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Refined electronics
Article taken from "Fieldbus & Networks", issue 263 - November 2003

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"Emerald" line

Uteco chose Unidrive SP by Control Techniques and Automa's Super-Flash to render the flexographical printing presses more competitive.

By Elena Bertillo - Luca Sartori

Created in 1985, Uteco Converting is a relatively young company which succeeded in reaching the market's peak in a short time, gaining expertise in the construction of machines for printed materials production for plastic bags, envelopes, food packing, etc. This achievement is even more remarkable if we consider that the sector in which the company operates is distinguished by an elevated competitiveness reducing the average profitability, as well as, by a continuous demand on technological innovations entailing elevated investments in research and development. Thanks to the definition and achievement of objectives oriented to both the excellence in the planning of vanguard and made-to-measure solutions and the offer of an efficient customer service, Uteco succeeded in being one of the most affirmed producers in the sector, with more than 1,500 printing presses sold (about 80 a year) to various sized companies worldwide (from companies with about ten people to multinational ones with thousands of employees). Just for rendering their own plants even more competitive, Uteco chose partners in a position to extend its know-how. Thanks to Unidrive SP, the AC converter signed by Control Techniques for driving plants electronically and to Super-Flash, Automa's development system for generating supervision applications, Uteco succeeded in constructing machines where characteristics and added values were just in the use of refined electronics.

For a first-quality printing
A typical printing press is composed of an uncoiler for sliding the material to be printed through printing units (from 4 to 10 for each plant). They reproduce the selected image on raw materials with ink collected from an appropriate tank. The printed material passes, then, through a drying bridge for fixing the ink. Finally, everything passes to a coiler machine for packing the final product in various sized rolls. A typical printing press produces about 300 m of printed material per minute. If a considerable size (20 x 10 x 7 m) is added at an elevated speed, it is understandable the importance of having all parts of the plant perfectly synchronized in order to obtain the best printing precision and minimal rejects.
The "Emerald" top line of Uteco's flexographical printing presses was, in fact, created for satisfying these important market needs. The numerous printing units (from 8 to 10 for printing in 8/10 colours) are "Gearless" (kinematics without mechanical reducer between engine and roll) rotating around an ordinary printing drum. Compared to the traditional "Geared" printing presses (kinematics with mechanical reducer between engine and rolls) this solution provides an elevated printing quality; an high precision level from 0.01 mm to 400 m/min; a total operating flexibility through independent control of all printing press components; a reduction of the 50% of the machine downtime for production exchange thanks to the absence of manual interventions for regulating printing registers and other mechanical components.
The architecture of the "Emerald" line automation system was studied by Uteco technicians in collaboration with Control Techniques, company that since 1996 is producing a driver totally programmable by end-users (Unidrive), planned for managing different engines (brushless, asynchronous in open and close loop, etc.). Unidrive SP electronic drivers manage directly and in a completely digital way the high-speed "CTnet" network communication. The brushless engine managing the printing drum has a nominal torque of 800 Nm and its encoder sin/cos generates the "master" for the colour cylinders. Unidrive SP drivers managing the brushless engines for the colour cylinders act, instead, as "slaves". Thanks to the high precision generated by the printing drum encoder through a complex algorithm, all the engines are controlled by an electrical tree in order to maintain the printing register errors constantly under the 0.01 mm.

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Unidrive SP

Unidrive SP drivers communicate with the supervision application realized with Super-Flash through a MODBUS32 driver developed ad-hoc by Automa. According to end-customers requirements, the HMI software communicates, then, with different PLCs through a serial protocol or with Industrial Ethernet.

Software quality
The supervision software is composed mainly of two parts: the first dedicated to end-users and the second to the machine final inspection where calibrations may be carried out.
Through key combinations and a password, it is possible to access to a panel control for enabling/disabling communication channels for the tests; determining the scaling range values to be later entered by operators; entering the necessary parameters so as to enable or disable specific functionalities for operator use; test the machine and save many values in the PC hard disk.

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Main screen

The end-user interface is composed of a mainpage with a plant synoptic showing the various units working status.
Then, various pages allow specifically the supervision and control of plant functionalities and parts such as the display page concerning units current absorption, the plant speed trend page and the one showing the trend relative to the material printing, etc.
There also is a section dedicated to work order management (up to 5,000) for entering, saving and modifying the work orders in a DBF-format database in order to make operators' work easier.

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User screen

By satisfying both integration with DOS and Windows operating systems and applications development easiness requirements thanks to a simple and intuitive graphic editor, as well as, to its advanced functionalities, Super-Flash was considered as the best solution for developing the supervision software.
Furthermore, it is possible to interface it with a lot of peripherals from various manufacturers thanks to a rich quantity of native drivers and applications performance stability due to MICROC hardware-independent language.
The close and lasting collaboration with Control Techniques along with the use of a reliable, open and easy supervision software as Super-Flash, gave Uteco the key to achieve and maintain the first place in the world market concerning flexographical printing presses.
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