In the past 30 years, Epson has continuously developed inkjet printing technology. Since the advent of the “first generation” inkjet printhead in 1984, Epson has stepped up its pace of innovation and established the “micro piezoelectric technology” of “second generation” high-performance inkjet printing in 1993. In 2013, Epson developed the “3rd generation” technology- the “Precision Core micro-thin film piezoelectric printing chip,” and has also expanded its business to commercial and industrial printers. Epson continues to explore the field of inkjet printing and has found a development path through pioneering and innovation.

Through a unique micro-electromechanical system (MEMS) manufacturing process, Epson’s I3200 printhead (4720) achieves a high density of nozzles, increases the ink discharge volume of the piezoelectric and vibrating plates, and reduces the problems caused by the physical differences in the nozzle holes, achieving stable high-definition image quality and consistent color.

The Epson I3200 series printheads have fully covered the water-based, UV, and eco-solvent printhead markets. So what are the differences between these three printheads? How to choose?

Epson I3200-A1 (water-based) is easier to understand. I don’t think anyone would want to use a water-based printhead for UV and eco-solvent solutions. It’s almost impossible to get UV ink with high viscosity and low surface tension through a water-based printhead and get good control. At the same time, the life of the print head must also be considered in this process. We won’t discuss more about unconventional thinking. Because that road has been verified by history, this road is impassable. So let’s focus on the difference between Epson I3200 U1 and I3200 E1 printheads.

I3200 Series Design and Naming

In the I3200 series, I stands for innovative and new technical architecture; 3200 stands for 3,200 nozzles.
A in A1 represents aqueous, water-based, and 1 should represent the first generation.
E in E1 stands for eco-solvent, and 1 should represent the first generation.
U in U1 represents UV, and 1 should represent the first generation.
On the surface, it is a question of printhead selection, but it is also an application problem because different printheads are aimed at different inks and different market needs. The original design intention of Epson’s I3200 series printheads was to improve consistency and coordination with ink and substrate, so they are divided into different types, such as water-based, UV, eco-solvent, etc., with targeted segmentation.

UV Ink and Eco-Solvent Ink

1. Stability of physical and chemical structure:

To understand this proposition, let us first understand the basic formula of each ink:

As can be seen from the rough composition above, the composition of UV ink is much more complex. Under the same conditions, UV ink is more likely to produce changes in physical and chemical properties.

2. Ink Viscosity

Both inks have a relatively wide viscosity range, generally 4 to 20 centimeters, but generally speaking, UV ink is much larger than eco-solvent ink in terms of solid content. Therefore, under normal circumstances, the viscosity of UV ink should be greater than that of eco-solvent ink. Of course, viscosity will be greatly affected by temperature. We will not delve into more viscosity details. Under normal circumstances, it is enough that the viscosity of UV ink is greater than that of weak solvent ink.

3. Surface Tension

According to information provided by relevant experts, both have a relatively large range of choices in terms of surface tension. The range is approximately between 22 and 35 dynes. The specific choice depends on the printhead.

4. Corrosivity

Both types of inks are corrosive to a certain extent, but their corrosiveness has not yet been investigated. It will also depend on the choice of formula from each manufacturer.

5. Warm-Viscosity Curve

The range of curvature and viscosity changes between the two at the same temperature change is very different. Therefore, it is obviously impossible to use I3200-E1 to deal with UV inks, and it is very reluctant to use I3200-U1 to adapt to eco-solvent inks. Even if the secondary ink cartridge is heated to 45°C, the viscosity value is still around 8, and can only be reached between 5 and 7 by improving the formula again. The viscosity value of eco-solvent ink at room temperature is also around 4.5.

In other words, if you use a UV printhead to print eco-solvent ink, although there is no problem with the smoothness, ink flying will occur and the shape of the ink droplets will change. This will cause the amount of ink to pass through to be different, and the accuracy will also be affected. This will bring about a series of problems, such as adjusting the waveform and reducing viscosity. This must be a test for the performance and stability of the UV printhead. This choice is also a way for equipment manufacturers to spend more time and energy on re-completing technical updates. In itself, Epson has made technical improvements to the printing environment and corrosion level of UV printheads.

Differences between Epson I3200-U1 and I3200-E1

From the above data, we can see that the two print heads (Epson I3200-U1 and I3200-E1) are mostly the same, have the same quality (conventionally said weight), the same accuracy, and the same ignition frequency. There are two differences:
1. There is a slight difference in the size of the ink droplets between single dots and multi-dots. UV ink droplets are about 1 pl smaller than eco-solvent ink droplets. However, whether this difference will be eliminated or amplified when we cooperate with ink, boards, and ink circuit systems depends on the actual testing conditions.
2. Although the difference in viscosity values ​​is not very large, there is no intersection in the middle. The viscosity value of UV is 5~7 mPa·s, while the weak solvent is 3~4 mPa·s; for UV ink, it must be heated to about 45°C to achieve a viscosity characteristic of about 7 mPa·s, and it is dynamic; However, eco-solvent ink has a viscosity of about 4 mPa·s at around 25°C.

Ink Selection Principles for Epson I3200 Series Printheads

From the ink-matching point of view:
Chemical properties: (composition, material, etc.) affect service life;
Physical properties: (viscosity, surface tension, etc.) affect output stability;
As shown in the picture above: When choosing Epson I3200 series printheads, you should make a professional choice according to Epson’s printhead guidelines. Different printheads correspond to different ink solutions and professional ink circuit designs and boards, and I3200-U1 copes with the UV ink solution and the I3200-E1 deals with eco-solvent ink solution. Professional products do professional work and can better reflect professional standards.