TAPPI JOURNALVol. 56, No. 4
April 2002 Abstracts
A Laboratory Study of Damaged Wastepaper
Fumihiko Mukae, Junta Egawa, Masanori Nikaido and Atsushi Yamasaki
Wastepapers turn yellowish-colored and damaged when exposed to UV light and
kept at high temperature during summer. When the damaged wastepapers are used
as raw material, the quality of recycled paper becomes remarkably inferior. Generally,
paper mills try to suppress the effect of damaged wastepapers to quality by increasing
the amount of chemical used during process, especially increasing the amount
of hydrogen peroxide is quite common.
There are two possible factors for the quality deterioration by using these wastes.
a) Adhesion of ink to fiber: Ink removal efficiency becomes low.
b) Increase of fine inks: Ink collection efficiency becomes low.
In this presentation, the cause of damaged wastepaper deterioration and solutions
for suppressing its effect to the quality of recycled paper are discussed.
What Papermakers Need to Know
Where to get Environmentally Approved, Quality Fibre
Allan G. Jamieson
AOK Innovations Pty. Ltd.
It has been shown that the papermaking quality of wood supplied to an integrated
fine paper mill is of more economic importance to the mill than is the price
paid for the wood. Papermakers, therefore, should take close interest in defining
specific technical quality requirements for fibre raw material. It is now evident,
though, that it is also necessary for the papermaker to ensure that the raw material
has suitable environmental credentials, i.e., that it is obtained from a resource
that is managed in a fully sustainable manner: Sustainable not only ecologically
but also in the context of economical viability and social desirability.
This paper examines two emerging man-made forest resources in Tasmania; "seedling" plantations
and "seed" plantations (also called regrowth forest). It is concluded
that Tasmania can supply high quality pulpwood fibre possessing excellent environmental
Scale Deposit Problems and their Contorol in ECF Bleach Plants
Yokkaichi laboratory, Hakuto Co.,Ltd.
Technologies of kraft pulp bleaching have been greatly developed in recent years
because of environmental consideration. New ways of bleaching are ECF and TCF
bleaching. ECF bleaching does not use both elemental chlorine and hypo chloride,
and TCF bleaching does not use chlorine compounds at all. In Europe and U.S,
almost pulp plants have completed to change their bleaching ways to ECF or TCF.
Many pulp plants in Japan are also trying to change to ECF bleaching.
Basically, scale deposit problems often occur in bleaching plants. In order
to apply ECF bleaching and to promote a closure of process water, the tendency
of scale problems in ECF bleaching comes to be one of the most important concerns.
In this report, we showed characteristics and control methods on calcium oxalate
and barium sulfate scale which should be especially considered for ECF bleaching.
Advanced Spray Coating Technology- OptiSpray ?
Metso Paper, Inc., Finland
Metso Paper KK
Over time we have seen a decrease in the trend of paper product prices. In recessionary
times, low value products lose their profit marginal quite easily. To achieve
good profitability, the value of the product must increase while at the same
time production costs decrease. The dream of every papermaker is to produce a
high-value product with economic raw materials while maintaining good runnability
at high speeds.
The demand for lower impact in the paper coating process is well known, as are
the difficulties in blade coating. Film transfer technology has taken a big step
in the right direction. The weaker base papers can be coated. Still there is
heavy web contact with many dependencies and interactions between coater and
paper in the film transfer nip. The coat weight variations caused by unevenness
of the base paper and changes in the cross directional tensile profile over the
coater are ready examples.
Thanks to film transfer technology, the coated and improved newspaper grades
are already available. With the help of an improved print image, four-color newspaper
printing will gradually attract the commercial advertising business. Even traditional
newspapers will be four-color printed on light-weight coated news grade, making
them as attractive for product advertising as the newspaper inserts are today.
Every cold-set newspaper printing house is seeking business use for available
day time hours.
Now, Metso Paper launched its new OptiSpray technology. The OptiSpray coating
process is based on a controlled, high-pressure spray application of coating
or surface size directly onto the surface of the paper or board, without any
direct machine contact. The coating is simultaneously sprayed at high speed on
both sides of the paper web. OptiSpray achieves excellent coverage of the base
The Development of New High Speed Paper Machine Series
Mitsubishi Heavy Industries, LTD, Paper & Printing Machinery Division
A new Mitsubishi high-speed paper machine development project has started in
1999 and concluded with product offering to the market in October 2001. The new
product is known as MJ series and is designed to complement the current MH series
Mitsubishi paper machines.
