The dioxin issue in Japanese paper industry has emerged October 1990 and the governmental organizations (i. e., Environment Agency and MITI) have taken immediate actions to investigate the current status of organochlorine compounds in paper mill effluents. The Japan Paper Association has created the Special Committee for measures against Dioxin Issue and announced on December 1990 the guideline for reducing AOX (Adsorbable organohalogen compounds) to 1.5 kg/ ton by the end of the year 1993.
The current dioxin issue is analyzed from a wider perspective of global environmental problems with particular emphasis on the government's action and the technological countermeasures by the Association.
The present status of dioxin research from chemical, toxicological and pharmacokinetical aspects are summarized. The recent advances of kraft pulping and oxygen bleaching technologies as countermeasures for reducing AOX in paper mill effluents are described.
The potential impacts of the current dioxin issue on recycled paper manufacture, environmental protection movements and consumer's movements are also described.

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Stress analysis of the bending deformation is performed for SCP medium (semichemical corrugating medium) of corrugated fiberboard under a constant moment. The constant bending moment is applied to corrugation along the bending axis coinciding with the machine direction.
In consideration for the behaviors to the moment of inertia of area, it is shown that the excellent bending strength is made from the corrugation shape.
The relations are analysed among the shape (thickness, wave length and height), the strength and strength efficiency E_f (strength per mass of the corrugated sheet). On the basis of these relations, it is concluded that the condition of the reasonable shape of SCP medium for the strength and for the values of E_f is to take the large value about the wave height of corrugation.

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With a view to evaluate the mass distribution in a paper sheet on real-time basis, the images of flocs were taken using two light projecting systems : TV monitor and strobe light. These images were fed into an image processing unit and the mass density was expressed as the level of grey scales. The mass distribution obtained by the image processing method showed a good correlation with that obtained by the conventional soft x-ray method within the limit of the present experimental conditions.
These findings suggest the possibility of obtaining the mass distribution more speedily and more easily by analyzing the transmitted light through the sheet.
The sequence of addition of additives to the stock highly affects the frequency of formation of flocs.
It is also suggested that the dual polymer system in this investigation helps to increase homogeneous mass distribution in a sheet as well as the increase in retention of fillers. The z-direction distribution of fillers in a sheet tends to be homogeneous in a dual system, however, the mechanism remains to be solved.

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