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(Research Institute of Oji Paper Co., Ltd., Tokyo) New pulping methods of hard wood have been studied eagerly in Japan, because soft wood has become scarce by overfelling.Characteristics of hard wood pulp depend on the properties of the fiber, that is, short and slender shape and rich content of pentosan.Blending the hard wood pulp in various papers, the printability of the papers are improved and such properties as formation, smoothness, opacities rise.(1) Bleached kraft pulp of hard wood are used in fine paper, and owing to blending, the printability of the paper is improved considerably. But viscous printing ink sometimes takes away the vessels from paper surface during offset printing.(2) Semichemical pulp and chemi-ground pulp are used in news print and photogravure paper.Properties of chemi-ground pulp are similar to ground wood of soft wood, but lower opacity.(3) Ground wood of hard wood has high opacity, and is used in news print.

In this paper we reported on the problem of petroleum resin emulsion sizing which was chiefly treated for the application in beater sizing. As the results of application in beater sizing it is obtained that the amount is 0.252% on pulp weight, as compared with rosin size showed slowly sizing effect, and increased paper stiffness.The required amount of aluminum sulphate are sufficient 1%.

Effects of fiber length on mechanical strength, chemical strength, chemical properties and hygroscopic characteristics were investigated. Mechanical strength especially was measured inthe normal condition (R.H. 65%) and dry condition. The dry condition was obtained by the folloNN ing ways ; the paper sample was dried at 105°C for 3hr, and was impregnated with water-free oil.1) Tensile strength for fraction pulp decreases with increasing average fiber length, and in case of the same average fiber length, the tensile strength for whole pulp is higher than that for fraction pulp.2) Folding endurance and tearing resistance for fraction pulp increase with increasing average fiber length. There is a straight-line relationship between the average fiber length and tearing resistance of paper.3) Pentosan content of pulp decreases with increasing average fiber length, but DP of pulp increases.4) Moisture regain, dimensional change, water of monolayer absorption and internal surface area of paper decrease with increasing average fiber length, but crystallinites of paper fiber increase.

Blending of staple fiber of viscose rayon and straw pulp was dispersed in water and handmade paper for calligraphy was made. The Indian ink absorptive quality of straw paper is improved by the blending of viscose rayon fiber. The adhesive capability of straw pulp to rayon fiber in the paper making is so much that it works effective so far as about 50% component of rayon fiber in the stuff without any other adhesive agent. Bearing of fineness of the rayon fiber on the paper making properties was discussed.

Synthetic Pulp, are fibrillatable and water dispersible and of a shape and size distribution similar to conventional wood pulp.Synthetic pulp can be used with natural cellulose pulps on conventional paper machine without special equipment requirements or handling problems.The synthetic pulp paper is characterized by heat sealability, dimensional stability, high brightness and opacifying ability.On the contrary, the more the ratio of synthetic-blends increases, the more paper strength decreases.The hat body paper and the converting quality test was accomplished by using synthetic pulp made from blends of polypropylene and polyethylene (Gosei-pulp produced by the Nippon Goseikagaku Co.) The most remarkable features of the hat for the summer are flexible and tough and have given excellent elastic recovery.The physical properties of these one ply paper and drycreped paper are shown in Table 1-4 and Fig. 2-4.Synthetic pulp for the summer hat will be used approximately 100 tons from October of 1972 till 1973 in Japan.

Synthetic pulp for papermaking may be manufactured by beating the fibers of polyvinylalcohol (the PVA) mixed-spun with starch or the fibers of polyolefins mixed-spun with PVA polymer. Various papermaking tests were carried out with this synthetic pulp to obtain the following results. 1) The more the PVA or starch content in the fiber, the more easily can it be fibrillated and the better are the dispersibility and other properties for papermaking. 2) The PVA fibers, if pre-mixed with starch on spinning, can be made into paper by beating without mixing any other material such as wood pulp, wether the fibers have been subjected to only heat treatment or to both the heat treatment and formalization in their manufacturing process. The fibers heat-treated only may also be used as a bonding material. 3) If the beaten PVA fibers, heat-treated, are formalized to eliminate interfiber bonds, then the strength of the paper made will depend on only the tangle of the fibers and it can be estimated at a quarter of the whole strength of the same paper but not formalized. 4) Polyolefins can be converted into another synthetic pulp by means of flash-or mixed-spinning. This pulp can be made into synthetic paper, being mixed with wood pulp.5) Hydrophilic synthetic pulp may be obtained by beating the thicker fibers that are produced by mixed-spinning the three polymers : polypropylene, polyethylene and polyvinylalcohol. Such synthetic pulp can be made into paper either by itself or by mixing wood pulp in any proportion, which will be, if calendered, not inferior at all in strength to the conventional paper of wood pulp

