What are the steps in the inkjet process for inkjet printers using piezoelectric technology?

* Question

What are the steps in the inkjet process for inkjet printers using piezoelectric technology?

* Answer

Inkjet printers that use piezoelectric technology follow a precise and controlled process to deposit ink droplets onto a substrate (such as paper or flexible electronics). Here’s a detailed breakdown of the steps involved in the piezoelectric inkjet printing process:

1. Ink Supply and Preparation

Ink is stored in a reservoir and delivered to the piezoelectric printhead.

The ink must meet specific criteria:

Viscosity and surface tension suitable for droplet formation.

Nozzle-compatible (non-clogging, chemically stable).

Filtered to remove particles that could block the nozzles.

2. Electrical Pulse to Piezoelectric Actuator

A voltage pulse is applied to a piezoelectric crystal or element located behind the ink chamber in each nozzle.

This causes the piezoelectric material to deform (bend or flex) rapidly, which either:

Compresses the ink chamber (push mode), or

Expands the chamber (pull mode), depending on the printhead design.

3. Ink Droplet Ejection

The mechanical deformation from the piezo element creates pressure, forcing a tiny ink droplet out through the nozzle.

The volume and velocity of the droplet are precisely controlled by:

Voltage amplitude

Pulse duration

Frequency of pulses

4. Droplet Flight

The ejected ink droplet travels through the air toward the substrate.

During flight:

Some systems use charge control or aerospace correction to improve accuracy.

Trajectory is maintained by carefully controlled jetting angle and environmental conditions.

5. Droplet Deposition

The droplet lands on the designated location on the substrate (paper, plastic film, PCB, etc.).

The position is governed by:

Printhead movement (usually via a carriage or a moving substrate platform).

Software-controlled rasterization and printing instructions.

6. Ink Drying or Curing

Once the droplet is deposited, the ink undergoes:

Evaporation (for water-based inks),

UV curing (for UV-curable inks), or

Thermal baking (in printed electronics).

This step ensures adhesion, durability, and color stability.

Summary: Steps in Piezoelectric Inkjet Printing

Additional Notes:

Piezoelectric inkjet printing is non-thermal, unlike thermal bubble inkjet systems.

It allows the use of a wider range of inks, including solvent-based, pigment-based, and functional inks (e.g., conductive, biological).

It’s widely used in industrial printing, printed electronics, bio-printing, and graphic arts.