Jos NotermansJos Notermans attempts to answer all your questions regarding textile printing in 'The Note'. With years of experience, Jos can tell you all about the basics of textile printing as well as the latest innovations that help you grow your business.
[The Note] The advantages of using reactive inks in digital textile printing
7 February 2019 | Jos Notermans
As a digital textile printer, the quality of the print you produce is of utmost importance to your customers. In order to benefit from the high printing quality of digital textile printing machines to the fullest, you need a type of ink that can deliver you that desired level of quality.
Reactive inks are a commonly used type of ink in the conventional textile printing industry. As a digital textile printer, of course, you would like to benefit from the advantages of reactive inks too. Are reactive inks suitable for digital textile printing and how do you choose which printing ink is most suitable for your printing process? In this blog, I explain what reactive inks are and what the advantages of this type of ink are for digital textile printers.
What are reactive inks?
Reactive inks are very flexible in their usage and enable you to print on natural fibers of which cotton is the most important one. On top of that, reactive inks can also be used when printing on silk, wool or viscose.
Reactive inks derive their name from the fact that the dye reacts with the chemicals in the printing paste in conventional printing. When the textiles are being steamed, this chemical reaction makes sure that the color molecules are bonded to the fiber.
Besides its flexible usage, there are two important advantages of using reactive inks. The first one is the high-quality of the colors produced by reactive inks especially when printing on cotton or viscose. And the second one is the high wash fastnesses. Especially for top-level fashion brands, high wash fastnesses are really important since this means that textiles can be washed often without losing its color.
Why are reactive inks suitable for digital textile printing?
Especially among digital textile printers, reactive inks are very popular. It was the first type of ink that was developed for digital textile printing purposes. And not without reason. This type of ink is very suitable for digital textile printing since its molecules are very small which makes it easier for the droplets of ink to go through the nozzles of the inkjet.
On top of that, reactive inks are very suitable for printing on natural fibers like cotton, which is the most used type of fabric in the textile printing industry. For digital textile printers, it is therefore highly necessary to have a type of ink available that enables them to create high-quality prints with high wash fastnesses. Digital reactive inks provide them with that opportunity.
The main difference between reactive inks for digital and reactive printing paste for conventional printing lies in the way the chemicals that need to bind the color to the fabric are applied to the fabric. In conventional printing, those chemicals are part of the printing paste where also the color is in. But as these chemicals are a rather thick substance with large molecules, they cannot be sprayed with an inkjet nozzle that is needed to achieve enough resolution and detail. So the chemicals are applied in a separate process before printing, called pretreating.
The substance that is used during the pretreatment consists of all the chemicals needed to later bind the color molecules to the fabric. The pretreatment is mostly done by padding the fabric through a chemical bath in front of a stenter (to dry the fabric). Some users prefer screen coating for it. The chemicals stay then really on the top of the fabric, so all the colors will stay there too. This is for instance attractive for printing very bright neckties, where color brilliance is important and penetration not at all.
When to use reactive inks and when to use other inks?
Nowadays, you can print with nearly every type of ink on a digital textile printing machine. Nevertheless, reactive inks remain the most popular choice. In which situations, however, would it be better for your print quality to choose to print with a different type of ink or is it even impossible to use reactives?
If it is a 100% cotton or viscose, then reactives are the preferred solution. In conventional printing often pigments are used, mainly because of price, with the trade off of less vibrant colors. I will make a special blog on digital pigments later, but the short version is that there is no reliable digital pigment solution available that is also cheaper than reactives.
If you want to print silk or wool fabrics then you have to take the application of the fabric into consideration. Is it a fabric that will be washed very often and of which the quality should not decrease too fast because of this? Then reactive inks are the best choice for your application. However, if you’re printing fabric that requires really high quality and vibrant colors but will not be washed very often (like scarfs or ties), then acid inks are more suitable for your application. Want to learn more about all the different types of ink available? Read my article on textile printing inks here.
Challenges of reactive ink in digital textile printing
Although reactive inks provide digital textile printers with many advantages, there has been one thing digital printers have been struggling with when using reactive inks. That challenge is creating the ultimate deep black. When digital textile printing was introduced, its black looked more like anthracite grey. The goal has always been to develop a blacker kind of black.
As a digital ink supplier, SPGPrints has always been busy creating an ink that could produce a more intense kind of black. In doing so, SPGPrints created special digital textile Reactive Black inks for both types of reactive colors that are used in conventional printing: VS ink and MCT ink. The difference can be found in the chemistry of the inks. VS ink, or Vynl Sufon ink, is a type of ink that produces powerful colors but is more difficult to maintain stability in the washing and steaming process. If you don’t have enough control over your steaming process, the black VS ink can turn out brown or even pink. MCT ink, or MonoChlor- Triazine ink, is far more easy to use than VS but produces a little less Deep Black colors.
Our black VS ink is the most intense black reactive ink out there. For digital printers not wanting to use VS ink, we’ve also created a black MCT ink that is way deeper and intenser than MCT inks used to be. When choosing between these two types of ink, you should first ask yourself if you’re able to maintain VS inks in your current workflow and if you’re willing and able to put in the extra effort to produce a deeper kind of black. If not, our black MCT ink is enabling you to produce a nice, deep black color too without requiring you to have optimal control of your workflow.
Unrivaled quality and color density with digital inks
The type of ink you use has a large influence on the quality of your prints. Therefore, we believe that you should only use the best inks available for your printing technique. Because of the large variety of inks available, it can be difficult to choose which one best fits your production process.
At SPGPrints we produce all types of inks for both conventional as well as digital textile printing. Our digital inks offer digital textile printers unrivaled quality and color density and reduce the chance of nozzle blockages or print head failures. Curious what digital textile printing and digital inks, in particular, can do for the quality of your prints?
Turkish manufacturer Tekboy Tekstil wanted to improve the quality of their output and meet their customer demands. The transition from conventional printing to digital textile printing enabled them to produce high-quality designs at a faster rate. Want to learn more about their success story? Download the Tekboy case study: