Analog Electronics: A Growing Risk
The Cerutti printing line dates from 1991 and still operated largely on analog electronics. "The line is extremely robust. It ran for thirty years with virtually no downtime. Three years ago, an electronic circuit board failed. We were down for a week and a half: the machine builder no longer existed, and the board was unavailable anywhere. We could only solve it by partially converting to Siemens control. But it was clear: if something like that happened again, we could be offline for weeks."
On top of that, Christian Schietse, the technician who built and maintained the machine for years, retired. "He was our walking encyclopedia," Kristof says. "Younger technicians simply have less knowledge of analog electronics. The risk had become too great."
The Solution: Complete Retrofit with Siemens
It quickly became clear that a retrofit was the best option. "The machine was mechanically in perfect condition. A new machine costs more money, and you also need more time and space to build and commission everything. With a retrofit, we could ensure the machine was perfectly reliable again, capable of handling new products, running safer, and consuming less energy."
Amcor chose Siemens for the third time. They had already retrofitted two laminating machines. "We wanted a partner with extensive technical knowledge and experience, backed by a headquarters to turn to when major problems arise. Proximity, the fact that they speak Dutch, the pricing—it all works in their favor. And we've been standardized on Siemens components for years, so we can maintain everything ourselves."
Siemens rebuilt the entire line in eight weeks. The controller is a SIMATIC S7-1516 TF, which also incorporates full safety functionality. SINAMICS S120 drives and SIMOTICS servo motors ensure smooth, precise control. The old push buttons and meters were replaced with two new HMI screens featuring a user-friendly interface.
"We spent a year preparing, produced extra stock, and planned everything meticulously," Kristof explains. "Thanks to that preparation, we were able to test the line after seven weeks and bring it into production on schedule. Siemens then performed some optimizations and provided support, but the line ran reliably at target speeds right away. We don't see that very often. Callewaert from Harelbeke, which was responsible for the new cabinets and cabling, also performed excellently as always."
Ready for the Future
"The biggest gain from this retrofit is the restored confidence," says Kristof. "We're good for another 20 to 30 years. If downtime does occur, it's now 1 day instead of 4 to 6 weeks. In the months following the retrofit, demand for various products increased. Thanks to the improved reliability, we met that higher production without any issues."
"Technically, we're now ready for the future. In the future, we'll increasingly work with recyclable films. These are more elastic, so tension control must be perfect. And it is. Thanks to the increased precision, we're already seeing a small quality improvement in some products."
"The machine also runs more efficiently. Siemens actively contributed to that. By optimizing the oven valve control, we now have less leakage air in our exhaust, allowing us to reduce motor speed. And through the common DC bus for the drives, braking energy from the motors can be recovered. All of this results in energy savings of around 10% in electricity and 3% in oven gas consumption."
Our operators are satisfied: the machine is safer, now fully complies with PLd guidelines and ATEX standards. It's also quieter thanks to the new AC motors. And they need to walk around less because the control is now in one HMI instead of scattered across the machine. The screens are programmed so operators can barely make mistakes, as they can use recipes. This also improves efficiency."
