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The author:Jörg Fischer, Paper Machines Board and Packaging

Oji Fuji N-2 –the five-star board machine

Four small and obsolete board machines,owned by the company, were to be re-placed by one new, larger machine. Whata challenge when considering Japanesetradition and market habits! In Japan, thecustomer is still the principal focus, butnow many small clients will have to beconvinced to accept a standardized prod-

Fuji City, south of Tokyo, is located atthe foot of the famous white top volcano, MountFuji, and is reachable within one hour by Shinkan-sen super express train. The area has been Japan’scenter of papermaking from the very beginning dueto its abundance of forests and clear water. Today,approximately 100 paper mills (most of themsmall and obsolete) in a city of 200,000 residents,still provide evidence of long tradition. Justrealizing this may have been one of the essentialspurs to tackle the project for building a new boardmachine N-2 at the Fuji mill. It was indeed anambitious, but promising project launched byOji Paper Corporation at the end of 1999.

uct instead of a grade that had alwaysbeen tailor-made for them. Producing anddistributing minimum order lots of onlytwo tons would be a logistic challengewith such a huge machine. There wouldalso be the problem of releasing manylong-time employees where previoustasks would now be eliminated throughnewer technology. This in a country whereemployment with one company for one’sentire working career is a standard wayof life. On top of all this, there is the dis-advantage of being in the center of a bigcity, operating under perhaps the strictestenvironmental regulations worldwide!

The only solution possible was a highlyautomated and flexible production linemaking use of the latest experiences intechnology and engineering from the be-ginning of the stock preparation systemand ending in the shipping department.The decision on the supplier of the board

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machine was made in favor of VoithPaper. Excellent references and the con-fidence in Voith Paper’s know-how andworkmanship were the main criteria forthe selection. The N-2 machine at the Fujimill is now the largest board machine inJapan, and with a designed productionspeed of 800 m/min, it will also be thefastest multi-fourdrinier machine forwhite lined chipboard worldwide. Theboard grades produced on this machineinclude top-side double-coated whitelined chipboard and two-side double-coated special board with a basis weightrange between 160 and 450 g/m2. 100%recycled fibers are used as furnish. Themachine has been specially designed tomeet the quality targets of the product:good stiffness with the highest possiblebulk; but even more important is an ex-cellent surface in terms of smoothness,gloss and printability. Surface propertieshave the highest priority in Japan be-cause boxes are mainly printed by gravureprinting, but are also offset printed.

The investment cost by Oji Paper for theN-2 project was 27 billion Yen (250 mil-lion EUR), substantially strengthening thecompany’s leading market position forfolding boxboard in Japan. This grade isone of Oji Paper’s strong points in theJapanese market besides their newsprintand coated paper grades.

The MillIn 1908, the first board machine wasstarted up at the Fuji mill. In the mid-six-ties, the deinking process was introducedinto the mill to substitute groundwood.The deinking process has been steadilydeveloped and improved over the years,

recently with special emphasis on high-brightness pulp. Today, the recycled pulpcapacity is more than 1,000 tons/dayconsequently making the mill one of thelargest worldwide. Virgin pulp is nolonger needed, since the mill operates arecycling line for used liquid packagingboxes. The recycled pulp is used not onlyfor board production, but also as furnishfor the N-1 machine. The LWC machinewith on-line coating started up in 1990and is running with 90% recycled pulp ata speed of 1,200 m/min.

For energy supply, the mill owns a 10 MWhydropower station and three steamboilers with a total capacity of 100 MW.Before the new board machine N-2 wasinstalled, the Fuji mill had been runningtwo smaller board machines. Owing to itsexisting resources in assets, as well asthe experienced and educated personnel,the Fuji mill was the preferred place tosuccessfully carry out such a project.

Engineering, Construction and InstallationOji Paper is one of the two major paperproducers in Japan and number seven inthe world ranking. Typical for most bigcompanies, it is well staffed with expertsin technology and engineering. No won-der that Oji was able to make great use ofits resources for the new project. Mill-owned engineering companies did the en-gineering for the stock preparation sys-tem and finishing department, the civilengineering and the detail engineering forpiping and electricity. The engineeringservices for ancillary equipment aroundthe board machine and the board ma-chine building were also performed by OjiEngineering, however this work was

Fig. 1: Oji Paper at Fuji City at the foot ofMount Fuji.

