JAPAN TAPPI JOURNALVol. 57, No.6
June 2003 Abstracts
Kraft Cooking with SAQ Suitable for ECF Breaching
Kawasaki Kasei Chemicals Ltd.
SAQR has been used as a cooking additive in many KP mills. This process is
known as "Quinone Cooking". In this paper, some new applications
of SAQR’s functions are proposed when ECF bleaching process is
introduced in pulp mills.
First, the effect of SAQR, which decreases bleaching load keeping pulp yield
and strength by lowering Kappa number, is explained. Also, SAQR’s
advantage comparing with dispersed AQ is mentioned, especially
when SAQR is used combining with Polysulfide cooking. Finally,
KKC’s study plan about SAQR’s applications to recent modified cooking
processes is described.
ECF Bleaching of Softwood and Eucalyptus Pulps−a Comparative Study
Lennart Meuller, Jiri Basta, Lillemor Holtinger and Gerd Wane
Eka Chemicals AB, S-445 80 Bohus, Sweden
This paper deals with a comparison in ECF bleaching and effluent characterisation
of kraft pulps based on softwood and eucalyptus. The study is made
for both conventional and oxygen delignified pulps.
There are similarities in the bleaching of softwood and eucalyptus looking at the bleaching parameters. In mill scale there are however normally differences in the number of bleaching stages for conventional and oxygen delignified pulps when bleaching to
90 %ISO brightness. Conventional pulps are mainly bleached in a five stages sequence with peroxide reinforcement in the alkaline stages, D (EOP) D (EP) D. Oxygen delignified pulps are mainly bleached in a four stages sequence, D (EOP) D D, especially softwood pulps. A three or four stages sequence, D (EOP) D D or D (EOP) D, is usually used when bleaching oxygen delignified eucalyptus pulps. For brightness levels of 88 %ISO a three stages sequence can be used for both oxygen delignified softwood and eucalyptus pulps.
In the ECF bleaching optimisation study we have used a five stages sequence for all pulps. The same bleaching sequence was used in the effluent characterisation study except for the oxygen delignified eucalyptus pulp where a three stages sequence was used.
Combined effluents from all bleaching stages were characterised and exposed
treatment. Characterisation studies were carried out both prior to and after
the biological treatment.
The characterisation of the main COD components; lignin, carbohydrates, methanol, low molecular acids and extractives prior to and after external treatment, corresponded well with the calculation of the total organic composition. The results showed that the organic composition varies for effluents from different pulps.
The COD composition of softwood and eucalyptus effluents were significantly different, which explains why the effluents from the eucalyptus pulps were more biodegradable.
Keywords; Bleaching, ECF, softwood, eucalyptus, COD, AOX, Effluent characterization,
New Refiner & Disperser Providing a Principle of Conical Refiner-DoubleConifiner & ConiDisc-
Aikawa Iron Works Co., Ltd
The DoubleConi-Finer is the latest designed refiner having both characteristics,
double disc type refiner and conical type refiner, which is used
for low consistency refining. The ConiDisc is one of the high speed
disc type dispersers, which is used as a disperser for hot dispersion
system and is also used as a high consistency refiner. It provides
two kinds of fillings, one is conical type, and the other one is
disc type which is fixed at outside of the conical type fillings.
Those refiners having unique design improve dramatically paper
characteristics and energy consumption. This paper reports the
constructions and the benefits of those new refiners.
Energy Saving RTS-TMP Pulping and its Pulp Quality
Masahiro Ohkubo , Tamio Fukuzawa and Chiaki Kawakami
Brad Cort and Marc Sabourin
RTS is a new Low Retention, High Temperature and High Speed TMP pulping method
developed by Andritz. While the pulp quality is kept the same as
conventional TMP, the energy is 15-17% less than the conventional
Extensive studies were conducted to evaluate the development of pine pulp
properties and energy requirements using two different thermomechanical
refining processes at a southern U.S. paper mill. The processes
included both a low intensity (TMP) and a high intensity (RTS?
