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This study gives a first insight into the use of wood flour as a plant-based and cellulosic-based alter-native additive for newsprint and paperboard production using 100% recycled fibers as a raw material. The study compares four varieties of a spruce wood flour product serving as cellulosic-based additives at addition rates of 2%, 4%, and 6% during operation of a 12-in. laboratory pilot paper machine. Strength properties of the produced newsprint and linerboard products were analyzed. Results suggested that spruce wood flour as a cellulosic-based additive represents a promising approach for improving physical properties of paper and linerboard products made from 100% recycled fiber content. This study shows that wood flour pretreated with a plant-based polysaccharide and untreated spruce wood flour product with a particle size range of 20 μm to 40 μm and 40 μm to 70 μm can increase the bulk and tensile properties in newsprint and linerboard applications.

Polymeric felts are commonly used in the papermaking process on the paper machine wet end, in the press section, and in the dryer section. They provide an important function during paper manufacturing, including as a carrier or support; as a filter media assisting with water removal on the paper machine; in retention of fibers, fines, and fillers; and in some applications, such as tissue and towel, to impart key structural features to the web. These felts can have highly interwoven complex internal structures comprised of machine direction and cross-machine direction yarns of varying sizes and chemical compositions. Here, we present a non-intrusive three-dimensional (3D) image visualization method using advanced X-ray computed tomography (XRCT). This method was used to characterize the complex 3D felt structure and determine the water removal characteristics of some commonly used paper machine felts. The structural features analyzed include porosity; specific pore-yarn interfacial surface area; 3D pore size distribution; 3D fiber or yarn-size distribution; and their variations through the thickness direction. The top, middle, and bottom layers of the felt have very different structures to assist with water removal and impart paper properties. The size distribution of the yarns, as well as the pores in the different layers of the felt, are also inherently different. These structural features were non-intrusively quantified. In addition, variation in the structural characteristics through the thickness of the felts and its potential role in papermaking is explored. In addition to the 3D structural characteristics, permeability characteristics and water removal characteristics, including rewetting of select felt samples, have also been experimentally determined. It is interesting to observe the relationship between key structural features and permeability and water removal characteristics. These relationships can provide additional insights into press felt design, as well as ways to improve product properties and the dewatering efficiency and productivity of the paper machine.

Drying energy demand in the after-dryer section for the surface sized paper is an important economic factor in papermaking. Using an efficient sizing solution with high solids content and decreasing the pickup weight can reduce the drying energy requirement in the after-dryer section. A dextrin-poly(acrylic acid) copolymer was used as an additive for surface sizing of linerboard, and its effect on the mechanical properties of linerboard, and drying energy consumption were investigated. Results showed that, addition of dextrin poly(acrylic acid) copolymer had beneficial effects on the holdout of surface sizing starch and provided higher compressive and bending strengths. It was possible to reduce pickup weight by 23% while keeping the compressive strength and bending resistance at a similar level. Consequently, the reduced pickup resulted in higher dryness after surface sizing. Even though, drying analysis of wet sized sheets at a laboratory gave a lower drying rate when the copolymer was used as an additive, the result from a mill trial revealed that steam usage decreased significantly when the copolymer was used as an additive for surface sizing, which was attributed to the reduction in the pickup weight and improvement in holdout of the surface sizing agents on linerboard surface that is more pronounced on a high speed paper machine.

Fracture toughness is considered to be a good estimate of the paper breaking tendency of a paper web in a paper machine and press room. Paper breaks are caused by many factors, such as the irregular vibrations of a paper machine, impurities in the fiber furnish, and presence of shive. On a paper machine, the dryness of the paper web changes very rapidly from less than 1% to more than 95%. We tried to measure the fracture toughness of a paper web at different dryness levels in order to acquire a fundamental knowledge of paper breaks. Stretches of wet webs were also measured and compared to the changes in fracture toughness. Four different fiber furnishes were refined to different degrees, and their fracture toughness values were measured at different dryness levels (40%, 60%, 80%, and 95%). Two fracture toughness measurement methods (essential work of fracture and Tryding’s load-widening method) were compared, and found to give identical results. However, Tryding’s method was much easier to implement. The highest stretch was mostly at 80% solid content, where the highest fracture toughness occurred.

