Paper Technology Journal

World paper market: Quo vadis newsprint?

News from the Divisions: Stock Preparation, Paper Machinery, Finishing and Service.

A Scandinavian Success Story. Notable Startups. Orderbook Highlights.

China, changing times in 3 the cradle of papermaking. Contents

Foreword 1 Corporate News

Highlights USA/Germany: Voith Appleton machine clothing. 55 Startups, orders on hand 2 Austria: World paper market The Andritz Group – partnering the Quo vadis newsprint? 5 pulp and paper industry 58

News from the Divisions Germany: Stock preparation: B+G Fördertechnik thirty years on 64 Membrane technology for the further close-up of paper mill water loops 14 Germany: Board and packaging Paper Machinery: pilot paper machine upgrade – Ortviken PM 4 – facing the future with tomorrow’s technology today 22 versatility 69 Paper Machinery: Latest generation of cylinder mould New names, new addresses formers – FloatLip former N, NO, S 28 Hunt & Moscrop: now Voith Sulzer Paper Machinery: Finishing Ltd., Manchester 72 Serang BM3/BM4 – the exemplary commissioning 30 Voith Sulzer Paper Technology: regional representation in Jakarta 72 Gap Former Technology: No. 26 DuoFormer CFD installation a success 37 Special awards for innovation and design Paper Machinery: New applications in multilayer Neusiedler Paper wins innovation technology 38 award with a revolutionary 3-layer headbox and NipcoFlex press 73 Paper Machinery: Brilliant Coating with JetFlow F – SPCI ’96 – impressive presence 73 data, facts, experience 44 Finishing: Advertisement of the year in Brazil 73 Econip – a new generation of deflection compensating rolls 48 China: Service: The changing origins of GR2 cover – next-generation paper – from hand-made performance leader 51 to machine-made 75

Cover picture: Ortviken – successfull start-up (see article on page 22). 1

Dear customers, dear readers,

It is now two years since Voith Sulzer Paper Technology was founded – a good time to look back of what has been achieved so far. The merger of the Voith and Sulzer paper technology divisions has been a complete success, with worldwide recognition of their combined strength. Order intake, sales and income have substantially exceeded expectations despite extraordinary restructuring efforts. Our sincere thanks go to all our loyal customers both old and new for their unwavering confidence in the new Voith Sulzer Paper Technology Group.

Since one of our prime targets is complete coverage of all market areas with comprehensive local customer service, we are currently strengthening our engagement in the world’s main paper producing regions. In North America medium-term business Hans Müller, President and CEO, expansion of about 30 percent is planned. The same applies to Asia, the fastest Voith Sulzer Papiertechnik GmbH growing market in our business. In China a new joint venture was signed in March 1996 with the founding of Liaoyang Voith Sulzer Paper Machines Ltd, and our new office in Jakarta has had a successful start. The world is indeed growing together – and we are growing with it. This is illustrated by two key figures from the 1995/96 business year, the second year of Voith Sulzer Paper Technology: with sales totalling 2.16 billion DM, the previous year’s result was exceeded by 40%!

We are particularly proud of our new orders and start-ups in Scandinavia – the fruit of our ongoing technical innovations. The paper industry needs these innovations for continuous, cost-effective quality and productivity improvements. The printing industry in turn needs this quality to compete against the flood of electronic media – a challenge which the paper and printing industries have to face together. On page 5 you will find some interesting observations in this connection by a long-standing newspaper publisher.

As we go on tackling the challenge “twogether” with our joint innovations, we shall certainly succeed. And in this spirit I wish you all the very best for yet another year of success.

Sincerely

Hans Müller 2

HIGHLIGHTS STARTUPS, ORDERS ON HAND

The following is an overview of outstanding startups from October 1, 1995 to November 30, 1996, together with main orders on hand.

STARTUPS

Stock preparation Waste paper processing systems and Rebuilds Hiang Seng Fibre Container Corp. subsystems for other types of paper Felix Schöller jr., Osnabrück, Ltd., Bangkok, Thailand. Australian Paper, Fairfield, Australia. Germany. Schwäbische Zellstoff AG, Ehingen, Waste paper processing systems KZP Kostrzynskie Zaklady Germany. and subsystems for graphic papers Chemical pulp processing systems Papiernicze S.A., Kostrzyn, Poland. Papeles Bio Bio S.A., Chile. Hiang Seng, Thailand. Mead Corp. Containerboard Div., Cia Suzano de Papel e Celulose, Dae Han Paper Co. Ltd., Stevenson, USA. Suzano-S.P., Brazil. South Korea. Stora Carton Board GmbH, Krkonosske Papierny A.S., UK Paper Plc, Great Britain. Paper machines Arnsberg, Germany. Hostinne, Czech Republic. Stora Feldmühle, Belgium. Schoeller & Hoesch, Gernsbach, International Paper Kwidzyn S.A., Holmen Paper AB, Sweden. Graphic papers Germany. Kwidzyn, Poland. Parenco B.V., The Netherlands. SCA Graphic Papers AB, Ortviken, PWA Dekor, Unterkochen, Germany. Repap Manitoba, Manitoba, Canada. Australian Paper Mills Ltd., Sundsvall, Sweden. Consolidated Papers Inc. Biron Div., Jiang Yin Paper Mill, Jiang Yin, Australia. Holmen Paper AB, Braviken Mill, Wisconsin Rapids, USA. China. Sepoong Co. Ltd., South Korea. Norrköping, Sweden. United Paper Mills Ltd., Igaras, Brazil. Halla Pulp & Paper Company Ltd., Kimberly Clark, Neenah, Wisconsin, Jämsänkoski, Finland. Sguário, Brazil. South Korea. USA. Alberta Newsprint Co., Whitecourt, International Paper Co., Augusta, Hansol Paper Co. Ltd., South Korea. Halla Paper Co. Ltd., Korea. Canada. USA. Trust International Paper Board and packaging papers Torraspapel S.A., Sarria de Ter, Spain. International Paper Co., Corporation, Philippines. P.T. Indah Kiat Pulp and Paper, Nippon Paper Industries, Riegelwood, USA. Serang, Indonesia. Ishinomaki, Japan. Westvaco Corp., Covington, USA. Waste paper processing systems Zülpich Papier GmbH, E. Holtzmann & Cie. AG, Maxau, Sonoco Products Co., Hartsville, and subsystems for Zülpich, Germany. Germany. USA. board and packaging papers Visy Paper, Australia. Stora Uetersen GmbH, Uetersen, Weyerhaeuser Co., Springfield, USA. SCA De Hoop, The Netherlands. Shaanxi Machinery & Equipment Germany. Appleton Paper, Newton Falls, USA. Smurfit Townsend, Hook, Import & Export Corp., Hanzong, Zanders Feinpapiere AG, Bergisch International Paper, Ticonderoga, Great Britain. China. Gladbach, Germany. USA. P.T. Indah Kiat Pulp and Paper Visy Paper, USA. Klingele Papierwerke GmbH & Co., Domtar-Cornwall, ONT, Canada. Corporation, Indonesia. VPK Oudegem, Belgium. Germany. Stone Consolidated-Grand Mere, Knauf Neg., St. Petersburg, CIS. Thai Kraft Paper Industry Co. Ltd., Daishowa Paper Co., Tokyo, Japan. PQ, Canada. P.T. Indah Kiat Pulp and Paper Thailand. Honshu Paper Co. Ltd., Matsumoto, International Paper, Jay, USA. Corporation, Indonesia. Tissue Japan. Torraspapel, Motril, Spain. Zülpich Papier GmbH, Germany. Al-Keena Hygienic Paper Mill Co. Ltd., Chuo-Paper-Board Co. Ltd., Roman Esteve, La Pobla de Corenso United Oy Ltd., Finland. Al-Keena, Jordan. Nakatsugawa, Japan. Claramunt, Spain. Thai Kraft Paper Ind. Co. Ltd., Cheng Long Co. Ltd., Tien Long, Rigesa, Celulose, Papel e Papierfabrik Hermes GmbH & Cie Thailand. Taiwan. Embalagens Ltda., Tres Barras, KG, Düsseldorf, Germany. Papeteries Emin Leydier, France. Papeles Industriales, Chile. Brazil. Smurfit Townsend Hook S.A. Papeteries de Bègles, Industria Cartaria Tronchetti, Borgo a Stone Container Corp., Missoula, Papermakers, Snodland, France. Mozzano, Italy. USA. Great Britain. 3

Joyce Dayton Corp., USA. KZP Kostrziynskie Zaklady Igaras Papeis e Embalagens Ltda., Ass Domän, Sweden. AssiDomän Frövi, Sweden. Papiernicze S.A., Kostrzyn, Poland. Otacilio, Costa Santa Catarina, Portals, Great Britain. Bataan Pulp and Paper Mills, International Paper, Augusta, USA. Brazil. Pap. Del Aralar, Spain. Makati, Manila, Philippines. Rhinelander Paper, Rhinelander, Yue-Li Machine Comp., Tien Long, IP Kwidzyn, Poland. Cartiere del Garda S.p.A., Riva del USA. Taiwan. Serang PM 3, Indonesia. Garda, Italy. International Paper, Jay, USA. Hygienic Papermill Co., Amman, Serang PM 4, Indonesia. Howard Paper, USA. Krkonosske Papierny A.S., J.R. Crompton, Great Britain. Coating technology Hostinne, Czech Republic. Munksjö, Sweden. Hansol Paper Co. Ltd., Korea. Winding technology Visy Paper Pty., Ltd., Gibson Island, Milliani, Hungary. SCA Ortviken AB, Sweden. – DuoReel Australia. Arjo Wiggins, Great Britain. Hong Won Paper Mfg. Co., Ltd., SCA Graphic Papers AB, Ortviken, Smurfit Townsend Hook, Snodland, Toprak Kagit Sanayii A.S., Turkey. Korea. Sundsvall, Sweden. Great Britain. Torraspapel S.A., Sarria de Ter, Holmen Paper AB, Braviken Mill, Machine calenders Spain. Norrköping, Sweden. Finishing SCA Ortviken, Sweden. Torraspapel S.A., Motril, Spain. Federal Tait, Inverurie Mill, Great Townsend Hook, Great Britain. Toprak Kagit Sanayii A.S., Turkey. Britain. Janus Concept Crown Packaging, USA. Hangzhou Shan Xin Paper Co., Ltd., August Köhler AG, Oberkirch, KNP Leykam Maastricht, Serang PM 3, Indonesia. Fu Yang Town, China. Germany. The Netherlands. Serang PM 4, Indonesia. Vorantim Celulose e Papel, Simao Kostrzynskie Zaklady Papiernicze, Rebuilds Jacarei, Brazil. Poland. Supercalenders Stora Uetersen, Germany. KNP Leykam, Gratkorn, Austria. Al-Keena, Jordan. Tianjin, China. Stora Kabel, Germany. Kymi Paper Mills Ltd., Kuusankoski, Hansol, Korea. Stora Reisholz, Germany. Finland. – Winders Daishowa, Japan. Cart. Toscolano, Italy. Veitsiluoto Oy, Kemi, Finland. Halla Engineering & Heavy UPM Tervasaari, Finland. Yuen Foong Yu, Taiwan. Hua Yang Technology and Trade Industries Ltd., Korea. Bosso, Italy. Koehler, Germany. Corp., Wuxi, Branch, China. Holmen Paper AB, Sweden. Yuen Foong Yu, Taiwan. Machimpex, America Inc. Font Lee, Fabricadora de Papel de Celulose Roll handling China. S.A., Brazil. Soft calenders Halla Paper, Korea. Genting Sanyen Paper, Singapore, Papeles Bio Bio S.A., Concepción, SCA Ortviken, Sweden. Papierfabrik Scheufelen, Germany. Malaysia. Chile. Hansol, Korea. KNP Leykam Maastricht, Kymmene Kaukas Oy, Kaukas, Haindl Papier GmbH, Schongau, Halla Paper, Korea. The Netherlands. Finland. Germany. Holmen Paper Braviken Mill, Cart. del Garda, Italy. Jiang Yin Paper Mill, Jiang Yin, Cia. Suzano de Papel e Celulose, Sweden. Burgo Ardennes, Belgium. China. Suzano, Brazil. Kymmene Wisaforest, Finland. NDI, The Netherlands.

ORDERS ON HAND

Stock preparation PWA Industriepapier GmbH, Peterson Moss, Norway. Nampack Paper Ltd., Bellville, Aschaffenburg, Germany. United Pulp & Paper Co. Inc., South Africa. Wellpappe Wiesloch, Wiesloch, Philippines. Waste paper processing systems Germany. and subsystems for graphic papers Moritz J. Weig, Mayen, Germany. Waste paper processing systems Paper machines Schwäbische Zellstoff AG, Ehingen, Papierfabrik Meldorf, Tornesch, and subsystems for other types of Germany. Germany. paper Graphic papers Papierfabrik Palm GmbH & Co, Klingele Papierwerke GmbH & Co, PWA Dekor GmbH, Unterkochen, Halla Pulp & Paper Ltd., Halla, Eltmann, Germany. Weener, Germany. Germany. Korea. Stabilimento di Avezzano, Avezzano, Danisco Paper A./S., Grenaa, Steinbeis Temming Papier GmbH, KNP Leykam, Gratkorn, Austria. Italy. Denmark. Glückstadt, Germany. Malaysian Newsprint Industries Cartiere Burgo S.P.A. Verzuolo, Danisco Paper A./S., Grenaa, Papeteries de Begles, Begles, Kuala Lumpur, Malaysia. Italy. Denmark. France. Nippon Paper Industries, Iwakuni, Stora Hylte, Hyltebruk, Sweden. Papeteries Emin Leydier, Saint Japan. Sepoong Co., LTD., Sepoong, Vallier, France. Waste paper processing systems Forestiers Alliance Inc., Dolbeau, Korea. Papeteries Emin Leydier, Saint and subsystems for tissue papers Canada. Vallier, France. Procter & Gamble GmbH & Co., China National Technical Import & Waste paper processing systems Kaysersberg Packaging, Germany. Export Corporation (CNTIC), China and subsystems for board and Kaysersberg, France. Kimberly Clark GmbH, Flensburg, Trans-National Paper Corp., packaging papers Corenso United OY LTD., Varkaus, Germany. Philippines. Europa Karton, Hoya, Germany. Finland. Serla Oy, Mänttä, Finland. Consolidated Papers, Stevens Point, Papierfabrik Tillmann, Sinzenich, Rigid Paper Produkts LTD., Selby, LG Cable & Machinery Ltd., USA. Germany. Great Britain. Dae Han, Korea. Sinar Mas Pulp & Paper Ltd., India. 4

Halla Thai, Thailand. Holmen Paper AB, Hallstavik, Stone Container, Missoula, USA. Finishing Mazandaran Wood and Paper Sweden. Stone Savannah River, Industries, Iran. Haindl Papier GmbH, Schongau, Port Wentworth, USA. Germany. Saica, Spain. Janus Concept Board and packaging papers Stora Kabel GmbH, Hagen, Germany. Torras Domeneck Flaça Gerona, Lang Papier, Germany. Visy Paper, New York, USA. Kübler & Niethammer, Kriebethal, Spain. Shin Ho Paper, Korea. Guangzhou Victorgo Industry Co. Germany. Daishowa Shiraoi, Japan. Oji Paper, Japan. Ltd., China. Haindl Papier GmbH, Walsum, Confidential, North America. Ningbo Zhonghua Paper Co. Ltd., Germany. KNP Leykam Gratkorn, Austria. China. Forestiers Alliance Inc., Dolbeau, Coating technology SFI Port Hawkesbury, Canada. Mazandaran Wood and Paper Canada. Tianjin Paper, Tianjin, China. Industries, Iran. Papel Imprensa S.A., Pisa, Brazil. Westvaco Corp., Wickliffe, USA. Soft calenders CMPC-Cia. Manufacturera de Sczetin Skolwin S.A., Poland. KNP Leykam, Gratkorn, Austria. Ningbo PM 2, China. Papeles y Cartones S.A., Chile. Chuetsu Pulp Co. Noumachi Mill, Felix Schöller jun. Papierfabriken Ningbo PM 3, China. Nohmachi, Japan. GmbH & Co KG, Osnabrück, Piracicaba, Brazil. Tissue PWA, Hallein, Austria. Germany. Siam Paper, Thailand. Wepa Papierfabrik, Germany. Crown Van Gelder Papierfabriken Guanzhou Victorgo Industry Comp., Ballarshah, India. Thrace Papermill S.A., Greece. N.V., Velsen, The Netherlands. Ltd., China Confidential, USA. Strepp GmbH & Co. KG, Germany. CadiDavid, Italy. Shin Ho Paper Mfg. Co. Ltd., Seoul, CMPC Procart, Chile. Asia Pulp & Paper, Indonesia. Papierfabrik Palm GmbH & Co., Korea. MNI Selangor, Malaysia. Papeles Industriales, Peru. Eltmann, Germany. Stora Hillegossen, Germany. Suzano Rio Verde, Brazil. City Forest Corp., Ladysmith, USA. Carl Macher GmbH & Co. Papier- Consolidated Paper, USA. Alliance Dolbeau, Canada. Bacraft, Brazil. und Pappenfabrik, Hof, Champion International Corp., USA. Sappi Blackburn, Great Britain. CMPC, Santiago, Chile. Germany. Alkim Akali, Turkey Consolidated Paper Inc. Stevens Zaklady Celulozy i Papieru Cascades La Rochette, France. Point, USA. „Cèluloza“ S.A., Swiecie, Poland. Winding technology Dae Han, Korea. Genting Newsprint Sdn. Bhd., Felix Schöller Junior, Germany. Victorgo, China. Malaysia. Hansol Paper Co. Ltd., South Korea. – DuoReel Berghuizer Wapenveld, Guangzhou Victorgo Industries SCA de Hoop B.V., The Netherlands. Halla Pulp & Paper Ltd., Halla, The Netherlands. Co. Ltd., China. Mondi Kraft, South Africa. Korea. International Tendering Company Assi Domän Carton AB, Sweden. KNP Leykam, Gratkorn, Austria. Machine calenders CNTIC, China. Korsnaes Aktiebolag, Sweden. Malaysian Newsprint Industries, Ningbo PM 3, China. ICEC Papcel A.S., Ruzomberok, Kuala Lumpur, Malaysia. Ningbo PM 2, China. Rebuilds Czech Republic. Nippon Paper Industries, Iwakuni, Shin Dae Yang, Korea. International Paper, Phoenix, USA. Pipsa, Chile. Japan. Dong Il, Korea. Chuetsu Pulp, Sendai, Japan. Strepp GmbH & Co. KG, Germany. Forestiers Alliance Inc., Dolbeau, K.C. Beech Island, USA. Papel Prensa, San Pedro, Argentina. Piet Retief, South Africa. Canada. J. Cropper, Great Britain. Mitsubishi Paper, Hachinohe, Japan. Westvaco Corp., Luke, USA. Tianjin Paper, Tianjin, China. Chuetsu Pulp, Nohmachi, Japan. International Paper, Jay, USA. Shin-Ho, Daejeon, Korea. Rebuilds China Banknote Printing & Minting, Appleton Paper, West Carroiton, P.T. Pindo Deli Pulp & Paper Mills, Ballarpur, India. Chengdu, China. USA. Pindo Deli, Indonesia. Volorantim-Piraciaba, Brazil. SD Warren, Skowhegan, USA. Roll handling Hokuetsu Paper, Niigata, Japan. Longview Fibre, Longview, USA. – Winders MNI Selangor, Malaysia. EDFU, Egypt. E.B. Eddy, New Westminster, Canada. Fabryka Papieru Szczecin-Skolwin Burgo Ardennes, Belgium. Nippon Paper Industries, Stone Container, New Richmond, S.A., Poland. Papierfabrik Scheufelen, Germany. Yatsushiro, Japan. Canada. Halla Thai, Thailand. Bauer Druck, Poland. The global paper market 5

Cinema

Television Radio

Video

Global paper market: Quo vadis newspaper printing?

