by Jeff Peterson, Plastics Decorating
The pad printing process began in Switzerland when a small gelatin pad was used to transfer ink onto a watch. The first industrial machines were invented in the 1960s, and that was the start of a full-fledged decorating industry that took off and has never looked back.
The essentials of the pad printing process have basically stayed the same over the last century, but the technology has obviously seen many changes over the years. Innovations with pads and clichés, as well as completely automated pad printing systems, have kept pad printing on top as one of the most popular choices for plastics part decorating.
New applications offer opportunities
Although new decorating technologies are replacing pad printing for certain types of applications, there are additional opportunities for the process. “We have seen pad printing replacing industrial labels, especially when short-run, quick-change labels are required,” stated Inkcups Now President Ben Adner. “Customers are seeing that applying the printed information directly to the product saves both time and money. This is especially cost-effective for one- or two-color applications.”
Julian Joffe, CEO of Pad Print Machinery of Vermont, said pad printing continues to be the “method of choice” whenever difficult shapes must be decorated. “With the flexibility of pad printing, product designers can focus on part function and aesthetics,” stated Joffe. He also sees opportunity for growth in anti-counterfeiting applications. “Pad printing and other wet ink systems are more forgiving versus inkjet systems for these types of applications,” explained Joffe. With the continued increase in counterfeit parts and products, there will be many opportunities to use specialized pad printing inks for security applications.
Another trend that is sparking growth in the United States is the on-shoring of pad printing for existing applications. “Many US manufacturers that had off-shored now are re-tooling American facilities with updated technologies,” explained Innovative Marking Systems President Trent Pepicelli. “More plastic processors are taking the time to learn how to do industrial pad printing correctly and investing in automated systems.”
Inkjet challenges, but doesn’t triumph
Inkjet decoration is one of the fastest growing technologies for printing and decorating plastics parts. There is little argument that it is and will continue to be an excellent choice for certain applications. “Whenever variable data is required, or short runs with fast changeover on relatively flat parts are needed, digital is probably the preferred technology,” said Joffe. As bar coding and other traceability technologies advance, inkjet will grow and replace other print technologies, he explained, because it is easier to date code and serialize with inkjet than with most other technologies.
Another advantage that inkjet holds over pad printing is that it is a faster and more economical way to apply multi-color (4-color) images to plastic part applications in many situations. “In terms of machine sales, we are seeing that multi-color printing is going to inkjet; but for one or two-color printing, the growth continues for pad printing,” stated Adner. This shift to inkjet for multi-color applications is due primarily to the decreased set-up time. Also, the consumable costs to perform multi-color pad printing are relatively high. Adner explained that one- and two-color pad printing still is the best way to perform high-quality work on a variety of substrates. “Two-color pad printing is fast, its still easy to set up and register, and you don’t need experienced operators,” Adner said.
Automation and training gain speed
Investing in the latest technologies seems to be the biggest trend with pad printing equipment. “Companies that have a long-range vision, the ones that are on-shoring applications and updating their technologies, are moving toward flexible, programmable pad printing equipment,” stated Pepicelli. “These companies have realized that spending more at the front end of a project, adequately training operators and retaining skilled technicians are significantly less expensive than the alternative.” Pepicelli went on to say that companies that do not invest and are “change resistant” are in the process of dying or already are dead.
Joffe agreed that trends are moving toward more automated equipment. “We continue to see the addition of automation such as loading, unloading, part manipulation during the print cycle, quick-change cliché set-ups and the use of programmable robots and servo-motors for part handling and tooling movement,” explained Joffe.
Direct-to-plate technology affects clichés
The trend toward laser plate making continues, giving customers the flexibility to create their own clichés in-house. This process eliminates the use of film and uses lasers to directly image the plate. “We expect that laser plate making will continue to evolve,” Adner said. “For a great majority of applications, a laser-made plate is of equal or better quality than one made with the traditional photo-sensitive emulsion process.” Adner believes that lasers will continue to become more affordable over the next few years, becoming a feasible option for most pad printing operations. “Lasers provide standardized depth every single time. They’re easy to use, and there are no worries about film, temperature of alcohol or line screen condition,” he continued.
Pepicelli added that 10mm thick steel clichés are becoming extinct. He explained, “In most applications, high-quality photopolymer and laser cliché media are being used where amortizing the cost of higher quality steel clichés isn’t cost effective.”
“Many firms are moving away from thick steel,” agreed Joffe. “Although clichés have not changed much in the last few years, the method of manufacturing has, and the industry will continue to move in the direction of direct-to-plate laser technology as the cost comes down.”
UV inks still on the horizon
One of the major trends with pad printing inks is the high level of regulations and paperwork as a result of concerns over hazardous materials. “While it has become a part of doing business, the reality is that pad printing inks have for a long time been formulated as non-toxic due to European regulations that have been in place for several years,” stated Pepicelli.
Although there is a lot of discussion about UV pad printing inks, there has not been a huge movement towards using UV inks due to the costs involved with the LED curing units that must accompany the process. “I have not seen a major increase in the use of UV inks yet,” said Adner. “I know the golf ball industry has adopted it, but for the average promotional products company or custom decorator, it’s not a practical option at this point.” The real benefit of using UV inks is their ability to dry quickly. This can be an advantage for many applications and will help with the growth of UV inks as the cost of pad printing machines with UV drying capabilities decreases in the future.
With new decorating/printing technologies available today and on the horizon, will pad printing continue to find its niche in the decorating marketplace? Only time will tell, but all indications are pad printing isn’t going anywhere. The uniqueness and flexibility of the process is here to stay.
“As long as there are designers out there keeping an eye on ergonomics and aesthetics, there always will be complex shapes that lend themselves best to pad printing,” stated Joffe. “Pad printing is on the planet to stay for many years to come.”
Plastics Decorating would like to thank Inkcups Now, Pad Print Machinery of Vermont and Innovative Marking System for their contributions to this article.