Drop Watching on the Print Head Doctor Enables Quick, Easy, and Precise Print head Testing
Digital Sign Technologies Inc.NewsJune 2, 2025At FESPA 2025 Digital Sign Technologies introduced a groundbreaking method for assessing nozzle performance on inkjet print heads during the cleaning process - directly on the Print Head Doctor (PHD) machine. This new technique, known as drop watching, offers a faster and more accurate alternative to traditional test prints and the widely used “curtain” method.
A Smarter Way to Test Nozzles
Traditionally, checking nozzle function involved printing a pattern or observing a fluid “curtain” under pressure. Our drop watching method changes that by enabling direct observation of ink droplets in flight, providing a clear view of each nozzle’s performance.
Here’s how it works:
- The print head, while being cleaned on the PHD machine, is electronically connected to the Print Head Tester (PHT).
- The head is placed on a specialized fixture, also used for curtain tests.
- The PHT and PHD work together to trigger individual or grouped nozzles at specific frequencies.
- A high-resolution camera captures droplet images in real time.
- These images are processed using advanced vision analysis to determine which nozzles are jetting correctly.
Precision Requires the Right Fluid
Not all cleaning solutions are suitable for this method. Only approved fluids can be used for drop watching. These solutions must meet strict requirements for viscosity and surface tension to ensure they can be jetted reliably at specific temperatures and through specific print heads.
