Two significant trends jumped out as we were putting together this all-new Buyer’s Guide for UV-LED Flatbed Printers: “new and improved” and “exponential market opportunities.”
As far as “new and improved” goes, printer manufacturers seem to be on a fast track to improve equipment with more features, more options, better printing and ink technology, more capabilities, faster printing and more options in printer choices at lower costs for both the equipment and the ink. New features and new machines are continually being introduced, and you will find plenty of bells and whistles on them.
According to Keira Lee, senior specialist of GCC product management, “Undoubtedly, UV flatbed printing has seen a rapid ascent in the marketplace. While the inkjet techniques mature, new technologies continue to evolve, including higher resolution print heads, smaller ink droplets, high-performance inks, greater reliability, and so on, to achieve higher printing quality which has become more and more important in the personalization market.”
Thanks to ongoing advancements in technology, there is considerable buzz about the expanded market opportunities and market growth in the recognition and personalization industry. Similar to the explosion we’ve seen in applications for laser engraving, UV printing appears to be headed down the same path. Just a short time ago, UV printing was considered a new and innovative way to reach a limited number of niche markets, but that appears to be changing. The ability to digitally direct print full-color graphics onto virtually any surface enables a recognition and personalization provider to offer goods and services that were previously either impossible or too cost-restrictive. Business entrepreneurs are reaching out into all types of markets—ADA-compliant signage, awards, promotional products, gift items, interior décor and more.
“Advanced UV printers are making it easier, faster and more cost-effective than ever before to print vibrant, detailed graphics on a vast array of substrates and objects,” says Daniel Valade, product manager, color products for Roland DGA. “These devices are enabling all types of businesses, including companies specializing in recognition, to better meet increasing consumer demand for personalized and customized products.”
This buyer’s guide takes a look at the UV-LED printers available from major suppliers in the industry. If you are interested in purchasing a UV printer, you need to consider numerous equipment features such as print speed, accuracy, resolution and the print size. The charts accompanying this article list the basic features of each of the systems available for quick comparison to help get you started. But first, what exactly is UV-LED printing?
What is UV-LED Printing?
A UV printer is a re-engineered inkjet printer that uses UV light-curable ink and an ultraviolet LED curing lamp(s). UV inkjet printing is different from conventional solvent inkjet printing. Instead of having solvents in the ink that evaporate into the air and absorb into the substrate, UV inks are exposed to the UV-LED lights that are built into the printer which almost instantly cure the ink to turn it from a liquid to a solid. Because the inks dry so quickly, there is no time for ink dots to spread, which optimizes dot gain and color saturation. The almost instantaneous cure time is also highly advantageous because multiple layers of ink can be laid down and cured, which builds up the ink and creates a 3D effect on the substrate. This is how ADA tactile letters and Grade II Braille are created using these printers, as well as textured effects, such as the dimples on a printed image of a basketball.
The use of an LED light as the curing system is a relatively recent technological development as previously the most common UV light source used in these printers was traditional mercury vapor lamps. In addition to eliminating environmental and workplace health issues related to the dangers of mercury-based lamps, the new LED technology has several advantages, including the ability to produce instant light at a lower temperature and a longer service life which reduces maintenance costs. UV-LED printers use much less power than mercury vapor lamps and can also print on a wider variety of substrates, including plastics, acrylic, wood, glass, ceramics, metals, fabrics and leathers, which opens up many different printing applications ranging from outdoor signage to golf balls. Most of these printers also have the option of using white ink, which allows printing white as a spot color and also as a base to print full-color images on dark or clear substrates.
Digital inkjet printer technology is just now evolving from its infancy and the thought of any new user going out to shop for equipment is quite daunting. What’s the difference between printers and what features are most important? To help you make this determination, we have included a series of handy reference charts with this article. Now let’s take a look at some of the specific features of these printers by looking at our first chart.
The General Specifications chart lists some basic information about each of the UV-LED printers in this guide. Price, of course, is important and in another parallel to laser engraving machines, we are starting to see the prices of this equipment come down somewhat. Just a year or two ago, very few people paid much attention to this technology because there weren’t many who could seriously consider the $20,000-$80,000 price tag. But as time has passed, the prices have dropped and more competition has come into the market, which has led to a much wider variety of printers and print options available as well as price points—even to the point that $15,000-$20,000 can now buy a lot of printing capabilities.
The type of printer is also noted in the General Specifications chart. Although this guide focuses specifically on UV flatbed printers, there are actually two different kinds of these printers available: flatbed and hybrid.
As the name implies, flatbed printers have a flat table where you place the item to be printed and then the inkjet printheads and/or the table move to print the image on the item. A big advantage of flatbed printers, at least for some applications, is that they can be used for printing on bulky or dimensional items that cannot be fed through a roll-fed system, such as golf balls, poker chips, pens, phone covers, sign blanks, awards, giftware items, promotional products, etc. On the other hand, flatbed printers tend to have a limited printing area because they are limited by the working range of the machine, unlike roll-fed printers which can accept rolls of material in exceptionally long sizes.
