RETROFIT MECCANICI

Model R950: high-evolution electronic retrofit

Developed in 2016 and installed in 2017

Model R950

It was the highest-automation model of the first 900 series, equipped with an automatic system for the printing cylinder’s changeover with the lengthwise movement of the trolley. In this particular case, the press had been designed to print coated paper, aluminium foil and laminated aluminium; max web width 42”; printing cylinders repeat 18” ÷ 40”; printing speed 2000 FPM (approx. 610m /min). The unwinder was not part of the Cerutti supply but bought separately from a third party by the Client, and has been connected to the press both mechanically and electrically.

Practicable on models:

On the following mechanical-axis models of the 900 series: model R910, R920, R930, R940, R945.

The case

It was a high-performance press both in automation and pure performance, with Reliance Maxitron M8500 digital drives and Reliance Automax PLC, which, at its time, was a top component with remarkable adjustment performances, of motors and of generic adjustment loops (such as tensions, positioning, temperatures, LEL dampers and so forth) as well.

Today (2018), and from several years already, many hi-tech electric components such as the drives and the PLC are highly obsolete, therefore a fault in one of these components may cause serious downtime problems and an increase in repair times due to the difficult availability of spare parts.

For these reasons the Reliance Maxitron drives for DC motors have been replaced with the new, digitally-controlled Rockwell PowerFlexDC models: on the main motor, on the rewinder’s reel axes, and on the infeed, outfeed and by-window pulling units, which means 6 drives of different sizes. 2 Reliance Automax CPUs have been replaced with the new Rockwell ControlLogix, and all of the Reliance I/O, European series, not available on the market anymore have been replaced with the new Rockwell 1756 and 1734 series.

Replacing the electric cabinets was not necessary, and works have been performed on the exisiting ones directly on site to reduce the installation time (and, as a consequence, the downtime). The materials to be replaced have been accurately prepared and pre-wired at Cerutti HQ to reduce installation time.

All of the press sequences, and in particular the automatic sequence for printing cylinders changeover, have been reviewed and improved; all of the parts damaged over time and of the defective sensors have been replaced; then a complete general test and inspection has been executed.

The management system has been replaced as well to match the new automation platform and the hardware and software state of the art, also implementing the possibility of connecting the press to the “24/7 by Cerutti” remote-assistance service.

Schedule

3-weeks downtime plus one week of assistance during production. The press underwent a complete general test and inspection, as well as the main print tests with the relevant materials.

Targets

The main goal was to solve the obsolescence of the electronic components; this is why the Client decided for a retrofitting focused on the electric / electronic side of the machine.

Furthermore the opportunity was seized to replace some transducers with other ones, of higher performance and updated to the state of the art, such as the thermal probes for temperatures survey, the electropneumatic transducers and several sensors.

Performance improvements

All of the most important sequences have been re-built, improved and enriched, notably the automatic sequence for printing cylinders changeover.

The management system too has been improved in its handling of several functions, such as the preset of operational units, tensions, positions of the compensating rollers, temperatures, acceleration slopes, taper on the rewinder, possibility of activation of a continuous (24/7/365) remote-assistance service.

Notes

On presses of this generation with a high-performance printing quality, this kind of retrofitting offers the best price / performance ratio, since it makes the press, even with its features of mechanical transmission with DC motors, perfectly aligned with the current state of the art in automation. These factors have a positive effect on the return on investment of such a retrofitting, taking into account also the further 10-15 years increase in the obsolescence term of the spare electronic components.