Regardless of industry, many companies rely on inkjet printers to mark and code thousands of products every day, which means it’s important to keep the printers in excellent working condition. If a printer runs into an issue, it can dramatically delay production processes and leave line operators with long periods of expensive downtime.

Unfortunately, an occasional issue is inevitable. Like all pieces of industrial equipment, inkjet printers are susceptible to several problems, including outdated filters, electronic problems, misaligned components, and clogged gutters. While many of these problems can be avoided with regular time-based maintenance, other issues can appear at random and mystify users. 

To help your operation sustain a high level of efficiency, we have produced a list of common issues with inkjet date coding and printing, as well as the most effective solutions to ensure maximum uptime.

Common Issues with Continuous Inkjet Date Coding and Printing 

First introduced to the public decades ago, continuous inkjet (CIJ) printers have been used by companies from a wide range of industries, such as food production and beverage bottling, to mark products with expiration dates, serial numbers, and barcodes for coding regulation compliance and supply chain traceability. However, even the best CIJ printers will run into the occasional operational issue. 

Below are four of the most common problems experienced by CIJ users.

1. Extra High Tension, or High Voltage, Fault

Extra high tension (EHT), also known as high voltage, faults occur when a CIJ system receives an electric current at levels that exceed established voltage parameters. If the machine registers an excessive current level, it will automatically shut down, display an “EHT Fault” icon, and remain unusable until the problem is resolved. 

Excessive current levels can occur for several reasons, which can make finding the right solution a complicated process. Some of the most frequent causes of EHT faults, along with possible solutions, are listed below.

1. The printhead is dirty or wet: Turn off the CIJ printer and clean the area around the deflection plate with a cotton swab and cleaning agent. Dry the area with clean air and test the voltage with a multimeter. 
2. There is a grounding anomaly: Examine your connection to ensure you are following grounding best practices and there are no abnormalities present.
3. The EHT (high voltage fault) Trip Value is too low: Use the system monitor to reset the Trip Value to the factory settings described in the manual.
4. The EHT (high voltage fault) output is too high: Use the system monitor to reset the EHT Range. Check your owner’s manual for the ideal range.
5. The EHT (high voltage fault) module, mainboard, or umbilical is faulty: Contact a professional to validate the problem and have them replace the faulty part.
6. The EHT (high voltage fault) calibration is inaccurate: Turn off the CIJ system and clean the area around the deflection plate with a cotton swab and cleaning agent. Dry the area with clean air and then perform the EHT or high voltage fault calibration once again.

2. Viscosity Fault 

Viscosity faults occur when the ink/makeup mixture in the CIJ system is five points above or below the target viscosity. As with EHT (high voltage) faults, viscosity faults can occur for a variety of reasons.  Below we detail the most common causes of and solutions for viscosity faults.

1. The CIJ system is falsely reporting low makeup or an empty makeup cartridge: Troubleshoot the issue using the instructions in the printer’s manual. After performing the troubleshooting steps, wait 10 minutes to check if viscosity levels have returned to normal.
2. The mixer tank is full: If the mixer tank is full, the CIJ printer will not allow makeup to flow into it anymore. In this case, drain the tank’s ink until the mixture itself returns to a level where more makeup can flow into it.
3. The ink is too thick: Allow the printer to add more makeup into the mixer tank (this may require following the steps described above in list item #2). Follow the progress on your system’s monitor. If the ink won’t return to optimal levels, contact an expert.
4. The ink is too thin: Keep the printer running until the excess makeup has evaporated. If the levels are not returning to normal, contact an expert to perform maintenance or examine the ink.

3. Makeup/Ink Cartridge Fault

Sometimes a CIJ printer will have issues recognizing the presence of a makeup or ink cartridge. These faults most commonly occur when a cartridge is either unplugged or empty. In these cases, a simple cartridge replacement will fix the problem. However, if the cartridges are full of fluid and are still unreadable, the following are possible causes and solutions:

• The printer cannot read the cartridge chip: If the printer cannot read the cartridge chip, the cartridge is simply incompatible with the CIJ. To ensure that the chip is actually at fault, perform the steps described below. If you follow all of these steps and the chip is still unreadable, try contacting the ink manufacturer.
  1. Check the cartridge and make sure that it is properly installed and locked in place.
  2. Remove the cartridge, clean it, and place it back in its spot.
  3. If there is another cartridge on hand, place it in the printer and see if the chip is readable.
  4. Examine the CIJ’s chip reader to check for proper positioning and cleanliness.

2. The chip detector has been disconnected from the mainboard: Open the CIJ system and check if the chip detection cable is successfully running from the detector to the mainboard. If it isn’t, contact an expert to replace it. 
3. The mainboard is faulty: Contact an expert to run diagnostics. If they discover the mainboard is malfunctioning, ask them to replace it. 

4. Clogged Printhead

Over time, CIJ printheads may become clogged due to challenging environmental conditions or ink buildup. In these cases, a simple printhead cleaning is likely the only action required by the user. 

A description of printhead cleaning best practices should be in your system’s operating manual. Although this process will slightly differ from machine to machine, the basic steps will resemble the following:

1. Follow the “stop printer” procedure in your manual, and turn off the printer.
2. Unscrew the printhead’s sleeve to reveal the printhead itself.
3. Place the printhead above a container to drain any excess liquid.
4. Once the printhead runs dry, apply a cleaning solution to its surface, making sure to spray the printhead’s gutter, nozzle, electrodes, and deflector plate.
5. Allow the printhead to dry for around one minute.
6. Once the printhead is dry, apply a cleaning solution to the inside of the sleeve, set the sleeve back onto the printhead, and secure it into place.

To avoid clogged printheads in the future, regularly perform routine maintenance and consider investing in a printer designed for challenging work conditions. 

Common Issues with Thermal Inkjet Date Coding and Printing

Thermal inkjet (TIJ) printers, which use heating elements to propel liquid ink towards a substrate, are popular in the coding and marking industry because they’re lightweight and highly portable. Even though they are generally considered to be highly reliable, TIJ printers can experience issues such as electronic or hardware failures. 

Below are the four most common issues and solutions for TIJ printers. 

1. Excessive ink consumption. Examine your printing habits. If you’re using a TIJ for ink-heavy applications, it may be worth considering switching to a different coding technology. You can also try changing fonts or lowering your dpi to reduce ink consumption.
2. Fragmented codes/assorted print quality issues. Clean the printhead in case there is dried ink on the printer’s nozzle. If this doesn’t fix the issue, check the ink formula to verify it’s compatible with the substrate and ensure the proper temperature and conditions for the printing environment. If there are still quality issues, examine the speeds of your printer and conveyer. If the two speeds are different, the cartridge may be unable to refill quickly enough for code application.
3. The printer’s inability to recognize a substrate. Check the triggers and sensors on the system. Fixing any issues with these can generally solve the problem. Consider adding a photo eye or another similar vision system element to avoid the problem in the future. 
4. Chronic overheating. Use heat-absorbing shields, reflective barriers, and dehumidifiers in strategic areas and increase fan velocities to improve AC performance.

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