Fig. 2: Press section with NipcoFlex™ press.

based on Voith Paper’s basic engineeringand recommendations. Limited space inthe center of an operating mill was achallenge for the planning engineers andconstruction companies.

In European countries, the use of prefab-ricated concrete elements is often con-sidered as the most efficient and fastestway to construct a paper machine build-ing. The Japanese have demonstrated thecontrary. Five months after starting thecivil engineering work, the first founda-tion rails were installed. From the base-ment to the operating level, the wholebuilding was made from on-site cast con-crete in a solid construction. From thispoint upward, steel construction wasused. The Fuji area in Japan is known tobe a high-risk earthquake region. Forthis reason, the board machine and thefoundations had to be designed for anearthquake factor of 1.3 g, making thebuilding and the machine heavier thanusual.

Voith Paper supervised the installationand start-up of the machine, while the jobitself was done by Oji Paper’s installationcompany together with the mill’s staff.The performance of installation, the man-agement of transportation and the reli-ability in keeping to the time schedulewere excellent. The majority of pre-pipingwas done outside the mill. The entireinstallation of the board machine wasfinished four months after the foundationrails had been put in place. After sixweeks of operational tests, the first boardwas wound on the reel, 18.5 months aftercontract signing. On October 1, 2001, theboard machine started its commercialproduction.

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Wet EndThe wire section comprises five four-drinier wires. The backliner is formed onthe bottom fourdrinier with a length of105 meters. The underliner back isformed on the first top wire, the secondtop wire with a DuoFormer™ D producesthe middle layer, and the underliner topand the topliner are formed on the thirdand fourth wires. All five headboxes fromthe latest family of MasterJet™ F/B head-boxes have shown an excellent perfor-mance. The middle layer headbox isequipped with ModuleJet™ dilution valvesand controlled by a Profilmatic™ M CDprofile control system. The expected CDbasis weight profile was achieved withina short time.

The press section has been designed fortwo nips and four felts. The first press isa double-felted suction press with suc-

tion roll web pick-up off the fourdrinier.The second press is a double-feltedNipcoFlex™ shoe press with the shoe intop position and a solid backing roll.Similar to the first press, the web is tak-en off the first felt, maintaining a com-pletely closed web run through the wholewet end. The shoe press can be loadedwith 800 kN/m, but usually a lower loadis used. Before the web enters the dryersection, an offset press without feltssmoothes both surfaces of the board.Upstream of the NipcoFlex™ press, aModuleSteam steam box is installedabove the bottom felt of the first press.

Cylinder Drying and Machine VentilationThe cylinder drying and machine vent-ilation equipment was not included inthe Voith scope of supply. Oji Paperpurchased it directly from domestic sup-pliers.

Calenders, CoatersAhead of the coater section, the web iscalendered in a Voith Paper hardnip cal-ender. A ThermaJet hot air blower withProfilmatic™ TJ control unit controls theCD thickness profile, both from VoithPaper Automation. Four LDTA coatingstations of the SmartCoater type with ap-plicator rolls, two for each side, are avail-able for coating application. Metering ofthe precoats is done by smooth rods, andthe top coats are applied in bent blademode. A combination of gas-fired infra-red dryers by Krieger, and hot air dryersby Langbein & Engelbracht, provide forsmooth and efficient evaporation. Onerow of the gas IR dryers is suited for CDmoisture control.

Web Run and Wind-upBefore winding up at the reel, the propersmoothness and gloss can be achieved

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45Design criteria of the board machine

Design speed 800 m/min

Drive speed 800 m/min

Speed range 200-800 m/min

Wire width 4,700 mm

Paper width on the reel 4,250 mm

Maximum roll diameter 4,000 mm

Gross production on the reel 800 t/24 h

Daily average sold production 650 t/day

Basis weight range 160-450 g/m2

Length from headbox to reel 230 meters

White-lined chipboard top side double-coated

and special board both sides double-coated

Furnish 100% recycledfibersDIP and magazines

by two soft nips. Two Voith Fibron va-cuum belts assist in tail threading in thetwo positions where the rope run is inter-rupted. They show an excellent perform-ance with all basis weights.

