|JAPAN TAPPI JOURNAL July 2008
Vol.62 No.7 Abstracts
Advanced Control of the Pulping Process by Using New Online Fibre Analysers
Product Manager, AB Lorentzen Wettre (Sweden)
Managing Director, Lorentzen Wettre K. K. (Japan)
Shape factor is maybe the most important measurement for kraft pulp. L&W
STFI Fibermaster was developed to be able to measure this important property
better than other instruments. Fiber length is measured according to ISO standard.
A number of other properties are measured and available for on-line measurements
as well as for laboratory analysis. Applications for modelling of pulp quality,
optimisation and control of refining and blending of pulp are described. The
latest development has been to analyse vessel cells and shives in more demanding
situations including recycled pulps.
The Latest Sensor, Online Analyzer and Control Technology for Chemical Fiber
Sales Manager, Metso Automation K. K.
The purpose of this paper is to review the best available measuring equipment
and controls for ECF and TCF bleach lines. The target for a complete chemical
pulp bleaching line is to bring the Kappa number down to zero and to reach the
final brightness target. However, to control a bleaching line, we have to look
at each stage separately and decide what the objective is, how we will monitor
the success of the stage, what we will control, and how.
Status of Use and Tasks for Gaskets to Replace Asbestos Gaskets in Alkaline Line
of Kraft Pulp Production
Sealing Products Department, Nichias Co., Ltd.
In Japan, the usage of sealing materials containing asbestos had been banned
across the board as of the 1st of September, 2006 in the facilities and equipment
in paper and pulp manufacturing industry.
We are herewith to introduce the properties, problems, recommendations as well
as the status of use for non-asbestos gaskets to be applicable to alkaline of
kraft pulp production which has been said to be the hardest to replace the asbestos
gaskets in paper and pulp manufacturing industry.
The Selection of Non-asbestos Sealing materials for Pulp & Paper Plants
Basic Technology Industries Development Division, Nippon Valqua Industries, Ltd.
The harmfulness of Asbestos and the necessity for alternative material had been
recognized, still in Japan the conversion has been delayed in comparison with
Europe and the United States. However, even in Japan, the seriousness of health
damage by Asbestos came to attract the attention and then the manufacture and
sale of Asbestos products were banned in principal by law enforced in Sep. 2006.
We as Gasket manufacturers have been carrying out research & development
of alternative materials and there are already many products with which can replace
asbestos in various applications on the market.
In this report, I am going to talk about soft gaskets and gland packing for Pulp & Paper
industries and explain the points of material selection in time of changing from
Asbestos to Non-asbestos.
The AIKAWA’s Newest Refining Technology
-From the Standpoint of the Refiner & the Refining Fillings-
Technical & Engineering Department, AIKAWA IRON WORKS CO., LTD.
Nowadays, we have two major issues in the Refining process.
One is to reduce the power consumption from this most power consuming process
in the stock preparation system.
Second is the suitable Refining method according to the changes of the resent
stock fiber condition. Hard wood pulp, OCC and ONP are most commonly used as
paper material. But recently, the ratio of plantation Hard wood pulp is rapidly
increasing and the recycling rate of OCC and ONP are also increasing which both
resulting to shorten the fiber length and becoming the lowering factor of fiber
To use this short and weak fiber, not cutting Refining but wet beating with less
fiber cutting and property (strength) improvement could be the solution. In general,
better Refining efficiency means the larger freeness drop with less power consumption
and not wet beating. But the resent need in refining is to achieve good balance
between these two, power reduction and property improvement with wet beating.
In this report, we would introduce our approach to these issues with our newest
technology, Aikawa Double Conifiner (ADC) and Finebar Refining plates, and its
Keywords: Refining energy saving, Planted hardwood pulp, Recycled OCC & ONP,
Fiber length & freeness, Cutting refining, Wet beating, Refining power consumption,
Fiber characteristics, Aikawa Double Conifiner (ADC), Finebar
Impact of the Design of LC Refiner
Sales & Technical Group 2, Andritz K. K., Japan
In Japan all kind of fiber material of paper furnish strength is becoming low.
For keeping the paper quality, refining process is very important now. Andritz
have long history of manufacturing the low consistency equipment and systems
for paper machine stock preparation. This report explains the Andritz 3 types
refiners laboratory results of fiber impact by design and Fractionation refining
process for keeping the paper quality by ecological method.
Selection of Fixative against Pitch Troubles, etc.
BASF Japan Ltd., BM Specialties, Paper Chemicals Technical Service
Change of environment around paper manufacturing and technology leads improvement
the paper-production efficiency. However, in the other hand, these cause change
of type of detrimental substances and amount of detrimental substances in paper
making system, and negatively impact to the paper-making. These negative impacts
to paper making are roughly classified into (1) troubles on the process and instability
of effects of wet-end chemicals and (2) problems on the paper qualities and dirt
of the machines. Therefore, it is necessary to select suitable measures (charge
control and fixation) and suitable coagulants (charge controller and fixative)
depending on the types of troubles happened at paper-making. Each evaluation
method of effects of coagulants has merits and demerits respectively, so it is
difficult to evaluate the effect of coagulant with only one method.
