From: Converter-Flessibili-Carta-Cartone

Towards a new way: the latest technological development in the flexo prepress sector

Digital Flex, Gruppo Nuova Roveco, a technologically advanced company in the flexo prepress sector, organized in collaboration with outstanding business partners, a meeting focused on state-of-the-art packaging flexo printing plate and sleeve setting up procedures.

The day, dedicated to the thorough analysis of technical issues, was planned by Digital Flex, Gruppo Nuova Roveco, in collaboration with their partners, Simonazzi, AKL, Artwork System Italia and Kodak, at their premises at Monza, and it was very interesting. It also gave an opportunity to introduce a new sleeve engraving technology which is supposed to revolutionize the Italian flexography market.
Renato and Andrea Vergnano, owners of Nuova Roveco, opened the meeting. This company has always been standing out for technological innovation, thus contributing to the enhancement of flexography in the flexible packaging, paper and corrugated board sector.
Dr. Andrea Vergnano, responsible for production and organization at Digital Flex, highlighted the key points of the evolution, which his enterprise has been going through, by playing a leading role, since 1964, when Nuova Roveco was established.
In 1997 they moved to Monza and widened their horizons on the national territory. In 1987 Nuova Roveco was the first Italian company installing a fully automatic line for the manufacture of analogical plates DuPont Cyrel 2001.
In 1997 Digital Flex was established. It was the first Italian company and also one of the first European ones, to install a flexo CTP system for the production of digital plates.
In 1997 Gruppo Nuova Roveco was established. It consisted of the merger between Digital Flex and Futurflexo and was the 4th European group using photopolymer materials.

MACDERMID FLEX-LIGHT 83 ASL

Andrea Vergnano presented the “attraction” of the workshop: the new plant MacDermid Flex-Light 83 ASL, the only installation of this kind running in Europe. It is equipped with a fully automatic 2m lighting unit that “is able to give our customers a helpful tool to meet fierce market competition”, says Vergnano. This new production unit, along with CTP Flexo Kodak, will ensure the digital non-stop manufacture of “Seamless” photopolymer coated sleeves. These sleeves can be either conventional with a variable thickness range or of the latest generation, like those manufactured by AKL (OptiFLEX® and by DuPont (Cyrel® Round).

WHY INVESTING IN THIS TECHNOLOGY ?

“There are various reasons which have been leading us to trust this technology: first of all, our belief that, during all these years, we have been able to help our customers operate in a proper way and to ensure them excellent products. All the rest was based on our will to make the difference, to become the engine of competition and to help our customers grow by supplying them with a tool enabling them to carry out “just-in-time”, repeatable and superior quality printing jobs with productive and qualitative advantages”, concludes Dr. Andrea Vergnano.

PHOTOPOLYMER SLEEVES BY AXCYL

Enrico Albani, Simonazzi’s Trade Manager and distributor for Italy of MacDermid’s and Axcyl’s products, presented Axcyl’s sleeves.
According to Axcyl, sleeves have to be flexible enough to be easily assembled under any circumstances (temperature variations, mandrel variables, any kind of plates and bi-adhesives), but paradoxically they also have to be stiff to ensure high quality printing. “In our opinion, a sleeve should reproduce the conditions of steel cylinders, but without presenting the issues, that are generally related to them. The sleeve structure is particular. It consists of an internal body made of Kevlar and is processed up to the required printing pitch with honeycombing. Externally, it is coated with epoxy resin and finished with a semispecular surface. The only vibration damping portion is the internal ring, which enables the sleeve to easily cling to the pneumatic mandrel”, says Enrico Albani.
Axcyl manufactures two kinds of sleeves: one kind with variable thicknesses (Coaxcyl EM) and another thin type (Type R), in addition to adapters. Sleeves with variable thicknesses enable to carry out several printing pitches on a single mandrel to maximum 10-12. This kind of sleeves can damp vibrations, have a light and consistent structure and can be easily assembled onto the mandrel. Moreover, some widia register lines and cutting drives facilitate the assembling.
Then Albani introduced the audience the results of a printing trial performed by DFTA, the German Flexography Association.
The trial aimed at highlighting the printability and damping capability of Coaxcyl EM sleeves on the press, as well as to prove that printing speed can be increased by 25%.
The sleeves of the second type are thin. Their thickness ranges between 1 and 4 mm, they are produced with technologically advanced fibres and can be customized. These sleeves are light and can be easily handled, although they are very resistant. Furthermore, there is no need to disassemble the plates, which enables to save a lot of time during the starting up stage, thus avoiding all risks related to the plate assembling.
Then Albani presented the adapters. He explained how they function and suggested that printers should equip themselves with a set of adapters in order to have various printing pitches available for just-in-time services. With a small investment you can sometimes save a lot of time, above all if you are a company manufacturing several jobs on the same printing pitch.
Finally, Albani gave some useful suggestions for sleeve and mandrel maintenance, cleaning and storage in order to obtain top quality printing. The inside has to be inspected and cleaned regularly because possible ink residues, bi-adhesive and paper pieces may jeopardize correct sleeve functioning.
Pneumatic mandrels have to be kept in perfect condition and cleaned with special solvents. As far as storage is concerned, sleeves should be stored vertically by means of pins driven into the wall and to which sleeves are clung: a practical and functional system also enabling to inspect the storehouse without wasting too much time.

