Commentary & Analysis
FREE: That's A Wrap: Blankets at drupa
Perhaps drupa 2008 should dedicate a pavilion to offset blankets.
By Patrick Henry
Published: June 1, 2004
Perhaps drupa 2008 should dedicate a pavilion to offset blankets. Indispensable but nearly invisible in the operation of a lithographic press, blankets aren't usually thought of as products that push the edge of envelope in printing technology. The reality is, however, that today's improved offset presses simply wouldn't work very well if their blankets weren't also continuously improved to handle higher running speeds, new plate characteristics, and other performance factors that directly affect the transfer of ink from plate to blanket to paper. This coda to our drupa coverage notes new developments from two leaders in the field as an indication of how far the technology of blanket design has progressed.
Day International exhibited a number of new products marketed by its flagship brands, dayGraphica, davidM, Varn, and Rotec. The most notable item in the blanket category was dayGraphica's Durazone compressible layer, a component said to increase blanket durability without sacrificing print quality.
According to Day, Durazone is a next-generation step in blanket construction that improves performance by limiting the loss of gauge (thickness) that occurs when a blanket is installed and run. The Durazone layer makes the blanket better able to resist gauge loss by helping it to absorb and minimize damage from web breaks and smashesa condition that occurs when a piece of paper or a foreign object dents the blanket and creates an ink void that prevents the proper transfer of the image.
The benefits of Durazone-reinforced blankets, says Day, include sharper halftones, improved registration, fewer web breaks, fewer washes per run, longer plate life, fewer press stops, and less waste. The Durazone compressible layer currently is available in the dayGraphica 5000 Series, a line of blankets for heatset web printing. Products in the series as seen at drupa include Durazone 5000; DayGraphica 5500 for directory and insert printing; and DayGraphica 5010, which includes Day's patented textured surface for quick release and sharp prints.
Also new from Day was the dayGraphica 3612, a blanket designed to accommodate the entire range of printing applications from heatset web through commercial sheetfed and sheetfed packaging. Day also manufactures a variety of blankets and blanket sleeves for specific printing applications.
Within its Varn brand of pressroom chemistry products, Day spotlighted Apollo 900 web conditionera product billed as an alternative to hand-mixed anti-static additives and silicones. Varn Apollo 900 eliminates static, marking, and ink smearing, according to Day. The company presented other Varn products including chemistry for conventional and CTP plate processing and a new line of coatings for wet-on-wet and wet-on-dry sheetfed applications in packaging and commercial printing.
Under its Rotec brand, Day exhibited a range of products for flexographic printing including Cyrel Round, a disposable, round, and seamless photopolymer plate being developed with DuPont; Greyback compressible foam for plate mounting; Omega Surface Technology for the new Blue Light Nx anilox sleeve; and the new Ani Light Nx, a super lightweight anilox sleeve.
Based in Hannover, Germany, ContiTech specializes in rubber and plastic technology as a development partner and OEM supplier to companies around the world. Although it is best known to the printing industry as a supplier of offset blankets, it also provides drive belts, vibration control units, and other components necessary for the operation of a press.
At drupa, ContiTech's emphasis was on blankets, which it develops in cooperation with press manufacturers to the specifications of individual presses. Spokesmen for the company described how ContiTech's factory customizing center tunes blankets to various press types by cutting them to size, fitting them with the appropriate tension bars, and rigorously testing them for thickness and compressibility.
At a press briefing, the spokesmen said that ContiTech has added new products to its blanket range and restructured the line for coldset, heatset, sheetfed, packaging, and metal printing. The new product lines, in which blankets are combined with a load-bearing layer of fabric or metal with a body and surface optimized for the particular printing process, are called True Rolling, High Compressibility, Metal Back, and Traditional.
The True Rolling feature gives coldset blankets with a fabric basis a neutral unrolling behavior said to extend blanket life at high running speeds. Metal-backed blankets for coldset and heatset presses permit small cylinder gaps, reduce vibration, and help eliminate streaking. The High Compressibility concept, applicable to sheetfed offset, updates the traditional, two-ply blanket carcass (lower layer) with a one-ply, double twist structure that allows more space for the compressible layer and a higher degree of compressibility. The Traditional line includes best-selling ContiTech products such as the FSR, Violett, Crystal, Prestige, Ebony and Spectral blankets. ContiTech products are distributed in the U.S. by Prisco (Printers Service).