|JAPAN TAPPI JOURNAL
Vol.62 No.11 Abstracts
Basic and Application of Wet End Chemistry
Pulp and Paper Research Laboratory, Oji paper Co.,
The purpose of adding wet end chemicals
and wet end chemistry practices are to achieve optimum
paper properties and enhance papermaking efficiency.
In recent years, papermaking condition has changed
by use of variety of recycled paper, high amount of
coated broke usage, increase in speed of paper machine
and closed water system in paper mill. These trends
complicate wet end conditions and make resolution of
wet end problems difficult.
In this paper, at first, basic wet end chemicals
are introduced, and show some examples of analysis
of deposition in paper machine and a useful way
for selecting chemicals to fix problems.
The Approach to WET- END Process Optimization
-The Analysis Method for WET- END Process and Case
BTG Instruments GmbH
Gaining greater productivity and paper
quality is a systematic and continuous process. This
statement is especially true for the Wet End of the
paper machine. Many strategic additives are introduced
to influence machine runnability and paper quality.
At the same time there are only few areas of the paper
machine with less automatic control. This paper will
present two case studies of waste paper-based newsprint
machines at the Papierfabrik Palm, Eltmann mill that
led to better control in the Wet End.
The Application of Fuzzicide in White Water Circuit
for Productivity Improvement
Hiroyuki Suzuki, Satoshi Kashiwagi, Sousuke Iwata,
Hiroki Katsura, Katsuhiko Hidaka and Takumi Sugi
Technical Section, Pulp & Paper Industry Department,
Kurita Water Industries Ltd.
The trend in papermaking is use more recycled
fiber in the furnish, maintain the pH of paper machine
at neutral, reduce fresh water consumption. These changes
accelerate the CaCO3 scale problems, the pitch problems
and the slime problems.
Fuzzicide is new inorganic slime control agent
and can keep all papermaking processes clean. New
monitoring tool can understand cleanness in the
These new techniques are able not only to decrease
the spot and the sheet break but also to extend
the operation period.
Optimization of the Passing Velocity for Primary
Screens on PM5
Yufutsu Mill, Nippon Paper Industries Co., Ltd.
The start of No.5 paper machine (PM5) at
Yufutsu Mill was in 1979. Currently, its capacity is
approximately 300 metric tons per day. Its product
mix includes wood free paper and base paper for thermal
paper and no carbon copy paper.
Originally, wet end was run at an acid pH. However,
the machine has been converted to neutral pH with
the use of calcium carbonate. The calcium carbonate
was originally supplied by purchasing from another
company. Then, as a cost savings measure, the calcium
carbonate was purchased from another Nippon Paper
When this change occurred, there were increased
incidents of screen baskets plugged with "stock
lumps". There would defect randomly and cause sheet
defects or sheet breaks.
This report shows the results of passing velocity
optimization of the primary screens to reduce stock
lump build up and plugged screen baskets.
Improvement of Cleaning Procedure and Deposit Prevention
in Stock Preparation
Nichinan Mill, Oji Paper Co., Ltd.
#2PM in Nichinan mill of Oji Paper was
established in 1956 and has been modified in the part
of stock preparation process in order to be satisfied
with quality of the paper. Now we are making some base
papers for Ink Jet printing paper, thermal paper used
as specialty, ticket, sketchbook, specialty paper used
as business card, and thick fine paper. These papers
are used for digital imaging print and require low
dart number because end users use them by a piece of
sheet and look the fresh printed paper carefully.
This is a report in regard to some improvements
of the process and the operation for stock preparation.
Improvement of the Runnability for Paper Making
by "Axisz System"
Technical Dept., Somar Corporation
Neutral papermaking and high recycle fiber
usage in recent years make papermaking more troublesome.
Conversion of acid to neutral papermaking reduced popular
use of alum. Increased recycled fiber usage promoted
by global resource protection and environmental concern
brings more foreign materials such as pitch and anionic
trash in papermaking system. At Somar we have been
working on wet-end improvement agent "Realizer A series" as
functional coagulant which maximizes the effect of
variety of wet-end chemicals. Latest polymer technology
help us to develop another functional retention aids
as "Realizer R series" and "Rexer FX series" which
are effective in fine and ash retention. Synergistic
effect of the combination of these chemicals to improve
wet-end performance is referred as "Axisz System".
It developed by Somar will give a solution to the
problems associated with wet-end operation. The
new chemical assists retention of other wet-end
chemicals, thus reducing total chemical usage.
It also improves drainage and fiber retention.
Optimization of wet-end operation using "Axisz
System" can be achieved by proper selection of
cationic charge, molecular weight and molecular
weight distribution. It depends on stock characteristics
and other chemical usage. Maximization of the effect
with "Axisz System " is demonstrated.
Operating Experience of "Intensa Pulper", The Newly
Developed Low Consistency Pulper
Oita Mill, Oji Paperboard Co., Ltd.
Oji Paperboard Co., Oita Mill has three
paper machines, No.1, 3 and 5, and produces gypsum
board, white and colored board, core paperboard, etc.
other than main product of linerboard.
As the blending rate of the old corrugated containers
(OCC) into the paper products now reaches around
80 percent here, the energy saving in the OCC pulping
process and the quality improvement of the recycled
pulp have become very essential and important to
realize more effective secondary fiber system.
