Is it time to rethink thermal inkjet coders?
When was the last time you checked out thermal inkjet (TIJ) for your small character coding? If it’s been a while, it may be time to look at them again.
A lot has changed with the technology over the years. Most importantly, TIJ is no longer just for porous packaging materials. When the packaging industry was first introduced to TIJ a decade ago, many users found themselves restricted with the technology because the applications were limited to porous material substrates such as kraft paperboard, non-coated paper labels, SBS cartons and pulp materials. Not true anymore. It is now possible to print small character codes onto non-porous materials with very fast dry times.
So, what happened?
When TIJ technology was first introduced, only water-based inks, which are not suitable for non-porous materials, were available. The need to date code consumer goods packaging materials with fast drying ink drove those who needed a non-porous solution to land on continuous inkjet (CIJ) printers, which are historically fraught with maintenance headaches. However, significant TIJ print head cartridge and ink developments have occurred over the last couple of years, producing inks with rapid dry time properties.
These ground-breaking new ink formulations and print head cartridges opened TIJ to a wide array of new substrate possibilities. What does all this mean? CIJ is no longer the only option for product coding primary packaged goods.
So, is TIJ right for you? Here, we’ll explore all of the benefits of TIJ, plus what you should know if you’re considering switching.
The many benefits of TIJ
TIJ print heads today are basically user-replaceable cartridges that contain the print head nozzles and ink reservoir. When the ink needs to be replenished, you get brand-new nozzles with every new cartridge, resulting in the best possible print quality.
This cartridge design simplifies ink replenishment and eliminates the mess and complication that CIJ is known for. No more solvent make-up and cleaning solvents, no more smell and no more filter changes as normally experienced when using CIJ. When the ink is all dispensed, you simply exchange the print head ink cartridge with another – a process that only takes 30 seconds.
TIJ coders using Funai inkjet cartridges are capable of using solvents such as ethanol and methyl ethyl ketone (MEK, AKA Butanone), meaning dry time on non-porous materials is as fast as one to two seconds upon contact. Now materials such as pouches, lids, acrylic varnish-coated paperboard and film foils can be inkjet coded with TIJ, making it a viable alternative to CIJ.
While TIJ ink cartridges may appear more costly over time compared to buying containers of CIJ ink, especially for higher-yield lines, they’re the perfect solution for companies that produce less than 30,000 products per day. This is due to the comparative reduction in costly maintenance and down time. Additionally, most TIJ coders are significantly less expensive than CIJ, and are typically much smaller and more portable – making it a smart solution if you need to frequently move your coder. In fact, because of the smaller price point and ease of use, some CIJ users have claimed that the cost of a TIJ coder is much lower than their spare parts budget to support a CIJ printer.
Thinking about switching? What you need to know:
Throw distance and substrate
TIJ coders are well suited for inkjet coding on flat substrate surfaces. Some examples of these substrates include: product labels before they are applied, continuous plastic film/foil roll stock, closure lids and folding cartons. But even these substrates, without properly adjusted material handling, can test the TIJ throw distance performance.
If you are looking to replace your CIJ small character printer with thermal inkjet, it’s important to understand your throw distance needs. TIJ is an open-atmosphere printing system, meaning the nozzle orifices are open to air and there is no valve seal at the orifice to allow ink pressurization. Ink pressurization is what helps propel the ink drops with a longer throw distance from print head to target substrate. For this reason, TIJ print heads propel the ink drops approximately half of the 10-mm distance of CIJ printers, making their throw distance 1 mm to 5 mm.
This is critical to understand because irregular or radial-shaped products require extended throw distance for optimum print quality. TIJ delivers the best print quality when you can maintain control of guiding the distance between the packaging material substrate and the print head.
The print head
Proper care is necessary to keep the TIJ print head cartridge clean. As mentioned before, the TIJ print head is an open atmosphere print head design, and that means it is important that the nozzles remain wet during the print cycles. Print idle time, also called decap time, should be kept to a minimum to prevent the ink from drying on the faces of the nozzles. Decap time is the maximum allowed time of print idle before the print nozzles no longer remain wet. MEK solvent in the Funai cartridge has a decap time that varies between 20 and 120 minutes, so if production on a conveyor line stops for longer than that time, it might be necessary to assist in wetting the nozzles by wiping the face of the print head with a lint-free cloth. When a solvent-based TIJ cartridge is no longer needed for coding, a storage clip that is provided by the manufacturer protects the nozzles and seals the print head cartridge to prevent solvent loss.
Redimark is a coding and marking company that is revolutionizing the small character printing industry. Redimark’s coding technology and fast drying inks can mark a wide variety of materials, including plastics, paperboard materials, bags, pouches and films, labels, and aluminum. The company’s reliable small character printer and inks are available for purchase online and provide consumer products manufacturers with a less complicated, more cost effective, and more accurate marking and coding solution.
For more information, visit redimark.com.