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Inline coating on 40-inch sheetfed presses

May 1, 2002 12:00 AM


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Printers today rarely purchase 40-inch sheetfed presses without coaters. They've learned the extra investment can yield big payoffs in terms of production efficiency, output quality and customer satisfaction. To get a close-up look at the role of coating systems in printers' workflows and sales strategies, AMERICAN PRINTER spoke with four printers about their fullsize presses, coating systems and the coated applications they produce.

Ed Sadler is the plant manager of Quality Graphics Center (Roselle, NJ), a 15,000-sq.-ft. shop that employs 50 people. The printer specializes in high-end applications, such as annual reports and advertising materials, for clients in the cosmetic, advertising, pharmaceutical and liquor industries. Quality Graphics Center does UV and aqueous coating on its two 40-inch, six-color Mitsubishi (Lincolnshire, IL) presses, both of which are outfitted with tower coaters. The first press, which has a Mitsubishi coater, was acquired six years ago to replace an aging press. The second press was purchased three years ago to accommodate the company's increasing workload. Quality Graphics Center opted to retrofit the second press with a Harris & Bruno (Roseville, CA) anilox coating system. “The Harris & Bruno system has faster makeready and wash-up, and it doesn't spit,” Sadler says.

Rand Graphics has two facilities located just two miles from one another in Wichita, KS. One plant houses the company's Litho division; the Screen division operates out of the other facility. Rand Graphics has 190 employees and specializes in point-of-purchase (POP) applications, including brochures, catalogs, books, postcards, door hangers and static-cling work. It has two Heidelberg (Kennesaw, GA) Speedmaster CD 102 presses equipped with Heidelberg coaters: The five-color Speedmaster was acquired two years ago; the eight-color Speedmaster was installed in November 2001. “We wanted to be able to coat inline, print up to eight colors, and apply an aqueous or UV coat in the same pass,” says president Randy Vautravers. “The configurations allow us to do everything we want to.”

Source Inc. (St. Paul, MN) doesn't have a specific market niche. “We do it all — whatever the customer asks,” says plant manager Ron Cole. The general-commercial shop has 95 employees and 50,000 sq. ft. of manufacturing space. Its two six-color Komori (Rolling Meadows, IL) Lithrone 40 presses are equipped with Komori inline aqueous coaters. Source also operates two 28-inch Komori presses, one of which features an inline Grafix North America (Burr Ridge, IL) CoCure system.

Universal Lithographers (Sheboygan, WI) is a strictly 40-inch-sheetfed printer that earns annual revenues of $6 million. According to executive vice president Jerry Keller, the company realized in the early 1990s that the printing industry was gravitating toward coating, so it installed a press with an aqueous coater in 1993. That press was later replaced by a six-color MAN Roland (Westmont, IL) 700 press with a MAN Roland aqueous coater. A few years after that, Universal Lithographers installed an identical six-color 700 with coater to assist in the production of high-end pieces such as art reproductions, annual reports, catalogs and corporate brochures. Universal Lithographers also offers full digital prepress capabilities and bindery services.

How does coating benefit your operations?

SADLER: Coating has enabled us to be more efficient and more productive with the printing process as a whole. With UV coating, sheets come out of the delivery dry, so you don't have to worry about offsetting or spray powder. You can turn the job over right away and take it straight to the bindery to fold, scorYe and cut it. With aqueous-coated jobs, you have to let them sit before you can cut, because the pressure of the cutter will block the job. But even with aqueous coating, you finish jobs faster, because you don't have to worry about marking, scratching, offsetting and all the normal printing problems.

KELLER: With our aqueous coaters, if we're doing a box wrap or a book cover, we can use a high rub-resistance, which provides a more utilitarian purpose to the sheet. Also, coating doesn't turn yellow like varnishes do — it stays clear longer. And the ability to run less anti-offset spray powder is a big plus.

COLE: The biggest advantage is quick turnaround — being able to turn jobs, seal the sheet.

VAUTRAVERS: We were able to attract new customers. In some cases, we took jobs from the Screen division that we used to silkscreen, and we're doing them in the Litho division now. Because of the coater, we're able to get more work overall.

Some industry pundits suggest that printers form a coating team that includes their press manufacturer, coating-system manufacturer, and ink and coating supplier(s). What do you think?

SADLER: We've worked hand in hand with Sun Chemical (Fort Lee, NJ) to develop its hybrid inks. There are a lot of things they can't do in a lab that can be done on a printing press. A lot of printers don't like to experiment — I'm open to experimenting if the vendor is willing to really work with us. If you work with your vendors, instead of beating up on them, I think you get more out of them. And it's helped us — I would say that we probably run hybrid inks faster and better on a sheetfed press than anywhere else in the country.

