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DONNANCONA leaps ahead

A new day has dawned for the employees at Alliance Forest Products’ Donnacona, QC, mill, a dawn that provides the promise of a secure future. The long-awaited new paper machine, PM 4, started up on Oc…

A new day has dawned for the employees at Alliance Forest Products’ Donnacona, QC, mill, a dawn that provides the promise of a secure future. The long-awaited new paper machine, PM 4, started up on October 22.

Built in 1912, the mill and its sister in Dolbeau, QC, were acquired by the newly-formed Alliance Forest Products in 1994 when Domtar decided the mills did not fit into its future plans. Running older, slower machines and producing commodity products, the sands of time were quickly running out on both mills. Dolbeau was the first beneficiary of the new regime with a rebuild of what is now PM 5 (Pulp & Paper Canada, October 1998). Then it was announced that Donnacona’s PM 3 would be rebuilt. However, this was a short-lived plan. In an interview with Pulp & Paper Canada in October 1998, Alliance president Pierre Monahan said the company changed its mind about rebuilding PM 3 because it realized the problems with PMs 1 and 2 would remain. Therefore, the company committed to the $275-million PM 4 project. The company also announced that PMs 1 and 2 would be shut. And, the company is spending to upgrade PM 3 also (see sidebar).

When the new paper machine ramps up, it will be able to produce 152 000 tonnes per year (t/y) of SC-B and SC-A paper grades for catalogues, magazines, flyers and inserts (brightness levels up to 72). Eventually, the medium-term goal for Alliance is to have the Dolbeau mill produce SC-B grades and Donnacona produce SC-A paper. The Donnacona mill will make 241 000 t/y, up from its present 178 000 t/y. The capacity of PM 3 will remain at 89 000 t/y.

To help with the project, Jean-Marc Simard, former mill manager at Dolbeau and involved with the PM 5 project, came to Donnacona in January 2000.

By the middle of 2001, the wood furnish will be 100% spruce chips, virtually all of them black spruce with a sprinkling of white spruce chips. The mill’s existing TMP (530 t/d) system will be used to produce the pulp. Depending on the grade, clay and kraft pulp will also be added, but as little as possible, Simard said.

The key to Donnacona’s pulp processing for PM 4 will be fibre fractionation. The process will be similar to the one used to great effect at Dolbeau, but a slightly more sophisticated version with more energy available. The fractionation needs to be improved for SC-A grades.

In the process, short and long fibres are separated. The long fibres will go through two Andritz 14 000-hp refiners. The long and short fibres will then go through two Sunds (now Valmet Fibre Technology) Conflo refiners. The goal, said Simard, is a 40 freeness pulp as the final TMP for PM 4.

Simard believes that fibre fractionation produces a better pulp than third stage high-consistency refining. This is because the latter refines all the pulp at high consistency. “Therefore, you are refining pulp (short fibres) that doesn’t need to be refined,” he explained. “We can custom refine pulp to its stage of development. In a third stage, you can break and, therefore, shorten fibres that don’t need to be.”

The main target the mill is trying to reach with its pulp is for the best printing characteristics for SC-B and SC-A grades. Good pulp strength is also critical to minimize the need for kraft pulp. “With fractionation, we can lower the freeness without losing strength,” Simard added. “We feel TMP quality is the big factor in final SC paper quality. That’s why we invested in fractionation. We need to put lots of energy into our pulp to get top quality.”

With an existing TMP plant, the changes made to the production process ahead of the new paper machine were the addition of Noss hydrocyclones, Sunds Delta screens and HC refiners as well as the Sunds post refiners.

The three paper machines (PMs 1, 2 and 3) had a common white water system. Now, PMs 3 and 4 will have separate dedicated systems with disc filters. This will give the machines better stability.

Another $12 million is being spent to install a second peroxide bleach plant. It will be operational in April 2001 The two bleach plants will be able to serve both machines.

