A new level of digitalization
After revamping, a 23-year-old board machine at Stora Enso’s Skoghall Mill in western Sweden is turning out state-of-the-art, lightweight, durable liquid packaging – at production levels never reached before. What makes this possible is comprehensive digitalization.
Whether for milk, juice, soup, yoghurt or wine, or for non-food products like liquid detergents and fabric softeners, liquid packaging board has to be lightweight, durable and food-safe. As simple as these requirements might sound, it takes a high degree of innovation, know-how and modern machinery to create board cost efficiently. One of the machines capable of the task is at the Stora Enso Skoghall Mill in western Sweden. There, the Swedish-Finnish company operates what is known as kartongmaskin 8 – or KM8 for short.
Increasing speed and flexibility
KM8 has been in operation since 1996. Yet despite its age, it can hold its own against any new installation. Two things enable it to produce today’s high-tech liquid packaging board: The first have been continual smaller mechanical modifications performed by the OEM. The other is updated drives and automation, a course of action Siemens and Stora Enso embarked on in 2017.
The changes became necessary as the drive system and entire automation started suffering performance losses and a number of spare parts were threatened by obsolescence. Therefore, an entire palette of improvements to the automation systems, software and drive system became mandatory – also in view of securing reliability. In addition, the implementation of a high degree of digitalization with state-of -the-art technology supported the re-engineering and made the machine fit for the future. And that in turn has increased KM8’s speed as well as flexibility – not to mention the ability to make innovative products.
That Stora Enso has such a machine in its fleet is a case of not settling for the status quo. “We realized quickly that if we make changes to KM8, we should look beyond the current technology. We decided to invest in a good, future-proof platform that can be adapted to the coming digitalization wave,” states Åke Ånesjö, Section Manager for Automation at the Skoghall Mill.
At the heart of that platform is a functional control concept tailored specifically for the pulp & paper industry, based on the Simatic PCS 7 process control system and the Sipaper Drives APL software standard. The latest adjustments to KM8 are taking digitalization to a new level, because they introduce self-optimizing and autonomous properties with digitalized engineering and simulation capabilities.
The next digitalization wave
An installation like KM8 consists of hundreds of process loops. An improvement in one area invariably has an impact on another. “However, to go back and make adjustments to all process loops impacted by a change – that would be impossible,” states Engelbert Schrapp, Siemens Principal Corporate Account Manager for Stora Enso. “Impossible for humans, that is,” he corrects himself. The new Control Performance Analytics (CPA) app that Siemens installed in the fall of 2018 is capable of the feat.
Based on MindSphere, the cloud-based, open IoT operating system from Siemens, CPA analyzes the data created by the individual process loops and makes improvement suggestions. Because long-term control data is factored in, it becomes possible to get a broad overview of where performance can be enhanced. In regard to KM8, it has meant increased throughput and product quality. In addition, lower resource input is required, and equipment lifetime has been maximized.
“Like a crystal ball”
KM8 has also been the subject of a pilot project for generating an open IIoT ecosystem platform. A use case is the prediction of upcoming critical issues with the ultimate goal of avoiding production downtime. Typically, hundreds of alarm and event messages are issued every minute. The challenge is to filter through them, a task that takes years of experience. Mistakes can occur and often lead to downtime. Process Event Prediction – also part of MindSphere – uses algorithms to predict when an event, like an alarm, will be issued. “It’s like a crystal ball for a plant,” says Schrapp. When events are predicted, operators also receive a prescription of which measures to take. “That way, no event or alarm can be overlooked and the risk for unplanned downtime sinks considerably,” he continues.
We realized quickly that if we make changes to KM8, we should look beyond the current technologyÅke Ånesjö, Section Manager for Automation at Stora Enso, Skoghall Mill
As complex as the solutions may be, a focus has always been on usability. “We are not just looking at what can be done with technology, but that it should be easy to use as well,” emphasizes Choy-Hsien Lin, Digitalization Manager at Stora Enso’s Skoghall Mill. The end users at the Skoghall Mill – the operators themselves – have responded positively to the new solutions. This is down to the fact that they helped design both the user interface and the process technology as part of the ecosystem approach.
Teamwork and tools
This open ecosystem approach brought three companies to the table – Siemens, Stora Enso and Atos. The skills and know-how of the individual project team members representing a range of expertise complemented one another, and the different members worked collaboratively on a common goal.
To create strong digital solutions for the pulp & paper industry, Siemens uses equally strong digital engineering tools. The Comos lifecycle management software makes it possible to speed up the engineering process, as well as increase and optimize process efficiency throughout the lifecycle in order to improve competitiveness. The Simit platform enables comprehensive simulation of automation applications and provides a realistic training environment for operators, even before the real startup. Thanks in particular to Simit, starting KM8 up after the new updates were installed was a breeze, and in the first month Enso Stora broke previous production records easily. Keep in mind: generally speaking, production in the first month after updates can be a bit lower than usual due to hiccups – but not so here. With these and many other digital tools, Siemens has helped make KM8 into a digital flagship in the pulp & paper industry.
The future is autonomous
What’s next for KM8? The digitalization drive will continue, assures Åke Ånesjö. The solutions in place today – along with the thousands and thousands of signals from machinery being generated and collected every second – are already paving the way for the next wave of digitalization. The goal is the autonomous mill, as defined in Siemens’ Digital Fiber Vision.
Technologies to come include a digital twin on which new methods and procedures can be tested before they are implemented on the actual machine. Or extending the implementation of artificial intelligence (AI). Yet at Stora Enso, there is no fear about AI taking over KM8: “Only the operators have the overall picture, creativity, flexibility and experience – AI cannot replace that,” Choy-Hsien Lin is certain. But it could help Stora Enso come up with even more advanced board for liquids of all types.
The renewable materials company, Stora Enso develops and produces solutions based on wood and biomass for a range of industries and applications worldwide. The company operates on the belief that everything that is made from fossil-based materials today can be made from a tree in the future. The Stora Enso group has some 26 000 employees in more than 30 countries.
Skoghall Mill in western Sweden is a modern world-class producer of cartonboard for demanding consumer packaging and printing purposes, including liquid packaging and dry foodstuffs board.
Annual capacity: 855 000 tonnes (board), 645 000 tonnes (pulp)
Number of employees: 770
Subscribe to our Newsletter
Stay up to date at all times: everything you need to know about electrification, automation, and digitalization.