Unscratching the Surface - Flexo Magazine
Thermal-spray coatings can turn worn or damaged
central-impression cylinders into top performers.
Less than a decade ago, reconditioning a worn central-impression cylinder was strictly a routine maintenance issue. Today, with huge advancements having been made in hypersonically applied coatings for central-impression cylinders, printers and converters are beginning to demand much more from coatings than basic maintenance. Coatings are now expected to deliver real performance improvements as well, and printers are looking beyond the old idea that the goal of a maintenance program is simply to put equipment "back to OEM specs." Now, companies are starting to view print quality as a factor in profitability and market expansion. Consequently, high-performance coatings for central-impression cylinders now figure into the business plan as much as the maintenance plan.
Since all coatings are not created equal, here are some criteria for choosing a coating and a vendor to apply it. As a bottom line, coatings for central-impression cylinders should:
- maintain a consistently high surface condition
- reduce risks of corrosion and "orange peel" to the cylinder
- be applied by a knowledgeable, ISO-certified vendor
- simplify ongoing maintenance tasks while reducing costs and downtime
But clearly, today's advanced thermal-spray coatings can do more. They actually improve the surface above OEM specs, giving client companies a competitive advantage, both in terms of cost effectiveness and print quality. For example, a high-performance nickel super-alloy coating could boast surface hardness twice that of the OEM surface, low porosity (less than 1%), high density and bondability. Such coatings are capable of producing finish-grind runouts of 0.0002 TIR and 8 R-N4S and better.
Another piece of good news is that on-site reconditioning of a standard central-impression cylinder is usually completed in under 72 hours – a minimal and quite tolerable cessation service for the press.
The process of reconditioning a central-impression
cylinder by applying a thermal-spray coating can be
completed in as little as 72 hours
Just Add Water
Without a doubt, the prevalence of waterbased inks has taken its toll on central-impression cylinders and maintenance supervisors. "We hear a tremendous amount of concern out there about corrosion and "orange peel," recounts Jacqueline Lehman, account manager for Bender Machine Services Inc., based in Los Angeles.
"Without question, battling corrosion is a big motivation for companies, but it's not only a maintenance decision anymore. Companies also want better print quality to attract new business and boost profits. I had a client last year go from having mounds of unsaleable product to winning third place in an FTA print competition."
One of the major proponents of a new philosophy for maintaining and improving central-impression cylinders is Zachary Deutsch, Vice President and General Manager of Mercury Plastics, an extruder, converter and printer in greater Los Angeles. Deutsch explains, "I wouldn't buy new equipment with anything but thermal-sprayed nickel, so why continue to operate older equipment without it? For me, maintaining print-quality levels for my customers is everything."
Trashing worn cylinders is bound to be an unpopular business decision, simply due to the cost involved. With the advances being made in thermal-spray technology, printers would be advised to consider re-coating damaged cylinders as a step toward a healthier bottom line.
Laura Duffy represents McFarland Advertising, based in Torrance, Calif. |
