Coating Color suffer the high-shear rate by coating speed and the blade after applied to base paper. The coating color carry the rheological behavior during the coating.
We pay attention to the rheological behavior of coating color. especialy we observed the rheological behavior of the coating color containing water retention aide. We have got some correlation between the runnability and the rheology of coating color from observed data. Also we considered the mechanism that bleeding occur.
We could change the rheology of coating color by SOMAREX and get the knowledge to be able to improve the runnability of coating by changing rheology of coating color.

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The main purpose of this paper is a morphological clarification of areas where picking of coated paper occurred during printing. Six kinds of coated paper model samples were prepared with choosing three latices having different Tg and two drying condition in combination of a clay carbonate starch formulation and a kind of woodfree base paper, and two types of picking tests were carried out.
In single press picking test with a high tack ink, the lower Tg latex gave the higher picking strength in both drying conditions. However, morphological SEM observation of picking areas showed that most of picking occrred in coated layer, all six samples gave no difference, the fractured position in Z-direction was very closed to base paper fibers.
In multi-press picking test with a low tack ink, the medium Tg latex gave the highest picking strength in both drying conditions. It was observed that the fractured position in Z-direction of picked areas became more shallow with lowering latex Tg.
These results could give some useful ideas to develop new latex products having better picking strength.

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Rutile TiO₂ is recognized as the most effective TiO₂ pigment to improve the opacity and/or brightness of paper production because it has the highest refractive index in all of the white pigments. However. rutile TiO₂ has not been widely used in the paper industry in Japan because of the image that rutile TiO₂ is much expensive pigment compared with other white pigments.
In North America, approximately 240, 000 tons/year of TiO₂ (including anatase TiO₂) has been consumed in the paper market, and about 50% of that has been used for coated paper production. This number means that its total TiO₂ consumption is about 12 times of that in Japan (about 60 times usage in coated paper application). The rate of TiO₂ consumption of North America based on the total paper & board production is about 3.5 times of that in Japan (about 30 times usage in coated paper application).
We understand that there are two reasons why total volume of TiO₂ consumption in North America is much bigger than that in Japan. One reason is the difference of several market trends, and the other is the difference of TiO₂ usage in paper industry. In this opportunity, we focus on the second difference and introduce “Effective Usage of Rutile TiO₂ Pigment in Coated Paper” by showing experimental data.

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Wet-end starch is widely used for dry strength and drainage improvement, increase fines/ash retention and sizing agent retention etc. Starch is an excellent wet-end agent that can play multiple roles.
Cationic wet-end starches are widely used and amphoteric starches which introduce cationic groups and anionic groups are also used for wet-end. Amphoteric starches have better drainage and fines/ash retention than cationic starches. But we have not utilized the potential functions of amphoteric starches yet.
Then we made R&D efforts to utilize potential functions of amphoteric starches. We tried to find most suitable quantity of both cationic and anionic groups. Also we tried to find ion balances and uniformity of ionic distribution in molecules.
As a result of our efforts, we have developed an amphoteric starch which best utilizes its functions. Although our starch is corn based, it has the same strength as potato or tapioca based cationic starches.

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Aerobic Biofilm system is easy to maintain the control. AD-System belongs to the system. ADSystem is still possible to endure more change of the loading. Also it is able to treatment of High Density as far as Low Density in response to a purpose. Because this system has not only the Honey-comb, but also the method of special aeration. As a result of over 15 plant are used for wastes of paper and pulp.
In this paper, we report how many data of actual plant are, and AD-System has not only Contact Aeration system's mere capacity but also high potential.

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Recently. refuse management has been spotlighted as a most important subject for every brunch of industry to maintain global environment and help saving energy. And it is a tendency expanded world widely that refuse to be disposed of is recovered in the form of heat.
To such demand, we have successfully developed our fluidized-bed combustion and heat recovery system to be applied to recycled paper waste. Such system can help realize refuse recovery and save energy.
Including characteristics of paper sludge firing and feature of TAKUMA fluidized-bed combustion technology, we will hereby introduce our thermal recycle plant composed of paper sludge incineration system. from which heat is recovered in the form of steam with effect.

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In recent years, the tend of the conversion to the neutral paper making has become active again.
In the process of this paper making, troublesome slime is easily formed due to the increase of bacterial activity and the activation of filamentous bacteria.
“SLACLEAN B-900” is newly developed slimicide, which is very effective to the slime control in neutral/alkaline paper making. In this paper, laboratory and field evaluation result on “SLACLEAN B-900” is stated.