Media competition is increasing, and newspapers are not immune to the consequences. Although the rationalisation effects of technological development have essentially resulted in improvements to product content, various questions remain open concerning the marketing of the newspaper print medium: How are the demands of readers and advertising customers changing? Which newspaper should be aimed at which target group? Does colour play a major role for editorial contents and advertisements? What challenges do future-oriented newspaper concepts pose to technical processes – and to the paper used? Answering these questions is Bernhard Theiss, graduate engineer in printing and media technology, management partner in the “Süddeutscher Zeitungsdienst Verlagsgesellschaft m.b.H.” newspaper publishing house, co-publisher of regional newspapers and member of the German Federal Research Ministry’s “Media 2000” commission. 6

Fig. 1: Distribution of total advertisement expenditure for mass media in 1994.

Dialogue between newspaper printers and newsprint manufacturers is progressing, USA albeit extremely slowly. Both sides basi- 70 billion ECUs cally agree that neither knows enough Radio TV 12% about the other’s problems. Magazines Newspapers The following article is intended to give Western Europe 50 billion ECUs an insight into current perspectives and 5% 36% problems faced by the newspaper. At the forefront is the interaction between content and technology, especially where 31% printing technology and paper come into contact. I can only touch on the publi- 13% shing aspect and the wide range of devel- 20% opment in terms of content. Germany 15 billion ECUs 5% The newspaper and its rivals 22% 39% We live in an era of media pluralism. An 21% 44% increasing number of competitors are 52% forcing their way onto the market from Source: Advertising & Media Forecast, NTC Publ. Ltd. which newspapers make their money. 1

They are threatening the newspaper’s reading and viewing, but also their biggest advertising medium in Germany, reader and advertising markets. Televi- demand for current information. Western Europe and the USA, but its sion has robbed the print media of much share of overall advertising expenditure of its brand product advertising. As we Newspapers must adapt to these chang- in the mass-media sector is sinking. reach the threshold between video and ing requirements, primarily in terms of While daily papers in Germany expanded print, “new” mag- their content: they must present in-depth by a further 3.4% in 1995, total adver- azines make news- news with a background rather than sim- tisement expenditure rose by 7.1%. Tele- papers look old- ply reselling what appeared on TV the vision even achieved a growth rate of fashioned. Radio previous evening, and they must be writ- 17.4%. In the USA, advertisement expen- has both a nation- ten in an exciting, reader-friendly way. diture for television almost equalled that al and local effect Secondly, they must change their image for daily newspapers (see Fig.1). on newspapers, by employing colour, printing convincing while direct adver- photos and graphics, and offering a clear Within the European Union, the news- tising is posing a overview. The result should be a neat paper’s share of media advertising challenge to the combination of text and pictures, laid out receipts shrunk from approximately insert industry. with the readers’ interests in mind. 34 percent in 1983 to barely 28 percent in 1993. Electronic media “The countdown has begun!” It is high have not only time that newspaper publishers began Advertising expenditure for radio, tele- The author: Bernhard Theiss, changed people’s actively participating in developments. vision and print media in Germany, Aalen habits in terms of It’s true that the newspaper is still the Europe and the USA may differ in terms Global paper market 7

Fig. 2: Daily papers,1994.

are many reasons for this: compared with Overall daily circulation (in millions of copies) Copies sold per 1000 inhabitants other regions, urban areas contain more

Japan 71,9 Norway 610 single households, a greater percentage of foreign inhabitants, and an above- USA 59,0 Switzerland 575 average number of unemployed people.

Germany 25,8 Japan 592 Major factors which are particularly detri- mental to newspaper subscriptions in India Sweden 21,7 472 Germany and other West-European countries include the fall in the birth rate and Great Britain 18,7 Finland 471 the number of households and families France 9,0 Singapore 355 being set up, and the increasing age of the population. Furthermore, media con- Russia 8,0 Austria 328 sumption by people aged below 20 has changed drastically. This category is Italy 6,5 Great Britain 321 dominated by radio, with 121 minutes of daily consumption, followed closely by Brazil 5,9 Germany 317 television (101 minutes). The daily paper Poland 5,7 Denmark 315 has slipped to merely 15 minutes a day. Over the years, the newspaper’s audience Source: World Press Trends, 1995 FIE 2 in this age group has shrunk more than in others. On average, only every second of media structure and consumption, but the brilliant colours of other media. Only person under 20 in Germany reads the at the same time, there is general evi- gradually are newspapers beginning to daily press on a regular basis. dence of the growth potential for non- offer improved service with more colour print media. It is not easy to define the and greater quality, thereby responding However, the euphoria surrounding radio, situation in individual countries or zones, to competitive pressure from other media television and other increasingly popular as a glance at the table for overall daily and to the prejudices of advertising agen- media is gradually reaching its peak. circulation and copies sold per 1000 cies and those who decide which medium According to experts, it is likely to burn inhabitants shows (Fig. 2). Nevertheless, to use. itself out shortly after the turn of the cen- one thing is certain: market conditions tury. Newspapers and magazines then and media competition for consumers have a real chance for the future, since in (viewers/listeners/users) and advertising The reader market comparison with quality print media, customers are similar everywhere. In Germany, newspaper circulation electronic media reveal distinct weak- remained at roughly the same level for nesses: consider the fact that 53 percent A media decision is above all a decision years. Now, it is falling slightly: 1995 saw of all television viewers avoid advertise- for or against a certain media type. And a loss of 0.7%. In concrete figures, this ments by flicking their remote control. in many cases, this boils down to the represents a drop in circulation of some even simpler question: electronic or 200,000 copies per year, amounting to Young people tend to escape advertise- print? Those who work in the media tend more than 10,000 tonnes of paper. ments more than elderly people. Well- to be prejudiced against daily news- educated people with high incomes also papers, claiming that advertisements are Newspapers in built-up areas have been change channel more frequently when difficult to plan, expensive, and often lack worst hit by circulation problems. There advertisements are shown. 8

In view of this, it is astonishing that the Convincing colour concepts must arouse veritable technical revolution has taken cost of launching a television advertise- the readers’ interest and show advert- place in this sector. Until the mid-seven- ment today is almost four times greater ising customers what a fantastic effect ties, the standard practice was to use line than it was in 1980, whereas the cost of a colours can have in newspapers. If it is casting machines (lead) for typesetting, newspaper advertisement has not even necessary to impress readers and advert- zinc plates for picture reproduction and doubled in the same period. Moreover, isement customers purely through the metal or plastic plates for printing. In an television advertisements are far more product’s appearance, then a little imagi- amazingly short time during the second expensive to produce than newspaper nation is also required. half of the ‘70s (somewhat earlier in advertisements. It is now the rule more Great Britain and the USA), typesetting than the exception that a 20-second long The market comes before technology. For on film was introduced, followed by com- TV spot costs several hundred thousand us as technical newspaper specialists, puter-controlled photosetting. Today, German marks to produce. this means giving our partners a clearer technology has reached the stage of fully picture of the connections which exist digital, integrated text-picture produc- Consequently, the newspaper is a more between preliminary stage and print tech- tion. effective advertising medium than its nology, and indeed the quality of the rivals, since its readers are more respon- newsprint. Seen against this background, it becomes sive to advertising. Complaints regarding clear how much of a role the ideal print- excessive media advertising are directed For the newspaper publisher, this means ing process has played in newspaper primarily at television (98 percent of thinking in the long term and giving printing. It was also in this sector that users), followed by magazines (50.3 per- greater consideration to market require- offset printing processes were first intro- cent), and radio (34.7 percent). For daily ments for quality, not only in terms of duced in the ‘70s, starting in medium- newspapers, the figure is only 25.2 per- service, but also as regards the printed sized newspaper publishing houses in the cent. Fortunately, words such as zapping, newspaper’s appearance. USA and England. browsing, switching and hopping are unheard of where newspapers are For the paper manufacturer, this means The letterpress-printing process is now concerned! that the newsprint must stand up to the almost obsolete in Western Europe, the challenge. As a modern print medium, USA, Australia and Japan, while the Flexo The newspaper is a medium which is the newspaper must not be defeated by print process (high printing from soft available everywhere. It does not require outdated quality standards for paper in rubber moulds) continues to play a role a technical infrastructure such as energy its raw form. in newspaper printing, albeit subordinate. or communication networks. But one However, it is unable to match offset thing cannot be denied: a newspaper What is demanded of us all is nothing printing in terms of quality. Rotogravure which is not good will not sell. And most less than acknowledging this home truth: is not used at all in the newspaper sector. newspapers are not yet as good as they the market comes before technology! could be. The decisive factor in favour of the offset printing process was its ability to achieve Life is colourful, and the newspaper high picture resolution (half-tone dots), should reflect this by using more colour. even on rough paper – direct contact with Colour is a form of information, and a Newspaper technology the paper is no longer made by a metal lack of it symbolises “old news”! Nobody printing plate, but by a rubber printing likes to sit in front of a black-and-white The demand for improved quality is blanket. By means of film- and photo- television anymore. something of a tradition in newspaper setting as intermediate stages, the light- printing. And over the last 20 years, a sensitive offset printing plate has added Global paper market 9

Fig. 3: “Braviken”, the most innovative newsprint machine in the world, began work at Holmen Paper AB in Norrköping, Sweden, in mid-1996. A record holder: 1800 m/min design speed, 9650 mm wire width, outstanding runnability, perfect flatness and paper quality for brilliant colour printing.

great momentum to the digital prelimi- with the result that previously unavoid- The speed of production always depends nary stage. Today, this area is rapidly able losses of information (and therefore on the newspaper concept. Its size, the developing into a media-neutral data-pro- of quality) will be eliminated through time at which it closes for distribution, cessing system, whose information can transfer and copying. In other words, the and the area to be covered are all in- be used for any conceivable medium. precise amount of information on the fluential factors. The web speed of printing plate, which can be measured current conventional machines varies Offset print processes and preliminary objectively, will constantly rise, and dif- from roughly 9.0 m/s (corresponding to stage technologies are able to satisfy the ferences in the final print quality will approximately 30,000 cylinder revolu- demand for more colour. The standard- increasingly be attributable to the combi- tions/hour) to a maximum of 12.5 m/s ization of colour-sensitive picture infor- nation of ink, water and paper. (approximately 42,000 cylinder revolu- mation has today reached a high and sta- tions/hour). ble level, resulting in generally problem- Newspaper rotary printing presses free reproduction of even the highest res- Until recently, the performance of a Today, the effective speed of production olutions. However, transferring this newspaper printing machine was judged is mainly determined by on-line produc- precise information from the printing by its ability to close editorial and advert- tion conditions at the printing machine plate to the paper continues to cause ising content as late as possible, to and further processing/dispatch. In some problems based on the process – the process large volumes in short time peri- cases, the system’s speed must be interaction of ink (fat), water, paper and ods (high number of pages and print reduced, especially if large and complex the machine (printing blanket, inking and runs), and to distribute them rapidly to inserts are to be processed. dampening system). the reader (e.g. in the letter box by 5.45 a.m. in Germany). Nowadays, it is Control station Physical dimensions of the also judged on its ability to print decora- Today, functions such as machine opera- preliminary stage tive colours and four-colour pictures on tion, web guiding and reel changing are What information is transferred onto the certain pages. carried out for the most part by auto- paper? The most precise structures mated control station technology. But measurable, which must be transferred to Our world is colourful, and colour is despite computer-controlled inking and the newsprint in a scale of 1:1, are information! The newspaper cannot ig- dampening systems, the printing process between 30 and 40 µm (e.g. 2% of a nore this fact. As a result, the main crite- still needs to be monitored by machine halftone dot or spot on frequency-modu- rion when configuring a newspaper rotary staff who, as a rule, should be trained lated screen). The layer of printing ink on printing press today is that it should pro- printers. The main things to be checked the paper is between 1.5 µm and 2.0 µm duce as many four-colour pages as pos- are print quality (register, colour intensi- thick. sible in a newspaper, without restriction. ty, effect of colour in comparison with original), the results of the interaction With a scan resolution of 300 dpi (118 The format of a newspaper is of con- between paper, ink and water (smearing, pixels/cm), a coloured A5-size picture siderable importance. Newspaper rotary emulsifying, dusting, formation of air (14.5 cm x 21.0 cm) requires app. 13 MB printing presses have fixed formats. In bubbles, plate abrasion). The latter must (mega bytes) of data, which must be Germany, the most common are the be monitored constantly. transferred onto the printing paper as Berlin format (315 x 470 mm, web width: completely as possible. 1260 mm), the Rhein format (360 x As a rule, the machines are fitted with 530 mm, web width: 1440 mm), and the paper-web feeding systems, which – Subsequent to positive initial trial runs, Northern format (400 x 570 mm, web depending on the product size and inking computer-to-plate technology (CTP) will width: 1600 mm). In the USA, web widths – are capable of feeding all paper webs be standardised during the coming years, of up to 1905 mm can be observed. into the printing machine. 10

Fig 4: Diagram showing paper guiding in a modern newspaper offset rotary printing press, from the reel (1) over the stacked modular print units (2) to the folding and cutting device with photo- electric copy check (3).

Reelstands now operate with exceptional precision, and work with a wide range of reel diameters above 1250 mm.

A certain problem which affects the web tension in particular is referred to as “plate-channel runout”. The plate and rubber blanket are laid on or clamped to the relevant cylinder. The clamps are located in channels, which are offset by half the width of the roll. Tensioning problems faced by the web and vibra- tional problems faced by the machine have now been minimised by introducing tiny slots for the pressure plates, made by so-called “cylinder bearers”. The tension of the rolls in relation to one another is determined by no-break metal rings at speeds of more than 35,000 roll revolu- tions/hour and modern bearing technology which eliminates bearing play.

Automated machine operation and high- quality print reproductions pave the way for corresponding improvements in web logistics. The paper web is first preten- sioned by an adjustable stretching device, and then pulled into the printing system mainly by the rubber blanket roll. One on top of the other, the collected 4 paper webs are driven by adjustable greatly influenced by the newspaper pub- As a rule, half or three-quarter webs are drawing webs in front of the folding de- lisher’s product and marketing concept. suitable for the printing units as well as vice. Drawing webs with reversing rods full webs. Quarter webs are seldom used. on the upper section are also possible, The publishing house is most concerned depending on the size and complexity of with the print quality achieved, the vol- the desired web mixture. ume and print run capacity, and the 9-cylinder satellite machine’s colour capabilities. The follow- Precise four-colour printing, since fan- ing list presents the printing units which out effect is practically non-existent . Machine configuration are currently most popular, together with Contrary to earlier, more technically- their combination into machines. Double- Problem: complex transmissions, espe- oriented decisions regarding the configu- width machines are taken as standard, in cially when reversing. Complex web guid- ration of printing systems, the design of other words 8 pages (4 wide, 2 high) per ing. Further printing units needed for a newspaper rotary printing press is now plate cylinder or 16 pages per paper web. back page. Global paper market 11

Figs. 5 and 6: The so-called eight-high tower – today, the most commonly-used basic configuration for four- colour offset newspaper printing. Stood one on top of the other, the H-shaped modules provide the greatest colour capacity with the shortest paper path. Each eight-high tower can print 16 four-colour pages or 32 two-colour pages. The necessary number of basic configurations are stacked in accordance with the size of the print run (paper web shown in yellow).

Eight-high tower 2 H-shaped modules on top of one another, greatest colour capacity with shortest paper path (4/4 colour printing on both sides of web). Problem: fan-out effect caused by free web guidance between the printing areas. According to print machine suppliers, approximately 80% of newspaper rotary printing presses supplied since 1992 were designed according to the eight- high tower configuration and delivered as such.

Further processing and dispatch Preprinted newspaper sections and advertising inserts are often added to the printed newspaper copies, which are then counted for sales rounds, packed and dispatched in trucks.

The processing speed of the technology in the dispatch department corresponds 6 to the production speed of the rotary printing press – in England and Australia, The fan-out effect represents the change high-performance lines insert, count, in web size which occurs due to damp- pack and transport up to 80,000 copies ening. In the case of free web guiding, an hour. the web’s width may increase by as much as three millimetres if dampened several The standards which newspaper copies times. are expected to meet in terms of precise folding and clean arrival from the folding system are correspondingly high – not 10-cylinder printing unit every newsprint can satisfy such specific Problem: free web guiding for four-colour conditions. printing, resulting in fan-out effect despite high machine-technical expendi- Paper logistics in reel handling is on the ture. Complex web guiding, deviations road to automisation – the continuous (smearing). process chain from unloading the truck through high-bay storing, unpacking and H-shaped printing unit preparation to changing the reel on the 2 basic modules, 1 upside down. Clear rotary printing press is already reality in 5 paper path. Short free web guiding. some printing and publishing houses. 12

Fig. 7: Rotary printing press for 16-page colour printing using the offset process: web widths from 1220 to 1680 mm, 16 pages per paper web, 70,000 copies per hour per folding system.