Detrimental substances that originate from deinked pulps and other raw materials tend to build up in paper machine circulation waters, hindering process efficiency and paper quality. The applicability of selective flotation to remove substances from circulation waters was investigated in a two-stage flotation process in which no chemical additives were used. The first stage of the process consisted of a flow channel for white water deaeration, including first-stage flotation. The overflow of the channel flow flotation was further treated in a separate second-stage flotation. The efficiency of the flow channel and a secondary flotation to remove bubbly gases, ink, stickies, and wood extractives were quantified in relation to the reject flow rates or solids yield. The total removal efficiency of a simulated two-stage flotation process was then analyzed for a specific case. The results showed that a considerable reduction of contaminant load can be obtained using a two-stage flotation process without affecting the deaerating function of the channel flow. Further optimization of the proposed internal white water purification scheme may provide substantial benefits to paper or board machine operations with reasonable solids recovery rate.

Paper forming is the first step in the paper machine where a fiber suspension leaves the headbox and flows through a forming fabric. Complex physical phenomena occur during paper forming due to the interaction between fibers, fillers and fines as well as chemicals added to the suspension. Understanding this process is important for the development of improved paper products because the configuration of the fibers during this step has a large influence on the final paper quality. Since the effective paper properties depend on the micro-structure of the fiber web, a continuum model is inadequate and the properties of each fiber need to be accounted for in the simulations. In the present work, a framework for microstructure simulation of early paper forming has been developed. The simulation framework includes a Navier-Stokes solver and immersed boundary methods are used to resolve the flow around the fibers. The fibers are modeled with a finite element discretization of the Euler-Bernoulli beam equation in a co-rotational formulation. The contact model is based on a penalty method and includes friction as well as elastic and inelastic collisions. The fiber model and the contact model are validated against demanding test cases from the literature with excellent results. The fluid-structure interaction in the model is examined by simulating an elastic beam oscillating in a cross flow. Finally, a simulation of early paper forming is performed to demonstrate the potential of the proposed framework. The unique modeling approach can be used to increase the fundamental understanding of paper forming and support process optimization.

地球温暖化防止のため世界規模でその対策が行われつつある中，温室効果ガスであるCO2排出量削減が重要視されている。そのため，化石エネルギー使用量の削減及び省エネルギーへの取り組みが急務となっている。新潟工場も1980年代に省エネ活動をスタートさせ大きな成果をもたらしてきたが2008年6月に9号抄紙機運転に備え，パルプ関連設備の新設・増強，同年9月9号抄紙機が営業運転を開始したことにより，エネルギー使用量の増加要因となっている。本報では新潟工場での省エネルギーへの取り組みと，2009年から検討を開始し実施に移して大きな成果を上げている，大型抄紙機を中心とした省エネルギー活動の内容及び事例を紹介する。

広幅・高速・薄物A3専抄をコンセプトとして，北越製紙新潟工場の4台目となるオンコーターマシン9号抄紙機（N9）は2008年6月ストックオンワイヤに始まりオンリール，カラーコーティング，グロスカレンダリング，リワインダリングへと順調に試運転工程の実施と調整を行ってきた。製品化に向けた品質確認として印刷テスト等を随時行い，ユーザーの評価を踏まえながら，更なる品質の向上と安定化を図っている。N9マシン稼働により既設3台のオンコーターマシンも含めた効率的生産体制が確立されるもの考える。ここではマシン選定のポイントや，新規設備の導入効果，建設および試運転の際のトラブル事例等をマシン設備中心に紹介する。

1989年, 上質紙抄造マシンとして操業を開始した呉工場5マシンは, その後の市況変化に伴い, 現在は, 中質微塗工紙も抄造している。2001年度, 社内「モデルマシン」指定を受け, プロジェクトチームを発足させ, 生産性向上に取り組んできた。対策として, 欠点および紙切れの削減を主目的とし, プロセス解析装置, 超高圧走行式ワイヤー洗浄装置 (Duoクリーナー), プレス脱水量測定装置 (エコフローメーター), 繊維長分析計, チャージ分析計, リテンション分析計等の機器を導入した。本報では, 導入した機器の内, Duoクリーナー, エコフローメーターおよび繊維長分析計の活用状況について紹介する。