The board is finally wound on a Sirius™reel, permitting roll diameters of 4,000mm. RollMaster control ensures a uni-form build-up of the roll during the wholewind-up process. The roll change is sup-ported by an IBS turn-up system, cuttingthe web with a tape. The Sirius™ reelallows easy roll changes with minimumboard loss.

Oji Paper purchased the automation sys-tems for the machine directly. However,it should be mentioned that the DCS con-trol system and the machine drive weresupplied by Toshiba, and the QCS controlsystem by Yokogawa.

Fig. 3: Oji Fuji N-2 board machine.

Fig. 4: Sirius reel with 4 m parent roll.

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HidekiYamamoto,ExecutiveOfficer of Oji Paper andMill Manager of Fuji Mill

The main machine parts for the FujiBoard Machine N-2 were directly im-ported from Voith Paper, Austria, owingto the excellent technological conceptand with a view towards saving cost.

This state-of-the-art and most advancedmachine has enhanced our productivityand board quality.

Our aim is to gain a leading position interms of board quality. With this newmachine, we are in no way behind otherlarge machines in Southeast Asia.

Only recycled fibers are used at the Fujimill, and I believe it is one of the largestmills of this type worldwide.

The Fuji mill, with its prime geographiclocation and this big investment made,has set itself the goal to become theworld’s best recycled mill.

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FinishingThe Voith Paper scope of supply ended atthe reel. Nevertheless, it is of interest tomention some highlights of the sophisti-cated finishing department. The latter hasbeen designed for supplying even smallorder lots to many customers withinshort-time intervals, without having tomake too many grade changes.

After the reel, the parent rolls are slit intosmaller rolls in the winder. The rolls arethen conveyed to a vertical roll storageunit with a capacity of 13,000 tons. Anautomatic crane with vacuum lift handlesthe rolls. From here, most of the rolls areconveyed to the sheeting department andcut on four Simplex sheeters. Others aresold as complete rolls. Rolls, which arenot totally sheeted, are returned to an in-

termediate storage area. The pallets fromthe sheeters can either be conveyed to asorting area or directly to the automaticreaming or wrapping station where paperis used as packaging material.

SummaryOn November 2, 2001, the new produc-tion line was inaugurated with an im-pressive and festive opening ceremony,marking the final point of the project.The Executive Officer and Mill Manager,Mr Hideki Yamamoto, welcomed 400 in-vited guests and was proud to demon-strate a flawless production line rightup to the last detail. The speeches werebrief and the main participants were themembers of the project team and the op-erating personnel. The President and CEOof Oji Paper Corporation, Mr ShoichiroSuzuki, emphasized in his address theimportance of the new machine. He point-ed out that the high quality and flexibilitywould make it easier to serve a difficultmarket, resulting in benefits for all cus-tomers.

With the Oji Fuji N-2 project, Voith Paperhas once again shown its strength in

group-wide sourcing and its competencein project handling in the Asian market.Due to new communication technologies,even a distance of 11,000 kilometers wasno real barrier, as almost all documentsand drawings were forwarded electron-ically. Nevertheless, local support wasvery important. The local office, VoithTokyo, today Voith-IHI, as well as thetrading company, Mitsui Bussan Plant &Project Corporation, rendered importantservices, such as local transportation,translation and communication with thecustomer, which were absolutely neces-sary for establishing and maintaining thelogistics and a good working environ-ment. It was easy and a pleasure to worktogether with the experienced and profes-sional Oji project team members.

Within one month of continuous opera-tion, the machine was running with nom-inal capacity and the essential qualityproperties were reached. We would liketo congratulate and to express our appre-ciation to our Japanese friends on theirgreat success, and acknowledge those inthe Voith Paper organization who con-tributed to the success of this project.

Fig. 5: Oji Fuji N-2 coater.

Fig. 6: A look into the control center.

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