Printing process and printing inks and dampening agents machine, printability and the results of which are precisely matched with one printing on certain newsprint. These are product quality another and with the printed paper. listed below:

The offset printing process evolved from During the printing process, impurities lithography (Alois Senefelder, 1796). It is such as washing agents, ink binding based on the chemical-physical repulsion agents, paper dust or pigment may pol- of fat (= printing ink) and water: the lute the dampening agent. Especially in hydrophobic picture areas to be printed the case of newspaper printing with List of parameters accept ink and reject water, while the uncoated natural paper, these impurities for newsprint: hydrophile areas not to be printed accept can upset the so-called ink/water bal- and absorb water. Extensive literature is ance. Considerable problems may also Suitability for printing machine already available regarding this process, arise as a result of current development Web passage (creases, wandering) and I will therefore restrict myself to techniques for inks, e.g. through the use Runout/manufacturer’s adhesive briefly summarising the main details, of plant-based fats, and the constantly Web break/wrong adhesive referring in particular to the interaction of increasing amount of recycled material Fibre design/stray dust ink, water and paper. used in newsprint. Washability of design Printability Offset printing is capable of very high The parameters must be redefined, and Ink acceptance picture resolution and sharp pictures since two major components are chang- Ink requirement edges, even on rough paper. The problem ing at the same time (ink and paper), the Water conditions/requirements lies in the interaction of ink and water situation at the moment is anything but Ink/fibre design/second impression and – especially in newspaper printing – clear and standardised. Of course, there set-off the paper’s reaction to the ink/water bal- are extensive lists of criteria for the Ink smearing/main rollers ance. During the actual printing process, assessment of newsprint quality. Thanks Wave formation after printing the effects of surface tension caused by to their production protocols, paper man- the interaction of ink and water play a ufacturers know much about their paper’s Printing result decisive role, as do the boundary layers mechanical properties: however, when Printout (full surface and screen) and wetting tension of the printing ink/ presented directly with this information Evenness (no structures) dampening agent and picture/picture-free by the manufacturer, the printer can only Spot increase areas. turn a little of it to his advantage – e.g. Show through/strike through weight, roughness, and perhaps the paper Stability against wiping The water’s overall hardness and its colouring. Paper colouring / lightness hydrogen carbonate content are of signif- Sheet stiffness icance, since both parameters have a Up until now at least, most of the other Polluted areas substantial effect on the offset process: information available has lacked any clear Further processing among other things, they influence the and specific connection with the prob- Ink blotting/smearing water’s PH value, which is reached lems arising in the printing process. Set off through the use of specially-prepared Behaviour in additives in the dampening agent. For So far, dialogue between printers and – Conveyor belt technical printing, the water should have paper suppliers has established a number – Buffer (winding) an ideal PH value of between 4.8 and 5.3. of practical parameters regarding the – Drum (or similar) The sensitive printing process requires suitability of the paper for the printing 13

The print quality of a newspaper is Together with baggy-webs, which are fre- because printers and publishers have assessed above all by sharp picture quently in evidence, and paper reels given up complaining about them. Never- edges, as well as by uniform and uninter- which have been wound out-of-round or theless, the paper manufacturers must rupted areas, and high print contrast. slack, this plays a role above all in the solve this problem – who wants to buy a context of the dampening of the paper “dog-eared” book , for example? Repercussions occur because the ink web in offset printing. does not dry physically in newspaper In view of the increasingly tough media printing, but is “absorbed” into the Colour printing is increasing. Every competition, the newspapers are adopt- paper. In order to achieve a brilliant, colour means a corresponding damp- ing a new position – colour pages are deep colour, more ink guiding is neces- ening of the paper web – e.g. with 4/4 now a top priority, as are product and sary. This encourages the ink to blot and colour printing in a eight-high tower, the print quality which can hold its own smear. The result is a direct connection web comes into contact with water eight against rival media. between certain paper properties times during the print process. Electronic (absorption, roughness and opacity) with register control systems are able to deal In both the preliminary stage and print print quality, enabling the newspaper to with linear expansion of the web, but not stage, newspaper technology has made hold its own against rival media. with lateral expansion, which can amount enormous efforts to achieve higher quali- to several millimetres – this is referred to ty, and is now moving in leaps and In contrast to heatset-web offset printing as the fan-out effect. bounds towards this goal. Progress has (in which the ink solvents are evaporated been so dynamic that it could be very at temperatures of 200°C), additional As a result, accurate compression in the well compared with the development of handling of the printed paper web is gen- µm area is no longer possible without recycling paper for newsprint. This makes erally avoided in newspaper-web offset altering the plate positions. one thing clear above all else – paper printing. In some newspaper printing makers (and those who supply their tech- houses, the use of infra-red heaters The problem can be solved by using nology) must pay much more attention to achieves very good printing results on printing-plate suspension pins with diver- the processing problems of their product. standard papers. Brilliant colours can be gent positions. These positions are fixed produced without smearing, thereby and correspond perfectly with the centre Printers and publishers must show clear- opening up new markets for newspaper of a corridor, which has standardised left ly where their products are heading, and printing. and right tolerance limits. Standard in order to confront problems, they must papers used for high-accuracy print give information about the connections Inevitably, scope for raising the quality of products must have expansion coeffi- they see between quality demands, print- standard newspapers by using improved cients which lie within the tolerances of ing processes and newsprint. All those newsprint is extremely limited due to the this corridor. Otherwise, it is impossible involved are certainly prepared for dia- high material costs involved. to achieve a good printing result without logue, since it is in all their interests. One considerable maculation. Folds in the thing is for sure: if the newspaper yields A decisive factor for publishing houses product are a phenomenen which no to media competition, the paper industry is the newsprint’s register tolerance. longer appear on complaint lists simply will feel the blow too! 14

NEWS FROM TH

Stock Preparation Division: Membrane technology for the further close-up of paper mill water loops

Modern process Appr. technology with Stock preparation Flow/PM tailored water Loop I Loop II Loop III management demands improved water loop cleaning Pulper Preclean MC-Screen ø Flotation I Cleaner LC-Screen // Disc Filter Press Dispersion Bleaching Flotation II Disc Filter Cleaner LC-Screen Paper Machine accordingly. Thanks to membrane technology, DAF 1 greater cleaning DAF 2

potential can be Reject Sludge exploited likewise Handling Treatment in conventional DAF 3 Biology Final Treatm. processing stages. 1 Current systems – A survey grades. Several loops separated from one This article There are basic differences between the another by thickening stages enable the reports on the furnish, technologies and requirements water to be channelled in a targeted man- latest findings on finished paper depending on whether ner in accordance with the counterflow with selected graphic grades or packaging papers are principle. The use of fresh water in the examples of involved. In the following systems for paper machine and sequential additions various processes white and brown grades based on the to the front loops in a cascade allow the and effluent current state-of-the-art are presented. fresh water in the process to be used to The authors: Ralf Mönnigmann conditions, thus maximum effect. and giving some idea White grades Dr. Michael Schwarz, Stock Preparation of the cost/ The process diagram in Fig. 1 shows the The degree of circuit closure normal Process Technology benefit situation. principle of water management for white nowadays is less than 10 l/kg. At this Stock Preparation 15

HE DIVISIONS

Fig. 1: System example for white grades.

Fig. 2: System example for brown grades.

level, Dissolved Air Flotation (DAF) stages represent an essential component LF for removing disruptive fibre admixtures (anionic trash, etc.) from large volumes of water. Cleaner LC-Screen // Disc Filter Press Dispersion Refiner Cleaner LC-Screen // Paper Machine

Each further reduction in the amount of Pulper Preclean Screening Fractionation fresh water added (and consequently the SF WWI production of effluent) must be paid for in the form of more retention agents in the paper machine as well as an in- WWII

creased requirement for auxiliary agents Reject Save All Handling in the stock preparation for flotation and Final Treatm. Biology Sediment. bleaching. More disruptions are caused by all types of sediments. As the degree 2 of circuit closure increases, the sulphate content also becomes a limiting criterion. ducing a range of white grades cannot shower water in the paper machine, re- The biological activity already taking reasonable reduce their specific effluent ducing the fibre losses after reject ma- place in all parts of any plant would be production below 7.6 l/kg. chines and gating out the most heavily multiplied several times over. Precipita- contaminated process water. The specific tion of these would import an additional Brown grades amount of effluent produced can be re- burden of chemicals into the system. In principle, the configuration of systems duced to 2 - 4 l/kg thanks to suitable This could cause new problems as a re- for packaging papers is always simpler process technology for the required sult of interactions with other process than for white grades (Fig. 2). The sys- product qualities. chemicals. tems are often single-loop systems and the stock consistency drops from the Effluent can be avoided completely if the In summary, it can be said that paper pulping stage to the headbox. Water substances contained in the filtrates from mills processing waste paper and pro- management is limited to treating the reject drainage, shower and channel wa- 16

Fig. 3: Substances in the process water.

Fig. 4: Principle of membrane filtration. ter are removed and the water returned to Range in µm 100 the process. It is possible to control the 0,001 0,01 0,1 1,0 10 technique of completely enclosed circuits Ionic Molecular Macromolecular Colloidale Macro range range particles with these products1,2. range particles Molecular Weight100 200 1000 10000 20000 100000 500000

However, the struggle against the nega- Lignins Lignins Relative Huminacids Lignosulphonates Coating pigments tive effects of circuit closure on product size of Monosaccharides Wood extractives Fines Fibres quality and manufacturing technology sub- Poly- and stances Oligosaccharides has been going on for the same length of Metal Ions Hemicellulose time. For example, even after a consider- Sulfates Tensides Latices, Binders able length of time has elapsed, highly Chlorides Synth. dyesVirus Bacteria volatile substances are still liberated Reverse Osmosis Ultrafiltration Particle filtration from the paper or are formed and lead to Separation Nanofiltration Microfiltration process unacceptable odour problems. Retention Evaporation problems have to be compensated for by 3 the increased use of auxiliary agents. In addition, only periodical or spontaneous taken on several plants. It has been which are known to be of relevance to the treatment with biocides can usually help known for a long time that biologically process. Most of them are organic sub- against uncontrolled biological activity in purified effluent can be recirculated stances (lignins, lignosulphonates, wood the dead zones of the system. through the system5,6, and in the mean- extractives, saccharides, hemicelluloses) time this possibility has been successful- but there are also inorganic substances The wellknown problem of sticky de- ly put into practice7. such as chlorides, sulphates as well as posits in the paper machine and on other iron and manganese ions8,9. equipment like motor fans also renders Current limits on circuit closure the operating of the plant. These more The maximum utilization of the water em- The type of these constituents is basical- difficult problems go right through to ployed is restricted by various sub- ly the same in all process waters. Howev- changed thickening factors in the cleaner stances in the process water which have er, their composition and quantity varies system. a disruptive effect on either the technology or the product. The concentration of Principle: Corrosion problems can never be fully these colloidal or truly solute substances, Pressure avoided in spite of choosing the materials referred to as “disturbing” substances, Pressure pump Module control valve for all machinery and equipment with the increases at a disproportionate rate to the utmost care3,4. degree of circuit closure until reaching the specific concentration equilibrium Feed Concentrate (retentate) The advantage of partially opening up (Fig. 2). loops and allowing a defined effluent Clarified water Membrane (permeate) quantity has been shown by measures Fig. 3 lists several of these substances 4 Stock Preparation 17

Fig. 5: Membrane filtration processes.

Fig. 6: Volume reduction coefficient. greatly from system to system. Amongst many other parameters, the most impor- Pressure 60 bar 15 bar 8 bar 3 bar tant indicators for the disturbing poten- µ µ µ tial are the filtered chemical oxygen de- Pore size 0,001 m 0,01 m0,1 m mand (COD) and the cationic demand. 100

80 Technologies for further circuit water cleaning 60 The membrane filtration is one of the processes which have to be used in order 40 to reduce further the limit values stated 20 above. Membrane filtration is used in TSS Cationic demand COD Conductivity many area of effluent treatment and for 0 Reverse Osmosis Nanofiltration Ultrafiltration Microfiltration concentrating process flows. (RO) (NF) (UF) (MF) 5 The membrane process In the broadest sense, a membrane can Furthermore, there are important influ- Pipe modules are not susceptible to be viewed as a filter which separates the encing parameters which determine the blockages in the inflow and can be components of a mixture of substances economic efficiency of the membrane used with suspensions containing a by purely physical means (Fig. 4). separation process: limited fibre content. However, they generally have a lower packing density In this process, the feed is separated into Flow channelling (ratio of the membrane surface area to a permeate (filtrate) and a retentate (con- I The inlet is parallel to the membrane the module volume). Plate modules centrate). Membrane processes are divid- so as to prevent or at least minimize with disc-shaped flat membranes at- ed into four principle methods depending the formation of a covering layer (“fil- tain a considerably greater packing on the transmembranic pressure differen- ter cake”) on the membrane which density. Their power consumption is tial and the size of particles which are to leads to a reduction in the through- be separated out. flow. This cross-flow principle guaran- Feed = Permeate + Retentate tees maximum filtrate output over long 100

Fig. 5 shows the details. In addition, the periods. 80 Permeate figure specifies a range of separation ca- 60 pacities for parameters such as COD, Designs of membrane modules 40 SCD and conductivity which are relevant I The core of every membrane plant is a Retentate 20 Permeate flux [%] to the process. The flow of permeate is technically expedient arrangement of Retentate flux [%] also used as a characteristic feature of membranes, referred to as the module. 0 12345678910 the membrane in addition to the retention There are three principle designs for Reduction coefficient capacity. effluent from a paper mill: 6 18

Fig. 9: Fig. 7: Lay out diagram for COD reduction of disk filter Membrane filtration pilot plant. clear filtrate.

Fig. 8: Fig. 10: Flux through membranes for paper mill effluent. Retention of different tested membranes.

lower thanks to the smaller circulating volumes. There is a risk of blockages with suspensions containing fibres. PI TI

Spiral wound modules suffer from a Back washing FI high risk of blockage. No fibres should cylinder Modul 1 6 bar pressurized air be allowed to enter the module. How- PI PIC 6 bar pressurized air ever, spiral wound modules do have Permeate the highest packing density as well as

a favourable price/performance ratio. Modul 2 FIC Membrane materials I The main division in this case is be- Feed PI tween organic and inorganic mem- Retentate brane materials. Inorganic membranes Feed pump Circulation pump are temperature resistant, strong and 0 ... 10 l/min 0 ... 400 l/min max. 16 bar Dumping max. 4.5 bar possess a high level of chemical resis-

tance. However, although this results 7 in a longer service life, they are more expensive. The broad range of organic membranes are considerably cheaper. 100 15000

h] 200 Microfiltration New materials can be used at tempera- 2 80 12000 tures up to 80°C and with high pH val- 160 60 9000 ues. This means long service lives can 120 Retentate usually be expected for applications in 40 6000 80 Ultrafiltration the paper industry. 20 3000 Nanofiltration Permeate 40 COD load reduction [%] COD concentration [mg/l]

Spec. permeate flux [l/m 0 0 Volume reduction factor 0 12345678 1234567 I The volume reduction factor (VRF) is Reduction coefficient Reduction coefficient often overlooked. Fig. 6 indicates its significance. 8 9

Temperature Retention [%] Microfiltration Ultrafiltration Nanofiltration I A rise in temperature leads to an in- COD 20-30 45-65 75-90

crease in the flow of permeate. The Cationic demand 70-80 98 99.9 reason for this effect is the reduction Conductivity 2-6 15-25 60-75 in viscosity as the temperature rises. 10 Stock Preparation 19

Fig. 11: Advanced water treatment for graphic papers (1st concept).

Possible applications and performance capability A testing plant built specially in our company was used for testing various mem- Process branes with some selected waters from paper mills (Fig. 7). The following equip- Reject and sludge Clear water Permeate dewatering partial flow (recovery) ment was used: ceramic microfiltration (recovery) (0.1 Hm pore width) and ultrafiltration DAF membranes (separation limit 10,000 Dal- ton) as a pipe module as well as organic Aerobic biology (except final clarifier) nanofiltration membranes (separation Biological limit < 200 Dalton) as pipe and spiral sludge Pre-filtration (Option) wound modules. The test involved paper mill water types, these being in general Ultrafiltration heavily contaminated circuit waters from paper mills for brown and white grades. Effluent to river In addition, tests were also conducted with the run-off from biological effluent 11 plants used in the paper industry. veyed substances and the volume reduc- computer-aided modelling studies and Examples of the principle configuration tion factor is a significant factor in the accords well with the empirical data ob- data which were worked out are shown in subsequent design of a plant and its inte- tained from many plants. Tests were con- the following diagrams. gration into the entire system of a paper ducted with various waters in order to mill. A detailed presentation of all the test prepare an optimum concept incorporat- Fig. 8 shows an overview of the through- results would go beyond the scope of ing more thorough purification stages. flow values achieved. The bandwidth of this report. Fig. 10 shows a summarized the through-flow is explained by the con- overview of the retention capacity for the For purifying highly contaminated rejects stituents in the different waters. In many most important parameters. effluent and sludge from white grades cases, microfiltration was unable to production, microflotation with partial re- achieve significantly greater flux values circulation to the mill water loops is despite the larger pore width; the mem- A feasible system concept for graphic state-of-the-art today. The processwater brane became blocked by extremely fine grades which has to be replaced due to contami- particles in the circuit water. At the start, it was explained why it is nation with dissolved and colloidal sub- impossible to achieve a specific effluent stances is drained off for biological treat- Fig. 9 shows an example of the retention production below approx. 7.6 l/kg using ment, where in most cases organic load- capacity of the NF membrane. The inter- standard process technologies. This lim- ing (COD) is reduced by 2-stage agita- relation between the reduction in con- iting value is the result of comprehensive tion. 20

Fig. 12: Advanced water treatment for graphic papers (2nd concept).

Fig. 13: Costs for the effluent treatment..