) refining configuration. The pulps produced with the RTS process
had 15%-17% lower energy consumption compared to TMP pulps produced
at similar freeness and handsheet physical properties. Despite
similar average fiber length results between the two processes,
the low intensity pulps had a higher percent by weight of fiber
retained on the Bauer McNett 14/28 fractions, whereas the high
intensity pulps had a higher percent by weight retained on the
middle fractions. Calendered newsprint produced from the high intensity
pulp had a lower roughness, which may be related to the lower fiber
size distribution. Light was thrown on this finding by porometry
measurements of the newsprint, which revealed a slightly lower
pore size distribution from paper produced with the higher intensity
pulp. Standard ink printing tests, however, provided similar results
between newsprint paper produced from the TMP and RTS? processes.
Applying Automatic Chemical Control from Stock Prep to the Machine
Roland Berger and Lydia Christen Bley
Muetek Analytic GmbH
Spectris Co., LTD. BTG division
For many years, retention-aid dosage has been controlled by the white water
consistency in newsprint, fine paper and board applications. This
control strategy is well known and has proven efficient and beneficial.
However, combining retention-aid control and charge demand control
with coagulant or fixative in the thick-stock area provides additional
benefits.An on-line charge analyzer, measuring the incoming furnish
charge level, allows controlled coagulant addition so that downstream
additives are applied more efficiently and economically. This control
strategy provides substantial cost savings to the mill. Costly
functional additive consumption is reduced and other chemical control
loops, such as retention-aid addition, are improved.
This paper explains the impact of white-water consistency on paper machine
outcomes such as basis weight variation, steam consumption and
wet-end stability. White-water consistency, dewatering and charge
demand control approaches are discussed, and practical examples
are used to describe how short circulation and chemical composition
of the pulp affects final product quality. Mill experiences with
the on-line units, and proposed gains and benefits of these measurements
to papermakers will be demonstrated.
Introduction of a New Type Filter for White Water
Ebara Corporation, Environmental Engineering Group
For the recycling of white water from papermaking, several kinds of techniques
have been developed and put into practical use, but mainly, sand
filtration has been adopted up to present for the reason that it
provides good water quality stably. However, with the conventional
white water filters, problems occurred in the maintenance and management
of operation, such as clogging of filter layers, slime troubles,
etc. caused by mud ball formation. In order to solve these problems,
EBARA has developed a new type filter provided with a surface washing
agitator which allows, during backwashing, the sand particles in
the filter layer to be cleaned by strong rubbing against each other.
An outline of this machine is introduced below.
Diagnosis of Microbial Problems on Paper Machines
Linda R. Robertson
Principal Consultant Paper Microbiology ONDEO Nalco Co., Ltd.
Senior Account Manager ONDEO Nalco Japan Co., Ltd.
Numerous microbes are capable of growth in paper machine systems. They form
visible deposits that result in sheet defects, holes or even breaks
in the web. Microbes are also responsible for performance loss
and spoilage of pulp and expensive functional chemicals. This spoilage
can lead to strength loss in fibers, formation of odors that result
in rejected products, viscosity loss in starch and a variety of
other problems. Diagnosis of microbial problems in complicated
by the fact that simple aerobic plating techniques on tryptone
glucose extract agar or PetrifilmsTM with a 48-hour incubation
period do not allow recovery of all of the microbes causing the
problems. Nor do the numbers of planktonic (free-swimming) cells
correlate to the severity of deposition on surfaces. This paper
will discuss the limitations of generally accepted plating techniques
and propose more accurate diagnostic methods for solving microbial
Increasing Productivity by Investing in New Technology- On-line
Concepts for Different Paper Grades -
Sumitomo Heavy Industries Techno-Fort Co., Ltd.
Running references prove that on-line technology can improve productivity
through lower costs and investments. Operating and technical demands
are higher, but they can be handled with good cooperation and hard
work. Every project is individual in terms of its demands and potential.
This means that on-line and off-line technology have to be considered case
by case in accordance with project targets and local factors such
as furnish. When applicable, on-line technology is one of the most
promising options for productivity improvement.
Mitsubishi MCCR / MJ Calender
Mitsubishi Heavy Industries, LTD., Hiroshima Research & Development Center
Mitsubishi Heavy Industries, LTD. (MHI) has developed a high performance controlled
multishoe crown roll to control the caliper cross profile and MJ
calender applied the technology from shoe press. Recently better
surface for high quality printing and bulky paper for saving pulp
consumption are required. MCC roll and MJ calender meets these
requirement. This paper introduces outline of MCC roll and MJ calender
and shows data from the pilot trial and field.
