Demystifying Functional Printing

There is an undeniable mystique about functional printing. Some people believe functional printing only means adding printed electronics or color-changing properties to a printed item.

But the definition is expanding to encompass changes in how products are designed, manufactured, packaged, sold, and shipped. For example, functional printing can describe the creation of in-mold electronics or the use of direct-to-object (DTO), direct-to-shape (DTS), and 3D printers to manufacture or decorate objects that exceed the performance requirements of most advertising graphics, simple packaging, publications, or changeable décor.

Advances in functional printing are enabling improvements in the design and performance of packaging, building materials, automotive and aircraft interiors, medical devices, apparel, and military equipment.

It’s hard to fully grasp how much functional printing work is already being done. Some screen-printing companies have been doing different types of functional printing for years. But these companies typically maintain a low profile, because their customers ask them not to talk about how their products are manufactured or what types of new products they are developing.

So even if experts at SGIA’s 2019 FP3 Conference on Functional Printing, Process, and Products couldn’t publicly discuss their most exciting projects, they did confirm that functional printing is gaining traction. Rapid advances in industrial inkjet printing systems will make it easier for even more companies to benefit.

Markets for Industrial Inkjet Decoration Are Growing

Printing industry veteran/consultant/inkjet evangelist Craig Reid of CTR Resources says interest in functional printing is growing for two reasons: (1) it’s become technologically feasible to inkjet print a greater variety of shapes and objects at higher rates of speeds; and (2) it is more economically feasible because ink costs are going down and business models are changing to meet customer expectations for more customized products.

For example, Reid estimates that about 50% of laminate wood flooring sold in the U.S. is digitally printed. Specialized inkjet printers and finishing equipment are used to print high-res scans of different types of wood onto papers that are laminated with a clear film to a wood substrate to provide a specific appearance and the durability wood flooring requires.

This shift is happening partly because business models are changing. Manufacturers of laminated wood flooring no longer must order bulk quantities of a few selected designs from China and store them in warehouses.

Today, consumers can visit home improvement retailers and choose from dozens of different wood floor designs for an upcoming remodeling project. Whatever quantity of flooring is needed for the job is printed and shipped directly to the consumers’ homes. The manufacturer saves on upfront production and inventory costs, and reduces the risk of being stuck with unsold inventory.

Plus, says Reid, “Manufacturers can shift from one design to another by pressing a button instead of making new printing plates and changing them out.”

As industrial printing technology has become more robust and reliable, the cost of inks used to digitally print wood laminates has dropped from about $700 per liter in 2010 to less than $150 per liter today, according to Craig Greenwood of Tiger Coatings.

Tiger Coatings is a leading manufacturer of powder coatings for agricultural and construction equipment, cars, furniture, architecture, engineered wood, steel structures, beverage can interiors, and appliances. They have adapted their knowledge of durable coatings to the development of TIGITAL Inks. Tiger Coatings makes jettable primers, UV-curable inks, water-based inks, special solvent inks, and jettable varnishes that industrial inkjet system integrators can use to develop equipment for specific applications.

Unlike graphic inks that are designed to work on a range of substrates, inks for functional printing are manufactured to be part of a system that delivers the performance characteristics required for a manufactured or decorated part.

“There’s a harmonic relationship between the substrate, primer, ink, and topcoat,” Greenwood explains. “Everything has to work together to meet the end user’s expectations for the product.” In addition to making sure that the combination of materials will provide the desired level of resistance to UV-light, chemicals, water, and abrasion, the materials must also meet the product manufacturer’s productivity and budget requirements.

Companies that make building materials such as flooring, outdoor decking, ceramic tile, architectural glass, and aluminum siding need functional performance that goes well beyond that of most inkjet graphics.

Dizal, a building-materials company in Quebec, uses an industrial inkjet printer from Cefla Finishing Group to decorate heavy-duty aluminum siding.

For example, the Quebec-based start-up company Dizal offers a 25-year warranty on low-maintenance, heavy-duty aluminum siding that is digitally printed and coated to look like wood. Architects can select from dozens of types of textures and shades, including Peruvian Walnut Charcoal, White Oak Maple, Light Gray Barn Wood, and Cumaru Variegated Dark.

At a 2019 architecture trade show, Dizal showcased outdoor decking material that can be digitally decorated to look like an extension of interior wood floors.

Other areas in which industrial inkjet decoration is becoming more attractive are the beverage and beauty product industries. Companies such as KBA-Kammann, Hinterkopf, Martinenghi, Velox, and other firms have developed industrial-speed inkjet systems that can print directly on bottles, cans, tubes, and other cylindrical items.

For example, the Velox IDS 250 can print up to 250 containers per minute at high quality, with 15 simultaneous colors and embellishments, including photorealistic images, tactile embossing, no seam, and tube-to-cap printing.

Some beverage and beauty product marketers believe that designs printed directly on wine bottles or perfume bottles have a higher perceived value than an item with a paper label, says Reid: “They want their bottles to have luxury appeal if possible.”

Reid formed the consulting firm CTR Resources to help educate potential users of industrial inkjet systems, including brands that are interested in digitally decorated containers and packaging.

Manufacturers hire Reid to help them find the most cost-effective way to produce a specific application. If the right ink chemistries, printhead, inkjet drive electronics, ink delivery system, production software, pre-treatments, and post-print exist, Reid helps connect manufacturers with system integrators who can help pull all the pieces together.

Sometimes, Reid directs clients to print-service providers that have the skills and equipment needed to develop prototypes or test the viability of their ideas for short-run production.

At the PRINTING United Show, Craig Reid will present an overview of current inkjet technology available for industrial DTO and DTS printing.

