A role Model for energy efficiency

A role Model for energy efficiency

Model Group, a packaging manufacturer headquartered in Switzerland, has upgraded a paper machine with 36 energy-efficient ABB motors including frequency converters, significantly increasing efficiency and reducing energy consumption by up to nearly 900,000 kilowatt hours a year – equivalent to 200 single-family houses.

A machine for making paper is a huge piece of equipment: almost 80 meters long, powered by dozens of electric motors, and in operation 24 hours a day, seven days a week.

Model Group operates two of these mighty machines at its main Swiss facility in Weinfelden. These machines generate paper for corrugated cardboard production, which takes place in the same factory.

Energy-efficient paper production is of the highest priority for paper manufacturer Model Group. Philipp Lenhard, Technical Manager, explains how, using the latest motor technology, they have reduced their energy consumption by 900,000 kWh per year.

The production of paper is energy intensive. In addition to the electrical energy needed to drive the machines, a lot of heat is required. “We get it as steam via a three-kilometer pipe from the Weinfelden waste incineration plant,” explains Philipp Lenhard, technical manager at the facility. “If we were to generate this heat ourselves, we would have to burn around 20 million liters of heating oil a year.” With such large amounts of energy required, increasing efficiency would result in substantial energy and economic savings.

Sustainability in the DNA

Sustainability is to a large extent in the DNA of Model Group, as recycled fibers from paper and cardboard are largely the starting materials for its products. In Weinfelden, recycled cardboard and paper is used as the starting material, which is first cleaned of any contaminated material in several steps.

The powerful second paper machine of the Model AG facility in Weinfelden was retrofitted for better efficiency.

“Recycling and energy-efficient production have the highest priority for us – from an ecological as well as an economic point of view,” says Lenhard. This priority also applied to the renewal of the drive systems for paper machine two in Weinfelden. Previously installed components were reaching the end of their technical life expectancy. Frequency converters suffered from a lack of spare parts, while the motors dated from 1991 and required extensive overhauling – a cost avoided with the retrofitting.

“When planning the retrofit, it was clear to us that energy efficiency was an important element when choosing a provider,” says Lenhard.

This planning had to take into account tight time frames. The machine basically runs non-stop, and only stands still for a longer time in the summer, but for just six days. During this short period, the new components had to be ready on site, installed, and put into operation.

In a first step, the frequency converters were replaced in summer 2019 with the latest ABB ACS880 Multidrives. Then, in the summer of 2020, a total of 36 electric motors were replaced with the most efficient IE4-class models, also from ABB.
“The offer from ABB was very convincing, technically speaking. And we already had reason to value the support we have received from their experts in the past, from configuration to commissioning,” Lenhard points out.

900 meters of paper per minute

The corona pandemic brought new challenges to the planning for the 2020 engine retrofit, but these were well handled. “We exchanged ideas through virtual meetings, and via tracking we were also able to see where the goods were on their delivery route. For us it was of the utmost importance that all the motors were here on time, otherwise we would have lost a year.”

“Recycling and energy-efficient production have the highest priority for us.”

Delivery and commissioning worked as planned. Paper machine two was able to start up again in August 2020 – quieter and more economical than before. “According to our calculations, we can save up to nearly 900,000 kilowatt hours a year with the energy-efficient motors and converters.” This is about the same amount of energy consumed by 200 single-family houses.

Today the 2.5-meter-wide paper web runs through paper machine two at some 900 meters per minute, although the new drive solutions are capable of running at a speed of one kilometer per minute. In addition, the new motors run at only 1,000 rpm – 33 per cent less than previously. This has made it possible to optimize or eliminate gears, thereby significantly reducing friction.

The final result of the retrofit is increased production speed, significant energy savings, and a return on investment (ROI) of five years at most.

Model Group

Model Group develops, produces, and supplies high-quality packaging made of solid and corrugated cardboard, from simple transport packaging to highly refined chocolate and perfume boxes. The group has subsidiaries in eight countries. The main markets include Germany, Switzerland, the Czech Republic, Poland, Benelux, Austria, France, Slovakia, Croatia, Slovenia, Hungary, and Bosnia-Herzegovina. The company’s headquarters are in Weinfelden, Switzerland.