Is There Salt in The Composition Of Inkjet Ink? Those Ink Secrets That You Don't Know And Are Often Overlooked!

Is there salt in the composition of inkjet ink? Those ink secrets that you don't know and are often overlooked!

Currently, thousands of different types of inks are used in a wide range of industries, especially in continuous inkjet printing, where products and packaging are directly coded and marked with inks. But how much do you know about the ink itself? Leibinger, a global leader in coding and marking system innovation, has been digging into the secret world of industrial inks and discovering some interesting facts you may not know. In this article, follow Leibinger's perspective and walk into the wonderful world of industrial inks.

TOP 01

Anti-counterfeit UV inks have the same composition as laundry detergents

Invisible UV inks can be used as a high-end anti-counterfeiting solution, that is, by adding hidden markings or codes that are invisible to the naked eye, to verify the authenticity of products. However, there is a risk of easy availability of conventional UV chromogens: the ingredient is widely found in household laundry detergents (its blue-purple hue neutralizes yellowing and maintains visual whiteness). As an anti-counterfeiting tool, invisible UV inks are only effective when they are difficult to imitate.

To this end, the new anti-counterfeiting ink adopts composite color rendering technology to improve the difficulty of imitation through multi-band spectral response. For example, black inks fluoresce green under ultraviolet light, and this cross-color response requires a sophisticated molecular structure that is difficult for ordinary counterfeiters to reproduce. This technology builds an insurmountable anti-counterfeiting barrier by increasing the spectral feature dimension.

TOP 02

The harder the PVC, the easier it is to print

More than 40 million tonnes of PVC are produced globally every year. Its pure texture is brittle and hard, and plasticizers need to be added to improve flexibility. For example, the plasticizer content in rigid plastic pipes is much lower than in flexible cable sheathing and food packaging films. Although the ink adheres perfectly to the PVC molecules, it is difficult to adhere to the plasticizer molecules. As a result, printing on rigid pipes is a breeze, but printing on materials with high plasticizer content, such as food packaging and cables, can be challenging. This can lead to "ink migration" – when the ink cannot be adhered to, it can easily pick up the surface of adjacent items.

In response to this problem, new ink formulations have appeared on the market, which have completely overcome the technical bottleneck of printing adhesion by enhancing the binding force with plasticizer molecules.

TOP 03

Invisible UV ink is used to make the product packaging more beautiful

UV inks are not only safe to use, but they can also be used to enhance the aesthetics of products. If brands think that a visible barcode or lot code will ruin the appearance of their high-end packaging, they can opt for invisible UV ink printing. Many daily visible product surfaces actually carry invisible encoded information to the naked eye, and these invisible logos can only be presented when irradiated by ultraviolet light, which not only improves the aesthetics of the product, but also plays a role in anti-counterfeiting traceability.

TOP 04

Green inks are more difficult to produce, but they are worth promoting

It's easy to mix colors, but how to develop eco-friendly inks is a mystery. To evaluate the environmental friendliness of inks, it is necessary to start with their core components: industrial-grade packaging inks need to have ultra-fast-drying characteristics, and about 80% of their formulations are solvent components, and after the solvent evaporates, the remaining substances are mainly binders and colorants. Traditionally, solvents and binders have been petroleum-based, which poses a significant environmental challenge for ink manufacturers. Leibinger has now overcome technical bottlenecks with innovative formulations – up to 85% bio-based content – that significantly reduce the pressure on global resources.

TOP 05

The perfect ink formulation requires a pinch of salt

In addition to solvents, colorants, and binders, there is another secret ingredient in continuous inkjet inks that not everyone knows about – salt. This is because continuous inkjet technology requires an electrostatic field to charge each drop of ink, which can be directed by deflection electrodes to the surface of the substrate to form text and patterns. The addition of salts is precisely to enhance the conductivity of the ink and ensure that the ink can respond to the electrostatic deflection command. As all good chefs know – a good chef, a handful of salt.

TOP 06

Every letter received contains UV ink

Machine readers, such as the millions of scanners used in postal sorting systems, work more efficiently with UV ink. This ink is more recognizable than ordinary black and white printing. When a letter arrives at a sorting center, an optical character recognition (OCR) scanner reads the address and then prints the barcode with UV ink. Subsequent scanners are able to identify the barcode quickly and accurately, speeding up the flow of letters through the postal system. If you've ever wondered why your emails are often printed with faint orange or pink barcodes, now the mystery has been revealed......

TOP 07

Ink characteristics reflect the specific needs of customers

There may be times when you want the numbers or barcodes you want to print are permanently visible, but some customers also need inks that can be removed under certain conditions. Therefore, it is necessary to develop inks with different durability or cleanability.

For example, when an empty bottle is recycled and refilled, the old expiration date is removed by the corrosive solution configured by the bottle factory, and the new date is covered in place. However, due to the frequent exposure of these glass bottles to moisture (whether it is condensation from an ice bucket or a drop of condensation when taken out of the refrigerator in hot weather), the ink must be water-resistant enough to ensure that it cannot be erased with plain water alone.

Although PET bottles cannot be refilled, ink stains must be removed during recycling to avoid residual pigments contaminating the whiteness of the recycled material. However, the temporary nature of some markings is more extreme – in automotive manufacturing, rolls of aluminium are often printed with batch numbers, but these codes must be easily removed when the sheets are stamped into body parts. There are often gradient differences in customer demand for ink durability, depending on the product characteristics and the end-user's use case. Therefore, customizing ink formulations with different adhesion on demand is the core value of all ink manufacturers.

TOP 08

Many printer manufacturers are unable to produce their own inks

Leibinger has a long-standing reputation as a manufacturer of industrial inkjet printers and inks. This means that we are able to help our customers achieve more accurate, efficient and sustainable prints because we understand the underlying logic behind the synergy between ink and printer. This is fundamentally different from many printing equipment companies that rely on third-party ink supply - the latter can only indirectly verify the ink chemical formula through the "composition analysis report" provided by the ink manufacturer, although in most cases it can also achieve the desired effect, but after all, it cannot replace the practical verification of measuring different inks on different printers.