Hybrid printers are also available which are designed to offer the best of both worlds with both roll-fed and flatbed capabilities. This type of printer can hold a roll of material for printing items such as large signs and banners, and can also convert into a flatbed unit, e.g. with front and rear flat folding tables for printing other substrates. There are a couple of hybrid printers listed in the General Specifications chart.
All UV printers come with some kind of RIP (Raster Image Processor) software which essentially is color management software that controls ink output to enhance color saturation, brightness and details, particularly in photographs. Usually, the RIP software is developed by the manufacturer for a specific printer and has various functions, such as translating images from your computer into raster images for the printer and enhancing color consistency. Although you may not be able to talk of and understand RIPs in any great detail, you can see the results in the printed image, such as vivid reds, bright white and the ability to smoothly transition from one color to another. This is an important feature to discuss with equipment suppliers.
The features in the Printer Specifications chart provide information about the capabilities of the printer. Some printers can be used to print on thick items, such as a guitar, while others are intended for large format, relatively flat printing on items such as signs and posters.
As far as printers go, many of these machines are fairly large and heavy. However, there are options at both ends of the spectrum, ranging from desktop sizes to very large machines that won’t pass through a single 36" wide door and weigh enough so that wooden floors will have to be reinforced prior to installing the printer.
The maximum print size, substrate size, substrate thickness and substrate weight are all important printer characteristics as they determine what you can and cannot print. For this reason, it’s important to have a good idea of what you want to print before purchasing a printer. If all you plan to print is flat acrylic, for instance, you might get by with a 2" maximum substrate thickness capacity. On the other hand, paying for a printer that can handle a 15" thick item for no reason would be a waste of money. The same is true with substrate weight capacity. A couple of printers included in the chart are capable of printing on items up to 250 lbs., but most of the desktop printers range from around 8-30 lbs.
One of the most popular features of UV printers recently has been the introduction of cylindrical devices for printing items like water bottles, cups, candles, beer glasses, wine glasses, travel mugs, cans, jars, vases and wine bottles. Cylindrical holding devices are offered as an option for most printers with enough thickness capacity to accommodate one, which is around 4" minimum. These fixtures typically consist of a set of rollers that rotate the item while printing. If you plan to print cylindrical items, you will want to check out the fixture offered by the manufacturer as the capacity of these fixtures varies in terms of the length of the cylindrical object (e.g. 1" to 13") and diameter (e.g. .5" to 4") that they can accommodate.
The next chart provides some additional details about the printers. UV-LED printers are capable of printing images at different resolutions. Resolution is typically defined in dots per inch (dpi) and signifies the amount of detail achievable; a higher resolution means finer detail. However, resolution is also directly related to the amount of time it takes to print an image—the higher the resolution, the more time it takes. In general, the ability to select the resolution you want for a particular job can be an advantage as it provides you with more flexibility when it comes to time vs. detail.
Printing speed is also worthy of note. The numbers might mislead anyone looking strictly at the chart and comparing speed. Print speed can be measured in many ways, so it’s important to make sure you’re comparing “apples to apples” when looking at print speeds. The numbers might vary drastically when comparing draft mode (360 x 720 dpi) with production mode (1440 x 1440 dpi or higher). Speed also varies when white is added as a base or clear is added as an overcoat.
Most of the printers listed in this guide have both unidirectional and bidirectional printing capabilities. Unidirectional printing applies ink in one direction or the other. This option is said to produce better results when the substrate is not very flat or has other surface irregularities. Bidirectional printing applies ink as the carriage moves in both directions, right-to-left and left-to-right. Bidirectional printing is another feature that gives increased printing speeds.
Every printer manufacturer offers their own inks, and there are several ink formulations available, ranging from “hard” inks that are chemical- and abrasion-resistant to inks flexible enough for use in membrane panels and on squeezable water bottles. This means it is ultimately important that you test both the inks and the printer to make sure they will work on the substrates you want to print prior to making any kind of buying decision or promises to customers. In addition, inks can’t easily be changed once an ink is selected and installed in the printer. Although ink changes are possible if you thoroughly clean the printer, this can be time-consuming and is not recommended for job-to-job use, another reason why it’s important to choose the best ink for your applications.
The Ink Specifications chart shows how each printer handles ink. UV printers are typically available as a six-color printing system or an eight-color printing system which refers to the number of inks (cartridges) the printer can use to print images. All UV printers use CMYK ink sets which includes the traditional four process colors of cyan, magenta, yellow and black (CMYK). Most UV printers offer a six-color ink set of CMYK plus white and clear (varnish). A few also offer the option of light cyan and light magenta (Lc, Lm). Today’s UV printers feature an eight-channel print head that is usually set up so there is one channel each for CMYK plus two channels for clear and two channels for white inks. In the case of a printer using Lc and Lm, two of the eight channels would be configured to dispense this ink (e.g. white and/or clear ink channels). In theory, you can reproduce any color using the CMYK ink set, but to achieve more pleasing and accurate color renderings for certain applications, it helps to add a few more colors to the CMYK mix. This is a choice you will need to make, so be sure to explore your options.