The effects of unplasticized and plasticized synthetic resin coating on the bursting strength (BS) of papers were studied.The commercial kraft papers were coated with two kinds of commercial vinyl latices (PVC latex and PVC-polyvinyldene chloride latex) of various cone. under various drying conditions.When the coated papers are dried below the film-forming temp. Tf of latices (M. Fujii and Y. Otsuka ; Chem. of High Polym., Japan, 12, 93 (1955) and see Report I), the BS of the papers are smaller than the BS of untreated paper, but the curing effect is great. Too much plasticizer content decreases the BS, in spite of good film are formed.The authors have discussed the experimental results from the Tf of the latices and the strength of resin mass, and have succeeded to show the important nature of Tf of latices for the paper coating (see Report I, II, III and IV).

Sizing is achieved by adding Petroleum Resin first to the pulp in beater and then, when it is well mixed with about 20% of precipitated calcium carbonate in the pulp, aluminium sulphate (“ alum ”). It will be observed the perfect of sizing on the tissue paper, or the test result of K.B.B Sizing test by sugar solution is indicated about 50 seconds, Stockigt method was 5 seconds. (40g/m2) Influences affected by the fluorescent whitening agent to the sizing effect were investigated.

Recently the fibers other than wood fibers have come to utilize as the paper making raw material worldly.The non-wood fiber resources for pulping is considered as useable economically for industrialization.In this report, several vegetable fibers are studied except the wood fibers as the natural resourees for pepar making pulp.

Poly (vinyl acetate) emulsion was incorporated to paper by (1) beater addition and (2) saturation. The addition of (poly vinyl acetate) solution to paper was also accomplished by (3) saturation. Measurements of percentage resin retentions of the modified sheets (gms. of resin retained per 100 gms pulp) obtained from the pulps of various degrees of beating by three different procedures (1, 2, 3) were made efficiently. The surface structures of the untreated as well as various PVAc resin treated sheets were examined by optical and electron microscopes. The effect of beating on the fibres and the sheets was studied. The differences in the surface structures of the modified sheets owing to the difference in the method of resin treatment and the quantity of resin retained to the sheets and the mechanism of polymer deposition were discussed. In the case of both emulsion and solution saturation it was found that the percentage of resin retention was decreased with the increase in the degree of beating but increased with the increase in the solid, content in the emulsion and solution respectively. On the other hand the beater added sheets showed an increase in the percentage of retention both with the increase in the degree of beating as well as the resin-pulp ratio The percentage of resin pick up (gms. of resin picked up per 100 gms of resin used) by the beater added sheets was found to increase remarkably with the increase in the degree of beating and showed a considerable increment with the increase in the resin-pulp ratio particularly those from the beaten pulp. The measurement of percentage of pick up gave some information to the study of the mechanism of polymer deposition on fibre by beater addition procedure.

In order to gain a quantitatively better understanding of the surface characteristics of paper and coated paper, the fundamental significance and the evaluation of surface profilograms obtained from a stylus method have been studied on the basis of morphological observation. It has been observed in comparison with scanning electron micrograph of the corresponding specimen surface that the profilogram shows good reproducibility of relatively large void originated from fiber-fiber pockets. Furthermore, it is important to note that the stylus cannot register the fine structure on the fiber and coated layer surfaces because of its scratching.Since the surface void distribution measured on the cross direction is nearly equal to that measured on machine direction, it is possible to calculate the surface void volume from the profilogram. Thereby, it is convenient to express the profilogram as a cumulative void distribution curve, an Abbott's bearing-area curve, for understanding of actual circumstances of the surface void.In a serial light-weight coating experiment, the leveling effect of the coatings has been investigated by a stylus method, and the relationship between the surface void volume and the coating weight is successfully discussed with taking account of internal void connected with the surface void.