For this purpose the first "Intensa Pulper" in
Japan, which was developed by Voith IHI Paper Technology
Co. was installed in the OCC pulping process with
result of the extensive power saving and the significant
improvement of the OCC defibering characteristics.
In this paper, what and how the Intensa Pulper
is and its operation experience and running effect
A New Design for Paper Dry Strength Agent and Its
Application Method in Wet End
Paper Chemicals Division, Arakawa Chemical Industries,
Encouraging environmental protection and
conservation program, an amount of recycled paper and
paper board furnish has been increasing in Japanese.
On the other hand, it has become very tight to get
used paper in the domestic market recently. A large
volume of used paper has been exporting towards China
with better price, therefore Japanese paper industry
must use lower grades furnish. Such fibre materials
cause papermaking conditions worse and hard to control
Many companies have introduced new machines in
East Asia, and production cost is very important
for domestic papermakers to survive in the market.
However, the price of used paper has been increasing
dramatically, and optimizing lower quality grade
fibre has to be inevitable. In order to produce
paper and paperboard by a high speed machine using
such grade fibre, high performance wet-end chemicals
must be developed to achieve better machine control
and cost reduction.
In this paper, recent technical trends of polyacrylamide
(PAM) based dry-strength agent and partially cationic
starch were discussed. In particular, treatment
systems of blanched chain structure PAM combination
was investigated, in which two or more type of
each PAM equipped different coagulation force.
This application could be useful for various papermaking
systems and it is expected to be applicable to
more complicated wet-end condition and high speed
kajaaniWEM & kajaaniRM3 - The Integrated Management
from Stock to Wet-end
Jukka Nokelainen and Takeshi Sato
Process Automation Systems Division, Metso Automation
This paper introduces two lately launched
superior tools for wet end management: modular multi
talent analyzer and consistency sensor. The consistency
sensor is stand-alone device that performs continuous
measurements from one sample point. It is ideal for
applications that require continuous total and true
ash consistency measurement and automatic control.
The new analyser is first in the world that provides
papermakers with all the right and relevant wet end
measurements. Here we describe by several living examples
of charge, pH, temperature, redox, conductivity, and
consistency measurements, how to get comprehensive
understanding over paper making from Stock to Wet-end
and point out process problem areas and find right
actions to correct them.
A Report on the 2008 Japan-China Pulp and Paper
Technical Exchange Symposium
Takashi Ochi*1, Yutaka Kaneko*1 and
*1Nippon Paper Industries Co., Ltd.
The second Japan-China technical exchange, "2008
Japan-China Pulp and Paper Technical Exchange Symposium",
sponsored and arranged by Japan TAPPI, China TAPI and
Shandong Light Industry Institute, was held on May
20-21, 2008 in Jinan, Shandong, China. The number of
participants of both countries was almost 200. Before
and after the symposium, Japanese participants visited
five paper mills.
A Report on the 21st ISO/TC6 Meeting
Takayuki Okayama*1, Toshiharu Enomae*2,
Yasuhiro Oba*3, Kyoji Kishi*4,
Shisei Goto*4 and Tadashi Kano*5
*1 Tokyo University of Agriculture and Technology
*2 The University of Tokyo
*3 Oji Paper Co., Ltd.
*4 Nippon Paper Industries Co., Ltd.
*5 Japan Technical Association of the Pulp and
ISO/TC6 meeting was held on June 9-13,
2008 in Seoul, South Korea. The number of registered
delegates representing seventeen countries was seventy
Eight delegates representing Japan attended WG
meetings, plenary meetings of SC2 and SC5, and
TC6 plenary meeting.
Theoretical Study of the Sheet Transport Speed
with the Rubber-Covered Roller
Takao Kobayashi and Shinji Nakayama
Pulp and Paper Research Laboratory, Oji Paper Co.,
In this study, systematic consideration
about the sheet transport speed was performed with
the finite element analysis. Poissonfs effect does
not appear in compressible materials such as urethane,
and volumes just decrease by compression whereas the
normal rubber shows the incompressibility which keeps
a fixed volume. The sheet transport speed ratio (the
ratio of the movement speed of the sheet for the peripheral
speed of the rubber roller) is almost in proportion
to a tension difference in front and back of the nip
without depending on a value of the sheet tension.
It has an increasing linear relationship with the contact
pressure of the roller in the case of the incompressible
rubber and has a decreasing linear relationship in
the case of the compressible material. It was confirmed
that this speed ratio depended on a tangential elastic
strain of the rubber roller in the stick region by
In the applied example assumed a printer paper
feed tray, we understood that when the sheet was
transported with a pickup roller, the frictional
force from back side of the sheet had an influence
on the speed ratio greatly. When a pickup roller
was located in the one side, it followed that frictional
force by the weight of the sheet became the resistance,
and skew occurred. When two pickup rollers were
arranged in parallel and the contact pressure of
each roller was not equal, the transport speed
difference caused skew. In this case, it is predicted
that buckling occurs if skew will be controlled
forcibly by side plates.
Keywords: finite element analysis, sheet transport
speed ratio, incompressible rubber, compressible
material, rubber-covered roller, elastic strain