In this latest post in our ink technology series, we look at the question of ink supply for the production inkjet print market. Our aim is to provide an insight in how to choose your source of ink and what to look for when considering your options. We’ll be focussing our discussion on water-based inks, but some of the points will be relevant to any type of inkjet ink.
Why the OEM Supply Dominates
It can be pretty simple to mix together some water and glycerol and bit of soluble dye and a dash of surfactant to make an ink that will jet. Maybe you’ve watched a video describing it? The real secret is making one that jets reliably, as well as delivering everything else you’ve come to expect, like the right colour and consistency on your desired media. Inkjet has taken many years to develop into the production tools of today. All wound up in that evolution is the fine-tuning of the ink-head interaction that is the secret to best jetting reliability.
As a result, the model of ink supply in the inkjet market has long been tied up with the original equipment manufacturers (OEMs). By capturing value from the consumables OEMs can lower the initial investment cost of the device and penetrate the market more easily. In the home/office printer market this has meant that consumers can pick up a printer full of up-to-date print head tech – for as little as $50. The same principle has been applied to industrial hardware, but with the click charge model often replacing expensive cartridges.
Pros and Cons of OEM Ink Supply
Given our introductory words, it almost goes without saying that the biggest advantage of the OEM as the ink supplier is the peace of mind, and the warranty it grants your device (including those expensive heads). You may be paying for a service contract separately or it may be included in a click charge, but either way it is likely this will include the cost of some preventative maintenance.
With OEM fluids, combined with all the hi-tech maintenance wizardry that goes on under the cover, the print heads should have a good chance of reaching or even exceeding their predicted operational life.
Of course, the big negative is the value being captured by the OEM, or their official distributor, in supplying all that service. Which, for the printers themselves, is simply a cost to be minimized.
An Aftermarket Analogy
The largest driver for aftermarket purchase is the price, plain and simple. But with that in mind, let’s take a moment least to consider a purchase decision that many of us make at home: You’ve just gone onto your favorite office supply store and bought the cheapest ink you can find for your home/office printer. Look carefully when you unpack it, and likely what you’ll get is a basic copy of the OEM cartridge. In the case of the CMY, it will have what looks like slightly see-through liquid inside, like in the left side of the photo below.
Compare that to the original inks, which probably costs at least 5x the price, and you’ll most likely see a difference. There’s a good chance you’ll notice that the OEM version is an opaque liquid. In the case of yellow again, it will probably be brightly colored, just like on the right side in the photo. This is the observable difference in dye versus pigment. Thus, if your OEM ink is pigment then you need to make sure you are swapping like-for-like or you won’t get the desired property from the outset!
Next, you unwrap your new purchase and pop the new cartridge into the printer. Even if the reviews said that 95/100 people didn’t have an issue, the mathematical fact is that in the other 5% of cases the cartridge might not be recognized, or if it is recognized you no longer have any idea how much ink is left because the copied chip does not work like the OEM one.
The rule here is to ensure you know what you are guaranteed, or if not make sure the price savings reflect the potential write-offs.
Extrapolating to Industrial
In industrial print sectors, like wide-format graphics, this risk does not exist in quite an extreme way. The applications are often displayed outdoors using solvent or UV-cured ink, thus using pigment is an absolute necessity and the reduced aftermarket ink saving reflects that technology requirement. It is a competitive market too, so suppliers differentiate themselves by offering inks that are made as top-loadable, color-matched and with some level of warranty commitment. This level of effort is the minimum you should expect of a reputable supplier or distributor.
For high speed production inks that likely come in barrels rather than cubies or cartridges, the manufactured chemistry and consistency is an absolute must. Whether being transported, sitting in the barrel or being pumped through the system, being able to maintain the properties that ensure the jetting performance and drying function to achieve repeatable print quality is vital. To date, all OEM manufacturers of high-speed inkjet require the printer to use validated fluids so that some level of machine warranty is offered. To some this approach may seem undesirable, but for those spending millions on high speed inkjet devices, the peace of mind that the ink has been manufactured and validated by the OEM, is worth the higher price.
So, let’s say that you’ve got that level of commitment to quality from your preferred supplier and the ink appears compatible and the printer accepts it? Great, what’s next? Beyond fastness, the main challenges arise in matching the drying on your favorite substrates and ensuring the print quality is equivalent. As we discussed previously in this series, the drying speed is finely balanced by material selection to match the equipment specification, so it is likely the replacement ink will have some difference. If it dries too slow then the ink may build up on the device’s rollers, but if drying too fast the heads might suffer. Slow drying can also affect print quality aspects like ink-ink bleed or even substrate deformation.
Finally, there’s the manufacturing. Most of the cost in inkjet manufacturing comes from the processing to turn that secret chemistry recipe into a full-blown inkjet ink that will squeeze out of a nozzle smaller than a human hair at 20-30 miles per hour. Even agreeable QA data like pH, viscosity, color or particle size distributions can hide issues with poor ink stability or insufficient filtration that might influence the longevity of your printer. If possible, request details comparing the potential supplier to the OEM equivalent and challenge what you see.
As we’ve discussed, different types of devices have different requirements for ink and changing from the OEM’s chemistry can have adverse effects upon the entire print process. Depending on the type of machine, however, this chemistry change may not cause any issues. Whomever you choose to manufacture your inkjet ink, be sure to understand all the variability which can happen within the device and on the media and print itself. Ensure each manufacturers ink warranty is fully understood and covers any areas of incompatibility as well as the costs incurred if you must change back to your original chemistry.
Mark Bale is the founder of DoDxAct Ltd in Somerset, United Kingdom where he consults in all aspects of inkjet R&D from ink formulation and manufacture through jetting & process integration to final application optimization in production inkjet, wide-format graphics, labels & packaging, decorative surfaces, photovoltaic manufacture and product coding.