The last day of the 6th Congress of the Ceramic Coating Industry, in Auditorium 1, was one of the most anticipated by the participants as it dealt with one of the most anticipated topics for potters: the Digital Decoration. With packed auditorium, Ana Virginia Lot, the Ceramic Coating Laboratory (LaRC) spoke covers “Assessment Method technical performance inks for digital decoration” new field and hitherto unexplored. According to Ana, 35% of production in Brazil is already done using the fingerprint, but most of the ceramic makes the purchase of ink based on subjective choices, either the price or the tradition of a certain producer, without testing to see what product is better or more suited to its production. This is because, to date, there is no test to report on the performance of the ink or color quality, presenting greater range of colors and liveliness.
In an attempt to initiate processes so that such assessments can be performed in the future, Ana presented the results of tests developed in LaRC, using as parameters the Extended Index, measuring how much ink drop extends on the substrate, which It is directly proportional to the resolution of the image; and the Colorimetric Analysis, which can be decisive for the efficiency of ink.
Analyzing the same parts in both dry such as with moisture 100g / m2 and also 300 g / m2, fixed firing temperature, the first observation is that moisture interferes with the extension index, increasing it to a certain extent and then decreasing. The parameters indicated that the lower the Extension index higher the image resolution, but less income, because the drop does not spread, needing more paint to occupy the entire substrate; and the more intense the vivacity measure the colorimetric analysis, the higher the image quality and higher yield, it is possible to use less ink for the same result as when using very ink with low vitality. The reported conclusion was that the image and the yield depends on the paint and drawing set, but the method was appropriate and its development could help the industry select their paints with empirical hits,
How to apply this research to production directly depends on the focus of the industry, ranging from the preference for higher yield or improved image quality.
Continuing the lecture series, Thiago Madazio, development engineer and Technical , Imerys presented a study developed by the company in Europe on the “Influence of kaolin in digital printing in an enamel layer.”
Introducing complementary ideas at first presentation of the day, Madazio completed saying that in addition to inks, the substrate also influence directly print quality, a fact already known sectors who work longer with the fingerprint, as is the industry event and graphical paper. The kaolins, thus directly influencing the process can vary according to the shape of its particles, shape factor, chemistry, mineralogy, surface area, among other factors.
For the test were analyzed four kaolin from Imerys Rio Capim plant in Pará, and made measurement of the size of the droplets sprayed under these substrates. It was proven that the higher the kaolin content, the higher will be the closest chip and areas of them, achieving the best performance with 10% kaolin. The ink tends to spread over the enamel greater the shape factor and the finer kaolin. The conclusion is that it is important to perform well enamel the correct ratio between the form factor and the fine fraction of the kaolin.
