Reactive Vs Acid ink
As the inks (reactive and acid) are made from dyestuff, knowing about dyestuff is important.
Let us see the difference between reactive and acid dyes from their application point of view. Acid dyes are used to dye protein-based fiber, like wool and silk. Similarly, reactive dyes are primarily made of cellulose fiber, but they can be used for silk also. Very recently, reactive dye is also used to dye wool. Thus, if we search for the right reactive dye, which can be used to dye cotton, silk, and wool, then we don’t have to go for acid dyes. Some well-known dye manufacturers have manufactured such dyestuff. Companies like Clariant and Huntsman have developed such types of dyestuff namely Dremeren and Lanaset respectively. In fact, Lanaset is a blend of reactive and acid dyestuff, the blended ratio is 50:50. It was about dyestuff. Now let’s come to the ink. Technically, it is better to use acid ink to print wool and silk because this ink is primarily made of wool and silk. But if you can find something that gives satisfactory results using reactive ink, then why should we use acid dyes? That is really good logic. But, there is a question about this logic also. And the answer is if you are printing wool and silk only then you should go for acid ink. But if you print cotton viscose/rayon also then you can use reactive ink.
To understand the above logic, let us see the dyes/ink types and printable fiber/fabric below
- Acid dyes - silk, nylon, and wool
- Reactive dyes - cotton, rayon, viscose, linen, and silk
Selecting dyestuff for dyeing and screen printing (manual print) is very easy. But for digital textile printing, it’s not so easy because there are choices among the ink types. Each ink type has universally accepted CMYK colors.
Pretreatment also known as padding is done as per the instruction given by the ink manufacturer or supplier. This process improves print quality. The chemicals which are used go inside the fiber and help to penetrate the ink in the fiber. Printing gum, urea, and some salts which are used in pretreatment also help to maintain uniformity in print. The final result, which is obtained by steaming the printed fabric, is also the result of good pretreatment. Ink penetration, sharpness, and uniformity all is obtained by good pretreatment only. But we should strictly follow the recipe given by the ink manufacturer for treatment; otherwise, an accurate result is not obtained.
To see the difference between, pre-treated and not treated fabric we have to print the same design on both fabric samples. Only then we can see the difference. It is confirmed that the desired result is not obtained in the not treated fabric.
Posttreatment is also a most important step, in fact, it is the deciding step that gives the final result. Different ink manufacturers have suggested almost the same temperature and time for steaming. But in practice, it is seen that usually, printers keep half an hour after reaching the 100-degree temperature at 1 kg/cm square pressure. But the ink manufacturer suggests 20 minutes after reaching 100 degrees centigrade at atmospheric pressure.
But whatever the practice it has to be understood that start sending the steam after stable 100 degree Celsius and keep it for half an hour at 0 kg per cm square. Let the steam pressure and temperature be constant so that we can send dry steam.
Acid ink is specially made to print wool, silk, and nylon. Reactive ink is made to print cotton. As reactive ink is also used to print silk and wool. But while selecting ink for a particular fabric, we have to think about which ink gives better results. It is confirmed that we should use acid ink to print wool and silk. But when we have to print cotton also then we have to think about changing the ink. Reactive is the only ink that is being made in such a way that manufacturers have modified its chemistry to print all kinds of fabrics. Having said that we cannot ignore acid ink, the brightness we get from acid ink cannot be achieved by reactive ink. There has been so much research on this issue, and we have to go following the success. As per the result, we have to pay attention to the pretreatment of fabric to get a better print result. So we must rethink this issue in our own way so that we can get better results. If there is anything we should do to see the print result of both ink, we should print a design using both inks, if one result is not as per our assumption, we should avoid that result which is not okay. One of the best ways of getting the right result is to select the best option which gives us a good result.
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