Uncoding the benefits of TIJ

Once the preserve of the pharmaceutical sector due to it being a cleaner method of coding, TIJ has been adopted by personal care and food companies responding to demands from retailers for clearer codes that can be easily read by consumers when products are displayed on store shelves. Furthermore coupled with a product handling system, coding placement is consistently good and speeds are high.

Much of the driving force behind TIJ uptake is the reduction in printer maintenance, which significantly cuts overall cost of ownership. Essentially, exchanging the print cartridge – which includes the nozzle assembly – replaces the entire ink delivery system, eliminating the need for repair and service contracts. Swapping TIJ cartridges takes a matter of seconds, so doesn’t disrupt production output.

In terms of print volumes, a million small simple codes can be produced from one cartridge, while for lot numbers and expiry dates, 350,000 is realistic, equating to around 20 pence per 1000 codes.

Not only have the economies of scale kicked in, resulting in lower unit costs but when the expense of ongoing consumables, maintenance cleaning and service contracts are considered, TIJ typically costs less than two thirds of the price of CIJ.

Unlike many coding technologies, TIJ can code onto primary and secondary packaging. In order to print on non-porous packaging substrates, e.g. glossy cartons, films and foils, and maintain the integrity of the code, solvent based inks are used. “Traceability for manufacturers today is critical and TIJ printers now use lighter solvents and can consistently print fast-drying, scratch-resistant alphanumeric text, graphics, logos, QR codes, 2D data matrix codes at up to 600dpi.

For controlled packaging production environments like food, TIJ is also one of the cleanest coding solutions. Hundreds of nozzles are contained within the printhead, firing at high frequency to deliver high-quality printing at high speeds.

Another criticism levelled previously at TIJ was that it could only print in grey – not black.  Amid the innovation undertaken in recent years, inks with high optical darkness have been developed. 

TIJ is also on-demand, whereas CIJ is continuous, a distinction that has a bearing on cost of ownership. CIJ printers take time to start-up and shut-down and to get a head running will often require a purging station, comprising a head bracket and funnel. Any ink drawn off must be disposed of as a hazardous waste, which requires specialist training. 

Environmental factors also need to be considered. Once running, CIJ printers are often left on all day (even 24 hours), resulting in fluids evaporating into the atmosphere even when no coding is taking place. In contrast, TIJ printers are operational as soon as the cartridge has been loaded into the printhead with ink only being consumed when codes are being printed. 

To prevent ejectable ink clogging the nozzles, additives have been developed and inks have been formulated to increase decap time to around 16 hours. This reduces the need for operator intervention after the machine has been inactive, enabling immediate start-up. 

Having a smaller footprint also adds to the appeal. Today’s industrial TIJ printers use surface mount technology, making it easier to integrate with legacy systems and reducing the amount of space machines occupy on a manufacturing line.

While TIJ is far from a universal panacea, for most packaged product applications, I believe the technology offers huge advantages over CIJ in terms of convenience, cleanliness, print clarity and cost of ownership.