Therefore, it is necessary for selection of coagulant to apply suitable combinations
from various evaluating methods depending on the purpose or problems should be
solved. Laser pitch counting technology that was developed by BASF can evaluate
the effect of coagulant as quantitatively by resulting pitch size distribution.
Therefore, it is one of powerful tool for fixatives with the feature in a past
evaluating method without. Further, it is also effective tool for the development
of new coagulants.
Pitch Control with Pulp Quality Change
Satoshi Wada, Chen Jiayi and Keiji Suruga
Paper Chemicals Section, Kurita Water Industries Ltd.
Recently, papermaking industry has executed waste paper recycling actively from
the situation of global environment maintenance and resources protection. With
this situation, pitch trouble has been increasing by increasing of the wastepaper
usage rate, neutralization of papermaking pH, reduction of papermaking machine
using water, speedup of papermaking machine. Pitch trouble is one of important
cause of paper machine run ability.
To reduce pitch trouble, various pitch control agent has been applying. And many
pitch evaluation methods has been using. Each method has various features and
is used depending on the situation and a purpose. We use evaluation method noting
“Deposit potential”, and we are applying pitch control agents and fixing agents.
In this article, we collect concerning the basic item of the pitch and pitch
control. And we introduce the example of application of the pitch control agent.
The Effects of Chemical and Mechanical Modifications of Pulp Fibers
Graduate School of Agricultural and Life Sciences, The University of Tokyo
Chemical and mechanical modifications of pulp fibers based on the chemical structures
of the pulp components and hierarchal tissue structures of pulp fibers are reviewed
in this paper. In the mechanical modifications, the highly crystalline cellulose
microfibrils and micropores formed in the cell walls during chemical pulping
process play a significant role in controlling paper properties as well as retention
of wet-end additives. On the other hand, carboxyl groups present in pulp fibers
are key interaction sites with various cationic compounds in papermaking and
coating processes. There have been various procedures reported so far to improve
carboxyl contents in pulp fibers. Irreversible adsorption of carboxymethyl cellulose
with low degrees of substitution on pulp fibers is a new and interesting chemical
modification of cellulosic fibers, resulting in increases of carboxyl contents
of the pulp fibers and in improvement of the effects of wet-end additives. TEMPO-mediated
oxidation of pulp fibers is also a promising procedure to introduce carboxyl
and aldehyde groups into pup fibers without any changes in crystallinity or fiber
morphology. Especially, cellulose single nanofibers 3-4 nm in width and a few
microns in length can be prepared from TEMPO-oxidized pulps by moderate disintegration
Development of Continuous Cooking Process for Kraft Pulping
Metso Paper Japan Co., Ltd., Fiber Business Line, Technical Support
Since Kamyr has invented the continuous kraft cooking system in 1949, it was
significantly developed along with the improvement of the cooking process in
order to meet the different requirement in the past 30 years. A number of cooking
processes such as MCC, ITC, and BLI were developed, and have been playing an
important role in Japanese paper industry even today.
Metso Paper’s fiber business line (former Kvearner Pulping) had fully inherited
Kamyr technologies, and developed COMPACT COOKINGTM system that has become a
most popular continuous kraft cooking process. COMPACT COOKINGTM system can fully
meet the requirement to, (i) build a new fiber line both for hard wood and for
soft wood, (ii) increase the capacity for the existing cooking system, (iii)
modify the existing cooking system for the purposes of increasing cooking yield,
bleaching ability, and pulp quality as well as for the purposes of reducing energy
consumption and environmental load.
Keywords: Continuous Cooking Process, MCC, ITC, and BLI, COMPACT COOKINGTM
Analysis of Relationship between Air Bubble Size Distribution in Flotator Cell
and Deinking Efficiency
-Progress in Development of a New OK-Flotator-
Pulp & Paper Research Lab., Oji Paper Co., Ltd.
With a view to improving the ink elimination in Flotator, We directed our attention
to the bubble size distribution and examined the relationship between operating
condition and deinking efficiency of the flotator. We found that higher rim speed
of the rotary tube blower could increase deinking efficiency and the brightness
gain drastically. At that time, higher rim speed caused smaller air bubble size.
When the speed was high, large air volume improved deinking efficiency and the
brightness gain, then would increase the number of small air bubbles.
On the other hand, when the rim speed was low, large air volume was not effective
in deinking, then would increase the number of large air bubbles.