The present investigation has aimed at establishing the paper making technique using a synthetic fiber, which has many superior characteristics. Vinylon fiber has been developed in Japan. This fiber has similar properties to cellulose fiber, since it has many OH groups in its molecule. Present work was carried out in regard to the relation between the characteristics of constructed fiber and physical properties of the paper. When a mixture of the vinylon fiber and pulp was beated and manufactured to paper, the short-cut vinylon fiber showed better properties than the long one, and the tow fiber better than the culed one. The increasing in the blending ratio of the vinylon fiber to pulp had a tendency to make strong the tearing strength and to weaken the tensile strength. In an effort to determine the effect of fineness of fiber on the physical properties of the paper, various polyvinyl alcohol fibers (PVA fibers) were used as binding fibers. It is observed that the more is the fineness of either of the basic or binding fiber used, the greater is the strength of the paper obtained. The strength of the paper is more affected by the fineness of binding fiber than basic fiber. Authors advocated the paper making process in which the web is previously formed using non-formalized vinylon fibers and the web is formalized subsequently Experiments showed that the paper made by this procedure had a larger wet strength. And other various physical properties were discussed in relation to the degree of formalization. It is found that vinylon fiber which is spinned with starch is divided into fibril by beating and is capable of making paper as well as natural cellulose fiber. This fiber is named “readily fibrillable vinylon”.

Insulation paper is primarily used in electric motors as slot cells, coil separators and phase insulation in integral horsepower equipment. The slot cell being defined as the basic ground insulation that provides mechanical and dielectric barriers from the magnet wire to the stator core. This definition emphasizes that the insulation paper forming the slot cell is mainly ground insulation.

This electron microscopic study was made with regard to the kaolin handcoated papers with various binders. The binders used are casein, modified starch and Dow Latex 512R. The contents of experiments are as follows : (1) In addition to one stage replica method described in our last paper, the two stage replica method modified was used. The later method was found to be useful especially for the case of using synthetic latex as binders. (2) By applying the above two methods, the surface fine structure of all specimens was successfully studied. Further, the effect of supercalendering was studied and it was found that effect were different with the binders used. (3) The clay handcoated papers with various binder levels were prepared keeping a solid content. Their surface was found to be covered with binder films in proportion to the binder levels. And also the etched surface of them by ion impact was observed. (4) In addition, the clay coated films were prepared on a glass sheet and their two sides were observed. The surface of the glass side was discussed in connection with cast coating technique.

A series of electron microscopic studies was carried out to make clear the surface fine structure of clay coated papers. The present work forms part of those studies and deals mainly with coating clays. The clays used are kaolin, sericite, roseki-clay and hydrated halloysite and were coated on a stock paper by using casein as a binder. The results obtained are as follows : (1) The one stage replica method, which was carried out by evaporating carbon an leaf, was found to be the most suitable technique for the purpose of this case. (2) The surface of clay handcoated papers was observed to consist of the clay layers parallel to paper surfaces. And it was found that their fine structure depends largely upon the shape and size of clay particles. (3) By comparing the surface of non-supercalendered coated papers with those of supercalendered coated papers, the effect of supercalendering was found to vary corresponding to the clays used.

The following results were obtained in consequence of the fundamental experiments on the manufacture of Nylon paper by using the traditional method of nagashi-zuki in order to make Japanese paper.1. Neri (obtained from the root of tororo-aoi) were preferred as the dispersing agent. N-methoxymethylated 6 nylon (type 8 nylon) emulsion were used as the bonding agent of nylon sheets.2. We employed nylon staple fiber of 15den. cut in various length (e.g.1, 3, 4, 5, 7 and 10mm) in making sheet of paper at 100kg/cm2 heat press using type 8 nylon as a bonding agent.Tensile strength gives maximum value at the fiber length of 4-5 mm, but decreases with increasing fiber length.3. “ Kamiko ” (Japanese paper clothes) in the Muromachi period and the Yedo period (1339-1867) is regarded as non-woven fabric using kazo of natural cellulosic fiber and neri as a dispersing agent, coating with konnyaku (a paste made from the starch of devil's tongue) and shibu the astringent juice of unripe persimmons as a bonding agent.These paper products were of two sorts : one was plain in color for the winter coats of popular use ; the other being made elegant looking by dyeing fancy figures upon like calico for the use of daimyos and the well.to-do. The distribution of kazo fiber length is the normal frequency distribution at the height of 10 mm. Tensile strength gives maximum value, blended with 20-30 mm cut to 7080%10mm cut fiber length.4. The weight of type 8 nylon remained in the sheet was measured, but were preferred 10-20%. The surface temperature of heated roller press was suitable 180-185°C at 50kg/ 30cm.

