Screen Printing asked industry experts to comment on the latest advancements in UV inks.
By Gail Flower
Curt Baskin Our firm invests significantly in the development and research needed to provide the highest quality UV inks in each of the various industries we serve. The automotive market is one area where we are working on advancements in UV inks. Auto manufacturers are increasingly using 3-D plastic parts that require robust and durable ink systems that pass the OEM’s specifications but still maintain elongation properties.
Are there problems with UV inks?
Steve Mitchell In some instances it is important as you increase cure speed of the ink or coating that you maintain flexibility as well.
Scott Schinlever Cracking can occur on some substrates when the lamps are not properly set for curing the ink. We have seen this on acrylics; however, there is now at least one company that makes an acrylic for digital printing that has eliminated this issue.
Curt Baskin There are limitations, but our ink formulations have been tested and designed to meet and often exceed customer and end-user expectations, when following our processing guidelines in terms of high productivity, consistent printing of solid and vibrant colors, and the reproduction of sharp lines to obtain readability of bar codes and small text. The ink must also perform as good as, if not better than, conventional inks in managing scuff and abrasion resistance, flaking, and fade.
Johnny Shell, Ray Greenwood, and Jeff Burton UV ink formulations are typically focused on a specific range of applications: usually rigid or flexible. Formulators are constantly working to bridge this gap; unfortunately, the monomers and oligomers commonly used have limited characteristics. For digital inkjet printing, bi-directional printing can still leave a visual path or swath (often called banding or bi-directional banding). Different manufacturers have ways of mitigating these stripes by either using a software solution or by using a varnish to create an equal gloss level over the entire print.
Grant Shouldice There are system challenges in UV printing and, as such, inks and presses and other inputs to the system need to work in concert to achieve the desired output for any application.
Michael J. Plier You bet. Please keep in mind that UV inks are 100% solids. Solvents are 30% solids, or in the case of digital inks, considerably less. Right form the start, UV systems have an initial disadvantage, as the cured ink film is considerably greater; with solvent, considerably less. With any coating or ink there are a variety of resins to choose from for a given application. Often to obtain the best overall performance, the blending of a variety of these components can offer an extremely broad range of adhesion and physical properties. The difficulty in such formulations is to find the correct ratios for the wide range of applications.
Larry Hettinger The primary problems are encountered when inks are not used for the intended application they were designed for. Current inks can be designed for greater application latitude than they were in the past, though inks must always be matched up with their intended use and application requirements. For instance, when you mention cracking—you might be asking about misuse of UV ink for applications such as printing double-sided on styrene and then diecutting or too much UV that can result in brittle ink and media that will cause cracking.
Click here to read Part II of this panel discussion.
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