The showpiece of the modernization is the Voith paper machine. Similar to Dolbeau’s PM 5, it features a ModuleJet dilution headbox, DuoFormer TQ gap former, triple-nip press with a NipcoFlex shoe press, DuoStabilizer single tier vacuum-assisted dryers, a Janus multi-soft nip calender and a Sirius reel.

There are four large approach flow screens: primary, secondary, tertiary and one for the dilution line. The primary screen is Voith’s new MSA model and at the time of purchase was the largest in North America. The MSA features a contoured body, designed to eliminate velocity fluctuations in the accepts chamber.

Differences from Dolbeau include a different design turbulence section in the headbox and the shoe press in the third press position. Voith’s regional sales manager, Sammy Di Re, said that as well, there are former section changes. The top side drainage unit is vacuum-assisted with multiple blades. The pressure of the opposed blades can be individually controlled.

The former features a slightly different design than Dolbeau’s. It has a larger forming roll and the wires separate over the couch roll. Di Re said this should provide good ash retention, good formation and minimal two-sidedness.

The NipcoFlex shoe press is in the third press position. It is designed to increase sheet consistency into the dryer section.

To minimize building length, the mill opted for a dryer design that is half single-tier and half conventional two-tier. The first three sections include 16 single-tier dryer cans in the Voith DuoStabilizer configuration. The sheet is fully supported by the felt for the single-tier run. This design provides complete support of the sheet for better runnability.

One novel innovation at Donnacona is a modern dryer drainage system that uses advanced controls to increase sheet quality, eliminate flooding and reduce energy consumption. The Johnson TechDry Pro system uses pre-programmed drying curves for specific grades of paper to optimize drying. The dryers are equipped with Johnson PT steam joints and cantilever stationary syphons allowing the system to operate with low differential pressures and blowthrough steam flows.

Operators can program preset drying curves for various grades and can adjust the system upwards or downwards if needed for special circumstances.

The 8-roll, 7-nip Janus online calender stack is the key part of the paper machine in producing SC-A quality paper, Simard said. Successful start-ups with similar Voith equipment at the Lang Papier (Ettringen) and Haindl (Schongau) mills in Germany have given Donnacona confidence in its choices. It features high-temperature, high-load capabilities.

The reel is the latest generation Sirius design and features a centre wind assist throughout the roll building process. Simard said they would be able to synchronize the two drives on the drum and reel spool. This should lead to better starts and less crepe wrinkling. As the jumbo reel spool is building, the mill can control the torque and, therefore, the torque differential between the reel drum and the jumbo roll. The mill can independently and sensitively control the nip load and the sheet tension.

PM 4’s wire width is 6.6 m and its trim width is 5.9 m. Design speed is 1500 m/min.

As with Dolbeau, Alliance opted for a Valmet Winbelt winder.

Advanced Dynamics supplied the roll handling equipment. This included the equipment needed to transport rolls from PM 3 to the common wrap line. The mill had to build a 50-m tunnel connecting the PM 3 machine room and the new PM 4 building.

As the rolls off PM 4 will weigh up to 8400 kg, Advanced Dynamics’ Ray Banham said the equipment had to be built with this in mind. Advanced Dynamics devised the heavy-duty equipment with special cushioning controls, primarily for the jumbo rolls. The whole idea, Banham added, is to handle the rolls as gently as possible.

Advanced Dynamics also supplied the pulper feed system. Pulp bales are placed on a conveyor in stacks four high. The system has the first
automatic, market pulp dewiring system in Quebec.

The new Lamb wrap line will handle all production from both machines. It can wrap jumbo rolls, 140 by 60 in. This gives the mill access to the new generation of roto presses. KSH Tessag of Montreal was the main consultant, “Maitre d’ouevre”, of the project.

A new warehouse has been built attached to the PM 4 building. About 67% of production is shipped by truck, the rest by rail. CN will service the mill with its new design rail cars, built higher to handle large rolls, which first went into service for the new Stora Port Hawkesbury paper machine.