The goal of MJ series paper machine is to produce quality paper at 2000 m/min
operation speed while being an operator friendly product. The MJ series has been
developed in the course of the intensive elementary study, program simulation,
model test, and final verification on our pilot paper machine in Mitsubishi R&D
center of Mihara, Japan.
This paper presents the concept and features of the MJ series paper machine.
Drainage of Forming Part−V.I.D. Formation System−
Kobayashi Engineering Works, LTD.
Licenser AES Engineered Systems(U.S.A.)
Various types of gravity and vacuum augmented foils have been used as typical
drainage equipment for conventional Fourdrinier machines.
In any type of drainage equipment, filtration mat formed in the early stage
of drainage is a limiting factor for the drainage efficiency in the later stage.
When we call this dewatering process as "filtration drainage", paper
makers already have made the possible efforts to overcome the negative effects
of "filtration drainage". It seems that the efficiency of conventional
drainage equipment has reached its limit.
This paper deal with a device, V.I.D. technology with its thickening drainage
process, which has been developed to provide the solutions for various issues
of conventional forming Application of DIA-BIOFRINGE to the Treatment of Paper
Hisao Murakami and Katsumi Sone
TOKAI PULP & PAPER CO.,LTD.
MITSUBISHI KAKOKI KAISHA,LTD.
The DIA-BIOFRINGE, an aerobic biofilm system which uses strings with ribbons
fixed to the metal frames and swaying in the water are used as biofilm media,
has many advantages such as no backwash operation required, quick startup, and
flexibilities in reactor design.
TOKAI PULP & PAPER CO.,LTD. recently introduced the DIA-BIOFRINGE into
their wastewater treatment plant to treat paper mill wastewater. In the demonstration
test carried out prior to its construction, a stable BOD removal have been obtained
at the BOD backfill volumetric loading of 1.5 kg-BOD/m3･day. Furthermore, it
was confirmed at the test that preliminary SS removal, usually necessary in ordinary
biofilm systems, are unnecessary. Thus, the introduction of the DIA-BIOFRINGE
is proved to be very advantageous from the fact that the system is totally simplified
and small investment in auxiliary units of the system.
technology. Examples of its field applications are also given.
Introduction of EBARA Water and Heat Recycling Systems
Ebara Corporation , Environmental Engineering Group
Based on its long experience and advanced technology, EBARA CORPORATION has
proposed and delivered mainly to the industry of foods and drinks EBARA water
and heat recycling systems which combine thorough on-site surveys with profound
water and wastewater technology and energy saving technology and take into consideration
even the production lines. In these water and heat recycling systems, the wastewater
and the waste heat, which were used on a one-time use basis and discarded in
the past, are regarded as "Renewable resources", that is, these wastes
are treated by the optimum renewal technology for reuse or cyclic use. This can
not only reduce the loading on the environment but also contribute to reducing
the water and vapor to be used in the plant. The results have already been highly
evaluated, and we started in the last year to propose these systems to the pulp
and paper industry. At this opportunity, we would like to introduce our water
and heat recycling systems.
Conversion to ECF Bleaching−A Comparative Study with Focus on the First Bleaching
Kvaerner Pulping AB, Sweden
Marcelo Moreira Leite
Kvaerner do Brasil Ltda., Brazil
(Translated) Michio Imai
Kvaerner Pulping KK
In the present paper, an investigation of some different ECF bleaching sequence
is presented, and the results compared. Special attention is paid to the importance
of the first bleaching stage after oxygen delignification, i.e. the so-called
delignifying bleaching stage. Two different mill-oxygen-delignified HW kraft
pulps were subjected to a number of different bleaching sequences. The first
pulp was bleached according to D(EO)D, D*(EO)D, (ZD)(EO)D, Z(EO)D and after interpolation
evaluated at 89% ISO brightness, and the second pulp according to D(EP)D, D*(EP)D,
(ZD)(EP)D, A*ZD(EP)D and after interpolation evaluated at 87% ISO brightness.
