JAPAN TAPPI JOURNALVol. 57, No.9
September 2003 Abstracts
Improving Runnability of Papermaking Machine through Optimization of Wet-end Operation
Koichi Tadaki, Munetoshi Yamaji, Tomoko Asada and Kenji Tsunekawa
FC Process Department, Somar Corporation
@Under world-wide increasing concerns for environmental issues and as an influence
of the trend toward neutrality of papermaking conditions, difficulties
are being added to the paper stock situations year after year.
Increased mix of deinked pulp or coated broke not only deteriorates
the wet-end properties such as fiber retention and drainage and
paper quality such as paper strength, sizing, etc., but also is
responsible for stain troubles in papermaking equipment. Countermeasures
against stain on a papermaking machine are currently one of the
major problems for improving productivity and runnability. In a
papermaking machine system, slime troubles due to microorganisms
and foreign matters such as pitches, anion trashes, etc. are sources
of stain in correlation each to the other. It is believed therefore
that a possibility would be accomplished for improvements of productivity
and runnability by totally addressing these matters together and
by undertaking rapid and adequate action therefor.
@By utilizing the know-how accumulated over years for handling
microorganisms with a slime controlling agent as the center item
and the experience relative to "Realizer" as a wet-end
improver which addresses foreign matters such as pitches and anion
trashes, we are making various proposals for countermeasures against
stain troubles in a papermaking machine addressed totally and analyzed
as a comprehensive matter.
Continuous Analysis of Suspended Materials Gives BetterControl of Pulp and Paper Processes
Spectris Co., Ltd., BTG division
@This paper deals with an optical method for continuous analysis of suspended
materials. It will find its main use in the pulp and paper industry
e.g., for the analysis of pulp, white water and effluents from
a mill. The instrument is based on the transmit measuring method.
One of the unique features of the instrument is the possibility
to simultaneously obtain separate values for the large particle
(fibers) and fine particle content (fillers/fine) of the suspension.
Changes in particle size will therefore have practically no influence
on the total consistency measurement. This is normally a large
problem for optical consistency meters, especially instrument for
the measurement of turbidity.
@The sensor is based on fiber optics and its design guarantees high reliability
with a minimum of maintenance. Clogging of the measuring gap is
practically impossible. Furthermore, the sensor is equipped with
a device for automatic cleaning. This means that the measurement
neither will be affected by variation in light intensity nor by
contamination of the optical surface.
@These analyzers have been installed, in different positions in the pulp and
paper industry, with good experience. After presenting the great
advantages of the measuring method, this paper will then explain
different applications and mill installations.
Anoinic Trash in Papermaking: Mechanism and Approach
Kurita Water Industries Ltd.
@Anionic trashes (AT) are released into the water phase from contaminated reused
water, recycled fibre, or broke, and form deposits at papermaking
process including the wet-end, press section, machine fabrics and
rolls. The AT can cause lowering of productivity by defective products;
sheet breaks; short shutdown duration.
@The lab and field trials showed that troubles from AT can be controlled by
dosing cationic fixing chemicals. This paper examines: the mechanism
of troubles from AT, variable wet-end factors, selection of the
most compatible additive; and monitoring machine performance.
ProRelease Stabilizer- Gentle web run -
Voith IHI Paper Technology Co., Ltd.
@Since its introduction, single-tier dryer section - equipped with DuoStabilizers
and ropeless tail threading technology - has proven extremely successful.
The complete single-tier TopDuoRun is now the preferred dryer section
configuration, especially for high-speed paper machines and lightweight
paper grade. Furthermore, in combination with double-tier dryer
groups - the CombiDuoRun - for heavy grades and at somewhat lower
speeds, it permits high runnability through stable web run and
reliable, fast tail transfer.
@The newly developed and already successfully installed ProRelease Stabilizer
now offers further optimization potential in the particularly sensitive
area of the first dryer groups by reducing the required tension
of the still wet weak paper web during detachment from the dryer.
Introduction of Ronningen DCF Filter
ITOCHU Sanki Corporation
@We started our relationship with RPA Process Technologies which are producing
well known RONNINGEN-PETTER filters in United States in year 1998.
As you may know, RONNINGEN filter is one of the best filter in
the world in liquid filtration from the Wet End to the Coater.
