Publication: Pulp & Paper International
Issue: November 1993
Author: Robert Yeager

Process Control:

Mills opt for optimization

Mill-wide information systems have greatly improved quality performance and process control at MoDo Husum in Sweden and Millar Western's Meadow Lake mill in Canada. Robert Yeager reports.

The concept of "optimizing" mill operations is growing in both appeal and usage, worldwide. Papermakers are recognizing that information of the right type, in the right hands, at the right time can create "knowledge workers" who can work together to raise mill operations to record levels of productivity. Mill optimization also leads to improved flexibility, allowing the mill to be more responsive to customer needs, while profits improve, due to higher overall efficiency. Quality is also assured, as real-time process and product information becomes available and understood.

The concept is being proven by two world-class mills - MoDo Paper of Husum, in Sweden, and Millar Western of Saskatchewan, Canada. These mills belong to the new breed of pulp and papermakers which has realized that better product quality, customer service and operating results can be achieved by providing mill personnel with more timely, complete and usable information about all mill processes and operations.

This new kind of supervisory information system is at the very heart of computer-integrated manufacturing (CIM) in the mills, which use the Mops mill-wide optimization system supplied by MoDo-Chemetics of Ornskoldsvik, Sweden and Vancouver, BC, Canada.

Husum: Up north and out front

The name Husum has become synonymous with top-quality white woodfree papers used in business and publishing applications worldwide. Husum's grades include one of Europe's leading office papers (DataCopy), quality business forms (e.g., MoDo Laser, MoDo OCR, MoDo Preprint), and a white kraftliner suitable for printing on corrugated boxes (MoDo Liner).

The combined output of Husum's three twin-wire machines, three winders and four sheeting lines is 475,000 tons/yr. About 80% of the mill's paper goes south for export, to Western Europe, the USA, Australia, Singapore and other markets.

Husum's excellence comes primarily from its people and the modern processes and technological tools provided for them by the mill; tools that allow them to be more effective and more responsive to the increasing needs of customers in the buyers' market of the 1990s.

"Our customers focus on quality and service," says Husum veteran Lars-Gunnar Lundin, manager of the Systems Development Department. "They want more specialized, value-added grades, and they need just-in-time deliveries."

Also, Husum's customers will no longer accept reel-quality summaries, but insist on quality data and profiles on the individual rolls and pallets in their shipments. "Their need for quality information continues to increase," says Lundin. "They want logistical and quality traceability right from the roll and pallet back to the jumbo reel and paper machine." This applies equally to the mill's internal customers, MoDo's coating mills in southern Sweden, which receive about 25% of Husum's output.

In response to these needs, the Husum mill established a formal "quality system" in 1990. In 1991, the mill received an ISO-9001 quality certification.

Building a bridge to information island

Husum is no stranger to mill-wide information. In 1980, the mill developed its own quality-information system. By the late 1980s, however, that system was an obsolescent "island of information". So, in 1991, Husum began a search for a commercially-available replacement, a system that could first be used in the paper mill, and could then be readily expanded into the pulping operations. The system had to do the following:

Integrate the entire supply chain in the mill.

Provide the quality information and traceability desired by the mill's customers.

Yield minute-to-minute quality data which could be used by operators to control the processes.

Serve as an on-line troubleshooting tool.

Ensure a tighter delivery performance.

Assist in gaining ISO-9000 registration and on-going re-certification.

Provide a competitive advantage in the market.

A procurement team was established, which consisted of the paper mill manager, the production manager, the engineering/ laboratory manager and the controller. The team was aided by systems analysts and MoDo's process control experts. Selection criteria for the system were defined as:

Functional power (e.g., relational database and 4GL programming).

Ease of use.

Adherence to industry standards, such as SQL database queries and Ethernet communications.

Available interfaces to the existing mill systems, including Measurex, Siemens, ABB/Afora and Ulma packages.

Current reference sites.

"We wanted to work in partnership with a supplier, to tailor the information system to our users and our mill requirements," says Lundin.

After reviewing the systems on offer, the team chose the Mops mill-wide information and optimization system. A MoDo-Chemetics/Husum team worked together to create a detailed functional specification, and to customize the installation for the mill.

System mops up required data

The applications of a mill-wide information system constantly expand as the system is employed. Husum currently identifies its key Mops functions as:

Collecting and sending data on from the Measurex, Siemens, Ulma, Afora and other computer systems. The data transferred includes order-entry, laboratory, and sheeter information.

Calculating and storing both real-time and transactional information.

Reporting and graphically presenting information in formats desired by users.

Storing all paper-quality properties, plus reel, roll and set information.

Distributing all information on the Ethernet network.