レンゴー (株) 尼崎工場8号機は, 坪量115～200 g/m2の中芯原紙を抄造している。同抄紙機は, 1979年設置にてワイヤーパートは, 1987年にデュオフォーマーF型に改造し操業してきたがプレスパートは, 設置当初のもので, 近年, 老朽化が著しかった事により2002年2月に新規プレスに更新を行った。機種選定に際しては, プレス出口湿紙水分の低減による省エネと操業性の改善を目的として検討を行い, 最終的に板紙分野では, まだ実績がなかったトライニッププレスを採用した。本報では, 8号機に導入した, トライニッププレスの設備の概要とこれまでの操業状況について報告する。

近年, 古紙の高配合が進められていくなかでシリンダーやカンバス汚れが厳しくなり, ワインダーでの継手作業・継手損紙の増加により生産性が著しく低下する問題を抱えるマシンが急増している。この問題に対し, 原料のスクリーニング強化, ピッチコントロール剤の添加, シリンダーのドクタリング強化 (W ドクター化), カンバスの高圧クリーナー設置 (超高圧水洗浄) といったさまざまな対策がとられているが, 原料事情や抄紙条件が悪くなる一方で, これらの対策だけでは限界にきている。そもそも, これらの異物は, 抄紙機に入ってくる湿紙の上では極めて小さなものであり, それ自体は欠点の対象とはならないが, ワイヤー・フェルト・プレスロール・シリンダーやカンバスの表面へと付着し, さらに付着した粘着異物が湿紙表面のピッチや繊維などをピックアップし, ある大きさまで成長すると紙に再付着 (落下) し, カレンダーなどで潰されて欠点となる。これが欠点発生のメカニズムであり, 当社では, 欠点の原因を根本から打ち切るべく, ワイヤーからカレンダーまでの汚れ防止技術を活用した総合的な欠点防止プログラムを提案している。ライナーや白板のマシンにおける適用例では, プレスパートの汚れ防止剤の選定がドライパートの汚れにも大きな影響を及ぼしていること, ドライパートとウェットパートの薬品ならびに薬品散布方法の組み合わせにより少ないコストで欠点数を大幅に減少することができることが分かった。今後は, 抄紙機各パートの汚れと欠点の発生メカニズムを総合的にとらえながら, 効果的な対策を講じてゆく必要がある。

省資源，省エネルギーを目標として製紙業界においては各種の取り組みがなされてきた。本稿では製紙業界が抱えている問題，特に抄紙機での問題解決に役立つ新しい機器を二件紹介する。一つがマシン白水の再利用を可能にするペタックス（Petax）であり，もう一つがキャンバス洗浄装置ロボクリーナー（Robo Cleaner）である。ぺタックスは白水を高圧シャワーに必要な水質まで濾過可能なフィルターである。近年はマシンの大容量化，抄紙速度の高速化などにより抄紙用具洗浄用高圧シャワーにより多量の清水が使用されてきた。しかしマシン用シャワー水として循環白水を使用する事は，清水原単位の削減だけでなく，清水温度をアップさせる為に消費されるエネルギーの節約にもつながるものであり，その再利用は重要な課題である。また古紙については更なる利用促進が検討され，原料調整設備の改良は年々進み，これらの要望に応えてきている。一方，抄紙工程においては今まで目立つことの無かったトラブル，特に古紙利用増加を原因とするトラブルが増してきたと言われている。このようなトラブルの一因である，ワイヤー（フォーマーパート），フェルト（プレスパート），キャンバス（ドライヤーパート）に付着するピッチなどの異物，紙粉等による汚れを取り除く洗浄装置がROBO, FF-Cleaner（Forming Fabric Cleaner），PF-Cleaner（Press Felt Cleaner），Dryer Canvas Cleanerである。

メッツォペーパーの最新技術を集積したOptiConcept抄紙機は，既に世界で何台かの稼動実績が上がっている。これらはいずれも高い紙品質と生産性を求められている。なかでも，ドイツで稼動しているワイヤ幅10m，設計抄速2，000m／分のオンラインLWC抄紙機を始めとして，新しく導入されつつある中国のOptiConceptマシンも関心を集めている。一方では，新設ではなく既設のマシンの改造によって紙の品質の向上，生産能力の増強，効率のアップなどを目標として，メッツォペーパーは改造技術の開発にも注力している。改造のための技術は個々のマシンセクションごとの改造からなっており，全部を合わせれば効果的なライン改造となる。しかし，実際には一度に全ラインを改造することで改善を図る代わりに，段階的な改造法を採り最大のポテンシャルを達成することになる。本稿では，多くのマシンセクションの中からいくつかの改造技術のトピックスを選び，紹介する。

