2004 Feb JAPAN TAPPI JOURNAL

 

JAPAN TAPPI JOURNALVol. 58, No.2

February 2004 Abstracts


Introduction of Advanced Metso Paper Technology into China
Hidehiko Yamazaki
Metso-SHI Co., Ltd.

@Recently Chinese paper industries have been showing rapid development, in which Japanese papermakers have a serious interest. While the paper and board demands in advanced countries including Japan seem to have reached ceiling level, the paper and board demand in China still shows rapid increase. Total production of paper industries in China in 2002 was 37.8 million tons, which showed 8.4 % increase compared to that a year before. Although new machines were installed in China year by year, the domestic demand of paper and board is expected to keep increasing due to further economic growth and large population of potential consumers.
@ Metso Paper has a regional company in Beijing, Service Technology Center in Wuxi and Valmet-Xian as a joint-venture company in Xian, which enhance Metso Paperfs business, production and customer service in China. Recent noteworthy point is that the world first OptiConcept machine was installed and started up in Nanping, China earlier than in European countries, and achieved satisfactory results.
@ In this paper, the future prospect in Chinese paper industries and representative paper machine technologies delivered by Metso Paper are described.


Treatment of Anionic Trash and Improved etention/Dewatering-Improved Productivity of Paper Making-
Keiji Suruga, Jiayi Chen and Takashi Saigusa
Kurita Water Industries Ltd.

@Recently high usage of recycle fiber and coated broke, proceeding mill closure, causes the papermaking conditions to have been getting worse. It includes Anionic Trash that causes pitch trouble on paper machine. Anionic Trash reduces the performance of retention/ drainage aids. As a result production rate and runnability of paper machine is decreased.
@ This paper presents the new approach for improvements of productivity of paper making that the treatment of Anionic Trash is combined with OPTI system (which is dual polymer retention/ drainage system developed by Kurita).


Closed System of Papermaking Machine and Wet-end Condition
Shigeru Kurose, Koichi Tadaki and Munetoshi Yamaji
Chemicals for Pulp & Paper Div. Technical Dept., Somar Corporation

@Strong world-wide interest on environmental concern in pulp and paper industry, and acceleration for white water closed system for paper making process cause number of problems in paper making process.
@ Neutral conversion of papermaking, higher use of de-inked pulp from recycled paper and higher content of coat broke makes built up of micro-biological slime, and pitch and anionic trash build up in the system due to lower effectiveness of Alum. Retention and drainage of wet-end operation will be affected as well as physical properties of paper such as physical strength and sizing degree which may be reduced. All these are related to deposit in papermaking system. These troubles cause operational problem which result to production slow down. Variety of chemicals is used to control these problems, which will accelerate deposit built-up because of high dosage of chemicals for system closure. It creates vicious circle.
@ Somarfs long experience in controlling microbiological deposit using slimecide "MICROCIDE", and capturing pitch and anionic trash using wet-end control agent "REALIZER", offers total control approach on machine deposit problem caused by white water closure. This paper describes several proposals on how to improve machine operation.


Wet End Chemistry and On-line Measurements
Hitoshi Nagao, Shigeru Motegi
Pulp and Paper Research Laboratory, Nippon Paper Industries Co., Ltd.

@The importance of wet end chemistry is increasing, due to the trends of high speed paper making. The stability of wet end process can be achieved when agglomeration and adsorption, which are the most important phenomena, are controlled well. Therefore, all measurable parameters that explain the condition of the wet end system should be maintained at the appropriate levels. Most of these parameters used to be measured by the off-line systems, however, recently several on-line measurement systems have been developed and they make it possible to monitor the change of the wet end.
@ In this paper, we present details of the recent online measurement systems, which have strong relation to the wet end chemistry, such as retention meter, cationic demand analyzer, and zeta potential analyzer with fundamentals and the examples of the measurements. Additionally, MOAS, entrained air analyzer , and slime monitor will be simply introduced.


The Improvement of Production Efficiency by
Stabilized Wet End
Tatsuya Sato, Masato Higashiyama and Keiichi Satou
Mitsubishi paper mills limited

@The fundamental of stock preparation is consistent supply of homogeneous and adequate stuff to the paper machine. Recently the control of consistency and flow rate, grade changeability and production stability were remarkably progressed.
@ However, we are still facing the fluctuation of drainage and first pass retention (FPR) at the wire part.
@ In this paper, we present a summary of test results of On-line Charge Measurement at our 7PM for the stabilization of wet end.
@ From the trails, it was recognized that the charge of coated broke can be controlled by the addition of coagulant and it improved drainage and FPR. However, the coagulant dosage without monitoring the charges of the systems would result in the instability of the systems.
@ Consequently, to get the reliable improvement of operation by charge control, the On-line Charge Measurement can be used as an effective sensor.


Operating Experience of POM System
Takeshi Shirao
Kasugai Mill, Oji Paper Co., Ltd.