The resultant bio-sludge is then separated out by sedimentation or sometimes flotation, and either removed from the system or returned to the agitation stage Process for maintaining the active sludge concen- Clear water Permeate tration. Reject and sludge partial flow (revovery) dewatering (recovery) In concept 1 (Fig. 11) biological purifica- DAF tion can be improved by ultrafiltration to Spec. treatment the point where the clarified water is suitable for freshwater replacement in the Aerobic biology Nanofiltration paper machine loops. By using tubular modules, the last sedimentation stage Final clarifier Pre-filtration Biological sludge can be bypassed completely, with direct Partial flow recovery ultrafiltration for removing bio-sludge amongst others. By feeding back this Effluent to river concentrate, higher sludge concentrations (up to 1.5%) can be set in the sec- 12 ond agitation stage, thus speeding up COD reduction. Approx. investment costs Approx. spec. operation costs 3 3 DM/m /h DM/m clear water Since production problems due to higher State of technology Biological treatment + 30000 0.4 salt concentrations are practically un- River water treatment 11000 0.3 known, and inorganic content largely de- (excl. buildings) pends on additives (such as aluminium 1. Concept sulphate), high recirculation rates are Biological treatment + 30000 0.4 possible even with ultrafiltration. Ultrafiltration (tubular) 13000 1.5 (incl. pre-filtration)

2. Concept Furthermore, part of the ultrafiltered wa- Biological treatment + 30000 0.4 ter can be further purified in a nanofiltra- Nanofiltration (spiral wound) 30000 1.5 (incl. pre-filtration) tion stage (spiral wounded module e.g. 13 for removing sulphates). Adding “pure” ultrafiltration permeate ensures high for disposal. Although the ultrafiltration with spiral wounded modules, while re- throughput rates and maximum service module is not prone to blockage, coarse taining the last sedimentation stage and life of the nanofiltration stage. The filtering is advisable if the residual fibre intermediate filtration. Thanks to the high nanofilter residue has to be separately content in the intake is high. Another al- separation capacity of the nanofiltration processed by precipitation/flocculation ternative (Fig. 12) is direct nanofiltration membrane, ongoing concentration in the Stock Preparation 21

Literature Anaerobic treatment of recycled paper mill effluent in 1 Mörch, K. A., Steinig, J., König, J.: Erfahrungen mit the Netherlands. Tappi Journal Nov. 1991, S. 109-113. einem geschlossenen Wasserkreislauf in einer Papier- 6 Huster, R.: Anaerobe Abwasserreinigung in der fabrik. Allg. Papier Rdsch. 110 (1986), Nr. 44, Papierindustrie. Allg. Papier Rdsch. Nr. 46, 1989, S. 1532 - 1536. 1320 ff. 2 Diedrich, K.: Betriebserfahrungen mit einem 7 Suhr, M.: Geschlossener Wasserkreislauf in der über- geschlossenen Wasserkreislauf bei der Herstellung wiegend Altpapier verarbeitenden Papierindustrie – altpapierhaltiger Verpackungspapiere. Stand der Technik? Vortrag auf der UTECH ’96 am Wochenbl. f. Papierf., Nr. 4, 1984, S. 116 - 120. 26.2.96, Berlin im Seminar „Weitergehende Abwasser- 3 Demel, J., Möbius, C. H.: Korrosion in Papierfabriken. reinigung“. Allg. Papier Rdsch. 111 (1987), Nr. 24/25, S. 746-756. 8 Linhart, F., Auhorn, W., Degen , Lorz: Störstoffe – 4 Börner, F., Dalpke, H. L., Geller, Göttsching: neue Aspekte ihres Wirkungsverhaltens, neue Anreicherung von Salzen im Fabrikationswasser und Probleme, Lösungen für die Praxis. im Papier bei Einengung der Wasserkreisläufe in Wochenbl. f. Papierf., Nr. 9, 1988, S. 329 - 336. Fig. 14: Papierfabriken. Teil 1, Wochenbl. f. Papierf., 1982, 9 Hamm, U., Göttsching: Inhaltsstoffe von Holz und Futural aspects for the installation of a membrane Nr. 9, S. 287 - 294. Holzstoff. Wochenbl. f. Papierf. Nr. 10, 1995, filtration. 5 Paasschens, C. W. M., Habets, L. H., De Vegt, A. L.: S. 444 - 448

although the selection of plant components and the harmonization of individual Costs for water sections will have to be undertaken very supply and treatment carefully. The situation is different with white grades. It is basically technically The limits by The product feasible to close the circuit completely. the legislation However, membrane filtration in the form of ultrafiltration or nanofiltration would be essential in order to remove micro-or- Membrane filtration processes ganisms, biological breakdown products and, in the case of nanofiltration, inorganic substances such as sulphate. Water The degree of closure management Initial results of long-term trials in paper mills have confirmed the operating relia- The chemical bility and good availability of membrane consumption filtration systems.

14 Nevertheless, the system configuration paper mill loops – except for monovalent As shown in Fig. 13, both these concepts for each individual case has to be opti- salts – is prevented. From the energy are not exactly cheap. Investment costs mized carefully, taking account of all in- point of view, using low-cost spiral for concept 1 – without partial nanofiltra- fluencing factors. Development tests wounded modules with large membrane tion – amount to some 13,000 DM per must go hand in hand here with empirical areas also allows direct nanofiltration m3/h, with operating costs around 1.5 data evaluation from comparable systems despite low throughputs. Since these DM per m3 of permeate. The second con- and computer-assisted balancing of fibre spiral wounded modules are liable to cept involves investment costs around additive concepts. blockage, prefiltration is particularly im- 30,000 DM per m3/h, likewise with oper- portant. ating costs around 1.5 DM per m3 perme- In future the economical and ecological ate, plus additional costs for treating the aspects of membrane filtration will be in- But long-term trials have shown that if nanofiltration concentrate. creasingly assessed for their affects on the membrane filter operating parameters product quality and chemicals consump- are carefully adjusted, no blockage will Prospects tion (Fig. 14). Bearing in mind the com- occur. The filter cleaning interval should In future, an integrated biological treat- plexity of paper mill loops, the cost-ef- be about 4-6 days, and here again, the ment stage will come into wide use in the fectiveness of membrane filtration cannot nanofilter residue has to be separately manufacture of packaging papers. There be assessed simply by comparing invest- processed by precipitation/ flocculation are no fundamental problems involved in ment outlay and energy costs with efflu- for disposal. returning the biologically treated water, ent treatment costs. 22

Paper Machinery Divisions: Ortviken PM 4 – tomorrow’s technology today

Early 1996, SCA bulk using an on-line paper machine LWC papers in regions with a large fresh Graphic Paper process including coating and calender- fiber supply. This led to the 1990 startup started up their ing. Voith Sulzer Paper Technology of of SCA’s first LWC machine in Ortviken. new PM 4 at Germany is the main supplier, in an High quality results were achieved imme- Ortviken, installation program that was completed diately, largely because of the superior Sweden. The in less than five months. properties of spruce fiber, the primary goals had been raw material. This very thin, strong, flexi- set high – Reasons for the investment ble and bright fiber, has proven superior produce LWC SCA’s twofold strategy is to produce to any other fiber for the production of paper with high newsprint paper in regions with a dense LWC paper. “It was therefore only a The author: opacity, high population and a therefore large amount question of time for SCA to take the next Marion Nager, Corporate Marketing gloss, high of wastepaper (for example at the Ayles- step and build a second LWC machine in density and high ford mill near London), and to produce Ortviken, the PM 4,” explained Kenneth 23

1 Eriksson, President of SCA Graphic of LWC paper, GraphoLux and out risking a decrease in opacity (i.e., Sundsvall. GraphoMatt, along with the already exist- high bulk at low weight). ing GraphoCote from the first machine. Quality goals GraphoMatt is a matt LWC paper with an Göran Nilsson, Vice President, Business GraphoLux is a paper designed for users attractive combination of low paper Area Coated Papers, explained the reason to whom opacity and stiffness are the gloss, high print gloss and very good for the investment from a marketing point most important attributes. It has a high opacity. It has been specifically devel- of view. He sees the trend of increasing thermomechanical pulp content, which oped for magazines where good readabil- consumption of coated papers, and his makes it bulkier than conventional ity is a must. market analyses showed that SCA cus- LWC’s. Its excellent opacity offers customers were interested in a broader tomers the choice of producing a maga- Asked if the quality goals have been selection of products. It was therefore zine that feels thicker and of superior reached with the new machine, Nilsson decided to create two unique new grades quality, or one with reduced weight, with- can only confirm, “Yes, we have reached 24

Fig. 2: While old PM 4 was still producing paper, the coating and the calendering section of new PM 4 were being erected.

Fig. 3: To shorten erection time a completely preassembled hood portion at the coating section was mounted as a whole. all the specifications. We are now producing the promised qualities and have been able to successfully trialprint the new grades at a number of press-rooms around the world with good results. Of course a lot of optimization work was and still is required in order to get maximum productivity out of this outstanding, innovative machine.”

Machine Concept The concept of the new machine was developed in close co-operation between 2 Voith Sulzer Paper Technology and SCA.

According to Kenneth Eriksson, Voith Sulzer Paper Technology made a good impression during the test trials before the decision, and during the technical negotiations. “Voith Sulzer Paper Tech- nology showed themselves as a very competent group of people. And they were well-prepared.” Asked for the reason Voith Sulzer Paper Technology was chosen as the supplier, Anders Johans- son, Production Development Manager, answered, “Voith Sulzer Paper Technolo- gy is ahead in technology, especially in the coating and in the calendering area.” And Örjan Petterson, General Manager 3 LWC Production, simply stated, “Voith Sulzer Paper Technology agreed to devel- The in-line process offers a reduction of machine calender, a DuoReel with center op a new, unique product with us.” personnel amounting to 30-50% (app. 9 wind, and other advanced equipment in persons per shift), a reduced amount of the coating and calendering area. In Equipment waste and a reduction of production space. addition to the machine, Voith Sulzer The new machine is a complete on-line PM 4 is equipped with a ModuleJet head- Paper Technology delivered complete production unit, with forming, drying, box, a DuoFormer CFD, a DuoCentri-2- machine-air ventilation with heat recov- coating and calendering in one process. Press with three press nips, a Combi- ery, steam and condensate system, cen- The reasons for this design are obvious. DuoRun pre-dryer section, a hard nip tral lubrication, hydraulics/pneumatics Paper Machines 25

Fig. 4: For the dryer section, steel framing was erected instead of concrete foundation to reduce down time.

Fig. 5: The framing of the wet end was preassembled before being mounted by crane.

4 5 and an extensive production monitoring machine would look like in the end,” said old PM 4, which had been sold to the Far system, the Technology Monitor VTM Johansson. East, finally was shut down and disman- 2000. tled in a record time. Fifty-five hundred Old machine still producing paper tons of steel were carefully removed in Civil Works during first phase of erection only seven days! Less than five months Civil works for the foundation of the new Voith Sulzer Paper Technology started later, on the 21st of January, 1996, the paper machine started in October 1994. erecting the new PM 4 on the 12th of new paper machine started up. “I don’t The fact that development work, includ- July, 1995. The old newsprint machine, think that such a huge machine has ever ing test trials in Heidenheim and in which was shorter than the new LWC been erected in such a short period Krefeld, were done parallel during the machine, was still producing paper when before,” said Kenneth Eriksson. design phase, sometimes made work the reel, calender, hot oil unit for the cal- difficult. “It wasn’t just a normal project ender, and two cylinders were being Uno Wallgren, project engineer for the where you knew exactly what the mounted. On the 3rd of September, the paper machine, said the project went very 26

well, especially in consideration of the tion between SCA’s and Voith Sulzer order to find solutions. In the beginning very short period, “It took only four and a Paper Technology’s people helped a lot in these meetings took place every day, they half months, and it was in an existing this phase. Anders Johansson remem- were then reduced to three times a week, building. It was really hard work for all bered that erection manager Alex Rieble and finally to once a week. involved due to the limited space in the and project manager Andreas Köhler The paper machine early showed its abili- building.” According to Wallgren, the “never saw a problem, always stayed cool ty to reach the forecasted quality level, erection crew led by Voith Sulzer Paper and always found a solution. They are whereas the new on-line coating and cal- Technology erection manager Alex Rieble skilled people.” endering technique took some time to get did a very good job. “We had a lot of pro- up and running. Several systems ject meetings. We also checked the man- Startup (tailthreading and drives) had to be ufacturing at Voith Sulzer Paper Technol- A time-schedule had been set up and adjusted, but because of the close co- ogy’s subcontractors, and everything steering committee meetings were held. operation, the changes were smoothly looked very good.” The good co-opera- Here problems were reviewed regularly in implemented. Uno Wallgren praises the 27

Fig. 1 (page 22) and 6: It is done! The new PM 4 is completed and in operation.

Fig. 7: Kenneth Eriksson, President of SCA Graphic Sundsvall AB.

Fig. 8: Per-Olof Wedin, Production Director of SCA Graphic Sundsvall AB.

8 work of the Voith Sulzer Paper Technolo- ty results: “Quality development since the LWC technique of the future.” Eriksson gy startup crew led by startup manager start-up was quick. We have reached our confirms, “We feel very comfortable with Ricardo Zorzin: “The whole staff is skilled goals for brightness, opacity, bulk and the quality we have achieved so far and and very open. We work very well with gloss. Runnability and printability also with our customers’ reactions, but we them.” And Per-Olof Wedin, Production seem to be superior.” Wedin adds, “The will of course continue to develop the Director at SCA Graphic Sundsvall, says: paper is very good and we will soon paper further.” “We appreciate the skills of Voith Sulzer reach a maximum production level thanks Paper Technology. Especially during to the good co-operation with the Voith Further SCA plans erection the high German standards were Sulzer Paper Technology team. In any case, development work at SCA visible.” will not stop, for as Wedin stated, “We We remain convinced that we have made want to be in the pole position when the Today’s performance the right choice regarding the technical next race starts.” Well, good luck for the Per-Olof Wedin is satisfied with the quali- solution. This is without any doubt the race! 28

Paper Machinery Divisions: Latest generation of cylinder mould formers – the FloatLip former N, NO, S

The VSPT short former, widely used for dewatering characteristics of the stock as the formation of individual layers of well as the slice geometry. Variations in board grades, has now been superseded the degrees of refining produce changes by the FloatLip former – very similar but in the dewatering pressure. Also imper- loading tube offering substantial improvements. fections of the cylinder moulds affect the dewatering pressure, as the clearance floating top lip This innovative but straightforward and width changes periodically in such cas- practical design not only ensures better es. Furthermore, the forces acting on the sheet formation on the cylinder mould, top lip of the headbox in conventional but also simplifies operation. One of the designs cause lip deformation over the innovations incorporated in this new width. Although this can be compensat- turbulence block development is already revealed by its ed, readjustments are always necessary 1 name: the FloatLip former. when operating conditions change. Adjustment of the basis weight profile on outlet slice remains constant. The pneu- Like its predecessor, the FloatLip former a shortformer is made by conventional matic hose on the top lip also ensures consists of a cylinder mould, frame with adjustment of the slice, so that the well- continuous support, thus avoiding defor- pan and couch roll and the headbox with known drawback of local changes in fibre mations due to bending. All in all, these the supply system. While the cylinder orientation negatively affects breaking innovations have an extremely positive mould and the couch roll have been taken length constancy and thus bending stiff- effect on end product sheet uniformity over from the short former without any ness over the web width. (fibre orientation, breaking length ratio, significant changes, the frame and pan of formation). the FloatLip former now form an integral All these disadvantages have now been unit. The real innovation, however, lies in eliminated by systematic development Another significant innovation comprises the completely new headbox and distribu- work on the short former. Although the the supply system with dilution water tion system. resulting innovations are not obvious at control and centrifugal distributor, which first sight, they are very important for supplies stock to the FloatLip former In conventional product quality and operating conve- headbox through a system of hoses. formers, drainage nience. in the sheet for- This centrifugal distributor is of similar mation zone is On the FloatLip former the top lip of the design to the central distributor, except determined by the headbox is no longer rigid, but adjusted that the stock enters the distributor predetermined to the suspension pressure by means of tangentially. Light-weight particles and nozzle geometry. a pneumatic hose. This keeps the dewa- undissolved air collect in the middle of This makes sheet tering pressure constant irrespective of the distributor and are removed out of The author: Dr. Günter Halmschlager, formation pres- fluctuations in the degree of refining. the top. Compared with lateral discharge Paper Machine Division sure dependent on Furthermore, the top lip can follow the from a cross-distributor, the quantities Board and Packaging the stock flow, the imperfections of the cylinder mould – the removed are insignificant, but sufficient Paper Machines 29

Fig. 1: FloatLip former headbox.

Fig. 2: FloatLip former with distribution system.

Fig. 3: FloatLip former: typical application ranges.

for efficient system deaeration in order to white top: prevent pinholes and irregular sheet type N structuring. The centrifugal distributor type NO not only removes the air from the system, but also eliminates the need for a type S

cross-distributor and lateral discharge, filler, back layer, underliner: thus saving energy in the supply system. type N

Based on the success of the ModuleJet, type NO the FloatLip former was equipped with a type S dilution water system for adjusting the CD basis weight profile. The ModuleJet 50 100 150 200 250 300 m/min 3 FL is a greatly simplified version adapted to the needs, with manually operated effects on fibre orientation and hence on leading position on the market also in dilution valves. The basis weight correc- breaking length ratio. application areas where ultra-high pro- tion effect due to dilution is so large that duction capacities or operating speeds only about every fifth FloatLip former Like its predecessors, the FloatLip former are not required. requires a ModuleJet FL. The Module is available in the N, NO and S versions, Jet FL allows precise adjustment of the type selection depending mainly on oper- Application range of the FloatLip former CD basis weight profile without negative ating speed and type of furnish. FloatLip I Folding boxboard formers are best used for layers with a I Grey board basis weight of 50 to 100 g/m2, the num- I Core board ber of formers depending on the required I Gypsum board mixing block basis weight of the finished product. ModuleJet FL Features of the FloatLip former I Adjustable dewatering pressure by FloatLip former sections operate at floating top lip speeds between about 35 and 400 m/min, I Centrifugal distributor with with basis weights ranging from 15 to ModuleJet FL more than 1000 g/m2. The maximum I Simple operation and maintenance working width is approx. 5000 mm. I High availability

The FloatLip former is an impressive Technological advantages demonstration of how well-tried concepts I Excellent formation with low energy

deaeration can be updated through innovations, consumption distribution pipe without unreasonable outlay. Together I Uniform thickness profile dilution water with other state-of-the-art developments, I Good printability it rounds off the Voith Sulzer Paper I High specific bulk and CD-stiffness 2 centrifugal distributor Technology product range to ensure a I Adjustable breaking length ratio. 30

Paper Machinery Divisions: Serang BM3/BM4 – the exemplary commissioning

Last year in This comprises a multiple stock prepara- pulping, flotation and disperging, with Serang, Indone- tion line and two board machines additional systems for chemical additives sia, a large Voith BM3/BM4 arranged back-to-back, which preparation, water loop treatment and Sulzer Paper apart from a few details are identical. rejects processing. Maximum overall Technology or- throughput is 1985 t/day oven-dry stock. der was handed Plant components over with out- The Serang board machines are supplied Each board machine operates with a mul- standing suc- by a total of seven stock preparation lines tiply 4-wire section, all plies being cess – a com- for waste paper, CTMP and chemical equipped with step diffusor headboxes.

