The cover of the March 2009 issue of Canadian Printer magazine looks a little different than usual. It actually has two covers. Its regular paper cover, plus a polyester overcover printed on a flexographic narrow-web press by Cenveo McLaren Morris and Todd, Mississauga, Ontario.
Pictured above is the Canadian Printer cover team: (back row, left to right) Kelly Roberts, president, Canflexographics Ltd.; Ben Abray, president, Autumn Graphics Ltd.; Sandra Shepherd, account manager, Cenveo MM&T; Jason Secord, press assistant; Saurin Desai, vice-president, sales, Webmark Engraving Ltd.; and Paul Lancelle, flexo applications specialist, Kodak Graphic Communications Group; (front row, l-r) Chris Arsenault, account manager, Multi-Plastics Canada Co.; Tony Martins, technical sales, Webmark Engraving Ltd.; Percy Agboat, director product development, North America, Sun Chemical Ltd; and Marcelo Marziali, flexographic division supervisor, Cenveo MM&T.
When Marcelo Marziali, flexographic division supervisor at Cenveo MM&T, was asked how he came up with this idea, he replies, “we wanted to do something not done before—produce a magazine cover on polyester substrate on our Gallus EMS 510 S 20-inch press. We also wanted to demonstrate the evolution in flexographic printing technology in producing high quality print on par with other reproduction processes.”
He goes on to explain that it is not just one element, but the combination of press, plate, anilox roll, inks and other technologies that make this possible.
“The Kodak Flexcel NX digital flexographic plate, for example, is one part of the equation that allows flexo printers to reach realms of print definition that were unattainable in the past. Stochastic micro-screens are now within our grasp.”
And the flexographic printing process allows extreme versatility, Marziali points out. “With our 10-station Gallus press, we have many possibilities for controlling production time and costs. We can do multiple functions in one pass, producing a finished product off the end of the press. Part of the versatility is being able to go from 1 mil unsupported film to 20 pt board. We have the option of using four different processes on the press in addition to printing (multiple die stations and silk screen heads, plus hot stamp and cold foil).”
All stations are interchangeable between the 10 units on the press to reach the end result the customer wants. Water-based and UV inks could be combined in the same job, which could also be embossed, perforated and creased in one pass.
For the Canadian Printer cover, Marziali chose to run a 5 mil polyester with clear areas to provide a cut out effect over the magazine’s paper cover. The substrate, supplied by Multi-Plastics Canada Co., was chosen for the cover because, as Multi-Plastics’ account manager, Chris Arsenault says, “it has high clarity, printability, durability and high temperature resistance.” He also points out that the substrate is recyclable, tying into the theme of the issue.
Marziali then chose the combination of flexographic print technologies complementary to the capabilities of the Gallus press. “The key aspect of the Kodak Flexcel NX flexographic plates being used is that there are no more hard edges. You can go from a 99 per cent solid to a 1 or ½ percent dot with fade away comparable to lithography. Dot gain is reduced and controllable, and improved ink transfer gives richer colours. Stochastic screening was selected for the cover to print an even sharper image.”
The right combination
The end print result is a compilation of the various components in the flexo process. Kodak’s plate technology was being used for the first time to print a magazine cover. On the market for not quite a year, its claim to fame is the flat top dot, and Marzial is challenging that claim on the Gallus press. But to understand what this means to the flexographic printer, we turn to Ben Abray, president of Autumn Graphics Ltd. who installed the first Flexcel NX flexographic plate system in Canada, supplied by Heidelberg Canada’s Flexo Division.
“For the flexo printer with print processes in control, this plate technology allows production of phenomenal work,” says Abray. “From a print process point of view, the printer can run higher line screens or different types of screening than possible in the past. It also allows the opportunity, in some cases, to reduce the number of plates, as more solids and screens can be combined on the same plate. There is less manipulation for highlight bumps and reduced tonal range as compared to typical flexo plates. And ultimately, it allows expansion into new markets where the flexo world has not been able to compete in the past.”
Abray continues that with the right anilox technology, the Kodak plates allow much finer line screens, while still getting excellent ink transfer in the solid areas. “Line screen can be pushed into stochastic, or well into the 200, 250 or 300 range. Under the right conditions, you are approaching the quality of a litho highlight transition with very fine highlight dots and smooth transitions. Flexo printers can now look at a broader range of packaging work, and designers have greater freedom to incorporate elements in their graphics they would not have been able do in the past, such as very soft shadows, light backgrounds that fade off into white and more detail in shadow areas.”
(above) Kodak flexo applications specialist Paul Lancelle (front) was on hand at the start of the press run and checks a plate with Ben Abray, Autumn Graphics.
As Abray points out, the anilox line count varies with the application. Wide web flexo using solvent inks for process work usually runs 700 to 900 anilox rolls, while water-based label printing is in the 800 to 1000 line count and UV label in the 900 to 1400 range.
