Printing equipment on the market uses micro piezoelectric printheads and industrial printheads. Micro-voltage printheads refer to Epson 3200 or 4720, etc., while industrial printheads are from Ricoh and Starfire brands. At present, the most commonly used nozzles on the market are Epson printheads. Industrial types are only used in large-scale printing equipment or white ink pure cotton direct-jet printing equipment.
Today we will explain in detail the difference between industrial printhead Ricoh G5 and Ricoh G6.
Ricoh Gen5 and GEN6: Parameters Comparison
|# of Nozzles
|UV, Solvent, and aqueous
|Max. # of Color
|Max. Jetting Frequency
1. Printhead structure: There are certain differences in the structure of the Ricoh G5 and G6 printheads. The G5 uses a one-piece structure, and its printhead and data line are connected and cannot be separated; while the G6 uses an integrated structure, and the printhead and data line can be separated. Generally speaking, the maintenance cost of G6 is obviously lower.
2. Printing accuracy: Ricoh G6 has higher printing accuracy than G5. The inkdrop size of the G6 is smaller, which can achieve higher resolution and more delicate patterns and is suitable for higher-demand printing applications.
3. Inkjet control: The G6 achieves more precise ink droplet control, upgraded from 7PL to 5PL, which can better control the landing position and diameter of the ink droplets, thereby obtaining more accurate printing results.
4. Printing speed: The G6 has a higher printing speed, and the ignition frequency is increased from 30KHZ to 50KHZ, which can achieve faster printing speed. This is great for high-volume printing and efficient production.
5. Ink compatibility: Ricoh G6 is compatible with both UV, solvent, and water-based inks, and has a wider range of uses.
In general, the G6 printhead is better than the G5 and can provide higher printing accuracy, more accurate inkjet control, and faster printing speed. But this also means that the price of the G6 printhead is relatively high, and it is suitable for professional fields that require higher printing quality. The choice of which printhead needs to be considered based on specific printing needs and budget.
GEN5 has been tested in the market for 9 years from 2014 to now and has been recognized and highly praised by a wide range of customers. With the cultivation and development of the UV market, it has now become widely used, and the requirements for production capacity are getting higher and higher. From the above parameter chart, It can be seen that the emergence of GEN6 just meets the needs of this market. This is why GEN6 is now widely promoted quickly. It can increase production capacity while ensuring accuracy or even improving accuracy. According to the parameters, it can Increase production capacity by 50%.
Comparison of eight technical performances of Ricoh G6 and G5 printheads
In the following part, Johope will compare and discuss the technical performance of Ricoh G6 and G5 printheads in terms of color blocks, small ink droplets, ink supply, heat dissipation of the printhead, supporting ink, mechanical accuracy, jetting frequency, and compatibility.
The Ricoh GEN6 printhead is named MH5320 (G6 for short). The ink droplets have changed from 7pl of G5 to 5pl. The smaller ink droplets reflect a more delicate transition pattern, which is a significant improvement in improving the details of the pattern. The basic ink droplets become smaller, and the large ink droplets will also become smaller accordingly (from the original 21 to 15 pl), which will bring new problems to the printing of color blocks. Under the same Pass conditions, compared with the G5 printhead, Its coverage depth and uniformity will be slightly inferior. In practical applications, it is found that the multi-pass method is not linearly effective for the unevenness of color patches on some devices, so it is not very effective in solving the problem of uniformity of large color patches simply by using the multi-pass method.
Small Ink Droplets
Compared with large ink droplets, small ink droplets lose more speed in flight in the air. When printing with the same spacing, the small ink droplet positioning effect of the G5 printhead is better than that of the G6 printhead. In terms of the three-dimensional feeling of the picture, the G5 will be better than the G6. Therefore, if you want to get an exquisite pattern after using the G6 printhead, the distance between the printhead and the medium needs to be smaller. After enabling small ink droplets, the airflow around the printhead is required to have an increased impact on the ink droplet placement. Due to the smaller amount of ink droplets, the G6 printhead is more prone to uneven printing than the G5 head when printing color blocks. This requires improvement and optimization in mechanical precision and control accuracy to match this printhead.
For G5, when working at the maximum jetting frequency, the maximum ink volume required per minute is about 33 ml, while for G6, it will increase to 57 ml, so whether the original ink supply system can still meet this flow requirement and whether pressure loss is still within a reasonable range must be calculated and verified. Otherwise, when the jetting frequency increases, ink breakage will easily occur because the ink supply system does not cooperate well.
Printhead Heat Dissipation
When the jetting frequency of the piezoelectric chip increases, the heat generated by the printhead itself will become more obvious. The temperature rise inside the printhead will affect the normal printing quality. At the same time, the heat dissipation issues around the printhead must be considered.
The jetting frequency of the G6 printhead has been greatly improved. What needs to be paid attention to is whether its shear rate at high frequency still has Newtonian fluid characteristics. At present, most ink factories on the market only focus on the static viscosity and surface tension of UV ink. However, they have not done much research and testing on whether the basic physical and chemical indicators of the ink change under dynamic and high-frequency conditions, resulting in the maturity level of the ink being much different than that of the G5 printhead.
To achieve the 50kHz ignition frequency of the G6 printhead, if the accuracy of the trolley’s moving direction is 600 dpi, the car’s moving speed will reach 2.1 m/s. When moving at such high speeds, higher requirements are placed on the mechanics.
When the pattern quality meets the general requirements, the ratio between the movement of the car and the falling of the ink droplets must be at least 1:4. However, the actual falling speed of the ink droplets on the G6 printhead is usually about 6-7 m/s when it is 1 mm away from the nozzle. To meet this requirement, you can only print with a horizontal movement speed of 720 dpi. If you choose 600 dpi, the ratio of horizontal and vertical speeds will be less than 1:4, and the print quality will drop a lot.
Of course, you can still choose if the customer’s requirements are not high. At the same time, it is required that the acceleration zone of a trolley with a high moving speed not be too large. At this time, the acceleration can only be increased. When the acceleration is greater than 1G, it will be challenging for the stability of the ink supply system. Therefore, the speed of the trolley must be increased without letting the speed increase. If the pressure fluctuation in the ink supply path is too large, a pressure fluctuation absorption device should be added to the ink supply system to reduce the sudden change in pressure on the ink supply path. At the same time, the accuracy and anti-fluctuation ability of the negative pressure system must be further improved.
Jetting Frequency Selection
If you want the G6 printhead to work stably and efficiently, you must find a jetting frequency point that suits it. After repeated tests, it seems that the ignition frequency point around 35kHz is a stable printing frequency point. However, if the jetting frequency is increased, the speed of the ink droplets will oscillate and fluctuate, which requires adjusting and optimizing the ink supply system and machinery to achieve this.
Compared with the G5 printhead, the G6 printhead’s compatibility with UV ink, reactive ink, coating ink, and dispersed ink has been greatly improved, and it can meet the needs of users in a wider range of industries.