2005年12月 紙パ技協誌

[プリント用ページ]

Paper quality at Dryer section

Takashi Nagaoka
Paper & Printing Machinery Division, Mitsubishi Heavy Industries, Ltd.

 Dryer section has been composed of multi cylinder dryers and steam heat has been used for drying from old time. On the point of view from paper quality, the moisture profiles at thickness direction and cross machine direction especially influence the quality in dryer section.
 In this paper, the development of dryer section, the trend of paper market, the required paper quality from the printing machine, the paper quality improvement by dryer section are introduced.


Latest Technology of Dryer Section
- Introduction of Voith HiDryer -

Osamu Yasui
Voith IHI Paper Technology Co., Ltd., Application Engineering Dept.

 During the last few years the paper machines around the world set one speed record after another. Today the speed limit of paper machine is defined by the strength of the wet sheet in the beginning area of the dryer section. Even in the single-tier dryer with modern stabilizer “ProRelease”, the considerable web tension is required for the better operation. So the solution for further paper machine speed-up is simply the dryness increasing before the conventional dryer section once more.
 The perfect solution comes with the development of Voith HiDryer with impingement drying system. Here we introduce this sophisticated new drying equipment for successful future.


The Latest Technology of Dryer Hood and Machine Room Ventilation

Kouji Saito
Metso SHI Co., Ltd., Application Engineering

 Dryer section hood and ventilation system has been developed together with the development of paper machine production. Flow volume of exhaust air from the latest dryer hood and ventilation system has been minimized by adopting high humidity in the exhaust, which has minimized the energy loss from the exhaust air by increasing the heat recovery efficiency as warm water and pre-heating of hood supply air. However, minimized exhaust air volume does not prevent evaporation from the paper by supplying sufficient amount of heated dry air to the pocket; in addition it improves web runnability by newly developed blow boxes. Modern air system consists of hood and ventilation mentioned above, air dryer system in the coater dryer, mist ventilation in the wet end and machine hall ventilation.
 The latest system of dryer hood with it’s history, heat recovery, mist ventilation and machine hall ventilation are introduced in this paper.


The Improvement of PM9 Production Efficiency by Retrofitting the Dryer Section at Shiraoi Mill

Yuji Hoshino
Shiraoi Mill, Nippon Paper Industries Co., Ltd.

 No.9 paper machine at Shiraoi mill, Nippon Paper Industries, has been in operation as fine paper machine since 1975.
 In 1995, it was remodeled for coatbase paper machine. We had difficulty problems result of increasing the machine speeds, and the modification of paper grades.
One problem was the sheet breaks caused by sheet flutters, and other was the sheet spots caused by dewdrops. In November 2004, we improved these problems with replacement of pocket ventilation systems.
 In this report, I introduce this replacement and the operating experience.


Basis Concept of Drainage Equipment

Yoshiyuki Gohoh
M・S Netsugakukogyo Co., Ltd.

 Dryness of Wet paper is an action that evaporates the moisture by heat, and is movement of heat and a substance. As for the basic concept of Drainage equipment, for these what ten years is not changing. In Drainage equipment, in connection with the M/C speed rise of a Paper machine, condensate water discharge apparatus evolved into high speed stationery siphon + blow through steam from bucket + steam trap.
 A regulation meter and control apparatus have also changed from panel board of an air formula to an electronic formula regulation meter or DCS. By this sentence, Drainage Maker plans to introduce the actual condition of the Drainage equipment design business centering on the heat calculation to some extent.


Technical Trends in Dryer Fabrics

Hideyuki Onishi
Shikishima Canvas Co., Ltd.

 Dryer fabrics, which are used on many parts of dryer sections of paper making machines, have longer longevity than other paper making clothing like forming fabircs and press fabircs. For this reason, they are necessarily required to be maintained good and stable condition for fairly long periods.
 To enable dryer fabrics to be used for longer periods on the paper making machines in Japan, which have been controlled by the highest standards of management and control system achieved by the Japanese paper making manufacturers, it will be very important and indispensable for dryer fabric manufacturers to continuously make every efforts in improving and developing the quality of dryer fabrics.
 In this discourse, the new technology incorporated in improving and developing dryer fabrics will be reported with specific examples based on following themes:
 The improvement on durability of dryer fabrics
 The countermeasures for anti-contamination of dryer fabrics
 The dryer fabrics for high speed paper making machines
Besides above, “The understanding on the present state of dryer sections” will be also reported, which we learned through our various measurments on site.