At present, over 1,500 points of "realtime" process information (e.g., from the Measurex, Siemens, Ulma and Afora systems) and 350 points of transactional data (e.g., from winders, sheeters, the quality laboratory and the roll-tracking system) are being monitored and collected by the Mops system.

Although one of the computers handles roll-tracking requirements and one operates Mops, each computer will take over both functions in the event of a computer mal-function. "We must have the information system available to the users 24 hours a day, every day of the year," says Lundin. A separate Vax computer is used for program changes and development, to ensure that any new program is robust and error-free.

The system is currently configured for 20 simultaneous users, some of which are listed in Figure 2. Other users include the roll- and sheet-testing specialists, the quality manager, the technical services manager, the Autoline (automated laboratory system) manager, and finishing operators.

Users access Mops through standard Compaq PCs operating in a client-server configuration which allows the PC to do local computing, thereby reducing the load on the Vax and the network. Any of the mill's 150 PCs may access Mops if authorized and connected to the Ethernet local area network. A PC terminal is also located in the production conference room to gain access to data during production meetings.

In addition, remote modem connection into the network is available to authorized users, including selected people at MoDo headquarters some 30 km away.

Overall, the mill sees the benefits of Mops as process improvement, quality performance and on-line control. "We can immediately observe changes in the processes," observes Lundin, "and easily correct them." In addition, the Mops information has assisted the mill in moving from a six-shift to a five-shift operation, substantially improving individual productivity. The paper machines also run more efficiently, producing paper that meets customer requirements more consistently. Further, Mops provides the quality traceability that the mill needs to meet on-going re-certification standards for both ISO 9001 and its own internal quality audits. "Overall, we run a higher-quality and more efficient mill, and provide far better customer service using the mill-wide information," says the paper mill manager. "Mills without this type of system simply will not be able to compete in the future."

Meadow Lake: more data, less effluent

In February 1992, Millar Western started up a market pulp mill amid the rolling farmland of Meadow Lake, Saskatchewan, Canada. This mill set new environmental standards by operating as a closed-loop system, with no liquid effluent stream. In addition, the 800-ton/day mill has a workforce of only 184, making it one of the most efficient in the business. "We set some very tough goals for ourselves," says mill manager, John Eccleston. "We saw no way to meet them without giving our people process, quality and production information in real time, all of the time." So, from the beginning, management planned for a mill-wide information system.

The mill's two parallel APP (Alkalide Peroxide Pulping) lines use logs of local aspen, which produces a high-brightness, high-yield pulp. Debarkers, chippers and screens provide chips for three stages of chemical impregnation. This produces a highly-destructured chip for the subsequent refining and washing processes, which are interspersed with peroxide bleaching stages. The final pulp is flash-dried and baled for shipment. Of the two lines, one produces pulp for tissue and toweling, while the other makes furnish for printing and writing papers. The mill ships to paper mills in the USA, Europe, Canada and Southeast Asia, with every lot customized to comply with specific customer requirements. "These mills demand absolute quality conformance," says Eccleston, "and high uniformity from order to order."

Prior to building the Meadow Lake mill, Millar Western had started up a similar pulp operation in 1990 at Whitecourt, Alberta, Canada. "That experience showed us the overwhelming amount of information that was needed to operate the mill properly," says Bob Leslie, operations manager and a Whitecourt veteran. "So in planning the Meadow Lake operation, we decided early on to give our people a tool that would allow them to manipulate and massage the data into the most usable form." That planning led to the decision to install the Mops system, which has also been installed at the Whitecourt mill.

The Mops system monitors every key process and operation in the mill. At present, this amounts to a total of over 3,000 points. About 40 desktop PCs access Mops through a Novell local area network (see Figure 3). Graphics can be stored on the local PCs. "This eases the Lan load as usage grows across the system," says systems analyst, Jennie Lai.

Although Mops is relatively new at Millar Western, the system is currently used for a variety of applications by different disciplines in the mill. As well as those mentioned in Figure 3, current users include accounting, shipping and the quality laboratory. In addition to their individual functions, all use the Mops data for "what if" analyses in spreadsheets and similar analytical programs.

Everyone in the mill has access to all the information on the system, which can be processed to suit the user's needs. "The ability to tailor-make charts means that workers are shown information exactly as they want it," says process engineer, Mike Kennedy.

In addition, a modem connection to the Vax server ties the system to the Edmonton office, which transmits customer orders to the Mops system. Through this connection, authorized personnel can also access Mops from outside the mill (e.g., from their homes), using laptop computers.

Some customers, meanwhile, even get a record of process conditions at the time their pulp was produced.

"Every day we find a new use for the system," says Eccleston. "It's surely been a godsend for the mill."

 

 

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© 1993 Miller Freeman, Inc. All rights reserved.