Embossing Puts on the Pressure
- Published: November 01, 2001, By Teresa Koltzenburg, Senior Editor
There's something intriguing about an embossed image. From the 3D-embossed book covers you see while browsing in the airport newsstand to the embossed, foil-stamped wine bottle labels at the market, embossed images not only catch the eye, they make you want to reach out and touch them.
At least, that's been my experience. I've always been compelled to run my fingers over embossed images (text, too), wherever I've encountered them.
Considering the longevity and the proliferation of the embossing technique, it seems many are drawn to embossed images, if only just for a feel.
Historically, a time-intensive, value-added type process, these days embossing competes against increasingly more sophisticated graphics. But, says John A. Pasquale III, senior VP at New Era Converting Machinery Inc., Paterson, NJ, equipment advances keep embossing competitive. “By using (at times) larger embossing rolls as well as very appropriate, concentrated heat just prior to the embossing roll set, we've been able to speed up the process.”
Pasquale adds the “value-added” part of embossing's appeal is changing as well. “I think many people want to make embossing a distinct process, not an add-on. Years ago, they said, ‘I may as well emboss since I'm going to be using two rolls to laminate.’ Well, today, embossing has become a major part of the process, and we often have to say, ‘If we're going to emboss a product, we have to really concentrate on that and fit everything else to it.’”
Complicated Simplicity
“You put tooling in, you put in a product, and you smash the [heck] out of it,” describes Dave Salsgiver, president of Contech, Goddard, KS. The actual embossing process sounds simple enough. But embossing (aside from the tooling engraving, which is an even more intricate process), Salsgiver explains, poses definite challenges. “One is just in material change. If you get a lot of change in your material, it can affect your emboss. And, if there's a color change, the density of the color and that material will change the emboss. Then, the problem you have is trying to match the first few hundred green to the next couple hundred that are red.”
Other problems, says Pasquale, can manifest with incorrect roll diameter. “[It's important to] determine the appropriate embossing-roll diameter to that of a pressured-roll. If you're not careful, you affect the pattern's sharpness or definition.”
Pasquale says improper temperature control also factors into the emboss quality. “Years ago, many would run very low-temperature cooling material, which causes condensation on the embossing-roll surface and can water-stain the product. Today, we find using a greater flow of cooling material at a higher temperature, and generating heat transfer by mass flow rather than by temperature differential, helps.”
Bobst's Peter Witzig, senior technical product manager, folding carton equipment, Roseland, NJ, says having personnel that possess a thorough understanding of the process is important in embossing production. “Many underestimate the pressure required; then they find themselves at the machine's limit very quickly.” Research, testing, and well-trained operators can reduce such issues, he suggests.
Of course, the engraved tooling needed for embossing affects the process drastically; that topic warrants a column unto itself. However, Witzig did touch on some advances in this area. “In the past, embossing plates were hand-engraved. Today, they're engraved by computerized machines. This computerization makes them very accurate and quick to re-order. Ultimately, the set up time is reduced.”
Wall paper, business cards, and labels: For years, embossing has bestowed its eye-catching sophistication to these products. Now, with engraving computerization, faster throughput, and precise temperature regulation, it looks as if embossing will maintain — and even grow — its graphic intrigue for years to come.
