When operating various models or brands of UV flatbed printers, it's common for print heads to experience clogging. This is an occurrence that customers would prefer to avoid at all costs. Once it happens, regardless of the price of the machine, a decline in print head performance can directly affect the quality of the printed images, which in turn impacts customer satisfaction. During the use of UV flatbed printers, customers are most concerned about print head malfunctions. To minimize and address this issue effectively, it's crucial to understand the causes of print head clogging to better tackle the problem.

Causes of Print Head Clogging and Solutions:

1. Poor Quality Ink

Cause:

This is the most severe ink quality issue that can lead to print head clogging. The clogging factor of the ink is directly related to the size of the pigment particles in the ink. A larger clogging factor means larger particles. Using ink with a high clogging factor may not show immediate problems, but as usage increases, the filter can gradually become clogged, causing damage to the ink pump and even leading to permanent clogging of the print head due to large particles passing through the filter, causing serious damage.

Solution:

Replace with high-quality ink. It's a common misconception that the ink provided by manufacturers is overpriced, leading customers to seek cheaper alternatives. However, this can disrupt the machine's balance, resulting in poor print quality, incorrect colors, print head issues, and ultimately, regret.

2. Temperature and Humidity Fluctuations

Cause:

When UV flatbed printers are manufactured, manufacturers specify the environmental temperature and humidity limits for the device's use. The stability of the ink determines the performance of the UV flatbed printer's print head, which is influenced by factors such as viscosity, surface tension, volatility, and fluidity. The storage and use environment's temperature and humidity play a decisive role in the normal operation of the ink. For example, excessively high or low temperatures can significantly alter the ink's viscosity, disrupting its original state and causing frequent line breaks or diffuse images during printing. On the other hand, low humidity with high temperatures can increase the ink's volatility, causing it to dry and solidify on the print head surface, affecting its normal operation. High humidity can also cause the ink to accumulate around the print head nozzles, affecting its work and making it difficult for the printed images to dry. Therefore, it's important to monitor changes in temperature and humidity.

Solution:

Control the temperature to ensure that the production workshop's temperature changes do not exceed 3-5 degrees. The room where the UV flatbed printer is placed should not be too large or too small, typically around 35-50 square meters. The room should be properly finished, with a ceiling, whitewashed walls, and tiled floors or epoxy paint. The purpose is to provide a clean and tidy space for the UV flatbed printer. Air conditioning should be installed to maintain a constant temperature, and ventilation should be provided to exchange air promptly. A thermometer and hygrometer should also be present to monitor and adjust conditions as needed.

3. Print Head Voltage

Cause:

The voltage of the print head can determine the degree of bending of the internal piezoelectric ceramics, thereby increasing the amount of ink ejected. It is recommended that the rated voltage for the print head does not exceed 35V, with lower voltages being preferable as long as they do not affect image quality. Exceeding 32V can lead to frequent ink interruption and reduced print head lifespan. High voltage increases the bending of the piezoelectric ceramics, and if the print head is in a high-frequency oscillation state, the internal piezoelectric crystals are prone to fatigue and breakage. Conversely, too low a voltage can affect the saturation of the printed image.

Solution:

Adjust the voltage or change to a compatible ink to maintain optimal performance.

4. Static on Equipment and Ink

Cause:

Static electricity is often overlooked but can significantly affect the print head's normal operation. The print head is a type of electrostatic print head, and during the printing process, friction between the printing material and the machine can generate a significant amount of static electricity. If not promptly discharged, it can easily affect the print head's normal operation. For instance, ink droplets can be deflected by static electricity, causing diffuse images and ink splatter. Excessive static electricity can also damage the print head and cause computer equipment to malfunction, freeze, or even burn out circuit boards. Therefore, it's essential to take effective measures to eliminate static electricity generated by the equipment.

Solution:

Installing a grounding wire is an effective way to eliminate static electricity, and many UV flatbed printers are now equipped with ion bars, or static eliminators, to address this issue.

5. Cleaning Methods on the Print Head

Cause:

The surface of the print head has a layer of film with laser-drilled holes that determine the precision of the print head. This film should only be cleaned with specialized materials. While sponge swabs are relatively soft, improper use can still damage the print head surface. For example, excessive force or a damaged sponge that allows the internal hard rod to touch the print head can scratch the surface or even damage the nozzle, causing the nozzle edges to develop fine burrs that affect the direction of the ink ejection. This can lead to ink droplets accumulating on the print head surface, which can be easily confused with print head clogging. Many wiping cloths on the market are made of non-woven fabric, which is relatively rough and can be quite dangerous for the wear-prone print head.

Solution:

It is recommended to use specialized print head cleaning paper.