Often Imitated, Never Duplicated
In today’s competitive marketplace, brand owners are looking for an edge—any edge that will catch a consumer’s eye or provide them with a certain tactile feel as a consumer selects a package from a shelf. Last month, packagePRINTING explored foil decorating as one effect brand owners employ to attract consumers. While a viable way to enhance the eye appeal of the package, there are other effects package printers can employ to ensure that once a customer’s eye is turned toward a product, he or she will hold on to the product once they select it from the shelf.
Screen printing offers package printers an economical, efficient process, the results of which cannot be duplicated using any other process, according to Rich Wayne, system design engineer with Gallus, Inc. “The screen effect brings an extra dimension of feel to an already high-quality package,” adds Terry Trexler, North American Screeny product manager, also with Gallus, Inc.
The bottom line is that anywhere heavy lay down of ink is required, screen printing will be the process of choice because of its ability to provide the tactile feel brand owners are beginning to demand more, and its ability to provide high opacity.
Emerging applications
Potential uses for screen printing abound today. Jeff Feltz, production manager, Mark Andy, notes one emerging application is screen printing of conductive inks, which he expects will open up new market opportunities for converters. He adds, “Electro illuminesence, thermal color shifting, and Braille are three effects that are effectively printed using screen technology.” Instances where inks must become “functional” are also suitable for screen.
“[One new application is] electronics and industrial printing applications where the heavy screen ink deposits are required for the inks to function. We see applications like RFID antennae and circuits for solar panels, that can be printed using rotary screen,” according to John Costenoble, sales manager, graphic print systems, Stork Prints America, Inc.
One example of a specific effect afforded by screen printing, explains Denny McGee, president of MPS America, LLC, is glow-in-the-dark properties for shrink sleeve labels. He also lists Braille as a potential application. Screen’s “ability to deliver sufficient Braille qualities allows for overprinting of Braille using a clear varnish, which allows copy under the Braille to be readable,” he says.
Steve Leibin, sales manager for Matik North America, adds, “Screen printing Braille is more permanent and can provide more depth to the Braille. Die-punched Braille can get compressed in packing and handling, and the surface will not be as raised as [with] screen printing.”
Costenoble relates that other tactile symbols for warnings also can be printed using screen. “We see a lot of tactile universal warning symbols being screen printed on hazardous products,” he says. “These tactile symbols are printed to warn blind people that they are handling a hazardous product.” He adds that high and variable height deposits of UV varnishes bring a tactile feel to consumer products. “The 3D print brings the consumer’s sense of touch into the product purchase and use,” he explains.
Leibin adds that screen printing can produce especially brilliant designs using fluorescent and metallic colors, fade-resistant pastels, and opaque whites and blacks. “The process applies an extremely uniform coating of ink without ghosting or streaks.
Screen also is an effective way to achieve tactile effects like ergonomic grips, says Dejan Trajkovic, Gallus system design engineer. “We see this trend gaining popularity in blow mold packaging with sport drink PET bottles. Packaging such as aluminum canisters can only be applied with ergonomic grips during the labeling process,” he states.
Screen vs. embossing
There are a variety of factors that impact the decision to go with screen printing effects or embossing effects. These include costs, length of the run, color requirements, customer needs, running speeds, and the type of material being converted.
“Price is key,” Trexler adds. “This is especially evident in shorter runs compared to the cost of purchasing and waiting for delivery of a die or mag plate.”
Feltz concurs. “When faced with short job runs, screen printing provides a much more economical solution than embossing. Larger runs will help justify the additional cost associated with embossing tooling,” he says.
Speed is also an issue. “Running speeds would be a consideration,” says McGee. “Embossing would typically run at a higher production speed than what rotary screen ink application speeds are, so longer runs could favor metal or photopolymer plate embossing.” Feltz adds that screen printing has many advantages, but a major disadvantage is speed. “An average screen process will be run at approximately 200 fpm. The limitation is the ability of the ink to flow and wet out at higher speeds,” he says.
Timing for getting on press is also critical. “Our customers can put a screen on press to get the embossing effect in [fewer] than 30 minutes,” says Wayne. “That is a very attractive benefit when you consider the time it takes to order a die.”
Some substrates just aren’t good for embossing, so screen is a way to get similar effects. “The type of material being converted also dictates screen or embossing, especially if the material would not take and keep the embossed feel through the [full] life cycle,” says McGee.
In the case of Braille, Wayne says screen can be applied successfully over a wider range of substrates. “Material substrates with elasticity characteristics tend to lose the embossing [over time] when rolled, [or] rewound,” he says.
Screen is not a hard-and-fast replacement for embossing. Like every print effect, it’s another weapon in your arsenal. “I prefer to say that screen printed emboss gives the converter another tool to use when creating added value [for] the package or label,” says Costenoble.
Creativity knows no bounds
According to Costenoble, “The creative printer who has screen printing capabilities can bring unique, high value-added, printed effect solutions to its customer base.” Trexler adds that with a large variety of screen meshes and thicknesses, converters can accomplish virtually any desired outcome, and some effects of which they may not even be aware. He recommends, however, “speaking to your screen supplier for practical advice on the benefits and cost effectiveness of rotary screen,” before making a decision.
The ability to combine screen printing with other processes also lends to its effectiveness. “Screen combines nicely with other printing processes, and thus, a printer can maximize the graphic performance effects for a label to the delight of [the] customer,” says McGee. Yet, there are clear-cut instances when screen should be used.
“Screen printing should be employed when heavy ink deposits combined with a high-resolution print can bring added value or functionality to a package or label,” says Costenoble.
Wayne sums up, “It’s fast and efficient, and provides a process that cannot be duplicated any other way.” pP