High Pressure Waterjet Canvas Cleaning Technology

Makoto Matsushita
KGK Engineering Corp., NUSM Division

 We started selling the High Pressure Water Jet Canvas Continuous Cleaning System presented by ProJet B.V., Meerssen, Holland, April 2004, and delivered the first system in September the same year. Ever since over less than one year, we sold total 15 systems and are enjoying ever ceasing sales and new inquiries. Over our sales activities as above, we have heard many cases in the past over the competitors’ systems that they did not bring about satisfactory cleaning results as was expected of.
 What secrets there are in the ProJet system that have resulted in such a remarkable surge in the sales over less than one year period? What are differences between ProJet system and others? Where we are planning to go to improve ProJet system further?
 We are going to talk and introduce about those topics in this workshop.


Solutions for Deposit on 1st Drying Part of PM1at Oita Mill

Katsuyuki Ohkawa
Oita Mill, Oji Paperboard Co., Ltd.

 In Oita Mill , we started up the PM1 in May 1970 , which at the time had Inverform machine. Originally the machine had four inlets which had a wire width of 4200mm , and produced 300T/D linerboard. Since then, the PM1 was rebuilt for the purpose of improving product quality and increasing machine speed.
 Presently we produce 600T/D of kraft pulp liner on average, with a maximum operation speed of 900m/min. But we had some trouble for deposit on drying part all the time. In October 2004 we remodeled the canvas cleaner on 1st drying part. Combi Cleaner, the name of the canvas cleaner, carries professional high pressure water jet.
 The following report describes the operational experience of the Combi Cleaner from initial start up to the present time.


A Report on the 19th ISO/TC6 Meeting

Takayuki Okayama*1, Takashi Yaezawa*2 and Tadashi Kano*3
Pulp and Paper Testing Committee, JAPAN TAPPI
*1 Tokyo University of Agriculture and Technology
*2 Oji Paper Co., Ltd.
*3 Japan Technical Association of the Pulp and Paper Industry

 ISO/TC6 meeting was held on June 6-10, 2005 in Stockholm, Sweden. The number of registered delegates representing seventeen countries was eighty three.
 Three delegates representing Japan attended WG meetings, plenary meetings of SC2 and SC5, and TC6 plenary meeting.


Physical Structure Characterization of High Viscosity Kenaf Bast Pulps

Sherif Keshk
Ain Shams University, Institute of Environmental Studies and Research (Egypt)
Wiwin Suwinarti and Kazuhiko Sameshima
Kochi University, Faculty of Agriculture

 The high viscosity kenaf bast pulps were prepared by using three different methods (A, B and C) and their viscosity values were 109, 63 and 102 cP, respectively. The physical structures of these samples were characterized by FT-IR spectroscopy, X-ray diffractmetry and CP/MAS 13C NMR spectroscopy. Although the FT-IR spectra of all pulp samples revealed the similar chain conformation, the magnitude order of mean hydrogen bonding, relative ether linkage and crystallinity index were in the same trend with the order of viscosity values. X ray diffractograms and CP/MAS 13C NMR spectra indicated the presence of residual lignin between the (1 10) plane of the pulp that subjected to the method B. However, FT-IR, X-ray and CP/MAS 13C NMR analyses showed the method A gives the highest crystallinity pulp.
 Furthermore, the relationships between the viscosity and the crystallinity index values in these three methods were in a high correlation (R>0.9), that indicates the viscosity is parallel to the crsytallinity.

Keywords: CP/MAS 13C NMR spectroscopy, crsytallinity index, FT-IR spectroscopy,
       kenaf bast fiber, viscosity, X-ray diffractmetry.