The filter which we are introducing here is built with the most
recent technologies that the filter does not need to be back washed
when operating as well as the traditional concept of the RONNINGEN
Mechanism of Sizing Behavior of ASA
Kunihiko Matsushima, Manabu Takaoka, Hirofumi Zako, Yuki Sakamoto and Yoshio Adati
Chiba Laboratory Research and Development, Seiko PMC Co., Ltd.
@Alkenyl succinic anhydride (ASA) is well known as one of the synthetic sizing
agents widely used in neutral papermaking and its role at higher
pH range sizing has become important because of environmental issues,
the lifting ratio of recycling pulp, anion trash increase in papermaking
system and so on.
@Although many literatures on ASA have been published, we studied the mechanism
of ASA sizing by using both ASA and ASAcid (hydrolyzed ASA) in
order to obtain further comprehension. In this experiment, sizing
treatment was carried out under ideal conditions where the filter
paper was immersed in ASA emulsion or in the toluene solution of
ASA, so as to retain the same quantity of sizing material in filter
paper. The same procedure was adopted in the case of ASAcid. Contrary
to our expectations, the most notable fact from the results obtained
is that the sizing effect of the filter paper treated with ASA
emulsion is superior to that of ASA toluene solution.
@These results suggest that the most essential factor to develop sizing is
morphology of sizing material distribution on fibers. We speculate
that the entirely uniform distribution of sizing material, like
a uniform thin film, is not necessary for sizing development but
the scattered distribution, like dots, is required.
Development of Longlife Suction Box Lip
Ryo Shimizu and Norio Fujita
Nomura Plating Co., LTD.
@A felt suction box is installed in the press section on a paper machine. It
is useful for removing white water and shower water for felt cleaning
by effect of vacuum. Our company developed of sprayed suction box
lip that is a round type at 1997. We started the development of
longlife sprayed suction box lip that is a flat face type for longlife
, lower price and lighter. Suction box lip combined a resin body
and spraying material on stainress steel. Result of fundamental
experiment , we chose special phenolic resin and FRP from resin
and epoxy adhesive from adhesive. We examined WC|NiCr spraying
, Cr2O3 spraying , Al2O3|TiO2 spraying , ZrO2 spraying , Ni|P plating
dispersing SiC, Ni|W plating , Cr plating and sintered Al2O3 by
referring the result of taber abration test. After the wear resistance
examination , we understood the followings by evaluate the lesswear
, damage of felt , scratch on lip surface. Regarding for wear,
WC|NiCr spraying and Al2O3|TiO2 spraying are superior than other
samples. Al2O3|TiO2 spraying is the most suitable about wear resistance
and spraying thickness. On the other hand Cr2O3 spraying is the
most suitable about effect of less felt damage.
The Development of Stainless Steel Weld Overlaying for Continuous Digesters
Daio Maintenance Co., Ltd.
@We have developed an overlay method for continuous digesters that substitutes
the lining of stainless steel plates. We carried out the overlay
(110u) at the NKP Continuous Digester in Daio Paper Co., Ltd. in
March this year.
@The superior points of our overlay method are the high welding
quality achieved by using new automatic welding machines, the short
term of the work and the high safety level for assembly, inspection
and dismantling that employed an automatic scaffolding system.
@Our method of overlay is capable of preventing corrosion of the welded parts
that stainless steel lining plates have and corrosion of the cladding
of continuous digesters.
New Agents for Kraft Process
Research & Development Dept., SAN NOPCO LIMITED
@The Kraft process consists of the cooking process and the bleaching process
mainly. In Kraft process, the weakest point is the low of the yield
of pulp in the cooking process. The kinds of quinone derivatives
or polysulfide derivatives are widely used as cooking assistant
agents to improve it. "Cooking Accelerator" is the agent
to accelerate the function that these agents have and to raise
the yield of pulp furthermore.
@In the bleaching process, chlorine is used as one of the bleaching agents.
But it may cause the occurrence of dioxin, so it is better to decrease
the amount of chlorine consumption from the environmental point
of view. "Oxygen Bleaching Accelerator" can raise the
ratio of delignification yield and decrease the amount of not only
chlorine but also sodium hydroxide and chlorine dioxide.
@Both agents are useful in the Kraft process, and can be expected in the future.
Next Generation Color Control- Its Strategy and Results -
Sales Department, Honeywell K. K.