The author: plete production pulp. These include all the key compo- Alexander Wassermann, line for coated nents of Voith Sulzer stock preparation The press section comprises a double- Paper Machine Division Board and Packaging, folding boxboard. technology, such as high consistency felted suction press followed by large Commissioning Paper Machines 31

Fig. 1: Wire section of Serang BM3.

1 diameter double and single-felted roll chine and cross-machine directions), and presses. These large roll presses may be After coating and the last drier stage, two paper feeding times. It also reduces in- replaced later on with shoe presses. The softnip calenders are installed. For board vestment costs and brings greater flexi- board sheet is prepared for coating in a grades coated on both sides, these oper- bility for extending existing lines. hard-nip calender. ate with alternate soft and thermorolls. With a total of three calenders, this con- For market reasons, the BM4 board The seven coating units (four on BM4 cept gives the same results as a machine machine mainly produces ivory board and three on BM3) have a maximum with yankee cylinder, but with the deci- (GZ1) from bleached chemical pulp and capacity of 24 g/m2, with precoating by sive benefit of higher runnability. CTMP at the present time. On BM3 stiff blade and top-coating by bent blade. duplex board is currently produced, but Two coaters on the back side are only This advantage mainly applies to grade solid bleached board, art board and used for special grades, with light sizing changing, humidity profiles (in the ma- Manila board also feature on the produc- otherwise. tion programme. 32

Fig. 2: Partial view of Serang stock preparation system.

gineering and production specialists and and control systems are not easy to mas- Commissioning – a challenge in optimal all members of the supplier consortium ter, but thanks to close cooperation with cooperation was particularly noteworthy. Already dur- the customer’s electricians and instru- Successfully commissioning a plant of ing the erection phase, which is critical mentation specialists, the long checklist this size demands perfect on-site coop- for smooth commissioning, customer was successfully completed in a very eration among all concerned. The same teamwork was outstanding. The first- short space of time. Operating personnel applies to erection and installation of in- class workshop facilities provided by the for the stock preparation line and board strumentation and control systems, and customer also contributed a good deal machines received training by the cus- to the subsequent technological commis- toward meeting the tight commissioning tomer’s papermaking specialists. These sioning phase. schedule. in turn had attended a training course in Europe prior to commissioning, where Cooperation between the customer’s en- The complexities of modern measuring they also had the opportunity of inspect- Paper Machines 33

Fig. 3: Felt threading on second press of BM3.

Fig. 4: Threading of filler wire on BM3.

3 4

ing a board mill in operation. Full prepa- The stable instrumentation air supply net- rations were thus completed for the com- During the loop checks, control system work so important for the pneumatic missioning phase, which commenced in links to the line aggregates and vice- systems was also ensured. November 1995. versa were checked. With about 5000 control circuits all in all, this took up After checking all the process control Functional commissioning most of the time required for functional circuits, each function was tested individ- At the precommissioning meeting in commissioning. ually and in its process context. This October 1995, a startup deadline was phase provided a further check on logical agreed for mid-February 1996. All checks To give a better overview and speed up sequencing of the line components. therefore had to be completed as quickly progress monitoring, check-sheets were as possible. The functional commission- filled out by the test engineers and hand- The final stage in functional commissioning phase, which includes loop checks ed over to the Voith Sulzer team. Any ing comprised startup tests on the nu- and dry operation tests, forms the basis problems noted in these check sheets merous drive systems. Since more than for final commissioning by ensuring trou- could thus be followed up immediately. 70 drives had to be coordinated on each blefree control and full reliability of all By this time all machine motions had board machine, this phase was extremely aggregates and machinery at startup been checked, meaning that also the hy- complex and time-consuming. Apart from time. This applies to all sections of the draulic aggregates were operational in- drive rotation tests, checks also had to be process control system as well as the cluding a reliable supply of cooling water. carried out on the central oil lubrication machine controls. 34

Fig. 5: Final section and reel of Serang BM4. system, steam and condensate systems. Drives in the wet section were first coordinated in the unloaded condition, since wires and felts could not be inserted until after water tests had been carried out.

Technological commissioning The first stage in technological commissioning comprises wet testing. Both in the stock preparation lines and in the board machines themselves, all lines are first operated with water. This not only serves for flushing and leakage monitoring, but above all for initial adjustment of control parameters and stability checking of the individual systems. Pressures in the screens and cleaners are preadjusted, valve settings are made, and trouble- shooting is carried out.

During the individual group startup tests, particular attention was paid to ensuring that all startup steps could be carried out by the customer’s operating personnel. The water tests offered a good opportunity for training the customer’s personnel in technical operating conditions on the running machines. Here again, the importance of smooth cooperation was impres- sively demonstrated. Since the operating personnel were divided into a field group and a process control system group, agreement between monitor display data and the process conditions was likewise an important theme.

During commissioning a recheck was al- 5 Paper Machines 35

Fig. 6: Great care is taken over examining the quality of a reel spool.

rect functioning of each stop device also regulation in the machine direction by had to be ensured, as well as startup of continuous consistency measurements in the correct pulpers with the appropriate each line. Particularly in the stock prepa- dilution water flow. On a line of this ration line, a large number of consistency length, five pulpers are required for control devices indispensable for correct troublefree web feed and adequate product regulation had to be calibrated. flexibility in case of breakage. In view of the rejects produced during startup, care was taken that these were Machine startup not fed back too thinly to stock prepara- The production schedule was agreed in tion. good time with the customer. Initially the 6 intention was to produce uncoated grey This early optimization resulted in ex- board (in three plies) for the customer’s tremely stable operation of the board ma- so carried out on all interlocks. For exam- spool plant. After a transition to white chines, certainly also one of the benefits ple faultless operation of the refiner con- covered duplex board, coated duplex of a concept without yankee drier. After trols in the stock preparation line was en- board was finally to be produced. The producing grey board and white covered sured, and dependable stock supplies as production programme was adapted to uncoated duplex for two weeks, produc- a function of production regulation by the current market conditions shortly before tion was changed to coated grades. The mixing centre control system. On the commissioning, however, in order to first laboratory test results confirmed ex- board machines, particular attention was commence production of fresh fibre cellent product quality. paid during this phase to interlocks in the board. approach flow and wire section. Since the Optimization of board machine settings Serang board machines have multiply This change made some adjustments The optimization work carried out during wire sections with 4-ply couching, inter- necessary in the stock preparation line, the next few weeks served on one hand lock complexity is very high. The vacuum but the startup deadline was still met. On to increase production output, and on the system in this wire section is much more February 14, 1996, the first stock arrived other hand to enhance board quality still sensitive than in a conventional four- on the wires. Adjustments were then op- further. Here again, close cooperation drinier machine, and was likewise timized in the wet section to ensure a with the customer ensured that any ad- checked very carefully. stable web transfer to the dry section. justment changes necessary were carried out straight away, with immediate avail- Last but not least came a simulation test Right from the outset of production, ability of results. on the web breakage control system – ex- great importance was attached to au- tremely important for startup – and re- tomation of the basis weight and mois- Machine operation was extremely smooth jects processing. The light barriers were ture control systems. The process/oper- right from the beginning. Hardly any positioned carefully, since any fluctua- ating control system supplier rapidly car- stoppages occurred, neither due to elec- tions in tension leading to web sag must ried out scanner adjustments, at the trical nor mechanical causes. Only three not be interpreted as web breakage. Cor- same time calibrating basis weight profile months afterwards, web breakages were 36

Fig. 7: Production manager Tsai Chuen Hsin (3rd from the left) with some members of the startup team.

7 limited to about once every two days. The case of two almost identical board ma- detailed statistics kept by the customer chines in the same line proved very ad- The customer’s operating personnel allowed systematic optimization of web vantageous here both for the erection received excellent training on the BM4 breakage frequency. team and test engineers. The few machine, and a number of shift leaders changes required to hardware and soft- were transferred to BM3 during startup of Production was then adapted continuous- ware were soon completed, and the re- this machine. ly to market demands, and in July 1996 vised function plan thus allowed a con- the guaranteed production output of siderable reduction of testing time. The These optimal conditions led to an exem- 650 t/day was exceeded for the first pre-optimized stock preparation line, al- plary startup of the second board ma- time. Product qualities always complied ready tested with water, was now started chine – only 45 minutes after stock feed with the customer’s specification. up with waste paper furnish. Of consider- release, board was already being able benefit here was the existence in the produced, which greatly impressed the BM3 startup same mill of another machine using customer. The outstandingly successful During the optimization phase on BM4, waste paper, which during the test phase commissioning of the Serang board pro- assembly work on BM3 had been com- was supplied by the new stock prepara- duction line thus shows once again the pleted, and loop tests and functional tri- tion line. Stable stock supplies to the enormous importance of first class coop- als had already commenced. The unusual BM3 machine were therefore ensured eration between customer and supplier. easily. Paper Machines 37

Gap Former Technology: No. 26 DuoFormer CFD installation a success

Consolidated Papers, Inc.’s Biron Divi- sion’s No. 26 paper machine is already manufacturing a first-line product following the installation of a DuoFormer CFD that was completed in only 18 days.

The gap former rebuild was originally scheduled to take 30 days. Effective planning and outstanding efforts by crews involved trimmed 12 days from the proposed schedule, resulting in major savings on the project. On March 7, stock was on wire and on March 8, the machine officially started up.

“It was a phenom- enal job by everyone involved in the James R. Kolinski, No. 26 rebuild Vice President, and gap-former Manufacturing Con- solidated Papers, Inc. project, including engineers, draft- ing, construction, members of the Kolinski, vice president, manufacturing. excellent, according to Ken Lepinski, yard and support “Other divisions sacri- ficed to support No. 26 superintendent. There is still some departments, us with their crafts people. Thanks to fine-tuning to be done on the machine, transfer employ- everyone who had a hand in this project. but it is already providing great results. ees, maintenance It’s a stellar, outstanding, world-class “The ModuleJet headbox is giving us an crews, No. 26 pro- effort.” outstanding profile,” Lepinski said. “From duction employ- the start-up we’ve been selling the paper ees, our purchas- “The prework, installation and start-up as a first-line product.” ing department, was outstanding,” noted Roger Wangen, vendors and sup- division manager. “The entire project was pliers, the Voith a success – the first day the coaters were Sulzer team and on, we were shipping salable paper.” Roger L. Wangen, contractors on Division Manager Biron Division Con- site,” said Jim The paper quality from the gap former is solidated Papers, Inc. 38

Paper Machinery Divisions: New applications in multilayer technology

Multilayer formation with several headboxes and wires is Multilayer headbox design state-of-the-art at the present time for board and packaging paper production. Fig. 1 shows a 3-layer headbox with ModuleJet consistency control for a CFD In this connection, the intensive research work carried out by gapformer. Up to three different pulp Voith Sulzer Paper Technology in close cooperation with grades can be fed to the headbox through customers has resulted in far wider applications of multilayer the large-diameter headers. If a symmet- technology over the last few years (several pulp grades in a rical sheet structure is required, the two single headbox). outer pipes are fed with the same kind of pulp, the lower grade pulp generally Voith Sulzer Paper Technology now markets a range of inter- being fed through the middle pipe. esting new designs, suitable for a wide variety of furnishes

The authors: and paper qualities as well as meeting specific customer The headers are often connected to the Dr. Elmer Weisshuhn, needs. headbox by flexible hoses. This not only Paper Machine Division makes the headbox more accessible, but Board and Packaging, Headboxes. A complete report on all these innovations would exceed the also dispenses with the need for inlet and Ulrich Begemann, scope of this article, which is therefore limited to a basic dis- outlet compensators in the headers. Paper Machine Division Graphic, Headboxes. cussion of hydrodynamics in modern multilayer headboxes. Alternatively, the headers can be directly Paper Machines 39

Fig. 1: Schematic arrangement of a 3-layer headbox.

Fig. 2: 2-layer headbox for board and packaging papers. flanged to the turbulence generator, thus Main quality criteria: resulting in a very compact headbox I Good coverage for a given basis arrangement with good accessibility. weight of the liner I Bond All multilayer headboxes can be swivelled I Tensile ratio in the same way as single layer headbox- I Formation es for adjusting the jet impingement I Stock consistency and throughput angle. range I Speed range At the outlet of the turbulence generator, two lamellas divide the nozzle into three Latest achievements in multilayer separate flow channels. The end of each headbox development: lamella comprises a sandwich structure I Significant reduction in minimum basis made of carbon fibre reinforced plastic, weight required for good coverage with zero thermal expansion coefficient. I Operating speed rise of multilayer This ensures invariable dimensional machines to about 1200 m/min accuracy at different pulp temperatures I Production at overall basis weights up 2 and is essential for a stable and flat fibre 2 to 300 g/m on Gapformers orientation profile. tant for good coverage, is not spoilt by Thanks to intensive cooperation between For board and packaging papers, the type slicer bar deformation due to cross pro- customers and manufacturer, and simul- of headbox shown in Fig. 2 is increasingly file control. taneous development work on several used. The headers are installed in a rigid Voith Sulzer Paper Technology facilities support structure and directly connected The headboxes shown here are a typical in Ravensburg and Heidenheim, a good to the turbulence generator. selection, taken from the wide variety of many product-specific solutions have designs required for meeting all the dif- been implemented in a relatively short Since the basis weight of high-grade liner ferent needs of two and three layer tech- time. has to be kept as low as possible, the nology for board and packaging papers, ModuleJet layer usually makes up at least tissue and graphic papers. These paper machine test facilities are 50% of the total basis weight. This is equipped with headboxes allowing easy enough to allow optimization of the total modification of the type of turbulence basis weight cross-profile by varying that New developments in multilayer generator, lamella and nozzle geometry. of one layer only. In addition to its gener- headbox design The headboxes can be operated with one, al benefits, the use of consistency control two or three layers on the Gapformer. on multilayer headboxes producers one Multilayer product quality depends far more advantage: the uniform jet thick- more on correct headbox design than The first tests on 3-layer production of ness for the liner, which is very impor- single layer products. copying paper in March 1992 resulted in 40

Fig. 3: Factors affecting jet quality R on a multilayer headbox.

Fig. 4: Poor coverage due to unsuitable nozzle geometry.

Poor Poor R R

Good Good 0 200 400 020408060

Jet length [mm] Lamella extension [mm]

Poor Poor R R

Good Good 500 700 18

Nozzle length [mm] End convergency [mm]

3 4

unsatisfactory coverage with streaks weight irrespective of operating speed Since formation and coverage character- when using two different pulp grades. and throughput. istics are often a direct function of jet During the following months, parameters surface structure, some jet pictures taken such as headbox consistency, jet length, During this phase the advantages of con- on a 120-mm-wide pilot headbox are nozzle length, lamella geometry and noz- sistency control, already known in single shown here. zle convergence were checked for their layer technology, were confirmed. effects on formation, bond and coverage. Fig. 5 shows the influence of nozzle con- As a result, good fibre orientation and vergence on jet turbulence, and Fig. 6 Fig. 3 shows the jet quality of a multi- basis weight profiles were also achieved that of lamella length. On the left hand layer headbox as a function of some of with the ModuleJet in multilayer head- side of Fig. 6 the jet spraying effect these geometrical parameters. boxes. caused by excessive wall friction is clearly visible. Increasing jet turbulence causes Fig. 4 shows a 2-layer board sample with Here again, the essential prerequisite for harder formation, and after exceeding a poor coverage, which was due to unsuit- a flat fibre orientation CD profile is an critical limit the result is poor coating. able nozzle geometry. Another task at absolutely parallel gap. In other words, Long lamellas, which would otherwise that time was to develop a user-friendly the flatness of the lamella ends is just as seem desirable for better layer separa- headbox control system, allowing adjust- critical as that of the apron. tion, are therefore not such a good idea ment and setting of each individual basis after all. Paper Machines 41

Fig. 5: Jet surfaces with different nozzle convergences on a test headbox.

Fig. 6: Jet surfaces with different lamella lengths on a pilot headbox.

Standard nozzle Convergent nozzle with linear convergence with extreme acceleration at nozzle end 5

Lamella overlap over nozzle end: 60 mmHeadbox Lamella overlap over nozzle end: 0 mm

The time exposure in Fig. 7 shows the jet sioned during recent years alone, which desired effect is much more pronounced surface of a pilot headbox fitted with one also operate with multiple stock grades. than on single-layer sheets produced lamella. The right hand side of the lamel- under optimal operating conditions. la has an optimized tip in CFRP sandwich Development work has likewise been construction, while the left-hand side has underway for some time now on the mul- Summary and prospects a 0.5-mm-thick tip. Table 1 indicates the tilayer production of SCA papers, the Multilayer technology for board and large number of Voith Sulzer Paper Tech- object being to enrich the filler on the packaging papers has now reached a high nology multilayer machines commis- sheet surfaces. As shown in Fig. 8, the level of sophistication, and numerous 42

Fig. 7: Jet surfaces with different lamella end geometries (time exposure on a pilot headbox).

Fig. 8: Filler distribution in SCA paper produced on a multilayer headbox.