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Minolta has developed a new spectrophotometer CM-3630 for pulp and paper having several unique features. Specially its new technology for the adjustment of the relative UV content in the illumination, called NUVC (Numerical UV control), enables the instantaneous adjustment with no moving part, while a traditional Gaertner-Griesser method, in which a UV eliminating filter is mechanically inserted to the optimal position in the flux for the desired relative UV content, requires a time-consuming procedure. Beside this advantage, NUVC enables the UV adjustment not only for a single index such as ISO brightness or CIE Whiteness but also for both CIE Whiteness and Tint and even for Total Spectral Radiance Factor from which all colorimetric indices are derived.

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In previous paper, the development of EPMA color mapping technique in application to pulp and paper specimen was described. In this paper, several examples of color mapping applied to pulp and paper specimens were demonstrated.
Distribution of fillers, pigments, binder (latex and casein), silicone, phenolic resin, lignin and xylan in the cross sections were exhibited. Average profiles of the elements along thethickness direction in papers were shown corresponding to the color maps.
The element tagging techniques were utilized to monitor organic substances which needed to tag with some easily detectable metal iron. It was found that Os tagged latex, casein, phenolic resin and lignin. It was also confirmed that lignin was tagged with either Br or Hg and xylan with Fe.
In the usual analysis by EPMA with STE (Stearate) as X-ray dispersive crystal, it was very difficult to analyze nitrogen in such specimen as paper because the concentration of carbon is extremely higher than that of nitrogen. We tried to use a new Layered Dispersive Element (LDE) instead of STE for the analysis of nitrogen (casein) in coated paper and found that the measurement of casein distribution in cross section of coated paper was possible with this procedure.
STEM-EDS (Scanning Transmission Electron Microscope-Energy Dispersive X-ray Spectrometer) proved very useful to measure the distribution of elements more precisely at higher magnification by using thin cross section of specimen.

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Wilhelmy technique was used to measure the single fiber advancing contact angle of AKD and ASA sized pulp fibers. When sizing performance was fully developed, the advancing contact angle of AKD sized pulp fiber was 85°, while the ASA sized pulp fiber was 95°. Waterdrop absorption measurement also indicated that ASA was a more efficient sizing agent than AKD. The single fiber advancing contact angle was linearly proportional to the AKD and ASA dosage until sizing performance was fully developed.
Lindstrom and co-workers have studied the esterification kinetic constant of AKD, while Marton has investigated the hydrolysis kinetic constant of AKD. We studied the esterification and hydrolysis kinetic constant of ASA. It was found that the esterification kinetic constant of ASA was three times that of AKD (pH=6.0). Similarly the hydrolysis kinetic constant of ASA was 40 times that of AKD (pH=8.0). Proper appreciation of the kinetic aspects of sizing should be helpful to optimize the sizing performance of ASA and AKD.

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We have studied the mechanism of enzymatic deinking because there is few papers concerning it. In the previous paper three important points were reported, namely, mechanical forces were necessary in enzymatic deinking, the main function of enzymes was to convert Hairy toner to Clean toner, and higher charge of enzymes gave a lower efficiency in ink separation at a flotation.
A new test method was developed for the easy evaluation of the convertion rate from Hairy toner to Clean toner because this convertion could be a key of the mechanism in enzymatic deinking. By this method several enzymatic conditions and six enzymes were evaluated.
The enzyme with higher Avicel activity could convert more effectively at a certain level of CMC activity. Therefore Avicel activity would be a key factor to remove fibers from Hairy toner along with mechanical force and CMC activity. And the enzyme addition could decrease mechanical force.
Comparing the results by both the test and usual deinking experiment, the close correlation between them could be observed. We can confirm that Avicel activity is important factor for the conversion.

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It is well known that paper restraint in a drying process affects the dimensional stability of dried paper. Hygroexpansivity and curl properties of the dried paper give reversible and irreversible dimensional changes by humidity cycle. A magnitude of the dimensional change depends on restraint force in the drying process. Paper shrinkage during drying is closely related to dimensional properties as expansion, contraction and curl. Some restraint drying methods are used for an actual drying process, like dryer fabric restraint on a steam drum, vacuum restraint and tension restraint. In this paper, a relation between the restraint drying methods, shrinkage and dimensional properties was investigated by static experiments of paper drying under restraint. Restraint force of 2 kPa with a dryer fabric repressed the shrinkage below 0.5%, and tension restraint force of 80 N/m made CD shrinkage increase over 4%. Curl tendency depended on which side is heated. Felt side drying indicated a curl toward wire side and wire side drying gave the opposite tendency. The larger restraint force and lower temperature dryingresulted in reduction of the total curl and irreversible curl.

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