The Technology Shift to UV LED Inkjet Systems

Jim Hingst explains how UV inkjet systems utilizing LED curing Systems differ from Mercury Vapor UV curing systems. 

There are two basic curing units used for curing UV inkjet prints: Mercury vapor UV lamps and UV LED curing systems. Mercury vapor lighting is an old technology, which has been around for at least a century.  UV inks were originally developed for this type of lighting, which emits a broad spectrum of UV light.

Mercury vapor UV lamps also generate significant  heat-producing infrared light. As much as 40% of the energy consumed is converted to heat, which serves no function in the curing process.  Since much of the media used in wide format digital printing is plastic, that heat can cause problems including shrinking, warping and discoloration.

UV LED curing systems provide a cooler cure for these heat related problems. Lower temperatures allow for printing on heat sensitive materials, such as pressure sensitive vinyls and unsupported polycarbonate films. Because UV LEDs minimize the incidence of warping media, the chance of a head strike is less likely.

One of the criticisms of UV LED systems is that the spectrum of light emitted is much narrower than that of Mercury vapor UV curing systems. In recent years, this issue has been diminished with the development of new UV LED systems and new ink formulations.

The latest generation of LED curing systems, which feature a more dense arrangement of the LEDs, produces a more energy to more fully cure the ink. The higher output of these newer systems also allows for higher production speeds.

As UV LED systems have improved and gain greater acceptance in the marketplace, ink manufacturers have shifted the emphasis in R&D to formulating inks for the newer, emerging technology. The challenge for the ink companies is in formulating inks which will cure fully when exposed to a narrower spectrum of UV light.

How well the ink cures is critical for a variety of reasons. While ink adhesion is vitally important, so are the physical properties of the ink, such as abrasion resistance, outdoor durability, chemical resistance and compatibility with a range of media as well as other components in a pressure sensitive sandwich, such as transfer adhesives.

Advantages of UV LED Inkjet Systems

Compared to Mercury Vapor lamps, UV LEDs provide the print provider with a number of cost advantages:

• Longer service life for a reduced lifetime investment in equipment;
• LEDs consume 60% to 80% less power, so operating costs are  significantly lower; and
• Fewer service issues, which reduces maintenance costs. Mercury vapor lamps deteriorate at a fast rate. By comparison, UV LEDs are said to perform continuously for 15,000 to 20,000 hours.   Component replacement costs are also lower.

UV LED systems are also more environmentally friendly than Mercury vapor curing systems in the following ways:

• UV LED systems contain no mercury;
• UV LED systems emit no ozone; and
• UV LED systems consume less power.

The transition from UV inkjet systems utilizing Mercury Vapor curing to those using LED curing will not likely happen immediately. Nevertheless this technology shift is on the horizon.  Because UV LED curing systems are more cost efficient to operate and more environmentally friendly, it is the smart choice for printers investing in UV inkjet printing equipment.

Vinyl Application Videos

Squeegee Technique. Nothing is more basic in vinyl application than the squeegee. But some squeegees work better than others. And there are right ways and wrong ways to use this simple tool. This video clip reviews squeegee selection, squeegee care and squeegee technique. Click to Link

Wet Applications. Dry applications are typically recommended for most vinyl applications. For those exceptions to the rule, this instructional video explains the right way to perform a wet application. Click to Link

Application of Window Graphics. Installing vinyl graphics on glass can be challenging, because the adhesive aggressively grabs onto this high energy surface. Repositioning graphics on window is generally difficult, if not impossible. This instructional video explains how to dry apply window graphics right the first time. It also describes the necessary steps required for surface preparation. Click to Link

Transferring Frosted Window Graphics Films.  Because frosted window films are highly textured, transferring cut vinyl graphics can be problematic. This video provides direction in selection of the right application tape and how to apply these films quickly, easily and without problems. Click to Link

3-Step Surface Prep. This instructional video describes how to properly clean the surface of a vehicle before applying pressure sensitive vinyl graphics to a trailer or doing a full wrap of a car or van. This three step surface prep involves detergent washing, solvent cleaning and a final wipe down with IPA. Click to Link

Vinyl Application Over Rivets. Applying vinyl graphics on vehicle surfaces with rivets is challenging for most sign makers. Vinyl failures to these surfaces are all too common. This video demonstrates some tips and procedures, used by professional decal installers, which will make these demanding applications easier and more trouble-free.  Click to Link

Vinyl Application to Corrugations. Learn how to apply vinyl graphics to corrugations in a relaxed state. Forcing films into the valleys of corrugations puts too much mechanical stress on the film. Sooner or later, the vinyl will lift or tent in valleys. Click to Link

Applying Air Egress Vinyls. Vinyl films with air egress release liners have almost eliminated bubbles and wrinkles from applied graphics. Air egress release liners with their highly textured surface structure are problematic. Not much will stick to these liners other than the vinyl film. At RTape our best premask solution for air egress liners is a special Conform® tape called 4761RLA. Click to Link

About Jim Hingst: After fourteen years as Business Development Manager at RTape, Jim Hingst retired. He was involved in many facets of the company’s business, including marketing, sales, product development and technical service.

Hingst began his career 42 years ago in the graphic arts field creating and producing advertising and promotional materials for a large test equipment manufacturer.  Working for offset printers, large format screen printers, vinyl film manufacturers, and application tape companies, his experience included estimating, production planning, purchasing and production art, as well as sales and marketing. In his capacity as a salesman, Hingst was recognized with numerous sales achievement awards.

Drawing on his experience in production and as graphics installation subcontractor, Hingst provided the industry with practical advice, publishing more than 150 articles for  publications, such as  Signs Canada, SignCraft,  Signs of the Times, Screen Printing, Sign and Digital Graphics and  Sign Builder Illustrated. He also posted more than 325 stories on his blog (hingstssignpost.blogspot.com). In 2007 Hingst’s book, Vinyl Sign Techniques, was published.  Vinyl Sign Techniques is available at sign supply distributors and at Amazon. 

Slides of Jim's Artwork

© 2016 Jim Hingst