All of the UV printers in this guide are capable of printing white ink. Until recently, the ability of digital printers to print white ink has been a challenge and, in some cases, impossible. Among other problems, white ink needs to have a high degree of opacity in order to cover non-white substrates, but increasing the opacity turns it into a thick ink that can play havoc with inkjet print heads. White ink also needs to be translucent enough for use in backlit applications. Recent advancements in ink, printing technologies and the hardware itself, however, have led to the development of white ink that manufacturers say now works well in digital printers. (For more information about printing with white ink, read “The Trouble With White Ink is… It’s White Ink,” Sept. 2016.)
The ability to successfully print white ink has several useful applications, including the ability to create unique types of transparent and backlit products. White ink can also be used by itself on dark substrates or serve as a base coat on non-white substrates on top of which other colors can be printed.
One problem common to all printing processes has to do with printing on various colored substrates. Many inks are slightly transparent, so if you apply the transparent ink onto a colored substrate, the end result can be an image showing the blend of the ink color plus the substrate color. For example, if you print yellow ink onto a blue shirt, the result can be a green logo (blue + yellow = green). A simple workaround for this problem is to first apply a layer of opaque white ink to the substrate, then overprint the white area with the desired color.
The clear ink, also referred to as varnish, is used to create different finishes, such as matte or high gloss finishes, and also adds additional durability. There are other options as well. For example, GCC recently introduced what they refer to as “advanced varnish printing technology” which allows applying colored varnish in your choice of 32 different patterns or your own custom pattern.
In addition, there are many substrates that UV inks will not adhere to without first applying a bonding or adhesion agent. Some printers can actually spray an adhesion agent on the substrate through the printer nozzles while with other printers, you need to hand apply it.
Another printer feature that has recently improved for nearly all the UV printers is the ink supply. Many manufacturers have increased the ink capacity on their printers, e.g. from 17 ml cartridges to 300 ml tanks, which are more efficient production-wise for longer print runs.
Ink circulation is another feature to look for. As mentioned, white is the difficult color. Because white ink needs to be opaque, it is typically very thick which presents issues with clogging the print heads fairly quickly. To compensate for this, most printers include some type of circulation (agitation) system which is an important feature to have. Some printers circulate only the white and/or clear inks while others circulate (or agitate) all the ink colors. Regardless, it is strongly recommended that you print something daily with your printer if possible as long idle periods can cause major headaches.
Another ink-related specification to know about is the ink droplet size. Just as inks are usually specific to the manufacturer, so are the print heads and rails (the bars that the heads and UV light run on). Some companies manufacture their own print heads and rails, while many others use assemblies from other inkjet manufacturers, such as Ricoh and Epson. Depending on the print head, the printer may be capable of varying the size of the ink dot from as little as a couple of picoliters to as much as 30 picoliters. By varying the dot size, the printers are better able to manipulate ink density, which results in sharper images and colors that smoothly change from one shade to another. Variable-dot printing is controlled by firmware from within the printer and its software.
We’ve covered the very basic features of UV-LED printers in this buyer’s guide. However, these printers have plenty of additional features not necessarily listed here. There are tons of bells and whistles on these printers. Some are super important to some users and not to others, while other options are absolutely vital to only a few. Figuring out which features are important to you and which are not is no easy task, but a wise buyer is going to do some serious research before plunking down a pile of cash.
Another consideration to point out is that these printers can be somewhat “finicky,” a fact reported by numerous first-time buyers. According to one UV printer distributor, it is important to understand that these printers require considerably more attention and maintenance than sublimation printers or laser engravers. They are highly technical and require an operator who can deal with their idiosyncrasies. Just bringing in a UV printer and letting anyone and everyone operate it is a disaster waiting to happen. Likewise, these printers require a good deal of ongoing maintenance, so it is imperative that you work with a supplier that you can contact for help when things don’t go the way they should—another important consideration when making a purchasing decision.
Is it For You?
As mentioned at the beginning of this article, UV printing is an area of the industry that is experiencing growth, both in terms of the technology and the marketplace. The flexibility and capabilities of these printers coupled with increasing user-friendliness are encouraging users to seek out new applications and an increasing range of products.
Explains GCC’s Keira Lee, “The GCC UV flatbed printer has the flexibility to handle not only different kinds of materials but also different shapes of objects, including flexible material, rigid material, up to 30 cm thick objects, cylindrical items and even roll media.”
Adds Roland DGA’s Daniel Valade, “We see increasing consumer demand for customization and personalization driving this market and further innovations in UV flatbed printing equipment for years to come. Advancements are enabling users to print on an ever-widening array of substrates and objects. They are also making this process easier and more cost-effective than ever before. We see the types of companies using this technology expanding and diversifying in the future. We expect this trend to continue, and demand for UV flatbed printers to continue growing, over the next several years.”
Whether or not UV printing is something that will work for your business is, of course, up to you. Either way, it’s a great idea to explore this new technology—it could be a great asset to your business.