COLE: We don't have a supplier team — there isn't any interfacing between INX (West Chicago, IL), our ink and coating supplier, and Komori, our press manufacturer. Wherever the problem is, that's where we address it. At one time, we had problems with our water-based coating, so INX took the coating and modified it slightly to get a better rub. I do rely on vendors to step in and help, even if it isn't their problem.

What factors motivated your buying decision?

COLE: Our presses with coaters were purchased because our business was growing — they weren't brought in specifically for coating purposes. But now I can't imagine that we'd put a press on our floor without a coater, because most of our work is coated; it's a convenience for customers. To add some versatility to our service offerings, we installed a halfsize Komori press with CoCure inline hybrid coating.

VAUTRAVERS: The POP market requires printing on many different types of materials. We opted to go with the Heidelberg press and hybrid inks because our plan is to print on substrates up to 40 pt., and we don't want to be concerned with offset and the related problems. When the substrate comes out of the press, it's dry to the touch. That's the main advantage.

KELLER: There were three main considerations for purchasing a press with a coater: The first was for graphic enhancement. Because the majority of our work is commercial, we wanted to spot-coat and offer overall enhancement. The second consideration was scheduling: The coater would allow us to handle sheets faster. The third consideration was the type of coater purchased. Our MAN Roland coater can be a reverse-nip roll coater, or a chamber doctor-blade coater that allows us to switch anilox cylinders that have different cell depths. That allows us to do more than just clear coating — we can put on metallics for a bronzing effect, or pearlescent coatings that have suspended solids.

How have you handled a unique or challenging coating application?

KELLER: Printing on lenticular lens — a ribbed plastic lens that shows motion when flipped back and forth — is really difficult. We use coating on the first pass of plastic to prevent scratching in delivery. It's a costly substrate and the prepress is costly, so we take every precaution as we're printing. Since we don't have a UV press, we find that putting aqueous, opaque white coating on the sheet serves as a barrier coat, protecting it as it comes into delivery.

SADLER: We applied coating to 60-lb. coated stock — we were doing labels for a client — which is not very easy. Foil, plastic and vinyl are difficult to coat. We coat just about everything we print, other than offset sheet. A lot of designers choose satin or velvet sheets, because they like the look or feel of them, but they're hard sheets to run — in the bindery, they have the tendency to carbonize. If you don't protect them, they will scuff in the bindery or on press. Even if you use super-hard dry inks, they still tend to scuff. The only way to get around scuffing is to add coating.

COLE: The spot coatings that we've been applying with the CoCure UV on our 28-inch press have been a challenge — perfecting the process, getting it applied to the sheet properly. What's even more difficult is doing spot coating regularly and keeping employees trained on it. In the beginning, there was not much spot-coating work, but now that we're doing it more, they're better trained on it.

How can coating and/or coating-related technologies improve?

SADLER: I'd like to see the cost of hybrid inks and UV coating go down — that would help printers that are hesitant to go into hybrid/UV, where the cost is considerably higher. I think the cost is high because not everyone is doing it, and ink manufacturers aren't producing quantities that are large enough to get the cost down. Our clients do know it's a premium product, and some are willing to pay for it, but some would rather not pay extra.

VAUTRAVERS: There was definitely a learning curve with the Heidelberg CD press that we installed last fall — we run UV on a 78-inch press, and that experience helped somewhat. But there's a lot to it: It was a difficult installation, and it requires more maintenance than other presses. But it has done well — it has done everything Heidelberg said it would.

KELLER: There are so many variables with ink, paper, press and image — and there are always going to be variables. It's always going to be a moving target. There isn't anything specific that we'd like to see improved — the only thing we do insist on from our vendors is product consistency, and they've done a very good job. We've been in situations where the coating viscosity is off, or we may have to thin it, but that doesn't happen very often.

COLE: The quality and consistency of the coating is important to me — it should go right in the press without our employees having to alter it. I've had problems like that before, and those vendors aren't here anymore.

What advice do you have for printers who are currently evaluating new press/coating system options?

VAUTRAVERS: Take a good, hard look at hybrid technologies, and make sure you have enough work to support it. It was definitely worth the investment for us.

KELLER: You have to take a careful look at the drying systems, to ensure you're getting one that will handle the amount of coating you want, depending on the job. If you're doing packaging and plan to use a heavy coating, you need a more powerful evacuation and drying system. Consider what you're planning to use the coater for, and try to envision what you'd like to use it for in the future — then communicate that to the drying-equipment supplier.

SADLER: Spend the extra money and buy an anilox-roll coater.