“While the outcome is dependent on the combination of components used in the print job—anilox, ink type—in every case where we have used this plate technology, we have seen improvements in the print results which rivals or betters other printing processes.”
As part of the combination for the cover, Marziali used the Harper XLT 1300 line screen anilox rolls, supplied by Canflexographics Ltd., as a higher line screen anilox is required to enhance the minimum dot held by the Kodak plates.
“Harper’s extended laser engraving technology using a digital transfer technique gives greater density capabilities and advantages in the highlight areas, maintaining cleaner minimum dots for a longer period of time,” explains Canflexographics’ President, Kelly Roberts.
(above) Examining the Harper XLT 1300 line anilox roll are Canflexographics’ Kelly Roberts and Percy Agboat of Sun Chemical.
As plate material and the anilox roll standards increase, so do the demands on the ink in order to transfer the right amount. Marziali used the Sun Chemical UV flexo MaxD inks, Platinum White and UV Satin Suncure varnish, all non-toxic and non-hazardous.
The ink lay down sequence on the inside of the polyester cover was black, cyan, magenta, yellow, Platinum White, cyan, magenta, yellow, black, varnish. An advantage of the UV Satin Suncure varnish is its conductivity. It acts as a microscopic ball bearing so that static is not conducted constantly. This gives better handling when stacking and trimming in the bindery.
“The UV MaxD (maximum density) chemistry is designed to allow use of today’s high line count anilox rolls up to 1800 line screen counts—maintaining density and flow,” says Percy Agboat, director product development, North America, Sun Chemical Ltd.
Marziali also used the Flint Rotec BLL (Blue Light Label) print cylinder sleeves. In narrow-web printing, he explains “we try to maximize use of the web and any out-of-circumference will show up as a light/dark sequence.” The sleeves came from Canflexographics Ltd. and Roberts explains that the sleeve technology incorporates a synthetic resin and fibre compound barrier layer under the polyurethane sleeve surface, which provides increased dimensional stability of the overall diameter tolerance. “This translates into a longer service life and register accuracy.”
Another component in the process has also undergone improvements to handle high end print requirements. The 3M Cushion–Mount Plus Tape E1315 was developed for printing clean fine-type reverses and richer halftones at high press speeds.
To die-cut the polyester cover on-press, a rotary magnetic flexible die was supplied by Webmark Engraving Ltd. Marziali has found that the magnetic dies work better on materials that generate static than do solid dies. As well as less static, he says that the release is much better.
The Webmark magnetic cylinder, made of high grade stainless steel, was designed to meet the dimension specifications of the press, and the flexible die was made to the cover specifications. A less expensive method as opposed to a solid cutting die. As to the reduced static build-up on the plastic substrate, Saurin Desai, Webmark’s vice-president of sales explains, “the properties of the rare earth magnets used in the cylinder help to dissipate the static as the polyester is cut.” PPiC
About the cover project partners
Cenveo MM&T has been a printing fixture in the graphics industry for many years with its extensive plant on American Drive, Mississauga, Ontario. Well-known for its publication and commercial web and sheet-fed printing, the company ventured into sheet-fed folding carton to complement services to key customers. “The next step we took in packaging was into flexo printing,” says Ken Oswald, vice-president operations, “with the establishment of a Flexo Division and the purchase of the Gallus EM 510 S, 20-inch flexographic press, again to meet customer needs for pressure sensitive labels, in-mold labels and shrink sleeves in a range of markets. This puts Cenveo McLaren Morris and Todd in an enviable position,” continues Oswald. “Our sales team can meet customer needs from commercial web and sheet fed products to flexographic packaging.”
Autumn Graphics Limited, London, Ontario provides prepress production, plate production, and graphics management services to consumer product companies, converters, printers and advertising agencies.
Canflexographics Limited, Burlington, Ontario is a sales and service organization serving the Canadian flexographic printing and converting industries with a wide range of systems, equipment and supplies.
Kodak Graphic Communications Group developed the Kodak Flexcel NX Flexographic Plate system and offers a wide product range to converters and printers.
Heidelberg Canada (Flexo Division), Toronto, Ontario provides consumables to the converting industry and training programs to help converters optimize their productivity.
Multi-Plastics Canada Co., Whitby, Ontario provides slitting and converting of thin gauge plastic film in roll and sheet for the envelope, carton, printing and packaging industries.
3M Canada Company, London, Ontario supplies a range of mounting tapes, plus other products to the packaging industry.
Sun Chemical Limited, Brampton, Ontario produces inks and coatings for packaging applications, including water, solvent, UV and EB curable packaging inks for flexography, gravure, digital, screen and offset.
Webmark Engraving Ltd., Woodbridge, Ontario specializes in rotary die and print cylinder manufacturing for the tag and label, and packaging industries.