The first installation of the sectional drive system of a paper machine by Toshiba was in the year of 1951. And then the DC drive system of thyristor Leonard had been applied to the drive system of the paper machine. And the sectional drive system has been developed dramatically to the fully digital controlled AC drives systems today. The latest system has the great advantage to the conventional systems, but the renewal to the latest system from the existing system have not frequently occurred due to the restriction of the period of shutdown, the initial cost of renewal, and other factors. Actually the existing system automatically have been getting old and old, so the reliability of the equipments have been getting poor and poor.In order to recover the reliability, the drive equipments should be renewed. If the equipments are not renewed. many problems would appear. The spare parts of the equipments may not be manufactured any more, and the number of technicians who can handle the equipments is getting smaller, and the down time of the paper machine may cause the reduction of the production of paper. The predictive maintenance and renewal of the equipments should be usually planed. It is not easy to renew the existing equipments at one time, so the gradual renewal should be considered with paying attention to the hybrid system.This article explains the points to be considered at the renewal of the drive systems for paper industries and the saving energy by applying the medium voltage inverter to fans and pumps with the merit of the inverter.

Increased stock quality and efficiency of the stock preparation process are the main focuses of the OptiFeed concept. A conventional stock preparation system, including approach system. has some major problems, such as uncontrollability of consistency of each furnish and large dead volume in tanks. Immediate problems with such systems are stability. such as consistency swing. and the extended time required for grade changes. Through applying the new process solutions. equipment and automation within the OptiFeed concept uniform stock parameters such as consistency and pressure of furnish fed to the paper machine can be achieved. At the same time. faster grade change time can be obtained which also results in better efficiency. In addition, less space and energy is required. which reduces investment and operation costs.In addition to several partial OptiFeed system is operation, the first full-scope references have been successfully started up. Those OptiFeed systems are discussed in this paper. including the first mill results and experiences.

A new Mitsubishi high-speed paper machine development project has started in 1999 and the new product is called MJ series to produce quality paper at 2, 000 m/min operation speed. The MJ series has been developed in the course of the elementary study, program simulation, model test, and final verification on our pilot paper machine in Mitsubishi R & D center of Mihara, Japan.This paper presents the several challenges we were faced with when we tried high-speed operation on our pilot machine and also presents some useful products for stable operation.

For many years. retention-aid dosage has been controlled by the white water consistency in newsprint, fine paper and board applications. This control strategy is well known and has proven efficient and beneficial. However, combining retention-aid control and charge demand control with coagulant or fixative in the thick-stock area provides additional benefits. An on-line charge analyzer, measuring the incoming furnish charge level, allows controlled coagulant addition so that downstream additives are applied more efficiently and economically. This control strategy provides substantial cost savings to the mill. Costly functional additive consumption is reduced and other chemical control loops, such as retention-aid addition, are improved.This paper explains the impact of white-water consistency on paper machine outcomes such as basis weight variation, steam consumption and wet-end stability. White-water consistency, dewatering and charge demand control approaches are discussed, and practical examples are used to describe how short circulation and chemical composition of the pulp affects final product quality. Mill experiences with the on-line units, and proposed gains and benefits of these measurements to papermakers will be demonstrated.

Modern automation solutions for papermaking wet end is a nice example how to utilize process analyzer as part of the machine controls. By wet end management we aim to have stable total and ash consistencies. drainage properties of the headbox suspension. and basic chemistryin paper machine short circulation. Stability is very important, because it's directly connected to paper machine runnability as well as to quality of produced paper. The level and variation of charge have a considerable effect on process status and operation. On-line charge measurement provides valuable information about the wet end chemistry of the paper machine. It is possible to perform charge contgrolbased on measurement by charge analyzer kajaaniCATi. The control provides many benefits for the papermaker. The benefits are process information, stability of process. runnability of papermachine and economical and effective use of chemicals.