OPTIFLEX® THINSLEEVE SYSTEM INTRODUCED BY AKL FLEXO TECHNIK

Edward Scheppink, Managing Director of AKLFlexo Technik (Germany), a company that has belonged to Stork Group since 2006, introduced OPTIFLEX® THINSLEEVE SYSTEM, a special kind of thin sleeve, also used by Nuova Roveco for their flexography plants along with the sleeves by Axcyl.
“We have realized that the use of UV flexo technology has been increasing in the flexible label and packaging sector. Above all, there has been a growth in the employment of graphics and colours in Mediterranean markets.
Thanks to the presses of the latest generation, the final printing job quality has considerably improved, and now it can be compared to flexography, gravure and even offset.
Moreover we have realized that, due to shorter runs and frequent daily job changeover, presses have a lot of downtime, which, besides being a cost, doesn’t allow the machine to reach its highest performance”, says Edward Scheppink, who adds: “Considering that sleeve technology is being widely employed in flexo printing even with narrow web machines, as it was proven by the last Labelexpo, we thought to develop a product capable of helping printers optimize production times. So we launched OptiFLEX® sleeves on the market and tried to minimize machining times”, continues Scheppink.
OptiFLEX® consists of a thin photopolymer sleeve and a damping adapter, whose layer thickness and hardness are variable to enable proper impression according to the application required. The adapter is equipped with a metal reinforced bayonet blocking system, a zero pre-register line and an edge fixing ring preventing the thin sleeve to slide during the assembling.
The standard photopolymer coating has a total thickness of 1.573 mm and ensures the same quality on each printing pitch, with black layer and consistent density, which is very important during the engraving stage to obtain an accurate and even job. AKL also offers a sleeve engraving service.
“Thanks to the studies and trials, we have been carrying out, we can ensure perfect printing register, minimum dot thickening due to the presence of the damping adapter, as well as a 25% reduction of machine starting up times with a 50% printing speed increase, which minimizes substrate and ink waste and reduces prepress times”, concludes Scheppink.

CREATING A NON-STOP SLEEVE FLEXO ENGRAVING SYSTEM

Artwork Systems Italia, which have recently developed a merger with Esko Graphics by creating the EskoArtwork company, produce complete and integrated solutions for the label, packaging and commercial printing prepress sector.
Massimiliano Ghezzi, responsible for the Artwork Systems application support, presented a Digital Flex solution based on the Artwork workflow implementation.
“The workflow for the sleeve digital setting up involves procedures and operations that have to meet processing requirements by giving players reliable information about the processing and data controlling stages”, says Ghezzi.
A file very often passes several times through the players operating in the prepress sector: customer (or agency)-technical office- prepress- file production- plate engraving. File inspections are carried out through PDF, with mail exchanges making processing control difficult. Artwork has introduced the Webway software into Digital Flex. The software has been developed for the job file exchange and inspection among all the players involved; each of them can gain access easily and safely, which, at the same time, enables them to leave a track, that everybody can see. In this way, a process is accurately traceable through controlled operations, always available for all those who are interested in them. All changes are registered, it is possible to report the name of the person who has carried out a change as well as to indicate the deadline of a job delivery term.
The whole process is managed via internet, without the need of installing any software. This will result in the production of a certified file being submitted to the rasterization stage.
Finally, Massimiliano Ghezzi presented the functions of the NexusRip software, which is also used by Digital Flex for the manufacture of seamless sleeves. Meeting graphic elements have to fit perfectly together and the job has to adjust itself to the sleeve circumference. The halftone screen weft has to be even and without any gap.

SLEEVE PRODUCTION BY MEANS OF CTP FLEXO KODAK THERMOFLEX WIDE II

Michele Pioli, responsible for Kodak’s Graphic Communication Division and Trade Manager of the company packaging sector, illustrated the technical features of Thermoflex Wide II technology, Kodak’s solution suitable for Digital Flex’ digital plate and sleeve flexo CTP. As a matter of fact, Thermoflex Wide II can process with the same mechanic system not only digital flexo plates, but also sleeves, both by employing the seamless system and the plates-on-sleeves method.
The system enables to switch from the drum unit, equipped with the relevant plate loading/unloading table, to the mandrel unit suitable for the sleeve loading/unloading with few simple operations, which can be carried out by a single operator without using a tackle. By means of hydraulic controls, the drum is parked inside the CTP, while the universal mandrel is quickly loaded by a simple trolley. The Thermoflex Wide II sleeve exposure system has a single mandrel for sleeves of different sizes, thanks to the employment of shells, light carriers that can adjust themselves to various sleeve diameters.
“This technology, thanks to which you can avoid to buy costly mandrels for the various flexo sleeve diameters and which do not need any storage”, explains Andrea Vergnano, “perfectly cope with our policy aiming at efficiency and at reducing production costs”.
Moreover, the shell loading onto the mandrel is facilitated by a mechanic compressed-air arm, which enables a single operator to accommodate the shells onto the universal mandrel and to load the sleeves without touching them, thus avoiding any risk of damages.
Also the Thermoflex exposure technology perfectly meets the quality and reliability properties required by Digital Flex. The exposure is carried out by means of a laser system consisting of 64 beams, which enables a high writing speed even when the drum is rotating slowly. Thanks to this feature, the system can self-balance, even though one or more plates are loaded partially and loading times are reduced. In addition, as the 64 laser beams can operate simultaneously under oscillation, the operator is able to work even though some laser diodes are out of order, thus fully exploiting the CTP.
“The flexography market is going through a positive stage”, says Michele Pioli, responsible for Packaging Sales in Italy at Kodak, Graphic Communication Group. “The use of flexo printing is growing. With our Thermoflex Wide II we can help flexo prepress companies exploit new opportunities and be successful in this market”.
The day ended with a visit to the production plants of Digital Flex, a modern structure covering 4300 sqm and employing sixty collaborators, three sellers and five executive partners, who are playing key roles at the company. There we were able to see the machines and technologies, illustrated in the reports by Digital Flex and their partners, running.