Less Coating, More Control
- Published: February 29, 2004, By Debbie Donberg, Associate Managing Editor
Coatings are getting thinner, and while there are a number of reasons for this — more value added, reduced use of energy, water, and solvent, etc. — the result is greater strains on coating machinery, says John Pasquale, senior VP at New Era Converting Machinery (neweraconverting.com), Paterson, NJ, USA.
For that reason, he cites the main issue in coaters today as the ability to control these precision coatings.
“Secondly, Pasquale adds, “is the ability to repeat the coating in a narrow window of operation. If a person wants to put down a coating that is a couple of tenths of a thousandth thick, they want to do it not only once but again and again.”
The issue of thinner coatings leads to today's other buzz word in coaters: speed. “When you deal with thin-film coating,” says Pasquale, “obviously greater speed comes along with it. In addition, you have to be concerned about not just the machinery, but the coating chemistry and the web it is coated upon. The web must be accurate, have a smooth surface finish, and be uniformly treated to accept the coating.”
Richard Greer, VP sales at Faustel (faustel.com), Germantown, WI, USA, agrees higher speeds and more precise coating application are top concerns today. When asked about recent changes in coaters, Greer points to movement away from solvent-borne coatings, greater automation in support of higher speeds and consistent quality, and multi-functional equipment.
Not only are coatings getting thinner, but substrates are thinner as well. “[Today's thinner materials] require better tension control and web-handling capability,” says Greer. He advises converters seeking new coating machinery to look for the most value for their dollar. “This is very different from price paid. It encompasses performance, technology, flexibility, reliability, and service.”
Tighter tolerances, both in machinery and in the coated product, are key to today's coating equipment, reports Lee Ostness, product manager of Coating and Drying Systems, Black Clawson Converting Machinery (blkclawson.com), Fulton, NY, USA. Like the others, he names faster speeds as one of the primary trends and adds “today's customers want open-end machines designed for future products, and [they want] lab trials to determine coating methods.”
Speed also is a key for Ralph Pagendarm, president of Pagendarm BTT GmbH (pagendarm.com), Hamburg, Germany. “The greatest changes in coaters today is the need for machines offering high production speeds and short changeover times from one product to the other. Flexibility is what counts.”
Another issue that comes up repeatedly is that of control. “[Our customers ask for] in-line coating weight control, moisture control, plus fully automatic width setting for all components, including the dryer nozzles,” says Pagendarm.
“Control” often is synonymous with automation, and Pagendarm lists automatic roll change with flying splice, full machine automation, and in-line measurement of coating weight and moisture as important trends today.
Speaking of control, Pasquale acknowledges, “The wider you go with thin films, the more difficult it is [to control]. With some people, if they're going to go faster and thinner, they may also go narrower because they can control it better.”
Where does radiation curing fit into today's coating world? Ralph Pagendarm finds UV-curable silicones still lagging far behind thermal curing silicones. “UV-curable acrylic adhesives are starting to be considered but still are considered ‘exotic.’”
“Radiation curing is getting more popular,” Ostness notes,” [due to] new laminating adhesives and primer formulations, new hardcoat/topcoat coating formulations, and webs becoming more frail and high-tech.” Greer's take: “Radiation curing is well established in certain markets such as gloss/protective coatings. It is moving more slowly in adhesive applications, but gains are being made in this area, too.”
Underlying all other issues to Pasquale is the importance of bringing together the equipment supplier, substrate supplier, and coating supplier to make sure a new line will work properly.
Looking ahead, Pasquale cites “evolution versus revolution,” saying in his 40 years in the coating industry, he has seen very little “new” technology. “You put a coating on a substrate; you dry it. The basics are there. What's changed is how we control the process and use the technology.” Thick or thin, those uses are likely to continue evolving.
Restrictions of time and space limit the number of companies, products, and trends that we can discuss in these reports. For additional information, see PFFC's features and departments each month, consult the June Buyers Guide, and check pffc-online.com.