Pulps made from Kozo (paper mulbery, Broussonetia kajinoki Sieb 29), one of the most essential fiber materials of the Japanese papers, were coated or impregnated with synthetic Latex resin emulsions and their mechanical and physical strength characteristics were tested.Good results in the strength test were obtained when coating was done with acryl amide water soluble resin.With regard to applying the synthetic resin in general, it was found that the results brought about by the internal addition into the fiber suspension were better than those resulted from outside addition, i. e. after the sheet is formed (and dryed to a certain degree).It was also revealed that the so-called nagashi-zuki (worker's own sheet forming motion on the mould along with his dipping out suspended fibers from the stock chest), which implies the most significant characteristic of the hand-made Japanese paper making techniques, becomes considerably difficult when the amount of the added resin exceeeds its maximum limit.

The flow properties of the coating colors containing acrylamide-modified polyvinyl alcohol (COBP) were studied at shear rate up to 3.5 × 105 sec-1 in a high pressure capillary viscometer and a printability tester.PVA was modified to achive a degree of carbamoylethyl substitution in the range 0.6-5.3 mol% and a degree of carboxyethyl substitution in the range 0.6-12.5 mol%. Reaction of acrylamide with hydroxyl groups of PVA was illustrated in the following equation. PVA-OH+CH2=CHCONH2 It was found that the flow properties of COBP coating colors were better than those containing the unmodified PVA, and the favorable properties of COBP were obtained by altering only the degree of carboxyethyl substitution.Also, it was found that the effect of carbamoylethyl substitution was to decrease the viscosity of the coating colors at the very low shear rate of a Brookfield instrument. In addition, the properties of the coated papers were determined.

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The tendency of pulp resin particles to coagulate and then adhere to wire and fibrous surfaces causes what is generally known in the paper industry as “pitch trouble”. This is almost specific to the production of pulp and paper from woods by sulfite process or kraft process, but it can occur to an equal degree in mills handling waste papers. An attempt was made to obtain some fundamental knowledge on the reduction of pitch-causing potential through chemical analysis of the pitch samples obtained in boardmaking mills. The result has indicated that the major components of deposited pitch are lignin substances and neutral resin compounds existing in pulp, and resin ous polymers originally located in the waste papers. This would imply that the pitch-causing potential of these waste papers would be no less than that of pulp material. A few methods which would contribute to the control of pitch problems encountered in board manufacture have been suggested on the basis of numerical figures obtained from pitch analysis.

A new type of insulation has been developed by the Bell System engineers and put into use for exchange area cables. This insulation consists of a continuous pulp or paper sleeve formed directly on the conductor by a modified paper making process. The manufacture and use of pulp-insulated wire cables involves unique changes in manufacturing equipment, materials and methods, in cable design and installation practises. The development has covered a period of some ten years and is the result of combined manufacturing, engineering, and field studies.

There exist two kinds of methods for pulp refining ; that is, the low consistency refining and the high consistency refining. The low consistency refining method (LCR) has been conventionally used, but it has proved to damages and shortens the fibres. On the other hand, the high consistency refining (HCR) loosens the fibre structure and makes it flexible with a minimum of fibre damages, despite of the fact that HCR method requires more power in order to produce papers of maximum strength. This paper presents comparisons between these two methods from the following points of view. (1) Comparison of paper formation measured by the Bata-Radiograph method. (2) Comparison of the microstructure of the fibre by the scanning electron micrographs. (3) Comparison of dry paper physical properties. Our experiments have demonstrated the following. (1) The scanning electron micrographs of paper produced by each different rifining method show different shapes of fibre : In LCR method the outer layer of the fibre is removed in the lumpy shape, while external fibrillation of the HCR fibre is seen extensively and the fibre surface becomes fuzzy. (2) The paper formation by LCR method becomes poorer with high beaten pulp and the paper formation by HCR method grows better with high beaten pulp on the contrary to our expectation. (3) Uniform refining is a most necessary to obtain paper of good formation.