The "*" here denotes a treatment at high temperature and log retention
time. Both the use of D* and Z efficiently reduced the yellowing tendency of
the pulps when compared to the conventional D-based ECF sequences. Based on the
laboratory trials, consumption figures were adjusted to reflect mill operating
conditions and the differences in operational costs between the different sequences
were calculated. The sequences with D* were economically very attractive, showing
high savings in operational costs compared to the reference D(EO)D and D(EP)D
sequences, especially when the target brightness was somewhat higher, i.e. 89%.
Considering the unit costs, the required investments needed for Z-based sequences
were found to be difficult to justify, especially when the target brightness
is somewhat lower, e.g. 87% ISO.
hardwood, Eucalyptus, ECF bleaching, chlorine dioxide, hydrogen peroxide, ozone,
hot acid treatment, hexenuronic acid, brightness reversion
Sectioning Technology of Papers for Observation and Analysis by Using OM, SEM
(1)Sectioning Technology for Optical Microscopy
In order to obtain the information about inner structure of papers being concerned
in production, development and printing of papers, observation and analysis of
paper sections by using OM, SEM and EPMA are very effective means.
In this paper, sectioning techniques for optical microscopy were descrived.
Many sectioning techniques have been developed to obtain sections without serious
artifacts such as the damage of fine structure and breakdown of section during
sectioning and following preparations. In observation by opyical microscope,
the specimens are desirable to be sectioned as this as 1〜10μm in thickness, so
embedding of specimen using plastics such as methacrylate resin, epoxy resin
and so on before sectioning is usually essential to prevent such artifacts.
Cross section which is cut at right angles to the plane of the paper is widely
utilized to observe paper structure in thickness direction but it is only representative
of a minute portion of the specimen. To improve the disadvantage of cross sectioning,
oblique and parallel sectioning were introduced.
The former is carried out by cutting at a small angle to the plane through the
paper, the latter is carried out dividing the specimen to several layers parallel
to the plane of the paper. The information of wider area can be obtained by these
Effect of Blending Ratio of Amphoteric and Anionic Latex on Print Quality of
Yong-Kyu Lee and Kyu-Jae Park
Department of Paper Science & Engineering, College of Forestry Science, Kangwon
University, Korea 200-701
Department of Biomaterials Science, Graduate School of Agriculture and Life Sciences,
The University of Tokyo
Effectiveness of amphoteric latexes was studied to solve the problems of binder
migration and uneven binder distribution in coating layers. The addition of amphoteric
latex was effective in improving rheological properties of coating color in alkaline
region through strong interaction with other coating components. As a result,
coated papers made with amphoteric latex showed better printing qualities, such
as paper gloss and surface smoothness.
Keyword ：Amphoteric latex, Binder migration, Rheological property, Coated paper,Printing
Methodology to Use Flatbed Image Scanner for Formation Analysis of Paper
Toshiharu Enomae and Shigenori Kuga
Graduate School of Agricultural and Life Sciences
The University of Tokyo
Versatility of a desktop flatbed image scanner with a transparency unit as an
image input device for formation analyses is exhibited and discussed. Optical
density of scanner output is defined as the logarithm of the ratio of gray level
in full transmission with no material to that at a given site (pixel) of a sample.
Optical density of the scanner output under satisfied prerequisite conditions
showed an excellent agreement with that of Elrepho type reflectometer and the
pre-calibrated values noted on a standard film though the proportional constant
is reduced from 1 due to aged deterioration of the light source after 1 year,
maintaining linearity. For stacked paper sheets, however, there remains distortion
in the output characteristics, that is, non-linearity even after the calibration.
So, unlike Elrepho type, optical density squared is empirically almost proportional
to the basis weight of paper. In application, formation of handsheets loaded
with calcium carbonate from softwood and hardwood pulps at different retention
times is quantitatively analyzed with the light transmission images obtained
by the scanner. The formation index, the standard deviation of optical density
squared correlated better with the subjective ranking by 6 panelists than that
of optical density or of gray level. Optical density squared divided by the basis
weight shows the highest Kendall's coefficient of correlation. In summary, the
standard deviation of gray level is found to lack in validity as a formation
index except comparison between papers with close gray levels.
Keywords:Formation index, Gray level, Light transmission image, Optical density,