COLE: The coater and the extra press automation are worth the extra money. A lot of people don't realize how important that is. And, training to use the automation is also important.

Avoiding coating headaches

Spitting and foaming. Glossback. Unreliable viscosity. Coating may have production and competitive advantages, but like anything else in the pressroom, it doesn't always run smoothly and can cause its own share of headaches. “I was pulling my hair out,” admits Ed Sadler, plant manager of Quality Graphics Center (Roselle, NJ), whose rubber-roller coater started spitting when the press reached speeds of 15,000 sph and above. Sadler wanted to run at or above 16,000 sph, which is the rated speed of Quality Graphics Center's six-color Mitsubishi press.

“There was no way to prevent the spitting — centrifugal force caused the coating to move out to the ends. The only thing to do was put some sort of stopper on the end of the roll to help contain it,” Sadler says. The company determined that an anilox-roll coater could handle speeds above 16,000 sph without spitting, because of its contained doctor-blade design. “We're able to run at coated speeds of up to 17,000 sph, which is fast for a sheetfed press,” notes Sadler.

Glossback (or dryback), a loss of the initial high gloss off the press, is another coating dilemma that printers face. Randy Vautravers, president of Rand Graphics, a Wichita, KS-based printer that specializes in point-of-purchase (POP) materials, says that using hybrid inks has eliminated dryback issues in his pressroom. “When the ink is dry after printing, you can cure within any station with those colors. Then, when you put coating down on a completely dry sheet, you don't get dryback — you get much more gloss,” he says.

The choice of coating material is another factor that can work for or against a printer. Source Inc. (St. Paul, MN) has eliminated some of the early problems experienced in coating applications simply by finding the right coating product.

“We run a good, high-gloss, all-purpose coating — it's for two-sided printing, and dries and flushes off quickly. We don't have sticking, and we're protecting the ink,” says plant manager Ron Cole, who notes that applying coating to jobs also helps avoid fingerprinting and scratching. “Coating isn't just for the pressroom — you have to look at how it will play out in the bindery, too.”

Proper storage of coating and ink material can also prevent on-press problems. “We have a climate-controlled pressroom, and we're careful about storing the aqueous coating material,” says Jerry Keller, executive vice president of Universal Lithographers (Sheboygan, WI), a $6 million sheetfed printer. “In wintertime, if coating sits on a truck overnight, it could freeze. We let the coating sit and acclimate to warm indoor temperatures before we use it, and we check all coatings to make sure the viscosity is correct for the unit.”

Coating system choices: standard or anilox?

When selecting a coating system, printers must decide if the coating will be applied with a standard set of rubber or chrome rollers or with a laser-engraved anilox roller and a chamber-type doctor blade. The advantage of the anilox roller is that it enables the press to apply heavier coating weights, as well as more precisely meter and control the thickness of the coating being laid down.

“The laydown of the coating is so much easier to predict and control with anilox,” says Bob McKinney, marketing director at KBA North America, Inc. (Williston, VT.) “Most of our customers started choosing anilox systems three years ago, when they were first introduced.” Today, about 99 percent of KBA's presses sold with coaters are equipped with anilox systems.

Anilox systems are said to be largely independent of press speed and are less affected by coating-solution viscosity fluctuation. The chambered-doctor-blade and anilox-roller system is suitable for applying specialty coatings such as metallics, some matte coating materials, blister coats and moisture, as well as other barrier coating materials.

For routine aqueous coatings, many believe the roller coating approach, although less precise, is nevertheless better because there are fewer consumable items such as seals, wiper and scraper blades. Standard rollers also take far less time to clean than chambers and anilox rollers. McKinney notes that coating circulators can ease some of the problems that arise with standard coating systems; KBA strongly recommends that printers invest in a coating circulator and conditioner, no matter which type of system they opt to install. Anilox coating is more commonplace in packaging applications than it is in commercial printing.

Eliminating hand-cut coating blankets

Spot- and pattern-coating jobs may look dazzling, but some printers are wary of the time and expense required to make a rubber or photopolymer coating plate.

At Print 01, Gerber Innovations (Manchester, CT) demonstrated an alternative to hand-cutting blankets. Its Sector blanket-production system automatically processes blankets for spot-, knockout- and flood-coating applications. It comprises driver software said to fit seamlessly into existing prepress workflows and a compact cutting unit that can be placed anywhere in a production facility. Blankets can be cut to the exact size of each coating unit, reducing the need for extensive blanket inventories.

A standardized blanket sheet from DAY International (Dayton, OH) accommodates midsize presses up to 33 × 42 inches. A rigid backing prevents stretching and distortion.