By applying these findings to OK-Flotator, and could succeed in improving the
Keywords: OK-Flotator, ink, bubble size distribution
Improvement of DIP by Optimization in Process Control
Chuetsu Pulp and Paper Co., Ltd., Takaoka Mill (Nomachi)
Collection of waste-paper and its recycling rate have been going up year after
year in order to establish an ecological society here in Japan. The recent trend
toward environmental preservation has spoiled a balance between demand and supply
of waste paper. There is no other choice but to use a poor quality waste paper
for recycling, according to the boost in domestic market price due to increasing
exports for waste paper. Under these circumstances, quality problems have been
increasingly caused by dirt such as stickies and plastic films residual inks
from the inferior waste paper during DIP process.
Deinked pulp contains many types of paper products at Nomachi in Takaoka Mill,
while strong demand for higher quality product is rising in the market.
This report described our effort to reduce obstacles in DIP production process
to satisfy the strict market demand.
The Technology of Deinked Pulp Made from Low-grade Recovered Paper
Research Laboratory, R&D Div., Nippon Paper Industries Co., Ltd.
Pulp Department, Yatsushiro Mill, Nippon Paper Industries Co., Ltd.
It is apparent that promoting the utilization rate of recovered paper in paper
manufacture is a key point to reach the target of 62% by 2010. The paper manufactures
have started to consume not only old newspapers but also old magazines and fine
paper printed. On the other hand, the recovery rate reached 72.4% in 2006 while
it was a strong growth of recovered paper export to China. The supply of high
quality recovered fine paper has been restricted.
Nippon paper industries has promoted the use of various grades of recovered fine
paper for paper manufacture to produce the stable deinked pulp. We describe the
latest technology of the high brightness deinked pulp production.
The Rebuild of DIP Lines at Kanto Mill (Katsuta)
Kanto Mill (Katsuta), Hokuetsu Paper Mills, Ltd.
DIP lines in Kanto Mill (Katsuta) have started its operation since 1975 with
a paper machine. Since there is only one paper machine, the operation of DIP
lines is matched with what kind of waste paper as raw material is needed for
production of the paper machine and how much amount of waste paper should be
required for it.
In the original plan, the DIP lines were designed for treatment of newsprint
as main raw material, but we installed drum pulper and kneader and remodeled
coarse-screen and bleaching process in order to enhance the volume of production,
quality and brightness.
Since then, the two DIP lines (one is BDP which has bleaching process, the other
is DIP which is non-beaching process) are operated and producing DIP, treating
newsprint, magazine, and woodfree-based waste paper.
This report shows the details of remodeling of the DIP lines and the result after
remodeling after 2003.
Countermeasures against Dirt in Waste Paper Treatment Process
Hachinohe Mill, Mitsubishi Paper Mills Limited
In Hachinohe mill, we produce deinked pulp with high brightness. The pulp is
mainly made from coated book stock (CBS). However, the procurement of CBS has
become difficult by the elevated price of waste paper. Therefore, we are forced
to utilize several types of raw materials such as waste magazine.
We have tackled the quality loss of the raw materials and stabilized the pulp
quality by performing several countermeasures: preventing stickies from being
subdivided in defibering process; reconsidering coarse-screen baskets for strengthening
dirt removal; removing color spots approached from defibering process and white
water treatment process; reconsidering bleaching parameters for restraining brightness
The conditions of waste paper market are changing at any time. This report contains
the efforts under consideration. We aim to continue the efforts for stabilizing
and upgrading the pulp quality.
Conference Report of the Cellulose and Renewable Materials Division in the 235th
ACS National Meeting & Exposition
Faculty of Agriculture, Kyushu University
The 235th American Chemical Society National Meeting and Exposition was held
in New Orleans, LA, USA on April 6-10, 2008. The ACS is the world's largest scientific
society founded in 1876, and the 2008 spring national meeting gathered more than
13,300 attendees from all over the world. This conference report focuses on the
interesting presentations in the Cellulose and Renewable Materials Division,
especially Anselm Payen Award Symposium honoring Prof. Fumitaka Horii: Structure
and Properties of Cellulosic Polymers, Assemblies, and Nanocomposites.
Evaluation of Chloroform Emission at an ECF Bleaching Pulp Mill
Technical and Development Division, Hokuetsu Paper Mills, Ltd.
Environmental Section, Niigata Mill, Hokuetsu Paper Mills, Ltd.
Graduate School of Life and Environmental Sciences, University of Tsukuba
Chloroform formation, balance, and discharge were estimated during 1997-2005
at an ECF bleaching hardwood kraft pulp mill that operated a complete airtight
type activated sludge treatment using pure oxygen for the bleaching sewer. This
was achieved by collecting and analyzing discharge water and gas samples that
contained measurable levels of chloroform. During the stable operation of ECF
bleaching, the average formation of chloroform was estimated to be 1.48 g/pulp
adt. At the activated sludge treatment of chlorine bleaching sewer, chloroform
generated being accompanied with decomposition of organic chlorine compounds
indicated by AOX. It was suggested that the activated sludge treatment could
remove or decompose the chloroform generated from ECF bleaching sewer.
Keywords: chloroform, bleaching, activated sludge, kraft pulp, hardwood