Thermal Inkjet Technology has undergone a breakthrough that is big news for food manufacturers
By Drew Weightman, Global Business Unit Manager, Videojet Technologies& Wolke
Flexibility is big for food manufacturers – flexible lines, flexible business streams and flexible packaging. We know the growth of the global packaging market is relentless, expected to hit 70 billion USD1 by 2017, driven by a growing number of packaging types and substrates. In turn, this generates a need among food manufacturers to look for more versatile printing solutions to meet packaging and branding requirements while achieving efficient production.
One coding technology, Thermal Inkjet (TIJ), has undergone rapid technical change in the last year, representing a new solution for food and consumer goods producers. As a result of new solvent TIJ capabilities, for the first time thermal inkjet is a relevant option for production teams looking for improved high resolution coding options for use on packaging materials that are non-porous, such as plastics, glossy cartons, foils and films.
The new technology means that TIJ can finally help address the need to mark complex variable data directly on food packaging. This includes certification symbols, expiry dates, batch or lot information, promotional offers, simple graphics or branding and regulatory information such as Country of Origin Labeling (COOL).
Q1. What has changed that now makes TIJ relevant to food and consumer packaging?
DW: In a word, “adhesion”. Thermal inkjet has long been the dominant coding method within the pharmaceutical packaging industry, largely due to its unparalleled ability to print ultra-high resolution variable date codes, logos and unique barcodes via a clean and easy-to-operate system. However, TIJ coding did not spread beyond pharmaceuticals as it was limited to printing on porous cartons and paper-based packaging materials. Marking on any sort of glossy coating caused the ink to rub right off. Printing on porous materials was sufficient for specially prepared pharmaceutical packaging, but not for the many types of packaging common in food or consumer goods.
However, in the last yearan exciting revolution occurred in thermal inkjet technology. Videojet, in partnership with itsWolke GmbH business, has introduced technology that finally enables TIJ to consistently print and adhere to non-porous materials. This is a game-changer. With the ability to mark most packaging materials, TIJ has become a viable option for packagers of food and consumer goods for the first time.
Q2. This sounds like a big change. What has enabled TIJ to be compatible with these new packaging materials and applications?
DW: The secret is a new set of printing systems that are hardened to withstand solvent inks of the type you would find in Continuous Inkjet (CIJ) technology. Videojet TIJ technology now falls into two broad classes, aqueous and solvent. The former, which remains unchanged, is a set of printing systems designed to use the traditional water-based inks for marking on porous packaging materials.
The new solvent class, on the other hand, features systems using inks that are able to dry on, and adhere to, non-porous packaging materials. The solvent class is further divided into systems for weak solvents and hard solvents. Weak solvents, such as acetone and ethanol, are suitable for
marking some non-porous materials like varnished cardboard cartons while the more capable methyl-ethyl ketone solvent (MEK)enables marking on more challenging plastics like films or rigid containers.
This sounds complex, and the technical development to make it happen certainly was, but the end result is remarkably simple. For producers of food and consumer packaged goods, there is now a thermal inkjet system that adheres to their packaging.
Q3. Current coding methods such as continuous inkjet seem to work pretty well. Why is this TIJ breakthrough relevant to production managers and engineers in food or consumer goods facilities?
DW: CIJ is a great technology and will likely remain the most flexible coding method for the foreseeable future. However, the world of food production and packaging is changing. Production teams face increased retailer pressure and a multitude of regulations demanding highly readable, content rich codes. They also must find ways to meet new requests from brand owners to print variable marketing codes, graphics and logos. All of this is happening just as they migrate to a wider range of packaging formats including flexible packaging and bio plastics.
These demandscan strain the capabilities of many older coding solutions. With its new technological breakthrough, thermal inkjet coding systems can now play a role in addressing these evolving demands.
Q4. What kind of demands are you talking about?
DW: A few simple examples I think will illustrate my point. Videojet’s thermal inkjet systems offer variable resolution up to 600dpi, though 300dpi (roughly four times than that of CIJ) is often the preferred choice to optimize ink consumption. Furthermore, unlike Laser or CIJ marking systems, Videojet thermal inkjet does not “scribe” the code with a single marking point but instead uses a large number of tiny printing nozzles simultaneously. The result is that complex codes or multiple lines of text up to 50mm (2inches) in height can be coded without any impact on production speed or print quality.
Thermal inkjet also represents one of the cleanest and simplest to operate coding methods, which benefits production efficiency. Such thermal inkjet coding systems, aqueous and solvent, feature a simple ink circuit with all ink contained in the expendable cartridge. With no ink pumps or filters, the operation of a thermal inkjet coder is clean, easy and reliable. When a cartridge is exhausted, an operator simply inserts a new cartridge and the coder is ready to print. For many food production operations this can be a huge advantage when compared with their current coding equipment.
These fundamental benefits of thermal inkjet simply couldn’t be unlocked in typical food production facilities due to the limited adhesion – until now.
Q5. The possibilities of this new breakthrough sound rather remarkable. Does this mean it’s expensive?
DW: Actually, it is just the opposite, though this is a common misperception about TIJ.
While the cost of individual TIJ cartridges can be higher than CIJ, the simplified operation, more efficient utilization of ink, reliability, and enhanced print capabilities typically result in a strong return-on-investment. Many of the new solvent systems we have installed recently into customer sites have been quickly followed by orders for additional units as production managers experience the savings and operational ease of thermal inkjet.
Q6. Does this mean that Videojet thermal inkjet will now replace all continuous inkjet?
DW: Not at all. CIJ offers a code “throw distance” of 10mm or more, which can be essential when marking curved surfaces such as beverage cans. Further, while CIJ can have difficulty marking complex codes, to mark a simple date code no technology can rival the linear speed of CIJ. Finally, the flexibility of CIJ is pretty impressive. Many manufacturers that intend to move a single coder around to multiple lines during production prize the easy setup and versatility. CIJ will remain the workhorse of packaging lines.
However, TIJ can really excel now in offering a whole new coding paradigm for food and consumer packagers. This is particularly true when thinking of analog coding methods such as hot stamp, roller coders, embossing wheels, legacy CIJ, or even situations where flexographic presses are marking static packaging elements that really should be variable or customizable.
Additionally, packagers that value the simple, clean, cartridge based nature of TIJ or that want finally to break free of the more traditional appearance of many printed codes are now discovering the possibilities of the new TIJ.
Q7. How does a food producer know whether this new solvent TIJ is now right for them?
DW: The first step we would recommend is to take a look at the new application possibilities of TIJ. Many food production and packaging experts may have taken a look at thermal inkjet technology years ago and concluded that it was not suitable for their packaging materials. With new TIJ ethanol and MEK technologies now available, the situation has changed dramatically.
That being said, production teams will need to keep in mind that TIJ still requires a relatively flat surface to mark the code on. This means marking round bottles, beverage cans or irregularly shaped containers will not be a good idea. However, for cartons, tubs, pouches, foils, films and a multitude of other packaging types that feature at least one semi-flat surface, the new TIJ technology is now a compelling choice.
I would suggest manufacturers sample any new TIJ codes directly on their packaging. Sharing these results with quality and marketing colleagues can elicit useful perspectives about the higher code quality. Plus, actual on-site trials can uncover the degree to which maintenance and operator headaches decline.