A Study of Sheet Gloss
Latex Research Center, Nippon A&L INC.
Recent years, requirement for sheet gloss of coated paper is steadily developing
because it is one of influential factors deciding the final quality
of coated paper.
In this paper, the relation between sheet gloss and the effective
factors such as surface roughness or optical properties was studied.
Coated paper samples were prepared with different latex binder
types or different pigment systems, then several types of surface
roughness or optical properties were measured in order to understand
which property is more influential to sheet gloss.
The concluding remarks gave the following understandings.
Firstly in surface roughness measurement, although both the average
roughness Ra and the average wave length of roughness frequency
Sm gave good correlations with sheet gloss, the later was more
influential. In addition, it could be understood that surface
roughness was affected by a degree of kaolin orientation.
Secondly in optical property measurements, the ratio of incidental
reflectance to the total reflectance including diffusion gave
a liner correlation to sheet gloss, the higher ratio gave the
better sheet gloss.
Improved Two-Drum Winder Technology
Voith Paper Jagenberg GmbH
Today many Paper Mills have to supply rolls at larger diameters to their customers.
Very often the existing two drum winders cannot cope with the quality
demands as larger roll diameters lead to increased roll weight
and therefore higher nip pressure between roll and drums.
Excessive nip pressure results in various roll defects. So paper mills are
forced to improve their winder technology. Ideally rebuilt packages
for the existing winders should make the winder matching with their
Voith Paper Jagenberg GmbH can offer tailored solutions for many applications
by supplying special roll covers which reduce the specific nip
The Stable Flow Measurement for Stock Flow by Capacitance Magnetic Flowmeter
Takashi Okada, Jun Nishimura and Seiji Tanabe
Yokogawa Electric Corporation
The stock feed flow from stuff box is very important factor to decide the
quantity and the quality of paper. Usually magnetic flowmeters
are used to measure the stock feed flow and the accuracy mainly
depends on the uniform of the conductivity and gas fed with stock
from stuff box at the start up action. We developed the capacitance
type of magnetic flowmeter and tried this meter to the line in
a series of the wet electrode type of magnetic flowmeter. The capacitance
magnetic flowmeter measurements are very stable and the outputs
of both flowmeters are quite different. This paper shows the state-of-the-art
technology on the stock flow measurement and describes the advantage
for the use of capacitance magnetic flowmeters.
Facility Diagnosis of Acoustic Signal−Acoustic Diagnosis Technology and Application Case−
Automation Asset Management Department, Yamatake Industrial Systems Co., Ltd
IF-ASSET is abnormal signal segregation and detection technique that was developed
based on inverse filtered acoustic/vibration signals, and was proven
effective in monitoring rotary machines, compressors, piping and
high pressures vessels. Now we intend to utilize IF-ASSET to monitor
several kinds of industrial machines.
Preparation and Evaluation of Mordants for Neutral
Rosin Size Emulsion from Lignin
Yasuyuki Matsushita and Seiichi Yasuda
Graduate school of Bioagricultual Science, Nagoya University
Mordants for neutral rosin size emulsion from lignin were prepared and their
abilities evaluated. To convert lignin into the mordant, an amino
group was introduced to lignin by Mannich reaction and the reaction
with glycidyltrimethylammonium chloride (GTA). In this study, Kraft
lignin and phenolated sulfuric acid lignin (P-SAL) were used. In
an experimental system composed of the handsheets made with LBKP,
sizing agent and lignin derivatives, a Mannich reaction product
prepared from Kraft lignin failed to exhibit any mordant characteristic,
whereas Mannich reaction products (MP-SAL) prepared from P-SAL
were highly effective as mordants. MP-SAL with ethylamino group
especially showed higher performance. The MP-SAL with the higher
pKa value of the introduced amino group also had higher performance.
In the rosin emulsion-alum system, MP-SAL and GP-SAL, which latter
are reaction products of P-SAL with GTA, enhanced the sizing effectiveness
under acidic to neutral pH range. The handsheets prepared with
MP-SAL or GP-SAL besides alum still showed the sizing effectiveness
after chloroform extraction, although the sizing effectiveness
of the handsheets prepared only with alum disappeared after chloroform
extraction. Thus, these results suggest that the enhancement of
sizing effectiveness contributed to greater association between
the size and the fiber surfaces with the addition of MP-SAL or
GP-SAL. A decrease in brightness was observed when MP-SAL or GP-SAL
was used as a mordant. According to the Kubelka-Munk theory, the
brightness of original pulp with 85% brightness was calculated
to decrease 16.9% and 4.3% by adding 0.2% MP-SAL and 0.2% GP-SAL,
respectively, but the brightness decrease of a pulp with 50% brightness
by adding 0.2% MP-SAL and 0.2% GP-SAL was only 1.9% and 0.6%, respectively.
