compares to thermal inkjet
Thermal inkjet (TIJ) covers many case and carton jobs: high-resolution codes up to 1" in one pass, 2" with stitched heads, from sealed cartridges with little scheduled maintenance, and the 160 mL cartridge for long runs. Piezo is the choice when the code has to be taller than that across a full case. Send us your case-coding requirement and we'll help you choose.
TIJ Print Solutions specializes in thermal inkjet. We’re happy to help you choose the right technology for your line — even when that conversation starts here. Explore our coding & marking inks.
Not sure which technology fits your line?
Tell us your product, substrate, and line speed and we’ll help you weigh the options — and show you where thermal inkjet is the simplest, lowest-maintenance fit.
Frequently asked questions
What is piezo inkjet coding best for?
Tall, high-resolution codes on outer cases and cartons: logos, text and shipping barcodes printed directly onto the box.
How does piezo inkjet compare to thermal inkjet?
Both are drop-on-demand. Piezo pushes drops out by flexing the printhead, runs a wider range of inks from a bulk supply, and prints taller codes. Thermal inkjet fires drops by heating the ink in a sealed cartridge, prints codes up to 1" (2" stitched) at high resolution, and needs little maintenance. The code height usually decides.
Is piezo the same as valve-jet?
No. Piezo flexes a printhead element to fire each drop and prints at high resolution. Valve-jet opens small valves to release ink and prints large, lower-resolution dot-matrix characters.
What does drop-on-demand mean?
The printer fires a drop only where the code needs ink, unlike continuous inkjet, which runs a constant stream and recirculates what it doesn't use. Piezo and thermal inkjet are both drop-on-demand.
Does TPS sell piezo coders?
No. We supply thermal inkjet printers and Odyssey inks, including the 160 mL cartridge for long case-coding runs. We're happy to help you compare.