Lamella end: stepped

25 Product: SCA paper Basis weight: 56 g/m2 20 Wet section: 3-layer headbox and CFD former Fillers content [%] 15 Lamella end: optimized US OS 7 8

Date commissioned Company Web width [m] Paper grade production machines have been sold within a short space of time. 08/1994 Visy Paper Inc. 2.7 Liner Sydney 6 2-layer With the plants already in operation, 01/1995 Visy Paper Inc. 5.4 Liner basis weights from 80 to 300 g/m2 can Conyers 12 2-layer be produced on Gapformers at operating 01/1995 Willamett Inc. 5.4 Liner speeds up to 1200 m/min. As shown in Campti 2 2-layer Figs. 9 and 10, coverage between individ- 09/1995 Neusiedler AG 4.9 Copying paper ual layers is good. Furthermore, invest- Hausmening 6 3-layer ment and operating costs are significant- 01/1996 Taiwan Tissue 3.8 Tissue ly lower than for comparable multi-ply Tien Long 2-layer machines. 03/1996 Visy Paper Inc. 3.1 Liner Brisbane 8 2-layer On the whole, basis weight and fibre ori- 06/1996 Industria Cartoria 2.8 Tissue entation CD-profiles are much better. Tronchetti 2-layer Moreover, this type of machine is as sim- Tronchetti 3 ple to operate as a single-layer machine. 02/1997 Visy Paper Inc. 5.4 Liner New York 2-layer For effective control of MD and CD 08/1996 KNP 5.4 Liner strength characteristics, the jet/wire Zülpich 2 2-layer velocity ratio can be adjusted over a wide 12/1996 Cartiera di Cadidavid 5.4 Testliner range. Cadidavid 2 2-layer Pulp and Paper Europe Multilayer technology for graphic papers Paper Machines 43

Fig. 9: Multilayer liner produced on a pilot machine with 2-layer headbox and DuoFormer CFD at 550 m/min and 126 g/m2. Top side: bleached chemical pulp, 56 g/m2. Back side: unbleached chemical pulp, 72 g/m2.

Fig. 10: Multilayer liner produced on a pilot machine with 2-layer headbox and DuoFormer CFD at 900 m/min and 118 g/m2. Top side: waste paper/chemical pulp (dyed), 46 g/m2. Back side: 100% waste paper, 72 g/m2.

has likewise reached maturity, but due to their lower basis weights special demands are placed on headbox flow conditions.

Although the use of multilayer headboxes for board and packaging papers, tissue and graphic papers will certainly increase over the next few years, this interesting technology is also subject to limitations, which are currently as follows:

I The minimum basis weight of top layers is around 25 g/m2 at the present state of development. If this limit is not respected, only a network is formed, but for some applications this

9 is sufficiant.

I Even with separate upward and down- ward whitewater drainage, inter-layer mixing of the fines and filler in a 2-layer headbox cannot be entirely avoided. This places limits on the maximum possible colour difference between layers.

Development potential in this relatively new field is certainly not exhausted by any means, however. It can therefore be assumed that future will open new application fields besides the classical multilayer technology. As well these applications will overcome today’s limits. One example of this is filler enrichment in the surface layers of SCA grades, as men- 10 tioned above. 44

Paper Machines Divisions: Brilliant Coating with JetFlow F – data, facts, experience

The number of For those of you who do not yet know too JetFlow F – advantages at a glance renowned com- much about the new process, its princi- panies that have ple is explained briefly below. For paper quality: I decided in favour Higher gloss I of JetFlow F is A precisely controlled thin film of coating Better coverage I steadily growing. color is applied to the paper as a free jet. Convincing printing result I In three Finnish The film is pre-metered, the required coat Disturbance-free coating film I paper mills, six quantity smaller and the application more Optimum coat weight profiles JetFlow F’s have uniform. Operation is cleaner, much For economic efficiency: I recently gone into faster, and pre-dewatering of the applied Less breaks I operation within a film is smoother and more uniform Maximum runnability I few weeks of each throughout the dwell time. The coating More flexibility I The author: Bernhard other – and all of color arrives in a more liquid form at the Reduced energy consumption I Kohl, Paper Machine them meet the blade and can be metered better, result- Reduced coating color losses Division Graphic, For your production and maintenance Coating Technology customer’s expec- ing in an improved coat structure. tations in respect team: I of quality and pro-duction. JetFlow F is JetFlow therefore offers brilliant advan- Clean operation I simply “Brilliant Coating”! Reijo Lind- tages! What are its benefits? Below are Less maintenance I holm, head of Production at Enso Publi- some interesting facts based on practical Longer blade life I cation Papers confirms: “This technolo- experiences and opinions received from Longer roll service life I gy represents a significant step our customers. No wear parts forwards.” Paper Machines 45

What economic advantages does solids contents which is, among other JetFlow F offer? Fields of application…proven success- things, beneficial to paper quality. In fully addition, the previous speed limit due to Maximum runnability Base paper the drying limitation of the coating Compared with all other blade coaters, -wood-free g/m2 40-140 machine was distinctly increased for sev- JetFlow F provides significantly higher -wood-containing g/m2 24-290 eral grades.” runnability, which means the efficiency of 2 the complete production line can be Coat weight g/m 4-20 increased. With JetFlow F, speeds of Speed m/min 330-2000 Reduced color circulation rate: 2,000 m/min (6550 ft/min) are a reality. Solids content % 45-70 m3/h · m Viscosity mPa·s 600-2400 AB

(100 rpm Brookfield) 27 25 -20% -30% 7,6 -10% 6,8 -36% 6,7 This means savings in expensive reten- 20 19 -28% tion agents and trouble-free processing 4,9 4,8 of even critical coating colors.

Reduced energy consumption Color circulation rate LDTA JetFlow F LDTA JetFlow F JetFlowF can operate with a higher color LWC coater Art-paper coater consistency. That saves energy. In addi- 3 months after rebuild 1 year after rebuild 3 months after rebuild Breaks per day (since May ’95) (since February ’96) LDTA JetFlow F LDTA JetFlow F tion, the color circulation rate is low and m = operating width in m color thickening is reduced. JetFlow F AB LWC coater Art-paper coater therefore cuts operating costs. (since May ’95) (since February ’96) Not only the lower color circulation rates but also the smaller color losses during Minimum thickening: cleaning reduce operating costs.

More flexibility The free-jet application places no special Users’ experience: demands on coating color rheology. The “Color losses on breaks are significantly color can be optimized for the paper but reduced. Prior to the rebuild we lost does not have to be adapted to suit the about 300 l of color with each break, applicator. JetFlow F is suitable for all emptying the color pan, whereas 100 l at customary coating colors and paper the most are now lost with the nozzle grades. applicator. Based on 5 breaks per day, this corresponds to a reduction of Users’ experience: approx. 1 t of color loss per working “An optimization potential with regard to Users’ experience: day.” coating color formulation was reached “Today, color thickening at Coater 1 has due to the significantly lower color thick- been reduced by 50 to 70 per cent, and “The total waste water losses could be ening and new degrees of freedom with at Coater 2 it is almost zero. It is there- distinctly reduced due to fewer breaks respect to color rheology.” fore possible to operate with higher and the reduced color circulation rate.” 46

How does JetFlow F improve your paper? Convincing printing results Users’ experience: Our customers say: “Experience with our “After installation of the JetFlow F, flick- Higher gloss new JetFlow F coater in the ULWC/LWC ering streaks in the coating layer have The free-jet application ensures a better- rotogravure sector shows improved been eliminated. The color rate setting is structured alignment of the pigments. printability of our high-quality papers.” reproducible. Barring on the blade is a The surface is more closed and has a thing of the past. The result is an higher gloss. “We can save co-binder, as the JetFlow F extremely homogeneous and uniform produces an improved coating holdout.” coat application.”

68 62 Optimum coat weight profiles 53

)in% LDTA JetFlow F ° Coat weight profiles can be controlled. With the innovative Profilmatic2 F the profile is controlled before the coating color even reaches the paper. Something no other system can do. Gloss (Hunter 75 SDTA LDTA JetFlow F Results with LWC offset Coat weight 2 2 Disturbance-free coating film 40 g/m + 2 x 10 g/m coat application +10% control range at 1500 m/min. The coating color is applied without turbulence or film splitting, thus eliminating associated quality defects. Better coverage -10% The free-jet film provides a visibly more

uniform coverage of the fibers. Coat weight -30%Nozzle gap +30%

JetFlow F As profiling is not done by the blade, the blade tip angle remains constant. Bleed- ing and non-uniform blade wear are reduced. This is extremely beneficial for high coat weights.

LDTA

1 Jet 2 Nozzle 3 Color application 4 Color return Paper Machines 47

What are the advantages for your pro- Less maintenance Longer blade life duction team and maintenance? JetFlow F has no wearing parts. Nothing The coating color gets to the blade in a has to be replaced continuously. Only the more liquid form, reducing blade loading Clean operation nozzle needs to be cleaned from time to and increasing blade life. Advanced The compact JetFlow F nozzle produces a time. And this is fast and easy. deckle adjusters minimize blade edge closed film, the coater stays clean. wear which also contributes to longer Splashing, misting and troublesome coat- blade life. ing deposits are a thing of the past. A production team: “We have never seen such a clean edge system before. The Users’ experience: clean, exact coat edges are a great “Cleaning of the system has become con- advantage. They can be adjusted remote- siderably easier and faster since the ly. The wear- and contact-free edge deck- installation of the JetFlow F. Compared les do not stress paper web or backing with the LDTA used earlier, there is no roll.” cleaning of the lead-in roll or a color pan.” Longer roll life “In the past, the edge deckles were very The clean edge deckles inside the nozzle sensitive to contamination and deposits. of JetFlow F prevent premature wear in The result were often breaks due to edge the edge zone of the backing rolls. cracks, whereas the integrated edge deckles of the JetFlow F remain clean and are wear-free.” Users’ experience: The nozzle can be rotated towards the “After the installation of the JetFlow F, See for yourself. During a visit to a refer- user and opened for cleaning. Experience the service life of backing rolls has ence installation, the users of JetFlow F has shown: “The nozzle is cleaned regu- increased from 6 to 10 months.” will certainly pass on their experience. larly every 4 weeks.” 48

Finishing Division: Econip – a new generation of deflection compensating rolls

Established for During the last few years many improve- Econip-TC over 30 years, the ments have been made to the Swimming The Twin Chamber (TC) roll is the only single zone, de- roll offering greater flexibility, improved roll currently giving extremely accurate flection compen- operation and extended service life. It is control in high speed, low lineforce appli- sating roll accept- these important developments which cations. In tissue combining, where bulk ed by papermakers have initiated this new generation of rolls loss must be kept to an absolute mini- worldwide and known simply as Econip, a name which mum, this is a vital consideration. These known generally more accurately reflects their relevance very demanding machines typically oper- as the Swimming to today’s papermaker and which compli- ate at speeds approaching 2300 m/min roll, has been ments the already well established NIPCO and down to virtually zero lineforce!

The author: manufactured at roll. Nigel Ashworth, the Manchester, A conventional single zone roll is outside Finishing Division England plant of The standard Swimming roll principle is its design parameters under these condi- the Voith Sulzer Finishing Division. well known. This new generation of rolls tions. Research has shown that control- has been developed from the standard ling very low oil pressure (0.1-0.2 bar) in Over 3600 of these rolls have been sup- design and falls into three main cate- one zone is impractical. It was also found plied to satisfied customers throughout gories all derived from the same princi- that as the roll speed was increased, a the world. Without exception they all ple.... Econip-TC, Econip-X and Econip-L. pressure wedge of oil formed behind one operate successfully in most sections of A fourth and ultimate roll incorporates of the seals. This overcame the loading the paper machine including the wire features from two of the main versions on the seal lip with a resultant loss of part, press section, breaker stack and fin- and will be marketed as Econip-LX. pressure in the zone. ishing calenders. Roll sizes and parameters produced over the years have, of Installing an Econip roll gives enormous The simple answer was to add a second course, varied tremendously with some benefits to the papermaker which become zone. This works in the opposing direc- of the more notable ones shown below obvious once a more detailed examina- tion with the differential pressure of the (Tab. 1). tion of the new roll designs is made. zones giving the required crown.

More manageable pressures can be Table 1: employed which at the same time exert Largest diameter: 1300 mm Press roll supplied to sufficient force on the seal to overcome Tampella Espanola, Spain the pressure wedge (Fig.1). Longest face width: 9550 mm Calender roll supplied to Abitibi Paper, Iroquois Falls, Canada Fig. 2 clearly shows the shaft assembly Highest pressure: 1050 KN/m Flexonip press roll supplied to with two sets of sealing elements before ThaiKraft, Thailand fitting into the roll shell. A further appli- Fastest Speed: 2286 m/min Tissue combining calender supplied to Fort Howard, USA cation of the Twin Chamber (TC) rolls in the intermediate position of newsprint Finishing 49

Fig. 1: Sealing system of the Econip-TC roll.

Fig. 2: Sealing elements of the Econip-TC.

Fig. 3: Econip-TC roll in a newsprint calender.

Fig. 4: Principle of the Econip-X.

Fixed axle

Outer shell

Pressure zone

Drain

Pressure zone

1 2

F F

e’X’tended bearing centres Relieving Loading 3 4

calenders where additional loading or Finite calculations show a significant extending the acceptable machine operat- relieving of pressure is required (Fig 3). improvement in lineforce distribution ing range. These maximised benefits using an e‘X’tended roll (Fig. 5). This sin- include a more uniform sheet finish and gle nip example taken from a Brazilian extended roll regrind cycles. Econip-X paper mill project shows that a standard The e‘X’tended roll is a simple but Econip roll was calculated to give a devi- extremely effective design concept. By ation of 11.2 KN/m whereas the Econip-X Econip-L extending the shell length and positioning roll gave a deviation of only 4.01 KN/m. The LoadContRoll (L) is a state-of-the-art the internal end bearings closer to those system developed for use in Janus and of the opposing roll, an improved bend- Supercalenders and will identify any dis- ing line of the two rotating bodies can be These improvements also benefit the ruptive forces arising in the calender roll achieved (Fig. 4). papermaker at low lineforce levels by stack and eliminate them by automatical- 50

Fig. 5: Lineforce-Deviation of Econip rolls.

Fig. 6: Econip application with LoadContRoll System.

35 ∆P ∆P

30 Normal 25 admissible deviation Control 20 System 15 Computer Econip (STD) 10

Lineforce-Deviation in N/mm 5 Econip-X Roll ∆P ∆P configuration 0 0 50 100 150 200 250 300 350 Lineforce in N/mm 5 6

ly regulating pressure in the Econip rolls. the roll edges. Likewise vice versa exces- General This concept with Econip-L rolls installed sive internal roll oil pressure will lead to For press section applications, the Voith in both top and bottom positions is a relieving of pressure at the roll edges. patented Vibrosoft vibration dampening shown in Fig. 6. Errors such as these would be compen- system can also be engineered into all sated for by the LoadContRoll system Econip rolls. Continuous monitoring also means that which has a measurement range of 10% when rolls are changed in the stack, oil of the total nip force. A new development currently under test pressure in the Econip rolls is optimised is the Thermo Econip roll. Further details for the new stack weight. Hydrostatic To summarise, the Econip-L roll senses will be available and completion is measuring devices situated underneath disruptive forces, balances them to zero planned for the end of 1996. the roll shell end bearings measure the by means of the computer control system forces acting on them. The force on each and automatically gives the optimum This continuous programme of design bearing equals zero when the lineforce lineforce distribution under all operating and development enables the Finishing and the Econip roll oil pressure are in conditions. Division to offer an unrivalled range at equilibrium. Any force disturbing the bal- deflection compensating rolls built to ance between the internal roll pressure meet the ever-increasing demands and the lineforce acts as a reactive force Econip-LX repeatedly asked of technology today. on the roll bearings which then leads to a The ultimate design combination giving worsened lineforce distribution in the the extensive benefits of both the Econip- nip. X and Econip-L rolls is designated Econip-LX. This roll provides both Excessive external loading induces a improved lineforce distribution and bear- reactive force at the bearings which ing load sensing and is readily built into results in an increased compression at deflected nip Janus and Supercalenders. Service 51

Service Division: GR2 cover – next-generation performance leader

In the late 70’s and early 80’s it was evi- ed severe vibration and wear problems various rolls con- dent that the paper industry needed a for the granite roll. These safety and ducted under replacement for their granite rolls. There operational issues were the impetus for operating condi- were several rolls which had failed in industry to examine granite roll alterna- tions in produc- operation, and in some cases had caused tives. In one case, a group of five tion paper ma- injury and death. Furthermore, the indus- Swedish paper mills formed a task force chines. try was beginning to use increasingly called the Granite Roll Group (GRG). This abrasive fillers in larger quantities, group had a goal of finding and promot- In 1990, the GRG increasing roll wear and reducing time ing the best working and most safely reli- ended their orga- between grinds to an unacceptable level. able press rolls for large, high-speed nization, but their Finally, higher machine speeds combined machines. The GRG carried out several work has been The author: Paul S. Haller, with higher loading in the presses creat- years of intensive study, with trials of published and pre- Service Division 52

Fig. 1: Inspection of the completed GR2-Cover.

Fig. 2: A magnified comparison of the GR2 Ceramic Cover (right) and granite (left) showing GR´s uniform texture. sented on several occasions. Earlier this year, an update on the state-of-the-art in granite replacement rolls was presented by a member of the GRG, Hans M. Erics- son, former Chief Engineer at Holmen Paper in Hallsta, Sweden. Entitled “Man- made Press Rolls,” the paper was presented to the Swedish Association of Pulp and Paper Engineers in Stockholm, Sweden during SPCI-96, World Pulp & Paper Week. 2 In his presentation, Ericsson describes the history of both synthetic resin covers few ceramic rolls in operation. The Applying the cover is an exacting and ceramic rolls. By 1991 there were ceramic roll cover’s entry into the market process. The roll body is first ground to around 60 synthetic resin covers in oper- was made more difficult since it was the correct finished profile. Any locking ation among 13 surveyed mills in Europe. being compared with the synthetic resin grooves or shell imperfections are These rolls exhibited acceptable vibration covers, rather than the natural granite it repaired prior to grinding. Once ground, and wear characteristics, and although was intended to replace. Nevertheless, the surface is cleaned and textured to the several cover failures occurred, none Ericsson notes that paper machines using correct roughness for application of the were of catastrophic proportions. Some ceramic rolls began to set speed and pro- barrier coating. This coating is then of the cover failures were repaired at the duction records across Europe. In North applied using special guns to create a mills, while others required a complete America, Voith Sulzer Paper Technology’s very dense, impermeable corrosion barri- roll recovering. Portland Service Center, having been in er approximately .030’’ thick. This barrier the Yankee coating business and on the layer enhances the bond characteristics Wood resin, chemical additives and fines leading edge of thermal spray technology of the ceramic layer while protecting the were still accumulating on some rolls, for 25 years, had also been developing a steel or iron shell from corrosion. and there had been sheet release prob- ceramic press roll cover. Having devel- lems that could only be solved through oped stainless steel coatings for wet felt Ericsson notes in his paper that the sin- the use of expensive release agents. rolls in the 1970’s, they applied their gle documented failure of a ceramic cov- Often, the synthetic resin covers were experience in this area to develop a coater (of Japanese manufacture) was due to also susceptible to thermal shock, and ing that would not only function, but sur- corrosion of the roll core beneath the could not be used in conjunction with a vive long-term operation in a paper applied ceramic cover. He also comments steam box. However, overall, the mills machine press application. The result of that VSPT’s GR® cover is the only roll considered the difficulties minor in com- this intensive development was the GR® cover to have a “corrosion barrier” base parison with the danger of natural granite roll cover, a plasma-spray applied ceram- layer applied over the original core before roll failures. Until 1991-1992, there were ic coating. the ceramic layer is applied. Once the Service 53

Fig. 3: Paper Quality Improvement

types of paper. Because the same roll cover can be used in multiple positions, Tensile there is greater flexibility in the design of machines and a reduction in the number of spare rolls maintained by a mill. Other Smoothness ceramic cover manufacturers require different grades and applications of ceramic Internal Bond for differing machine positions. For instance, one supplier requires one coating formulation for heated center press rolls Stretch and another for extended nip presses.

