RETROFIT MECCANICI

Model R940: high-evolution electronic retrofit

Developed and installed in 2017

Model R940

Electric-shaft model R940 press with high performances both in speed and in performance according to the materials to be printed.

In this particular case the press had been designed to print paper up to 70 g/m2, film in the 9 ÷ 50 micron range, 50 micron LDPE; in-line lamination; max web width 1430 mm; printing cylinders repeat 460 ÷ 920 mm;  max printing speed 500 m/min.

Practicable on models:

On the electric-axis models of the 900 series, such as model R940, R950, R960.

The case

High-performance press with very particular and specific productions, used intensively, equipped with two different automation platforms:

  • on the main and secondary unwinder and on the rewinder: Eurotherm Drives (today Parker), both for the AC drives (type 620) and the PLC part (Link)
  • on printing units and the remaining parts: Siemens, MasterDrive drives and S7 PLC

The printing units are equipped with vector- and motion-control AC motors; the press is of the electric shaft type (“shaftless”).

Eurotherm Drives components are highly obsolete since january 2015, therefore a fault in one of these components may cause serious availability problems of the spare parts. Anyway, the Client owns a spare parts kit ensuring some continuity, even if limited in time.

The Siemens MasterDrive drives managing the printing units’ independent motors will not be available anymore, not even as spare parts, as from october 1st, 2020; therefore the Client decided to retrofit this part, as a first step of a subsequent retrofitting also of the Eurotherm Drives part.

The intervention, then, has been a retrofitting of the printing units’ automation system, with drives replacement and regeneration of the electric shaft with new technologies, and the addition of several functions for waste optimization as described later. This approach demonstrates the modular structure of the retrofitting activities, that can be directed, and shaped, for an execution in subsequent stages (in this particular case, by planning two interventions in two subsequent years).

On printing units, the Siemens MasterDrive Motion Control drives for AC motors have been replaced with the new Siemens Sinamics Simotion models: on the independent drives, the laminating unit, the pulling unit, the by-window and the relevant power sources, which means 12 drives of different sizes and 2 power sources.

A Siemens Simotion CPU replaced the previous solution, based on the out-of-production S7 FM458 board, for the electric shaft’s management.

Replacing the electric cabinets was not necessary, and works have been performed on the existing ones and on some parts aboard the press 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.

Schedule

2-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, with particular attention to the above-described optimizations; at the same time the register control system has been replaced and tested.

Targets

The main goal of the retrofitting was to extend the plant’s technological life and to prevent long downtimes in the event of faults in components not available anymore on the market, notably in the electrical part.

The second goal of the retrofitting has been to reduce, via new technologies, the start-up times and the economical impact on the Client of the start-up wastes.

Performance improvements

This retrofitting, in addition to being an evolutionary intervention on the press and to its great impact on the obsolescence risks of the electric and electronic components, allowed to implement new functions such as the AUTOPRESET, AUTOZERO and SMART START* sequences to optimize and greatly reduce waste at the start-up of a new or repeated production and most of all at the restart after a press stop.

* for further details on the great advantages of these technologies, please see the AUTOPRESET, AUTOZERO, SMART START white paper.

These functions need a strong interaction with the register control system, which in this case has been replaced as well with a new model with the suitable features.

Notes

For the reasons listed in point F, this retrofitting is suitable to reduce the obsolescence risk of the electric and electronic components and the impact of start-up waste, which in turn allows a reliable pay-back planning on the Client’s part.