Thermal vs. Piezo Technology
Thermal
+ Less expensive technology
- Limited inks useable
- Limitations on ink properties

All of these designs and their drop performances ultimately determine the quality and throughput of a printed image. The trend in the industry is in jetting smaller droplets for image quality, generating faster drop frequency through a higher number of nozzles for additional print speed, while inevitably trying to keep the cost of manufacture down. In an attempt to achieve this, what we have seen is the continued miniaturization of the inkjet print head design, where consequently, reliability issues have become even more critical.

Because smaller ink drop volume is required to achieve higher resolution printing, the nozzle diameter of print heads has become increasingly small. With the trends towards smaller diameters and lower cost, the laser ablation method has become increasingly popular in the manufacture of inkjet nozzles. This trend towards smaller nozzles can more easily be achieved using piezo technology.

The nozzle

Independent of a print head’s configuration, one of the most critical components in a print head design is its nozzle. Nozzle geometry such as diameter and thickness directly effects drop

volume, velocity, and trajectory angle. Variations in the manufacturing process of a nozzle plate can significantly reduce the resultant print quality. Image banding is a common result from an out-of-specification nozzle plate. Various nozzle geometries have been designed for inkjet print heads: the two most

widely used methods for making the orifice plates being electroformed nickel and laser ablation on the polymide (other known methods include electro-discharged machining, micro-punching, and micro-pressing).

Piezo

+Wide range of inks useable

+Modulate drop size -> better resolution

+Higher drop rates

+Longevity

-Limited number of

nozzles per row

- Higher costs per nozzle

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