MD Tensile Energy Absorption Finally, Ericsson comments that the years of experience gained at the Portland facility have been transferred to the other ser- Lint Reduction vice centers, with VSPT now producing ® 0% 5% 10% 15% 20% 25% the GR cover on three continents: at the Level of Improvement 3 Service Centers in Portland, Oregon, USA, St. Pölten, Austria, and São Paulo, barrier coating is applied, the GR® coat- possibility to grind away cover damage Brazil. VSPT now has over 65 GR® rolls ing is applied with a different type of resulting from objects passing through installed or on order worldwide, used in plasma spray coating system to produce the nip. Since the cover has a minimum all plain press roll applications, as well as a very openporous coating, offering supe- thickness limit of 0.10’’, there is ample with variable crown rolls and profile rolls. rior release characteristics. This coating material for multiple regrinds. This prop- is applied with a thickness of .060’’. erty becomes somewhat a moot point To conclude his presentation at SPCI-96, with GR® rolls operating up to six years Ericsson summarizes the operating data VSPT’s operating experience with the without a regrind. One such roll has been from 1987-1995, stating that synthetic GR® roll cover is exceptional. The firm inspected twice during that time, once at resin and ceramic covers are at the fore- has produced the GR® cover since 1990 one year and one at four years, and there front of press roll technology. With one and has never experienced a cover fail- were no detectable differences in diame- type of roll for every possible grade of ure. The rugged endurance of the GR® ter or profile from when it was new. paper and position on the machine, cover is the result of careful application GR®’s wear resistance, durability, coat- of the corrosion barrier combined with a Ericsson discusses several advantages of ing thickness and ability to withstand ceramic layer thicker than most compet- the GR® cover over other ceramic covers high temperatures make it the leader in ing covers. This additional cover thick- in his report. One is that a single compo- ceramic roll cover technology. ness allows for crown design changes sition of applied ceramic is suitable for over the life of the roll, as well of the all positions on the paper machine and all 54

GR2 Technical data I Consistent operation Solution: Physical properties: I Surface characteristics do not change Replace the third press granite roll with a I Hardness (no nip deformation) I More durable cast iron roll with a GR2 cover. I Color: gray/blue I Higher loading capability Results after 28 months of continuous I Thickness: overall about .090’’. I No water cooling required. operation: GR2-layer approx. .060’’ GR I No vibration at press I Porosity: 5% to 6% open I G Felt life up 25% Particle hardness: Approximately 9 on Higher Loading Capability I No felt barring a moe scale. Diamond is 10. Reduced Vibration G I No sheet marking Comparison to granite: Longer Life Between G I No hole problems due to doctoring I Longer life between grinds Grinds Excellent doctor blade life (the blades I Lower vibration Not Susceptible to Corrosion G last over two weeks and are changed I Reduced web tension over time in or Bond Failure only during scheduled outages) most cases No Change in Surface G I Sheet quality improvements. I No safety concerns Characteristics During Case history two: I Usable around a steam box Operation I Not susceptible to thermal shock Useable with a Steam Box G Paper machine: Consistent surface and properties over I Twin-Wire Gap Former time. I Tri-nip center press Comparison to other ceramic covers on Case history one: I Newsprint I Speed 4500 f/m. the market: Paper machine: I Larger porosity I Fourdrinier, 276’’ trim Problem: I Better release I Twinver center press I Center press I Less susceptible to thermal shock I Two roll third press I Release I More cover for changes in crown or for I Third press 800 pli, single felt, granite I Vibration grinding out damage against steel vented cover I Holes I Consistent surface properties I Off machine coaters I Breaks. I Not susceptible to corrosion or bond I Speed 3900 f/m. failure Solution: I Usable with a steam box Replace the existing cover on the center Problem: 2 I press roll with a GR cover. No special wash water temperature I Third press vibration requirements. I Felt barring Results: Comparison to composite covers: I Sheet marking I Draws reduced I No release chemicals required I Grind frequency on press rolls I Vibration caused by the center roll I Usable around a steam box I Sheet quality eliminated I Not susceptible to thermal shock I Doctoring/holes. I Holes and breaks reduced. 55 CORPORATE NEWS

USA/Germany: Voith Appleton machine clothing

1 Voith Sulzer Paper Technology is the Düren, Germany, were taken over to Liri in Italy, which belongs to Appleton world’s only paper machine manufacturer become Appleton Pohl, who now make Binet and specializes in equipping paper to operate its own clothing group – press felts and dryer screens for all machines in the narrow size range. Voith Appleton Clothing Group – which grades of paper. currently incorporates five production Lindsay Wire, Florence, USA joined Voith companies. A special role is played by Appleton Pohl Appleton Clothing Group three years ago. as clothing supplier for tissue machinery, This company manufactures forming fab- A start was made a field in which the company has rics and dryer screens and was acquired in 1983 by taking achieved technological leadership. by Appleton Mills, whose name it now over Appleton carries. The innovative approach of Lind- Mills, Appleton, Like the other group members, Binet Feu- say Wire is documented by the numerous USA. This compa- tres of Annonay, France has a long- patents taken out on its products – some ny is now one of standing company tradition. Taken over of them exclusive – delivered to reputed North America’s by Voith in 1988, the firm was renamed tissue manufacturers. leading producers Appleton Binet in March 1996. Its prod- of press felts, with ucts are likewise press felts and dryer The group is becoming increasingly the biggest press screens, and this company is one of the known in all markets under the common felt manufacturing leading manufacturers of dewatering felts name of Appleton Mills. Together with The author: Raimund Waberski, plant in the USA. in particular. state-of-the-art production facilities, the Managing Director Two years later collective know-how of some 750 group of Appleton-Pohl Pohl & Co. of The smallest group member is Binet Sul employees meets the highest demands 56

Fig. 1 (page 55): Appleton Mills, USA.

Fig. 2: Heat setting machine for wet felts and screens.

Fig. 3: Needling machine.

3 Corporate News 57

Fig. 4: Principle of flow control felting.

Fig. 5: Pressure characteristic in a classical roll press.

Fig. 6: Pressure characteristic in a NipcoFlex press. for all kinds of paper machinery world- At the present time the group is techno- the same way as dynamic pressing in a wide. logical leader in press felt production, classical roll press as shown below: particularly for tissue-making applica- In Kunshan, China, a new production tions and for third and fourth presses. facility is currently under construction for This leadership has been attained thanks supplying this rapidly growing paper to innovative flow control drainage felts market with clothings. Here again, the which drastically reduce or prevent anti- group adopts an unwavering philosophy: rewetting effects in the press section. I Full integration in the Voith Corporate Paper drainage Identity. The group has taken out worldwide

patents on this product, whose operating Line force I Sales responsibility is in the hands of principle derives from the sealing effect paper engineers trained in applications of a microscopic fibre membrane worked Paper rewetting technology, including specialized ser- into the felt. This prevents water flow – vicing, Scan-Tech analyses, vibration back into paper after leaving the press measurements and dry section investi- nip. Pressing zone length 5 gations. In other words, sales and ser- vicing are no longer treated as sepa- In the same way as a non-return valve, The drainage mechanism in a NipcoFlex rate fields. this membrane releases the water when press is as follows: under pressure in the nip, but closes as I Group members market the entire soon as pressure is released in the press range of paper machine clothings, outlet. including forming fabrics, press felts and dryer screens, via a common sales This innovative idea was derived from nip organization in their respective areas. pressing theory, according to which the There is no competition between group paper drainage mechanism behaves in members in the various markets. Paper drainage Line force I Strict compliance with the rules of Paper rewetting total quality management, particularly Paper with regard to environmentally friendly manufacturing methods, leading to early fulfilment of the ISO 1401 eco- Pressing zone length audit. 6

I Manufacturing in each production cen- Assuming appropriate selection of the tre is concentrated in defined phases, other felt parameters, the result is with- thus reaching the highest possible out exception an increase of 0.5% to 2% Water Water quality standards through specializa- in dry content, and less felt contamination. tion. Water Water

I R&D activities are concentrated at Appleton Mills, Wisconsin. 4 Corporate News 69

Germany: Board and packaging pilot paper machine upgrade – facing the future with versatility

Higher, better, further: these were the The main objects of this upgrade were as after which the Olympic-sounding targets of extensions follows: machine founda- completed last September to our board I To allow trials on various sheet tions were com- and packaging pilot paper machine in the formation concepts: single/multilayer pletely excavated. Ravensburg R&D centre. and single/multi-ply This made room I Greater availability through shorter for higher vacuum Higher means raising the limits on cus- conversion and setup times and greater capac- tomer trials and system tests, thanks to I Longer testing times, particularly with ity required to shorter setup times and greater flexibili- multiple furnish operation increase the dry ty. Better means more accurate results, I Higher dry content before the press content before the and with the upgraded test facility we can section press section. now go further with our technical devel- The author: Jürgen Prössl, opments. Extension work started in April 1996 by The paper machine Paper Machine Division dismantling the existing wire section, is supplied with Board and Packaging, R&D 70

Fig. 1 (page 69): Pilot paper machine, wire section.

Fig. 2: Pilot paper machine, wire section layout.

stock from three approach flow systems. the entire process, from raw materials The new wire section was added (Fig. 1) In the course of the extension stock preparation to finished paper sheet. – a cantilever frame design – allows the capacity was increased with three new development and optimization of various storage chests. This doubles or triples Incorporated in the extension is a 2-layer different sheet formation concepts. available testing time in batch operation, Step Diffusor Headbox for the DuoFormer depending on the number of different fur- CFD, whose design allows numerous pos- Fig. 2 shows two examples of possible nishes, and with higher stock capacity, sibilities for further optimization of all trial arrangements in this connection: customer trials can now be carried out main influences on sheet structuring. under even more realistic production These include individual layer separation, I A DuoFormer CFD with DuoFormer DK conditions. Thanks to the link with the stock consistency in each layer, individ- (top of Fig. 2) stock preparation division’s R&D centre, ual jet velocities, and geometrical para- up-to-date technology is available for meters such as nozzle shape, lamella I A fourdrinier and DuoFormer DK optimizing product characteristics over overlap and turbulence generation. (bottom of Fig. 2) Corporate News 71

Fig. 3: Pilot paper machine, press section.

The DuoFormer DK can be converted into a DuoFormer D, which can be installed in various positions to allow for predrainage sections of different lengths.

For operating the secondary headbox (Fig. 2, top) and running the bottom fourdrinier as a hybrid former (Fig. 2, bottom), a further DuoFormer D is available which can likewise be installed in various positions.

The press section after sheet forming allows for testing all the current press concepts applicable to board and packaging paper production. The influence of line force on dry content and technologi- 3 cal properties can be tested under realistic conditions, for example using various test results, which are available to the and gap former compare with respect types of felts. At the time of writing, a customer in tabular form on modern data to product characteristics? DuoCentri 2 press and a NipcoFlex press carrier systems. I Effect of raw material on plybond in are installed (Fig. 3). and between individual layers/plies? Important technological parameters, such After the press section, the sample as plybond and compression strength of I Influence of headbox stock consisten- sheets or webs are dried on a separate multilayer and multi-ply board and pack- cy, jet/wire velocity and drainage con- dryer unit. In the up-to-date Ravensburg aging papers, can now be optimized more ditions on product characteristics? paper laboratory, stock and sheet sam- precisely by using the customer’s raw ples are tested according to international materials. Furthermore, trials can be car- The test results supply the necessary methods (DIN, TAPPI, SCAN) as well as ried out to answer some typical questions data for drawing up guarantees, and indi- Voith Sulzer Paper Technology standards. as follows: cate possible solutions to troubles aris- This allows customers to check the suit- ing in practice. In addition the pilot plant ability of our machinery and components I How to reduce cover layer basis weight also serves as a training facility for com- for their products according to the test as a function of raw material and for- missioning personnel and customers’ methods most familiar to them. mation? operating staff.

I Sheet structure optimization, single Our test recording and evaluation system The substantial investments made by and multilayer/multi-ply – how does it enables the connection of all main Voith Sulzer Paper Technology in extend- affect strength, properties, coverage machine and process control data with ing the pilot plant reflect the importance and formation? the respective laboratory figures. This we attach to board and packaging paper ensures fast and reliable evaluation of I How do the fourdrinier, hybrid former developments in future. Corporate News 73

Special awards for innovation and design

Neusiedler Paper wins innovation award with a revolutionary 3-layer headbox and NipcoFlex press. The first Pulp and Paper Europe Award was recently won by Austrian paper pro- ducer Neusiedler AG, Hausmening – for the world’s first office paper machine with 3-layer headbox and shoe press.

This has introduced a new era and a completely new type of paper. The innovative technology – known as Triotec® – is the result of intensive research efforts by Neusiedler AG and Voith Sulzer Paper SPCI ‘96 – impressive presence advertiser of the year for 1996. This prize Technology, with more then 1000 joint The exhibition organizers set two “best was awarded for the high level of techni- tests. The new 3-layer headbox now stand” award criteria at last year’s SPCI: cal innovation and information incorpo- makes it possible to produce 3-ply office for the most convincing technical presen- rated in our advertising. According to a stationery made of different raw materials tation, and for the most inviting atmos- reader poll, both text and graphics gave – rather like a sandwich. Each fibre is phere for visitors to discuss and the most convincing impression of prod- positioned where its properties are best exchange experience. Voith Sulzer Paper uct benefits. Edgar Horny (right) of Voith utilized. And the shoe press specially Technology’s stand – in the new corpo- Sulzer Papiertechnik Sào Paulo, was designed for this purpose allows bulk rate design – met the jury’s high stan- delighted to receive the award from Clau- retention of the 3-ply structure during dards as one of the best at the SPCI ‘96. dio Vielva, “Anave” spokesman. pressing at high production speeds. And visitor figures confirmed this vote: the Voith Sulzer Paper Technology stand was a favourite rendezvous – much to the satisfaction of our marketing managers as well as the exhibition “backroom boys”, whose design and planning work normally stays behind the scenes.

Advertisement of the year in Brazil Wolf-Dieter Baumann (left) Managing Director of The Brazilian paper, pulp and carton the Paper Machine Division Board and Packaging, association journal “Anave” has cited in St. Pölten, Austria, congratulates Director Josef Welsersheimb of Neusiedler AG (right). Voith Sulzer Paper Technology as best 74

1 China: the cradle of paper in times of change 75 CHINA The changing origins of paper – from hand-made to machine-made

According to the National Bureau of on their shoulders to meet the challenges time were very Statistics, total paper and paperboard in the coming centuryspan period. pleased to have production in China for the year 1995, paper available at the last year of the Eighth Five Year Handmade Paper a cheap cost, and Plan, was 24 million metric tons(1), It has been unanimously acknowledged writing on expen- equivalent to a growth of 12,2% over among paper historians that the art of sive silk cloth was 1994. Yet, for a population of 1211 mil- papermaking was originated in China(2). eventually being lion in the country, this amount of Ts’ai Lun, an eunuch in the Imperial abandoned. machine-made products, plus around Court, was given cred it for the invention 200,000 metric tons of handmade paper of the art of papermaking. It was said In the advent of and an additional 3 million metric tons that Ts’ai Lun presented the very first years, during the of imports, would mean only about 22 sheets of paper in the world to Emperor spread of the art kilograms percapita consumption, far He of the East Han Dynasty (25-220 A.D.) of papermaking in behind the world average of close to 48 in the year 105 A.D. At that time, Ts’ai the country, a num- kilograms. Lun happened to be the official in the ber of important charge of the Imperial Workshops for achievements It took the Chinese hundreds of years to making almost all major necessities of were being switch over from handmade paper prac- the Imperial Court, from daily needs to claimed. Among tices to machine-made production. And weapons. As recorded in the history of them, there were a tremendous efforts had been undertaken Ancient China, Ts’ai Lun was awarded the couple worth men- by the Chinese papermakers, especially honorary title of Marquis for this particu- tioning. The first during the last half of this century, to lar achievement in the art of papermak- one was the keep pace with the developments in the ing. And, for a rather extended period of exploitation of global paper circle. It has been most time, paper made following the method new fibre re- gratifying for the Chinese, therefore, to practiced by Ts’ai Lun was named by the sources other than have found that their efforts had at last public as “Paper of Marquis Ts’ai”. those used in Ts’ai The Authors: brought the Chinese paper industry rank- Lun’s time. It Xiang-Ju-Zhong, ing third place among the major paper “Paper of Marquis Ts’ai” was so very turned out that, Prof. Emeritus of Beijing producing countries in the world, right much applauded by the scholars of the besides bark, flax, Institute of Light Industry after the United States and Japan. time that the art of papermaking began to rags and used and Senior Advisor of International Liaison, China, spread to many parts of the country to fishing nets exclu- Technical Association of the There is no doubt that more and more satisfy the need of scholastic circle, aside sively used in the Paper Industry. (CTAPI). paper and paperboard will be needed in from supplying the governmental offi- early days, suc- the future years to satisfy the everlasting cials. This eventually led to an end of cessful attempts Walter A.J. Müllner, J.M. Voith Beijing growth of the national economy. Chinese writing on heavy and clumsy wooden were reported for Representative Office. papermakers are well aware of the burden strips and bamboo slips. Scholars at the making paper with 76

