Does inkjet ink contain salt? Ink secrets you don't know and are often overlooked!

Does inkjet ink contain salt? Ink secrets you don't know and are often overlooked!

Currently, thousands of different types of inks are used across various industries, especially in continuous inkjet printing, where ink directly encodes and labels products and packaging. But how much do you really know about the ink itself? Leibinger, a global leader in coding and marking system innovation, is a company that produces both inkjet printers and inks. It has been exploring the secret world of industrial inks and has discovered some interesting facts you might not know. In this article, we follow Leibinger's perspective and step into the fascinating world of industrial ink.

TOP 01

Anti-counterfeit UV ink contains the same ingredients as laundry detergent

Invisible UV ink can serve as an advanced anti-counterfeiting solution, verifying product authenticity by adding hidden marks or codes invisible to the naked eye. However, conventional UV colorants carry the risk of easy access: this ingredient is widely found in household laundry detergents (whose blue-purple tint can neutralize yellowing and maintain visual whiteness). As an anti-counterfeiting measure, invisible UV ink is only effective when it is difficult to replicate.

To address this, the new anti-counterfeiting ink uses composite color development technology, increasing the difficulty of imitation through multi-band spectral response. For example, black ink glows green under ultraviolet light, and this cross-color response requires precise molecular structure design, making it difficult for ordinary counterfeiters to reproduce. This technology builds an insurmountable anti-counterfeiting barrier by increasing spectral feature dimensions.

TOP 02

The harder the PVC, the easier it is to print

Global PVC production exceeds 40 million tons annually. Its pure texture is brittle and hard, requiring plasticizers to enhance flexibility. For example, the plasticizer content in rigid plastic pipes is much lower than that in flexible cable sheaths and food packaging films. Although ink can perfectly adhere to PVC molecules, it struggles to adhere plasticizer molecules. Therefore, printing on rigid pipes is easy, but printing on materials with high plasticizer content, such as food packaging and cables, is quite challenging. This leads to the phenomenon of "ink migration"-when ink cannot adhere, it easily stains the surfaces of adjacent items.

To address this challenge, new ink formulations have emerged on the market, which enhance the bonding strength with plasticizer molecules and completely overcome the technical bottleneck of printing adhesion.

TOP 03

Uses invisible UV ink to make product packaging more attractive

UV ink is not only safe to use but can also be used to enhance the aesthetic appeal of products. If brands believe that visible barcodes or batch numbers will spoil the appearance of their high-end packaging, they can opt for invisible UV ink printing. Many everyday product surfaces actually carry encoded information invisible to the naked eye. These invisible marks only appear when exposed to ultraviolet light, enhancing the product's aesthetics and providing anti-counterfeiting traceability.

TOP 04

Green and eco-friendly inks are harder to produce but worth promoting

Mixing colors is a breeze, but developing eco-friendly inks is a hidden trick. To assess the environmental friendliness of ink, we need to start with its core components: industrial-grade packaging ink must have ultra-fast drying properties, with about 80% of its formulation made up of solvents. After the solvent evaporates, the remaining substances are mainly adhesives and colorants. In traditional formulations, both solvents and adhesives are petroleum-based, posing significant environmental challenges for ink manufacturers. Leibinger has now overcome technological bottlenecks and launched an innovative formula-with bio-based ingredients accounting for up to 85%, significantly reducing global resource consumption pressure.

TOP 05

The perfect ink formula requires a pinch of salt

Besides solvents, colorants, and binders, continuous inkjet ink contains another secret ingredient that not everyone knows about-salt. This is because continuous inkjet technology requires an electrostatic field to impart charge to each drop of ink, allowing it to be guided by deflection electrodes to the surface of the substrate to form text and patterns. The addition of salts is precisely to enhance the ink's conductivity, ensuring it can respond to electrostatic deflection instructions. As all great chefs know well-a good chef is like 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 when combined with UV ink. This ink has stronger recognition compared to ordinary black-and-white printing. When the letter arrives at the sorting center, the optical character recognition (OCR) scanner reads the recipient address and then prints the barcode with UV ink. Subsequent scanners can quickly and accurately identify the barcode, thereby accelerating the flow of letters within the postal system. If you've ever wondered why emails often have faint orange or pink barcodes, the answer is now revealed......

TOP 07

The ink characteristics reflect the specific needs of customers

Sometimes you may want printed numbers or barcodes to be permanently visible, but some customers also require ink that can be removed under specific conditions. Therefore, we must develop inks with different durability or cleanability.

For example, when the shelf life marking of recyclable glass bottles is recycled, the old shelf life must be removed using a corrosive solution prepared by the bottle factory, and the new date must be covered in the original location. However, because these glass bottles frequently come into contact with moisture (whether condensate from an ice bucket or condensation droplets generated when taken out of the refrigerator in hot weather), the ink must be sufficiently water-resistant to ensure it cannot be wiped off with ordinary water alone.

Although PET bottles cannot be refilled, ink stains must still be removed during recycling to avoid residual pigments that contaminate the whiteness of the recycled material. However, some labels have even more extreme temporary requirements-in automotive manufacturing, rolled aluminum sheets usually have batch numbers, but once the sheets are stamped into body parts, these codes must be easily removed. Customer demand for ink durability often varies in gradients, depending on product features and end-user usage scenarios. Therefore, customizing ink formulations with different adhesion strengths on demand is the core value of all ink manufacturers.

TOP 08

Many printer manufacturers are unable to produce their own ink

Leibinger has a long-standing reputation as a manufacturer of industrial inkjet printers and inks. This means we can help customers achieve more precise, efficient, and sustainable printing results, because we deeply understand the underlying logic of ink-printer synergy. This fundamentally sets it apart from many printing equipment companies that rely on third-party ink supplies-the latter can only indirectly verify ink chemical formulations through "composition analysis reports" provided by ink manufacturers. Although ideal results can be achieved in most cases, they ultimately cannot replace practical testing of different inks on different printers.