The Advantages of an Elastomer Print Sleeve
Elastomer sleeves are thicker and more durable and can print 2-4 times longer than polymer plates and sleeves. This eliminates the need to buy multiple plates or polymer sleeves for long runs and repeated abusive short runs that require many cleanings and press cylinder mountings. This leads to cost saving in the long run, and cost predictability. A typical comment from printers who have switched from Polymer to Elastomer sleeves is, “Elastomer usually costs less than polymer, and we’re only buying one set instead of two – so the savings are great, and our print results are more consistent”. Further cost savings are realized because elastomer sleeves eliminate the need to purchase expensive cushion adaptors and replace them in the future.
Sleeve durability does not just come from elastomer materials’ increased ability to stand up to press pressures, corrosive inks and cleaning solutions, but also from the way they are imaged. Digital control of the halftone shoulders contributes to dot stability and reduces break-off which adds durability and consistency. Below surface engraving also produces a more consistent product by reducing highlight press gain — even if a job is slightly over squeezed from press to press and operator to operator. We’ve been told by many print customers, “our pressmen love sleeves.” They love elastomer sleeves even more because below surface engraving reduces the risk of printing shoulders and the risk of inconsistent dot gains. Control of the shoulders allows for razor sharp text even at 1 and 2 point and the ability to print smaller reverse text without filling in.
Elastomer customization is possible through the chemical and physical processes of sleeve manufacturing itself. “It is now possible to create a special elastomer compound specifically for your press to get the absolute best from your fingerprint,” says Moravcik. “Because elastomers have no photographic layer, which is the time consuming part of new polymer development, customized materials for your specific needs can be developed in weeks and not years,” he continues, “Slight changes in elastomeric compounds can increase ink transfer for specific inks and substrates where polymers have hit a dead end.”
A wide variety of elastomer materials with different durometers and ink lay down characteristics are now available. Higher ink densities allow printers to achieve higher press speeds and maintain print contrast. At a test run with a set of custom laser engraved elastomer sleeves, a customer was amazed at an unprecedented printing event, “The density was so high we had to cut it… That’s a good thing!”
Quality control is another area where elastomer sleeve manufacturing and imaging have grown leaps and bounds, led by the Kodak Flexcel Direct System. Kodak has developed a system whereby all sleeves are quickly pre-scanned on the engraver to check for a flawless surface and rejected before imaging if any imperfections are detected.
Laser engraved sleeves also have an inherent quality control advantage over photopolymer. Laser engraved sleeves have three steps to imaging: file prep, engraving, and rinsing. This means that the sleeve only has to be mounted one time, engraved, rinsed, and shipped. Photopolymer sleeves have many more steps: file prep, mask ablation, exposure, development, wash-out, and several options for drying, post exposure, etc., and then shipment. This adds several more variables to the imaging process, each of which adds more analog steps and points of failure in the imaging process.
Another supply chain innovation has led directly to cost savings with elastomers: the ability to regrind and reimage sleeves. “Elastomer sleeves can be produced with wall thicknesses from .125”to .500” with phenomenal print results on all,” claims Carey salesman and Flexo technology expert, Ed Stolzman. Elastomer sleeves can be kiss ground to the next lower repeat and re-imaged once the sleeve is done being used, creating as many as 3 to 4 uses of the same sleeve. When considering overall ROI – this will drastically reduce costs.