Not many sawmills today can claim—like Dansk Træemballage A/S (DTE) can—to have begun operations in 1581. Even more amazing is that the company can claim its facility is now Denmark’s biggest producer of wood for packaging. You don’t achieve that kind of record without continuously improving operations over the years and deploying state-of-the-art automation technology.
Upgrading to a CC-Link IE communications network helped the facility achieve a 1% improvement in yields for an estimated 300,000 Euros ($330,700) in annual savings. In addition, production has increased on existing lines over the past five years by about 30%.
The network is expected to continue reaping benefits for the company into the future. “CC-Link IE will help us to continuously improve the productivity and performance of our sawmill,” says DTE co-owner Orla Poulsen. “Even better, we also are achieving this in a cost-effective manner.”
As the mainstay facility for the company’s pallet production operations, the DTE sawmill processes over 300,000m3 of raw timber every year. The lumber is then distributed among the company’s five production sites to produce 150,000m3 of finished wood for crates and pallets.
“Running a sawmill means continuously improving the speed and productivity to get the most out of the wooden raw material,” Poulsen explains. “A quality finish is also particularly important, as we mainly focus on the food industry, which has strict standards on the end quality of crates and pallets, like mechanical stability and dimensional accuracy.”
Approximately 35 trucks bearing conifer logs arrive daily at the saw line in Ribe, Denmark, where the logs are transformed into lumber. The sawmill comprises a number of processing stations that turn logs into rough-cut timber and eventually finished lumber by performing debarking, profile cutting, sawing, storing, and stacking activities. All these processing stages require high-quality, reliable and responsive inverter drives to correctly position and efficiently power processing equipment, such as grinding rolls and other machinery.
Over 100 networked inverter drives power the sawmill’s automated systems, all of which need to be controlled simultaneously and in real time. This requirement led DTE to choose CC-Link IE, an open gigabit Ethernet system designed specifically for real-time industrial automation tasks.
“Accuracy is fundamental,” says Carstein Olesen, technical manager at specialist firm Hans Folsgaard, which DTE selected as its technical partner when upgrading the plant’s automation system. “That’s why DTE asked us to find a fast automation network.”
The CC-Link IE network is used to connect I/O, multiple standby power supplies, and inverters to the programmable logic controllers (PLCs) in DTE’s harsh production environment, ensuring that machines can safely and instantly adjust their parameters for optimal performance.
“Effective high-speed transfer of data creates a highly responsive system,” explains Lars Venborg, DTE technical manager. “In order to improve the quality of our lumber and increase our productivity we wanted higher speeds and therefore faster responsiveness from the variable frequency drives [VFDs] across the processing line. The old fieldbus network had become slow by comparison and could no longer support our manufacturing needs.”
CC-Link IE provides data transfer rates of 1 Gbps for high-speed communications. Because it supports over 120 stations per network, it also accommodates all the existing VFDs across DTE’s saw line and assures support for future growth.
“As the world’s first open Gigabit Ethernet for automation, CC-Link IE offers high-performance capabilities to DTE for controlling the inverters across the shop floor,” explains John Browett, general manager of the CC-Link Partner Association (CLPA) Europe. “The result is a more reliable and productive application, as well as increased business competitiveness as quality and output both rise without changing the mechanical aspects of the plant’s machinery.”
Adds Browett, “It is very important that DTE can get the maximum yield out of each log. By benefitting from the high-speed response time and bandwidth that Gigabit Ethernet offers, the machines on the saw line are able to assess the dimensions of each log as it goes through the mill very accurately and in real time.”
Ease of use is another important benefit of CC-Link IE, since setup doesn’t require any programming. “It will simplify management and maintenance for DTE,” says Venborg, “Because when required, it will be very easy to replace or add inverters during operation since we won’t have to change anything in the software setup.
“This wasn’t true with our previous system,” he adds. “We had to modify the software every time we replaced an inverter. As a result, we used to struggle with downtime, and we always needed both technicians and programmers to replace or add a drive, affecting uptime and productivity.”