@The PM4 at Kasugai ‚lill, Oji Paper, has been introduced the POM system and in operation since March 2002, in order to improve the efficiency of small batch production. In this system, conventional white water silos and seal pits are replaced by POM pumps and their small supply tanks, which have centrifugal de-aeration function, consequently total volume of the wet end system could be notably reduced. As a result, we could expect reduction of time for grade change and inhibition of sliming in the wet end system.
@ At the PM4, the loss time for grade change including significant variation of color and ash content has been cut down by up to 47% compared with that of the conventional system. In addition, shut down for cleaning attributed to slime in the wet end system has been reduced. This report describes the outline, operating experience, and the benefit of the POM system.


Operating Experience of High Pulp Consistency Ozone ECF Bleaching
Shuuichiro Mochizuki
Nichinan Mill, Oji paper Co., Ltd.

@High pulp consistency ozone ECF bleaching plant was started up at Nichinan mill in 2002. This bleaching system is the first one in Japan. The operation is now stable through the solution of a couple of troubles during starting stage.
@ Since we found that the pulp consistency and pH would be effect on the reaction efficiency on ozone stage, they have been carefully controlled as key factors.
@ The bleaching cost of ozone ECF has been slightly increased than before. This difference corresponds nearly to the electricity cost for oxygen and ozone generation.
@ There would be almost no difference on pulp quality between ozone ECF and chlorine bleaching. The paper quality and runnability of paper machine seems to be same in both cases.
@ The content of AOX and chloroform in effluent has been remarkably reduced, by >90% and >99%.


Automatic Sheet Creating Unit for Sticky Contamination Monitoring
Mineo Hashiba
Yufutsu Mill, Nippon Paper Industries Co., Ltd.
Mitsuhiro Sugino
Technical & Engineering Div., Nippon Paper Industries Co., Ltd.

@Nippon Paper Industries Yufutsu Mill reinforced new DIP process to increase the rate of recycled paper for newspaper production. The new DIP process can use old magazine for the main materials. By increasing the rate of DIP, and the rate of old magazine, sticky contamination trouble carried from these materials was worried. For this reason, Sticky Contamination Analyzer (SCAN-‡U) was introduced in order to grasp change of the sticky contamination in DIP stock.
@ SCAN-‡U automatically collects the sample from each process of DIP and creates the sheet which can be measured to count the sticky contamination. Using this unit, the measurement of the sticky contamination, and the flat screen treatment which man performed before, were simplified. Moreover, by catching quickly change of the sticky contamination, the quick action for the quality control in the news paper production is possible.
@ This report introduces the fundamental mechanical contents of SCAN-‡U and the operation experience at production plant.


Paper Counter Equipment
Takao Shimatsu
Nippon Paper Unitec Co., Ltd.

@This is the equipment which measures the paper on a palette using CCD camera,and counts the number of sheets of 200-micrometer thick paper with high precision and high speed.
@ By using this equipment you can expect to cut down the number of workers in the finishing process and to stabilize the quality of the product.


The Fully Automatic System for the Measurement of Dirt Count Characteristics of Chemical Pulp
Nobuo Oikawa
Kitakami Mill, Mitsubishi Paper Mills Limited

@For the purpose of the measurement of dirt count characteristics in pulp slurry, we developed the original system.
@ Our system is composed of a slit screen, a dewatering unit, a circulation tank, pumps, CCD-camera and software.
@ This system enables to measure a large amount of pulp by automatic operation, and has good reliability, quick response, and accuracy. These points are also discussed in this paper.


Development of On-line Fiber Orientation Meter Based on the Light Guide Effect
Yuji Abe and Hidenobu Todoroki
Pulp and Paper Research Laboratory, Nippon Paper Industries Co., Ltd.

@A new technique, based on the optical property of fibers, has been developed for the online measurement of fiber orientation in whole layers of paper sheet. Due to the light guide effect, the focused circular light spot cast on one side, the elliptical light spot is observed on the opposite side of paper. The shape of the elliptical spot represents the fiber orientation of paper.
@ A prototype sensor was assembled and installed to the pilot coater. The sensor using YAG-laser, which has 7n second pulse width, can successfully measure the fiber orientation of paper running at 1000 m/min.
@ To downsize the sensor, we thought laser diode (LD) was the hopeful candidate as a light source, and assembled the prototype sensor using LD and optic fiber. Since the size of the light spot must be small for the reliable measurement, it is very important to optimize the diameter of the optic fiber. It was found that ƒΣ=60?m is small enough for the focusing, and the prototype using the optic fiber and LD can measure the fiber orientation of paper running at 1000 m/min as well as the one using YAG laser.

Keyword : Fiber Orientation, On-line, Light Guide Effect, Laser Diode


Progressing Report by LCA / Environmental Label
Working Group
Motoi Matsui
LCA / Environmental Label Working Group of Japan Paper Association

@In 1997, Japan Paper Association organized LCA working group (WG) within the technical and environmental section to investigate the LCA of pulp and paper manufacturing along with the establishment of LCA Society of Japan by the industry-university-nation complex. WG was called LCA / Environmental Label working group for type ‡V environmental label system in 1998. The works of WG are summarized as follows.
(1) Report of LCI data for paper and board production.
(2) Draft of the industrial guideline on paper and board products for type ‡V.
(3) Propose of the simple calculation procedure of LCI for the production stage.
(4) Translation and examination of GHG calculation tools developed by NCASI (USA)


Surface Chemistry of Deinking Process- Effects of Nonionic Deinking Agents and Fatty Acids on Foaming Properties in Flotation Deinking of Old Magazine -
Shisei Goto and Takanori Miyanishi
Pulp and Paper Research Laboratory, Nippon Paper Industries Co., Ltd.