@Paper manufacturers and end-users have become more critical about shade variation
and product appearance. These requirements span the entire grade
structure from tissue to multilayer board, including the whites
through to deeply dyed grades. While invisible quality variables,
such as basis weight, moisture and caliper may be undetected although
well outside specifications, small differences in shade can be
easily detected by a relatively untrained eye, potentially resulting
in substantial product rejection. The requirement for minimum color
variation in paper products has forced papermakers either to maintain
a group of operators whose time is nearly 100% dedicated to controlling
product color manually, or to implement closed-loop color control.
Over the past twenty years, the popularity of supervisory closed-loop
color control has increased significantly and has produced excellent
@In a push for greater efficiency, the industry has been seeking ways to reduce
color change times and resultant broke losses. Typically, manually
controlled color changes can require up to one hour, depending
on the complexity of the change. Today's trends toward reduced
inventories and faster delivery to paper customers denies papermakers
the luxury of scheduling a well-established progression of shades
and forces shorter production runs of each shade, resulting in
frequent, more difficult shade changes.
@As the new solutions for above requests, the Honeywell new color controls
provide robust models which are both responsive and capable of
maintaining the color coordinates closer to target than ever before.
VERIS Power & Environment Monitoring System Real Time Monitoring & Analyzing System by PC
Nittou Shoukai Ltd.
@Veris Industries has the sensors and systems for building, factory control
and automation: patented current sensor with integral relay, microprocessor
controlled and analog current sensors for variable frequency drives,
power meters, energy management meters, Modbus data acquisition
products, humidity (RH) sensors, temperature sensors, carbon monoxide
(CO) detectors, carbon dioxide sensors for monitoring indoor air
quality, pressure sensors, electropneumatic pressure controllers,
combination sensors for humidity/temperature/carbon dioxide measurement,
power supplies and accessories.VERIS has developed Power and Environment
Monitoring, Energy Saving systems using these sensors. We introduce
VERIS real time Power and Environment Monitoring, Analyzing Systems
Reduction of Chloroform Emission from Hypochlorite-bleaching Process
Kengo Magara, Olov Karlsson* and Shuji Hosoya
Department of Chemical Utilization, Forestry and Forest Products Research Institute
@Chloroform was readily converted to formic acid through the nucleophilic attack
of hydroxyl anion under the certain reaction conditions ( pH > 12,
temp. > 70 ). When guaiacol was reacted with hypochlorite at
such reaction conditions, the generation of chloroform was almost
completely reduced. Successful reduction of the chloroform generation
was also observed in alkaline hypochlorite bleaching of kraft pulps
and DIP without any loss in pulp quality.
@Even when the hypochlorite bleaching was carried out under the open system
(no sealing of the reaction vessel), nearly 90% of the generated
chloroform was converted to formic acid.
Key words: chloroform, alkaline hypochlorite, bleaching, dehalogenation.
Stress Analysis for Gripe Hole of Corrugated Fiberboard Case- Relation between Hole Breadth and Stress Components -
Guest Professor, Research Center of District Corporation, Ehime University
Professor Emeritus, Ehime University
@An elastic analysis for side plates of the corrugated fiberboard case (breadth
L=240`302.5mm, height 207.5mm and length 440mm) with grip holes
(length ¢L0=0.0`62.5mm of parallel line, hole side radius r=12.5mm
of semicircle arc) applied uniform applied stress p in ¢L0 range
was performed by finite element method, and from this analysis,
stress components of their plates were considered.
@Large absolute values of normal stresses Ð and Ð in breadth and height directions
and shear stress Ñ concentrate near upper edges and sides of
holes. Maximum of Ð is at centers of hole upper edges in ¢L0<1.6r
and at centers of plate upper edges in ¢L0>1.6r, and maximum
of Ð is at centers of hole upper edges in ¢L0<1.6r and
at hole sides in ¢L0>1.6r. And Ñ is negative value and maximum
of Ñ is at centers of hole upper edges in ¢L0<1.6r
and at positions r/2 along upper direction from hole sides in ¢L0>1.6r.
Maximum values for Ð and Ð increase and maximum absolute values
for minimum Ð decreases with the ¢L0 increase, and maximum absolute
value for minimum Ð and Ñ decrease initially and increase with
the ¢L0 increase.
Keyword: Computational Mechanics, Structure Analysis, Elastic Bending, Strength of Corrugated Fiberboard, Elastic Stress Analysis, Structure Strength,Numerical Analysis, Stress Concentration