Pixel Printing
When the designing team at look to expand the potential of new technologies, their work often goes far beyond testing a particular piece of equipment. While there are those proprietary developments that might prove especially useful to the industry, the most important projects generally offer new ideas for using readily available equipment and supplies that can help improve productivity and quality.
What Sanjay Vyas, Head of Textile Design & Technology, is now doing with pixel printing certainly reflects this universally useful approach. He, in fact, emphasizes that it's not really about the specific Pixel printer but exploring the possibilities of this burgeoning technology.
"A major consideration was choosing a printer equipped with an ink delivery system called Piezo," Sanjay explains. "Instead of using heat to force the ink or dye out, it relies on an electro–potential charge that moves a piece of metal which moves the ink onto the surface to be printed. This allows us to use all of the different dyestuffs for cotton. When you consider pigment dyes, for instance, the new method involves printing the dye and binder together. If you were to heat this solution, you'd have a real mess on your hands," he says.
In fact, experimentation with pigment dyes is an important direction for Sanjay's pixel printing research.
"The big advantage is that these new dyes don't form a stiff film on the printed fabric, so the hand is softer. When pigment dyes are used in the Pixel printer, you don't have to pre–treat, steam or after–wash, as you do with reactive disperse and acid dyes," Sanjay says. "Advancements in pigment dyes for Pixel printing has led to a nice range of colors, which were originally limited to pastels. The availability of jewel tones and other darker colors is giving Pixel printing a boost. The question now," he adds, "concerns the durability of these new dyes.
"Evaluation of pre– and post–treatments for improved dye fixation is our current developmental focus with regard to Pixel printing," Sanjay notes. "For example, we have been working with different pre–treatments that will enable us to print on cotton fabric with acid dyes."
In addition to using different dyes in the Pixel printer, Sanjay is experimenting with different fabric constructions. "Pixel printing was initially limited to wovens," he notes. "We have been running knits smoothly with minimal stretching in the machine. We have also been testing sliver knits, non–wovens and even velvet. By adjusting the distance between the print head and the fabric roller, we have been fairly successful."
By working directly with several mills, Sanjay is using Pixel printing technology for realistic applications. "Different companies are sending us files of prints they are currently using. We can pull them up, and give everyone from designers to production managers an idea about how their designs will look on different substrates," he says. "We have also been working with our Head office to create fabrics for the ‘Cotton Characters’ used as models in our print advertisements. The folks in Head Office send us prints they are interested in using, and we can scan, reduce, and clean them up and then show the re–sized pattern printed on 100% cotton fabrics."
But it's Pixel Printing that remains the prominent focus at work. "The possibilities seem unlimited. Even the most sophisticated screen printers are limited to 16 colors and it takes a long time to set up or change patterns and designs," he emphasizes. "With Pixel printing, I can quickly download a huge variety of fonts and even photo files, which can be modified in innumerable ways. I can even print several color-ways or several patterns side by side."
This represents huge potential for everything from haute couture to active-wear, he adds, as printed looks are increasingly in demand.