@Foaming properties of pulp suspensions of old magazine (OMG) were investigated with regard to dynamic surface tension of pulp suspensions containing deinking agents, and effects of fatty acid Na salt addition to nonionic deinking agents on foaming properties were elucidated. Dynamic surface tension of water containing deinking agents was measured by means of the maximum bubble pressure method. An interfacial rheometer was employed to measure surface viscoelasticity of supernatants of the pulp suspensions. The obtained results showed that OMG/ONP (old newsprint) mixtures generated more foam in flotation than ONP only, when the nonionic deinking agents were used. Compared with ONP suspensions, turbidity of the OMG/ONP suspensions was high due to the high amount of ash content. Moreover, cationic demand and static surface tension of the OMG/ONP suspensions were lower than ONP suspensions. These results suggest that the OMG suspensions are easy to generate and stabilize foam, and thus some deinking agents having relatively low foam generation and stability are required for flotation deinking of OMG. Surface tension measurements showed that nonionic deinking agents containing fatty acid Na salts gave higher initial dynamic surface tension of water, and generated smaller volumes of foam. In fact, the addition of FA (a mixture of stearic acid and palmitic acid Na salts) and OA (oleic acid Na salt) increased dynamic surface tension of the OMG/ONP suspensions, and decreased their foam volumes. Furthermore, the addition of FA to the nonionic deinking agents increased surface viscosity of the supernatants, and decreased their surface elasticity. On the other hand, the addition of OA to the nonionic deinking agents did not change surface viscoelasticity of supernatants of the pulp suspensions. These results implied that the mechanism of the decreased foam volume was different between FA and OA due to the difference of their solubility in water and/or solid-liquid interactions in pulp suspensions.

Keywords: deinking agent, dynamic surface tension, foam, OMG, surface viscoelasticity


The Evaluation of Paper Sludge (PS) for Zeolite Synthesis(Part 3)-Weekly Change of Chemical Composition of PS and the Aptitude for Zeolite Synthesis-
Takao Ando, Masato Saito, Shigeo Muramatsu and Kimio Hiyoshi
Fuji industrial research institute of Shizuoka prefecture
Junsuke Haruna, Naoto Matsue and Teruo Henmi
Department of agriculture, Ehime Univ.
Osamu Shimada
Gakunan daiich cooperation of paper manufacturing association

@In the case of zeolite synthesis from paper sludge, PS ash, it is necessary to investigate its chemical and mineralogical stability.
@Our previous study showed that the suitability of PS ash for zeolite synthesis remarkably depended o nn the CaO content of PS ash.
@The relationship between CaO content (x) and XRD intensity (y) assigned to zeolite, Z index, was found as y=-0.36Ln (x)+1.33. Less than 21.5% of CaO content was suitable for zeolite synthesis, on the contrary, more than 28.8% content was not suitable. When the content was in the range between 21.5% and 28.8%, hydroxyl sodalite was dominantly synthesized. The fairly well linier relation between the atomic ratio of Ca to Si, XCa/Si, and Ca to Al, XCa/Al, was found, that is, XCa/Si/XCa/Al0.86`0.97. The mineralogical ratios (talc, kaolinite and calcite) of representative PS ashes were determined by the normative method and ideal mineralogical composition ranges for zeolite synthesis were summarized in talc-kaolinite-calcite triangle figure. PS ashes were classified into 4 types of mineralogical composition ranges. The ranges (A) and (B) were suitable for the zeolite synthesis and ranges (C) and (D) were not suitable. The PS ashes in the ranges (A) and (B) never changed into the rage (C) and (D) for 5 days.
@In this study, we investigated the weekly change of PS ashes mixture gathered from 16 paper mills, which compose a cooperative association for the PS disposal in Fuji city of Shizuoka prefecture, for 4 weeks. The PS ashes unsuitable for the zeolite synthesis contained less than 10% of the ash fraction and more than 30.6% of CaO. We compared the chemical composition of PS ashes mixture discharged from the association with the calculated chemical composition excluding the above unsuitable PS ashes. As a result, the following conclusions were obtained.
‡@ Even if the unsuitable PS ashes for zeolite synthesis are excluded from PS ashes mixture, the chemical composition will scarcely changes.
‡A PSfs discharged from the paper mills that are manufacturing the paper products including a lot of kaolinite are suited for zeolite synthesis.
‡B To obtain zeolite more easily for industrial purpose, it is desirable only to use the PS involving much kaolinite.

Keywords: zeolite, paper sludge, calcite, talc, kaolinite