“We want to be a very good SC paper producer,” Simard stressed, “equal to or better than our competitors. We have to concentrate on brightness, but especially on smoothness and gloss (both paper and print).” Alliance’s strategic plan calls for the mill to be a low-cost (cost per tonne) producer (in the first third) in specialty and SC papers It is also aiming to position its products in markets with good long-term demands. Manhours per tonne are expected to drop to 3.0 from 4.0 when PM 4 is at design production. This is competitive for a value-added producer, Simard said.

Helping to reduce the manhour per tonne figure is the new machine’s controls system. It is said that PM 4 will be one of the most integrated paper machines in Canada. ABB is supplying virtually all the controls including the complete drive system for the paper machine, calender and winder, an AccuRay quality control system including web inspection system, and the distributed control system (dcs).

The dcs integrates all systems into a single platform. It also integrates third-party supplied control systems. Salem Tajeddine is general manager, pulp and paper industries, automation segment, ABB.

Europe has used these types of systems for years and North America is slowly moving in that direction. An integrated system maximizes the transfer of information and enhances a mill’s ability to implement its control strategy in the most technically effective way. He noted that grade changes, an important aspect of Donnacona’s operation, take place simultaneously in all systems.

The machine will have continuous retention monitoring in the wet end. The dry end will feature all the “classical” scanners: thickness, profile, ash and moisture content. The profile reporting will be more sophisticated. It will be tied into the ModuleJet dilution headbox.

By 2001, Donnacona will have a complete mill wide network. Simard compared the process network system to a big doughnut. It will include all areas of the mill — TMP, fractionation, bleaching, paper machines — including the roll tracking and quality control systems. A process information system is being installed on the network.

The last purchases for the information system included a Honeywell high-speed camera system for PM 4. This will track breaks and defects and give operators a visual record of them and their causes. An SKF temperature and vibration monitoring system for the paper machine bearings will also be installed.

The addition of the new paper machine will not increase the load to the effluent treatment system as two older machines will be shut at the same time. The bigger effect will come from the new bleach plant. “With PM 4 and the second bleach plant, we will have to spend some money to add polymers to the primary and secondary clarifiers,” Simard said.

Training

There will be a learning curve for winding. There will be new winding “recipes”, Simard said. “The paper is very smooth so it reacts differently on the winder. We saw this in Dolbeau, going from newsprint to SC-C to SC-B. We will have to develop new recipes. The density, thickness and smoothness of the paper are all different from what employees know now.”

To prepare employees, an intensive training program for the people who will staff PM 4 was started in late 1999. Those who wished to work on the new machine applied. A series of tests were given and standards had to be met.

The mill identified five people as coach/trainers. They have been involved with the project since its beginning. Along with the suppliers and consultants, they devised the training programs and helped write the manuals.

There will be five crews staffing the new machine. During start-up, each will have its own coach/trainer for the duration.

There are seven people per shift, one more than usual, noted Simard. This is because the machine crews are also responsible for fractionation.

A new labor agreement included scheduling and vacations during the PM 4 start-up period, manpower movements and the introduction of semi-autonomous teams (production and maintenance).

Although the number of employees will drop from 376 to 335 when PMs 1 and 2 are shut and PM 4 comes online, Simard said the mill was able to absorb close to 100% of the job cuts through attrition or retirement packages.

There is another important human resources point to make. Simard said Alliance is working hard to ensure it has one mill in Donnacona with two paper machines, not two mills. That is, there will be no “second class citizenship status” with those working on PM 3.

A participative management principle is also being followed with employee participation. An executive committee meets monthly to discuss safety, training, quality, performance and working organization issues to name a few.

The new style of management is going over well, Simard said. “People are excited about the new machine because they realize it gives a future to the mill. They had been hoping for this project since 1991. They know the mill could not have survived otherwise. It is a challenge for them because it is a high-tech, sophisticated machine.”