This suggested that the lignin derivatives are as capable as a
mordant in newspaper and mechanical papers, which do not require
a high level of brightness.
Keywords: lignin, sulfuric acid lignin, rosin size emulsion, mordant, Mannich reaction, epoxy reagent
Study on the Dispersion Stability of the Two Components Slurry, Composing from SAP and MFC (Part III)Study on the Composite Structure of SAP and Microfibrillated Cellulose
Japan Absorbent Technology Institute
School of Agricultural and Life Sciences, The University of Tokyo
A dispersion liquid can be obtained exhibiting a high viscosity at a low concentration
by uniformly dispersing microfibrillated cellulose (MFC) or bacterial
cellulose (BC) in a mixed medium of water and hydrophilic organic
Particulate SAP as dispersed in this dispersion liquid, SAP particles can
be stably dispersed with a high concentration in the dispersion
liquid by virtue of the viscosity exhibited by MFC. In addition,
possible coagulation and recoagulation to be caused with SAP particles
otherwise coming near to each other can be almost entirely prevented
by the SAP particles being dispersed in the dispersion liquid by
the action of the dispersion of MFC, so that a dispersion slurry
of a long and stable pot life can now be prepared.
The respective behaviors of SAP and MFC in such mixed medium have been reported
in Part I of "Study on the Composite Structure of SAP and
Microfibrillated Cellulose", "Swelling & Coagulation
Behaviors of Acrylic Acid Base SAP in Water & Water Miscible
Organic Solvent Mixture" 1) and in Part II "Study on
the Dispersion Stability of the MFC or the BC in a Solvent Mixture
of Water and Organic Solvent" 2) in this Journal.
As reported previously, the authors believe that they have made clear the
nearly whole picture of the conditions for stably dispersing each
component, SAP and MFC, alone in a dispersion medium. When it comes
to a two component slurry system of SAP and MFC in coexistence,
various unexpected phenomenon come to take place caused by the
concentrations and concentration ratio of SAP and MFC, their different
mixing mechanisms, changes with time, coating conditions, etc.
In this report, studies have been made on the process flow of SAP
and MFC being added and mixed, their dispersion limits, stability
with time of their mixed slurry, stability at their temperatures,
etc. so that the following results have been obtained:
1) It is found that MFC has the following effects in the slurry
of SAP and MFC in coexistence:
.MFC even if at low concentrations prevents coagulation and re-coagulation of SAP by virtue of its high viscosity;
.MFC being dispersed keeping a finely particulate shape prevents bonding in groups of SAP particles to each other;
.While SAP tends normally to swell to 1.5 to 2.2 times larger than its original form as it selectively absorbs water in a dispersion medium, it is prevented by MFC in coexistence from swelling with MFC retaining water out of the dispersion medium by virtue of its high hydrating property; and
.MFC prevents the selective water absorption of SAP so as to cause the dispersion
medium not to undergo changes in composition for a long period of time.
2) The optimization of the preparation conditions of subject
slurry contemplated in a commercial process:
.In a procedure of preparing a slurry, a dispersion liquid of MFC should be first prepared and then SAP is to be added;
.SAP has been found to be wide in its stable dispersion region if it is such as cross linked on the surface, of spherical shape, of small particle diameter and is obtained by being reversed phase suspension polymerization;
.The limit concentration of SAP in coexistence with MFC is 20 to 40 %;
.The limit concentration of MFC in coexistence with SAP is 0.4 to 1.0 %;
.Possible change with time of the slurry with MFC in coexistence can be prevented by properly selecting SAP and the water content of the dispersion medium and keeping the concentration of around 15℃.
3) It has been found that the conditions of stably forming sheets can be established
by defining a range of conditions for stabilizing the slurry.
Keywords：SAP, MFC, SAP/MFC co-existence slurry, partial swelling of SAP, dispersion condition, sheet formation condition