Markets for In-Mold Electronics Are Developing

In-mold electronics (IME) is a process for creating 3D-shaped objects that include embedded circuitry for sensors, heaters, wireless communications, energy storage, or other functions. The circuitry is screen-printed with conductive inks onto plastic sheets. These sheets are then thermoformed or injection molded to form a functioning part. These “smart plastics” are much lighter and smaller than traditional electrical components, mechanical switches, and wires encased in a box.

In theory, IME can provide a lower-cost and more reliable alternative to adhesive-bonded printed switch technologies. IME can also enable products to be manufactured with fewer parts and steps. But IME also represents a disruption to traditional manufacturing approaches.

A lot of research and experimentation is underway because product designers regard in-mold electronics as a means of increasing design aesthetics and functionality of automotive interiors, medical equipment, appliances, industrial control panels, wearables, and other products.

“The market is still emerging,” explains Erika Rebrosova, electronic materials technology manager for Sun Chemicals. One challenge suppliers are tackling is the development of conductive inks and flexible materials that can withstand the elongation that occurs during thermoforming and the heat and pressure of injection molding processes. Conductive inks shouldn’t crack when thermoformed or wash away when injection molded with high-temperature, high-pressure molten resins.

At FP3, Rebrosova discussed Sun Chemical’s second-generation of inks for in-mold electronics and emphasized that Sun Chemical can tailor electronic inks to withstand the specific conditions of different manufacturing steps in the IME process.

Velox Ltd. develops and manufactures industrial-grade direct-to shape solutions for the rigid container industry. These samples are examples of digitally decorated tubes and aerosol containers.

The IDTechEx technology-research firm estimates that the market for IME devices will exceed $1.1 billion by 2029. A large portion will come from automotive companies who have established their own teams of printers, molders, and assemblers to design and test prototype parts for control panels, consoles, and other automotive body parts.

“While there is high interest in IME within the automotive sector, the development cycle is long and the reliability of the technology must be thoroughly validated before IME parts are put into cars,” Rebrosova explains. Many car manufacturers are now evaluating materials and developing IME manufacturing processes so they can incorporate in-mold electronics when the market is ready.

Rebrosova encourages screen-printing companies that have experience in in-mold decorating or printed electronic designs (such as printed switches and interconnects for backlighting) to seek clients that have shorter product-development times and less demanding performance requirements than auto manufacturers. For example, makers of industrial controls and coffee makers and other small kitchen appliances are interested in the possibilities of IME.

Screen Printing Firms Are Evolving

ECI Screen Print, Inc. is a fast-growing, privately held company in Watertown, Conn. ECI provides custom screen-printed graphic overlays, membrane switches, and printed electronics to clients working in the fields of manufacturing, medicine, avionics, consumer goods, and food equipment.

Screen printers got into functional printing early, explains ECI Screen Print owner Ed Cook, because with screen printing, it’s possible to print on almost any substance, onto any flat surface imaginable, and decorate functional and durable products used throughout the world.

“I printed my first membrane switch in 1986,” Cook recalls. Today, ECI Screen Print works with entrepreneurs from a variety of industries as well as other printing companies who want to find ways to incorporate electronic components into a wide range of manufactured products, packaging, signage, apparel, and fabrics.

“We’re working on things now that five years ago you never would have imagined that people would have asked for,” Cook says.

Functional printing is different than printing advertising graphics for a short-term campaign, because “when we produce a part for a company, that part number has a long life expectancy,” says Cook. Once ECI Screen Print finds the right combination of materials to produce a working part, they are typically expected to be in production making those parts for the next decade or more. Working with these types of customers, ECI Screen Print is more like a contract manufacturer than a printing company.

“The business must have a lot of controls in place,” Cook notes. “Consistency is extremely important. Colors can’t shift job to job, year after year, and your materials must stay consistent as well each time you make a new production run of parts.”

ECI Screen Print is equipped with inkjet printing technologies and will recommend a combination of screen-printing and inkjet processes when it’s the most efficient way to create certain products. But Cook says, “We’re still running screen printing presses all day long.”

He points out that ink chemistries, materials, and processes have advanced considerably over the past 20 years.

Customer education is an everyday process, Cook says, because the types of companies who work with functional printing experts come from many different industries and backgrounds. For example, doctors may have a great idea for a medical device, but may not know the first thing about how to manufacture it.

Sometimes designers know that digital inkjet printing can print on almost anything, but need to understand that digital technologies might not have the durability required to execute a specific product life expectancy or environmental requirement for a particular product.

Unique and creative solutions are where ECI’s expertise can help customers with design issues. At first glance, a product ECI prints for a client may not look extraordinary. But ECI works with the client to find the right combination of inks, coatings, and techniques that enable the printed product to survive in many difficult situations. One customer submerged their product six feet underwater 24 hours a day.

How More PSPs Can Benefit

While major manufacturers seek customized industrial inkjet printing systems that can be used internally for higher volume production, many smaller manufacturers and start-up firms will seek job shops that can help them prototype products or experiment with ideas for DTO, DTS, or printed electronics.

Cook says functional printing requires more of a manufacturing mindset than just printing in general. It helps to understand engineering, manufacturing, design, and “lean” production methods, as well as various print methods, inks, and materials.

You may also work with a broad range of customers with various levels of knowledge. So, not all of their ideas will be feasible. In some cases, your shop may invest a lot of time and research for an order that never exceeds the prototype phase.

ECI Screen Print offers on-the-job training to visual artists who grew up with digital technologies and want stable jobs that aren’t routine. According to Cook, “They don’t understand much about printing when they start, but when we show them what’s possible with printing, they’re very quick to develop a passion for the craft!”

He believes many new employees are attracted to functional printing because it requires a high degree of creativity: “Many times, we are doing projects and trials that have never been done before. New projects are happening all the time.”