1. Entering 1990 s, world's pulp and pulp and paper market tightened with prices getting firm everywhere in the world, although there were some differences in degree of firmness depending upon areas. From mid-1990 s, however, the market began to soften due to stagnant economic climate and adjustment of speculative demand. As a result, paper manufacturers were forced to curtail production to balance inventory. The sluggish market bottomed out in late 1996, but the tempo of recovery has been rather slow.
2. In the meantime, there have been some trends worthy of attention. Among them are changes in supply sources. During the fifteen-year period from 1980 through 1995, production share of North America dropped by 5.2 percent from 41.1 percent to 35.9 percent, and that of Europe was up only 0.8 percent point from 25.6 percent to 26.4 percent, whereas in Asia, it increased by as much as 10.4 percent from 17.5 percent to 27.9 percent. That Japan's production share remained almost unchanged, or from 10.6 percent in 1980 to 10.7 percent in 1995 to be exact, means other Asian nations, Korea, Indonesia and Thailand in particular, expanded a sizeable volume of production capacity during the period.
Along with the fast-growing economy in East Asian countries, the industry in Korea, Indonesia and Thailand have been accelerating capacity expansion and it is almost certain that Asia become one of the three largest paper-producing regions in the world comparable to North America and Europe in the year of 2000.
The other noticeable trend is concentration of paper manufacturers. A number of mergers among the big paper companies have taken place over the years to be internationally competitive and to be better prepared for the ever-stringent regulation for environmental protection. Consequently, ranking positions of paper companies change every year. In Europe, for example, mergers among the paper manufacturers are in progress to have a competitive edge in the EU market. Stora, SCA and MoDo in Sweden and UPM-Kymmene, Enso Gutzeit and Metsa-Serla became now oligopolistic through mergers and restructuring. In the U.S., International Paper bought out Federal Paperboard and Kimberly-Clark merged with Scott Paper. Likewise, two big paper companies were created in Japan through mergers ; Nippon Paper Industries (merger between Jujo Paper and Sanyo-Kokusaku Pulp) and Oji Paper (mergers between New Oji Paper and Honshu Paper).

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The Japan Paper Association (JPA) established the guideline for dioxin measures on December 20th in 1990 to prevent dioxin pollution of effluent discharged from bleached kraft and/or dissolving sulfite pulp mills. All mills cleared the selfimposed standard of less than AOX 1.5 kg per one ton of bleached pulp before the end of 1993. The standard was completely attained by the deadline. The JPA measured dioxins concentration of effluent from the bleached pulp and paper mills to examine effects of AOX reduction in March 1996 and it was confirmed that dioxins in effluent of these mills was decreased to 86% in average concentration and to 96% in weight as compared with those in the year of 1991. Also it was observed that no relationship existed between dioxins and AOX under such extremely low concentration of dioxins.

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Causticizing and lime kiln process are important parts of recovery process for recovering spent-cooking liquor and converting it into active sodium hydroxide. This is one of vital parts which have contributed the development of kraft pulping process.
Basic theories were established and the changes of equipments are not fast these days. Direct causticizing was well researched, but no commercial systems are in operation. Fluidized-bed calciner was introduced, but a few systems are in operation now. In Japan, Wet (long) or dry (short) kilns have been installed these days. The principles and typical equipments as well as new ones including various types of white-liquor filters are presented in this paper.

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Wet-end additives can give new functionalities to papersheet efficiently in the papermaking process. The additives have various forms ; molecular-order compounds, emulsions, their coagulants and others. The appearance of functionalities on papersheet is also various, depending on the way to coagulate the wet-end additives and/or that to adsorb the coagulated compounds on pulp fiber surfaces in wet-end. The research fields of wet-end additives have remarkably advanced, as the new methods for determining wet-end additives in papersheet have been established recently, such as pyrolysis-gas chromatography and SEM-EDXA.
In the case of reactive sizes such as AKD and ASA, the chemical structures to react with water is necessary for efficient sizing of papersheet. Surface charges of the emulsion particles of the reactive sizes turn from cationic to amphoteric in wet-end, and thus efficient retention of the reactive sizes can be achieved. Furthermore, lower coagulation behavior of size components on pulp fiber surfaces is maintained by the water-reactivity of reactive sizes in press and drying processes, and sizing features appears efficiently on papersheet thereby.
Sizing and retention mechanisms of rosin soap, rosin emulsion and rosin-ester sizes also have been studied using new analytical techniques, from the aspects of structures of rosin molecules in papersheet and roles of alum in wet-end and in papersheet.

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1) New profile wrapper equipped with the heater roll press made of soft rubber facilitated the wrapping at uneven base of a cupboard door. The best bonding property for the wrapping with fancy paper with two component urethane adhesive was obtained with the following condition : dry zone of adhesive; 35°C, temperature of the roll press in the front; 70°C, temperature of the roll press in the back; 70°C, pressing speed; 6 m/min., glue spread; 100 g/m², roll press pressure; 0.60 kgf/cm².
2) Wrapping at uneven base with developed fancy paper had a very good bonding ability. And nothing abnormal in dry adhesion test and accelerated weathering test was found on the surface of the product.

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Improvement of coated paper stiffness was evaluated by determining Young's modulus of the coating layer. Then effects of color formulations and double coating were examined.
Stiffness is one of the most important properties of paper in printing processes. Troubles such as jamming in a copying machine often stern from poor paper stiffness. In the case of coated paper, Young's modulus of the coating layer considerably affects the stiffness of the whole coated paper because the more external layer, the higher strain in a bending mode though other mechanical properties are generally dominated by the basepaper layer.
Theoretically, the method of calculating Young's modulus of the coating layer of a one-sided coated sheet was discussed in terms of materials mechanics. Besides, the accurate interpretation of Clark stiffness enabled to calculate Young's modulus of a coating layer from Clark stiffness.
Empirically, calculated Young's modulus from Clark stiffness and pure bending stiffness showed that an impervious film such as PET (polyethylenetelephthalate) must be used as a substrate in place of paper for a true Young's modulus of a coating layer because the basepaper, when wetted with only water, swelled and the thickness was increased, the basis weight became higher due to hysteresis, and a coating/basepaper interface became rougher than the basepaper surface. They resulted in an incorrect Young's modulus when values of unwetted basepaper were used for calculation.
Formulation of starch improved Young's modulus of starch/SB-latex blend film, suggesting that Young's modulus of a coating layer of the same binder composition would tend to become higher with the starch content. The coating layer containing the PP (Plastic Pigment) of the shorter particle diameter had higher Young's modulus, but was at most equivalent to that of calcium carbonate. However, the lower density of PP was expected to be advantageous to resistance to a bend by the weight of its own. In double coating, arrangement of a stiffer coating layer containing more starch on the top side was found to improve the coated paper stiffness.

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A computation Method for the elastic analysis of KL (kraft liner) and SCM (semichemical corrugating medium) of SCF (single wall corrugated fiberboard) under the shearing force in the machine direction of the KL surfaces is studied. And this method is applied to the stress analysis for SCF.
Then following main results are obtained. On both sides of joints for KL and SCM, absolute values of lateral (direction of the shearing force) and vertical loads and fixed moments at joints are equal respectively. And directions of both lateral loads are equal and the fixed moment on the side of the shearing direction becomes opposite on the opposite side. Extremal values of stresses for SCM are at joints on surfaces, and maximum values of absolute stresses are on inner surfaces. Then for plus or minus stresses on the side of the shearing direction, stresses on the opposite side are inversely minus or plus. Absolute stress values for SCM decrease with increases of the thickness and the wavelength and increase with the increase of the wave height.

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