本レポートは, 抄紙機におけるプレスセクションの設定およびルーチン作業の最適化を促進するべく設計された最新のプレスフェルト測定システム, フェルトビュー™に関するものである。当該測定は, 水分率, 透気度および各フェルト温度についての特性ならびに傾向についての情報を与えるものである。この情報をプレスセクション直後の水分率測定システム, エンバイロスキャン™と組み合わせることにより, 製品の品質, フェルト性能及びプロセス効率の向上を可能とし, しかも加圧および乾燥作業のエネルギー消費を低減可能とする。特にこのパートは従来から操業者の経験と推測による操業が行われているが, これからはフェルトビュー™やエンバイロスキャン™の実データをもとに合理的な操業指針をたてる事が可能になる。本報告は既にフェルトビュー™を使用しているユーザーから提供されたデータをもとにまとめたものである。

The latest drives system for a paper machine has high speed data link with optical fiber. The various drives data can be shown on the supervisory CRT. On the other hand, Information Technology (IT) has progressing very fast. Internet connecting facilities is getting familiar. The remote maintenance system and alarm messaging system via Internet has been realized.

A new Mitsubishi high-speed paper machine development project has started in 1999 and concluded with product offering to the market in October 2001. The new product is known as MJ series and is designed to complement the current MH series Mitsubishi paper machines.The goal of MJ series paper machine is to produce quality paper at 2, 000 m/min operation speed while being an operator friendly product. The MJ series has been developed in the course of the intensive elementary study, program simulation, model test, and final verification on our pilot paper machine in Mitsubishi R&D center of Mihara, Japan.This paper presents the concept and features of the MJ series paper machine.

Increasing the size of rolls of rotogravure, LWC and newsprint, increasing the speed of printing press, and evolving of paper grades and paper making processes require to match the capacity of winder to the paper machine operated with high speed.Based on these demands, minimizing manual operating and increasing operation productivity, Metso developed the completely new multi-station winder called “WINROLL”. There are many automated functions such as “splicing at unwinding stand”, “web threading”, “core handling” and “tail fastening”, which make one-man operation possible.The WINROLL winder is able to produce 10 ton and 4 meter width rolls by new technologies.

We previously reported that we had drawn directly watermark on cylinder paper machines. But the following problems were arisen.· It is difficult to remove the drawing materials that were seeped into the inside of cylinder paper machines.· The watermark was removed by organic solvent.· There is big risk if we draw watermark on cylinder paper machine.Therefore, we investigated watermark that the method of drawing on transfer paper.The following results were arisen.· The new system is more simple than that of last year.· is possible to control the line of watermark by the velocity of drawing and the shape of the pen.· The watermark of transfer paper is transcribed to the cylinder paper machine by the flatiron.· New removal liquid of watermark was invented.· The removal liquid is aqueous solution and doesn't harm for our health.We were able to use the cylinder cover of the watermark repeatedly.

Neutral papermaking and high recycle fiber usage in recent years make papermaking more troublesome. Conversion of acid to neutral papermaking reduced popular use of alum. Also recycle fiber usage and worldwide concern in environmental problem brought various contaminations, anionic trash and unwanted ions in papermaking process, which would harm wet-end operation. These harmful materials could deposit on papermaking equipment, and lower machine speed, fiber retention and paper quality. As a result production rate and runnability of paper machine is affected.“Realizer” developed by Somar will give a solution to the problems associated with wet-end operation. The new chemical assists retention of other wet-end chemicals, thus reducing total chemical usage. It also improves drainage and fiber retention. Optimization of wet-end operation using “Realizer” can be achieved by proper selection of cationic charge, molecular weight and molecular weight distribution. It depends on stock characteristics and other chemical usage. Maximization of the effect with “Realizer” is demonstrated.

A retention control system trial was performed for the wet part of a papermaking machine. By introducing two intelligent pulp and ash (filler) low consistency sensors (Kajaani : RM-200 M) to the stock supply line of head box and the white water (WW) filtrate line of wire part, we can monitor its wet end process conditions continuously. The retention control system using these sensors stabilizes the wet part process by controlling WW consistency, that is by an appropriate action of the retention aid dosage using a gap added PI (Proportional plus Integral) controller. As many grades production is running and grade changes are run frequently in this paper machine, it is difficult to determine the target set value (SV) of WW consistency. So we developed a new algorithm to judge the process stability by itself and to determine the SV target value of WW consistency automatically.