This paper reviewed on the recent bleaching technology in BKP making by paying attention to the recent inovation in bleaching processes. They emphasize enviroment preservattion as well as a more rational use of energy.
It is well known that a reduction of the chlorine applied in the first stage contributes to a decrease in the pollution of the effluent.
As the most attractive processes to accomplish these purposes, this paper reviewed on 1) Modified Kraft cooking, 2) Effective washing, 3) Oxygen bleaching including its pretreatment, 4) Condions in chlorination stage, 5) Oxidative extraction, 6) Short sequences, and proposed my comment on these ideas.

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Behaviour of water removal through clothing of a paper machine is dependent on wetting, penetration and draining, which occur dynamically in a very short time.
Dynamic wettability of paper-making wire can be observed from contact angles of a water drop in every 10 milli-seconds after reaching a fabric surface. Physical characteristics of wire filaments influence the dynamic wettability in dry states. The contact angles of a plastic multi-layer and bronze fabric decrease rapidly in a wet states.
The fabric of the small number has a higher drainage volume. The magnitude of the drainage volume is in the order of triple layer, double layer and single layer. Bronze wire, which is more wettable, shows larger drainge volume compared with plastic one. Higher water retention of a fabric, larger pore sizes and higher wettability of fabrics induce tendencies of better water removals.
The surface structure of paper making wire, dewatering time and water removal by couching through the network of paper making wires are effective to the wire mark, respectively. Uneveness of surface of a handsheet prepared by the above fabric can be observed by a stereo scanning electron microscope. It shows such uneveness is approximately of the same pitch as the knuckle and the void of the fabric. Also, uneveness of the wire side of the wet web in a case of a short dewatering time is greater than that of in a extended time. Water removal by couching enhances the degree of uneveness.

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This paper descripes a current instrumentation technology in pulp and paper industry especially this month in sensors.

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The surface characteristics of felt which change under compression determine the aggregate structure of paper fibers, the surface condition of paper, and the light reflections from paper. Few studies, however, have been made about surface properties of felt. In this paper, we report the results of the study of the influence of compression on the surface condition of the felt. The investigation has been carried out using an apparatus which we have developed. We propose a new method of analysis of the contact surface of felt. Five different sample felts are made from four different denier nylon fibers and one modified nylon fiber.
The analysis were carried out for contact images which are characterized by such variable as maximum length, contour length, shape factors, nominal diameter, area, numbers, and smoothness of contact spots.
For the four sample felts made from regular nylons, the shape of fibers grew flat and became rugged as press cycles proceeded ; the line of contact of a fiber with a flat plane became shorter and fragmented. For modified nylon, though the shape of fibers also grew flat and rugged, the contact lines with a plane were not fragmented because of its elasticity.
From the distribution of angles between the directions of surface felt fibers and wefts of felt, we found that the fibers don't have randomly oriented structures and tend to stay away from the warp and the weft direction.
By using the Morishita's Index I_δ and Clark Evans Index R, we also conclude the distribution of contact spots to lie regular distribution. Furthermore concurrence probabilities and power spectrum show that contact spots occurred periodically.
From the above results, it is clear that the apparatus we have developed is capable of measuring the contact behavior and our method of analysis for the contact features of felt is variable.

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The washing of solvolysis pulp is certificated by extraction method of cooking solvent from pulp varying temperature, solvent concentaration in washing liquor and amount of the washing liquor. Washing sequences are considered countercurrent process both in the batch digester and in the multiple diffuser washers.
Hot water can extract the cooking solvent but can not extract the degraded lignin from cooked chips. Fresh cooking solvent have to use to extract lignin and the cooking process must be converted to Displacement Heating system before contact with washing water.
Obtaining the correlation of D.F.-D.R., the material balance around the cooking and washing process is constructed.

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