Fig. 1 (page 74): Traditional Chinese papermaking with bamboo, showing how the bamboo rods are supported Fig. 2: and soaked in pure water. Tsai Lun. rattan, bamboo, paper mulberry and oth- paper, sanitary paper, firecracker paper, ers. The second major achievement of fireworks paper, spiritual paper and oth- interest was the use of bamboo screens ers. It was reported that total handmade in place of linen cloth as a dewatering paper production in 1949 was 120,000 medium in web forming. metric tons. Then, in the fifties, there was a slight increase in handmade paper pro- Paper historians beiieve that there were duction. From the fifties to the eighties, several eras of prosperity in the growth handmade paper production fluctuated of handmade paper in the country. It was between 200,000 to 300,000 metric tons said that from the later years of the fifth perannum, and seemed to have become century to the seventh century, dyeing, stagnant at around 200,000 metric tons sizing, surface coating, and, possibly, since 1988. calendering of paper were being developed. Such historical recordings were 2 It goes without saying that Chinese confirmed by contemporary archaeologi- papermakers value highly the inheritance cal excavations of relics of paper, identi- Such interests and liking in fancy papers of this art of papermaking from their fied to be dated as far back as the later persisted through the years up to the forefathers. But they also realize, at the years of the East Jin Dynasty (317-420 days of the Qing Dynasty (1644-1911 same time, that traditional manual oper- A.D.). Tang Dynasty (618-907 A.D.) and A.D.). ating process of low productivity will Song Dynasty (960-1127 A.D.) were have to give way to highly efficient mod- regarded as the most prosperous eras of The art of papermaking was inherited and ern technologies. When machine-made handmade paperproduction in ancient lasted for hundreds of years without any paper began to flood into the market, China. It was in the early days of the innovative changes in its method of pro- heavy blows were being experienced by Tang Dynasty when Buddhism was intro- cessing. Handmade paper managed to the Chinese handmade paper industry. duced into the country, and copying of become a big business. It was not until But, lucky for the handmade paper work- the Buddhist Sutra was very popular. the later half of the nineteenth century shops they had never lost their market in when Chinese handmade paper suffered Chinese art paper. They managed to keep Later on, people began to have the its first impact from imported machine their foothold firmly in the Chinese artis- Buddhist Sutra carved on wooden blocks made products. tic circle. Chinese art paper has always and printed on paper. The demand for been favored by the Chinese painters and paper was thus greatly increased. Then, Handmade paper dealers began to realize calligraphers. And, among the various type printing, initiated by Bi Sheng of the that they were not in a position to com- Grades of Chinese art paper, Xuan paper Song Dynasty and further improved in pete with the less costly and high quality bears the highest fame, not only in China the subsequent years, had apparently machine-made paper. The situation proper alone but also in many other served as another driving force in pro- seemed to get worse and worse every countries. moting handmade paper production. It day. A number of handmade paper work- was also known that in the days of the shops were forced to close down. The Xuan paper, normally composed of a fur- Tang and Song Dynasties, a variety of market for printing, writing and packag- nish with refined rice straw pulp and fancy paper with decorative patterns ing paper was almost totally taken over wingceltis, is reputed by its persisting became very popular among the intellec- by machine-made paper. It followed that snow-whiteness, excellent receptivity for tuals, the poets in particular. Most of handmade products were forced to con- Chinese ink, superior dimensional stabili- these fancy grades were dyed and/or sur- fine to such traditional grades as Chinese ty and indisputable permanency. It has face coated with attractive coloration. art paper, Chinese writing paper, window been regarded as the “Precious Rose” of China: the cradle of paper in times of change 77

Fig. 3: Paper made by the Tsai Lun process. handmade paper in China. It is said that I Dispersing of the pounded mass with since the later years of the seventeenth water to form a dilute fibrous suspen- century, almost every piece of artistic sion in a vat. work composed by famous painters and/or calligraphers was done on Xuan I Dipping of a mould, with a bamboo paper. This goes true with contemporary screen on it, into the dilute fibrous Chinese artists as well. suspension to pick up a certain amount of fibre plus water. Presently, the production of Xuan paper is monopolized by the Xuan Paper Mill I Taking out of the mould, held in a hori- company, located at Jinxian in Anhui zontal position, form the fibrous sus- Province. Imitation Xuan and other pension. grades of Chinese art paper, mostly bamboo-based, are also being produced else- 3 I Holding of the mould horizontally in where in the country. Chinese writing the atmosphere and above the vat to paper, primarily for penmanship classes compiled by Song Xing-Xing in 1637 dur- allow dewatering from the wet web in schools, constitutes the second major ing the reign of the Ming Dynasty (1368- with momentary vibration of the mould handmade grade. 1644 A.D.). It is a comprehensive collec- to regulate fibre orientation in the web. tion of written descriptions on the crafts- Other minor handmade products still manship of a number of important prod- I Transferring of the bamboo screen managed to have a share in the market ucts. The volume has been regarded as from the mould to a piece of linen include firecracker paper fireworks paper, among the best manuscripts dealing with cloth which is previously place on a and religious paper. In recent years, dec- craftsmanship techniques. bottom wooden board, (or, alternative- orative napkins are being made in a few ly, onto the top of a wet web pile workshops, primarily for exportation. Chapter Thirteen of the Volume is totally formed during preceding operations). dedicated to the description of the art of Traditionally, most handmade paper papermaking. In this chapter, a general I Taking away of the bamboo screen with workshops are located in the provinces of presentation of the various vegetable the newly formed wet web left on the Zhejiang Fujian, Jiangxi, Hunan, Anhui fibres for making paper and method of linen cloth. (or, onto the wet web pile). and Sichuan, though one can always find processing is given, followed by more handmade paper workshops still operat- detailed specific discussion on bamboo- I Repeating of steps 3 through 8 until ing also in every province in the country. based paper and bast fibre paper, accom- the wet web pile reaches a certain panied by illustrations. The basic proce- desired height. The art of papermaking dure for making paper, totally manual Handmade paper had long been regarded operating, can be summarized as follows I Placing of another piece of linen cloth as an important craftsmanship industry as entered in the chapter. and, then, another wooden board on in China. It is not surprising, therefore, to I Retting of the vegetable fibre, with or the top of the wet web pile. notice that the art of papermaking was without lime, followed by washing in a entered as one important chapter in the running stream and whitening under I Loading of weights on the top wooden volume “Tian Gong Kai Wu”, translated the sun. board to effect further dewatering of as “The Development of Materials and the wet webs in the pile. Products Through Workmanship” in Eng- I Pounding of the retted mass in a mor- lish. This is an eighteen chapter volume, tar with a wooden or stone peg. I Removing of the weights, the top 78

Fig. 4: Traditional Chinese papermaking with bamboo, showing how the bamboo rod is boiled in a mixture of pure water and slaked lime.

digesters instead of retting with lime. And beating in beaters has replaced pounding in mortars. But, the procedures of web formation, pressing and drying are being carried out in the traditional way.

The fundamentals of the procedure described above have even been kept quite closely in modern pulp and paper technology. Digesting has taken over the process of retting. Pounding has been replaced by beating and refining. And, web formation, pressing and drying com- bine into a continuous operation on a Paper machine. The essentials of the traditional art of papermaking have seem- ingly been sustaining through the years and everlastingly.

Machine-made paper The art of papermaking was eventually spread eastwards to Korea and Japan as well as westwards to the Arab countries and, then, to Europe. It was in Europe where the manufacture of paper began to step over to machine-made. It was not until in the years of the late nineteenth century when machine-made operations 4 found their way, reversibly, back to wooden board and the top linen cloth (or, from the hangers) and having China. from wet web pile. them stacked as a pile of finished product. China Paper Mill Company, (Huazhang I Peeling off of the wet web one by one Paper Mill for its Chinese name), founded from the wet web pile. Such a general procedure for producing in 1881 and started operation in 1884, handmade paper has been adopted for was claimed to be the very first fully I Brushing of the individual wet web hundreds of years without any major mechanized paper mill in China(3). This, onto the surface of a fire wall. (or, changes and can stili be seen practised in presumably, was a kick-off in the history alternatively having them hung in the an number of handmade paper work- of contemporary machine-made paper air for loft drying). shops in present day China. Most of the industry in China. The Mill was invested existing handmade paper workshops, by Chinese merchants and two Americans I Taking away of the dried sheets one by however, have resorted to the cooking of were employed to oversee the operations. one from the surface of the fire wall the vegetable fibres in rotary spherical Maithand served as mill manager and China: the cradle of paper in times of change 79

Fig. 5: Traditional Chinese papermaking with bamboo, showing how the sheet is formed with flexible bamboo screen out of the brickwork vat.

Fig. 6 (back cover): Traditional Chinese papermaking with bamboo, showing how the paper sheet is dried on a heated cavity wall.

T.J. Waters as engineer. The 2 tpd capacity mill employed rags as its major fibrous raw material. Major facilities in the mill included a rag cutter with a rail- road duster, a 730 cubic feet rotary digester, another cylindrical digester, seven beaters, a 96 inch fourdrinier Paper machine and a sheet cutter. Writ- ing paper was the principal grade produced in this mill in Shanghai.

For an extended period of over one hundred years, the mill had experienced successful hours and sorrowful failures, changed hands in ownership many a time, reformed and retrofitted and managed to survive to the present day as the oldest contemporary paper mill in the country, still operating energetically at the original old site. Tianzhang Recording Paper Mill, the present name of this hundred year old mill, is now devoted to the production of special coated grades.

For a period of 30 years from 1881 to 1911, a total of around 32 machine-made paper mills were reported to have been built. They were all located in cities, including Shanghai, Yanbo, Tianjin and Hankuo. The capacities of these mills 5 were all very small, mostly around 2 tpd. materiale were undertaken by several the United States. This happened in the Longzhang Paper Mill, in Shanghai, pro- mills. And, in 1901-1903, Shanghai Paper East Branch of the Tianzhang Paper Mill ducing 13 tpd writing paper, was said to Company, (Huachang Paper Mill in Chi- in Shanghai. In 1921, presumably, this be the largest mill in those days. No sta- nese), initiated the production of was the first time the Chinese ever made tistical figures are available for the paper bleached rice straw pulp on their own. It groundwood and newsprint on their own. production in those years. Not any more may be interesting to note that this than 200,000 tpd may possibly be a good Shanghai Paper Company happened to be After the downfall of the feudalistic Qing guess. the first joint venture paper mill in China. Dynasty in 1911, civil war persisted for The mill was financed by American, quite some years. Moves toward national Almost all of the 32 paper mills were French and Chinese merchants. Another industrialization were very much held up. using rags for making their paper. Even- innovation of the time was the manufac- Nevertheless, the Chinese paper industry tually, rag supply became so very acute ture of newsprint with groundwood made managed to move ahead, rather slowly that searches for alternative fibrous raw in a three pocket grinder purchased from though. 89,000 metric tons of paper 80

Table 1: Total Paper and Paperboard Production (1949-1995) Year Total Machine- Machine-made Hand-made made + Hand-made Amount % Share Amount % Share 1949 228 108 47.50 120 52.60 1950 380 141 37.10 239 62.90 1960 2037 1801 88.50 235 11.50 1970 2637 2414 91.65 220 8.35 1980 5626 5346 95.01 280 4.98 1990 13530 13330 98.50 200 1.50 1991 14989 14789 98.67 200 1.33 1992 17451 17251 98.85 200 1.15 (machine-made) were reported for the 1993 18879 18679 98.94 200 1.06 year 1936, the year before the outbreak 1994 21554 21354 99.07 200 0.98 of the Sino-Japanese War 1937. 1995 23200 24000 99.17 200 0.83 Source: 1996 Almanac of China’s Paper Industry, China Technical Association of the Paper It was some hard time for the Chinese Industry, Beijing P.R. China (In Print). economy during the years of the Second World War. The Chinese paper industry, Table 2: Average Annual Growth Rate (1950-1995) both machine-made and handmade, suffered heavy blows. The year of maximum Year Span Average Annual Growth Rate % paper production was reported to be Machine-made Hand-made Machine-made Hand-made 1943, when 165,000 metric tons of 1950-1960 22.60 6.84 machine-made paper were claimed. It 1961-1970 9.75 3.24 should be pointed out, though, that this 1971-1980 8.84 2.93 figure had taken into account the manu- 1981-1985 10.65 –6.20 facture of paper in Japanese occupied 1986-1990 8.89 1.56 areas. The situation was not much 1991-1995 12.50 0 changed in the subsequent years after the War. And, total paper and paperboard Chinese papermakers are well aware of and traditional technologies. Further- production dropped to 108,000 metric the challenging confrontations they are more, most of the small pulps are operat- tons in 1949. facing. The Chinese paper industry has ing without any chemical recovery. True been non-wood based for many a year. enough, the small enterprises did con- The leaps and bounds in the development Over 80% of the current production are tribute greatly in the past years in easing of the Chinese paper industry did not made from reed and its homologues, up the local demand, especially in the begin until the later help of the fifties of wheat straw bagasse, bamboo and other provincial level in many cases. However, this century (Table 1). It took the Chinese cereal stalks, usually with woodpulp as a more stringent environmental regulation papermakers quite some effort to arrive supplement in the furnish. It has been enforcement will eventually bring about at the current production level. During realized that for upgrading papermachine pressure on small pulp mills operating the past decades, the Chinese paper speed and for quality product production, without chemical recovery. And, it is industry managed to develop at a com- more woodpulp should be used in the going to be unavoidable that small mill paratively high rate of growth, averaging furnish. Therefore, for the healthy growth managers will, one of these days, find around 10% perannum (Table 2). of the industry, more and more woodpulp themselves noncompetitive in the market. will be needed. This would call for the Merging of small pulp mill to form into To meet the everlasting growth in better management of the government one sizable enough to warrant the eco- demand, a preliminary goal of 30 million owned forestry plots such that the prob- nomical feasibility of incorporating some metric tons of paper and paperboard pro- lem of pulpwood availability can be better sort of chemical recovery appears to be a duction has been set for the turn of the tackled. It should also be noted that over logical approach for the future years. century. This would mean an average 50% of the current production comes Being sizable would also mean better increases of 1.2 million metric tons from contributions by small pulp and chances in competing in the market, both capacity every year in the next five years, paper mills. Yet, admittedly, small enter- in selling price and in product quality. It equivalent to an average annual growth of prises are actually operating with defi- would be unavoidable that some small around 8%. Evidently, much strenuous cient cost-effectiveness and are heavy enterprises will have to close down and efforts will have to be undertaken by the pollutant contributors, since they are thousands of employees will find them- Chinese papermakers to reach this goal. mostly running with out-dated facilities selves disemployed. Appropriate mea- China: the cradle of paper in times of change 81

sures will have to be taken to have such a Most of them are seeking for the needed cially during the last half of the century. problem of unemployment solved. capital investment. Obviously, most mill And, most Chinese papermakers are con- managers will feel contended if they can vinced of the performances and reliability It has been known, recently, that any get foreign loans, soft loans in particular. of Voith equipment. For instance, the greenfield projects submitted for And, of course, joint venture partners will Voith Duoformer has been running approval must not have less than 15,000 be most welcomed. smoothly with reed furnish at the tpy capacity and must be accompanied by Jincheng Paper Mill in Liaoning province. some sort of chemical recovery. Con- J.M. Voith AG and the Chinese Paper struction of sizable wood-based pulp Industry Voith, undoubtedly, will be involved, one mills will be greatly encouraged. As a There is no doubt whatsoever that the way or another, in some of the projects matter of fact, this has been carried out development of the Chinese paper indus- drawn for the development of the Chinese in the past years. This includes the Hexi- try before the turn of the century as well paper industry in the years to come. an Pulp Mill in Guangxi, and Qingzhou as in the first years of the twenty-first There will be much for Voith to do in the Paper Mill (expansion project) in Fujian, century, will include a number of sizable competitive Chinese market. both being on stream since late 1994. greenfield and/or expansion projects. New projects under construction are Nan- Needless to say, it is going to be a chal- ning Pulp and Paper Mill in Guangxi, lenge not only to the Chinese alone but Siamo Paper Mill in Yunnan, Guangning also to suppliers all over the world. Evi- Paper Mill in Guangdong, Yueyang Paper dently, the Chinese market for advanced Mill (expansion project) in Hunan etc. equipment and innovative technologies will be highly competitive. And, to get On the environmental side, recent reports oneself into a more advantageous posi- have disclosed the immediate closing of tion, one needs to understand better the over a hundred small pulp mills along the oriental mentality. Make your company banks of the Huaihe (river Huai) and in known to the average Chinese papermak- the regions upstream of the Three Gorges er, the managers and young engineers in on the Yantze River (Changjiang). An particular. True enough, you may find overall dredging of the Huaihe, a major yourself handicapped by a language bar- tributary of the Yellow river, calls for a rier. But, do not worry too much about general clean-up of all pollutant con- this, you can always find some English tributing enterprises along its banks. The speaking Chinese willing to help you. Fur- three Gorges Project, which involves the thermore, there is always the internation- construction of a huge water dam and a al engineering language there (engineer- hydraulic power station, requests the ing drawing) at hand. It is a fact that elimination of all polluting sources most Chinese papermakers have come References upstream. Small pulp mills are facing the across the name of Voith at one time or 1.Economics Daily, March 1st, 1996. fate of shutting down, and, many small another. Most young engineers learned (in Chinese). 2.Dard Hunter: Papermaking – The History and mill managers are now talking about about the specific features of the Voith Technique of an Ancient Craft. 2nd ed. (Dover merging together at some new site. beater. As a matter of fact, there are still Publications Inc., New York, N.Y. U.S.A. 1948), a number of Voith beaters operating in pp. 4 49-50 (in English). A number of greenfield and expansion many small mills in the country. Voith 3.Dai Jia-Zhang: Brief Account on the History of the Art of Papermaking in Ancient China. (Light projects have been proposed for the has been engaged in business dealing Industry Publishing House, Beijing, P.R. China, Ninth Five Year Plan period (1996-2000). with the Chinese for many a year, espe- 1994) pp.76-77 & p. 255-256 (in Chinese). "twogether" is published twice annually Published by: in German and English. Contributions by Voith Sulzer Papiertechnik GmbH independent authors do not necessarily reflect the opinion of the publisher. Editor: Paper Technology Journal Please address all correspondence and Dr. Wolfgang Möhle, Corporate Marketing, inquiries to the editor. Voith Sulzer Papiertechnik GmbH, P.O. Box 1970, D-89509 Heidenheim Tel. (++49) 73 21 37 64 05 Fax (++49) 73 21 3770 08

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