On the process of chemigroundwood pulp manufacturing by neutral sodium sulfite, small part of black liquor, after cooking, has been usually recovered and great part has followed with cooked chips which are passed to fiberizing, screening in low consistency and washing processes. The majority of waste black liquor has been difficult to be recovered for its low concentration.Nowaday, many methods have been used…separating out black liquor from cooked chips by squeezing equipment, screw press etc. before fiberization…pressing out black liquor from fiberized chips by screw press and washing out dilute black liquor by vacuum drum washer to separate it from fiber…and so on.These methods above have many troubles which are low yield recovery of black lipuor if kept in high concentration, on the other hand low concentration with expensive recovery if kept in good washing.Recently the method of counter current washing chips through washing tower has been developed and gave high attention. Black liquor is recovered as relatively high yield and concentration by this method.At Futatsuka Mill, Tonami Paper Co., Ltd., chips are washed in global digester which is used for cooking, in counter currency to chips with two grades of black liquor in middle and low concentration and hot water on three stages by diffusion under pressure.We have succeeded to get black liquor in high concentration to be able to be mixed to kraft recovery process from chemigroundwood process and good washing.

Polychlal fiber are produced by the wet spinning method of polymer-blend solution which is derived from polyvinyl alcohol and vinylchloride emulsion.In hot water, these behave to melt easily and not do. The former was mixed as an adhesive and the later was used as a subject of the paper. On the other hand these was mixed with the PVA adhesive fiber or wood pulp being utilized as the adhesive or the subject of the paper from usual.The obtained paper were investigated for these physical properties principally, and following results were given.1) The former displayed the function enough to adhere fibers, and that was possible to make the paper of polychlal fiber only. 2) On the paper strength, polychlal fiber was inferior to the PVA adhesive fiber, when it behaved as a fiber-fiber binder.3) The former behaved to strengthen the paper to mix and make the paper with the wood pulp.4) The paper made with the polychlal fiber alone had the flame proofing property.

If alum is cut back or removed from the wet end, retention of fines and filler in the sheet is generally reduced, which may result in poor formation of the sheet. Thus, in this paper was discussed the filler retention in producing base sheet for surface sizing by both laboratory applications and field pilot scale trials.Calcium carbonate (both ground limestone and precipitated calcium carbonate) was compared with the hitherto generally use clay and with other fillers. In particular, it was thought that ground limestone would be a very advantageous filler, because it had superior optical property and very low abrasiveness, and could be obtained at a low price. Thus, it was evaluated to determine whether it would be useful at filler for base sheet for surface sizing.As a result, it was found that ground limestone of a small particle size (for example, 1.8μ) improved the opacity (scattering coefficient) of the sheets. The use of filler retention aids proved more effectively with the ground limestone than with the precipitated calcium carbonate. The ground limestone was retained up to 80% by adding 0.010.02% cationic or anionic synthetic polymer based on filler weight as a retention aid continuously to the riffler just prior to the headbox. What is more, this was a sheet having a higher optical property and greater strength property as compared with the sheet of a clay/rosin/alum system. It was known that when ground limestone filled sheet was surface-sized at size press, it could be made into a sized paper having a remarkable sizing response just as in the case of precipitated calcium carbonate.Ground limestone filled paper has the following advantages;(1) Ground limestone itself is a lower-priced filler.(2) It has a better optical property and a very low abrasiveness than clay.(3) It has a superior strength property as compared with the sized paper of a clay/rosin/alum system. Thus, more of the expensive pulp weight has been replaced by the low-cost filler.

Light metals alloys for heat-treating, e. g. Lloyd, Alcoa 61S 53S, etc., which had been observed as ship-building materials owing to the strength of their mechanical natures and the suitableness for farbrication, have been put to the various tests and studied by the Committee of Light Metals for Shipbuilding Industry scince 1952. As the experiments, which had been made on the questions of process, fabrication and anticorrosion by the said Committee, resulted in finding some weak points in anticorroding, the painting anticorrosive method, as an important theme, has been studied by the Committee of Light Metals for Surface Treatment.This is one of the reports on testing the adhesion of paints film anticorrosion, and anticlimate of Lloyd sheet, as compared with those of 52S, under the following conditions.1) the Primer coat is given by Zinc-chromate.2) The ouer coat is given by Phthalic acid resin enamel.3) The conditions of undercoats treatment are as follows:a) Non-treatmentb) Treated by phosphate alcholc) " " sand paperd) " " wash primere) " " sand paper and wash primerf) " " wash primer after caustic soda washingJudging from all the tests abobe, Lloyd sheet is inferior to 52S in adhension of paints film due to the major component of oxide film during heat-treating process.It is considered as the best way for Lloyd sheet to apply wash primer after eliminating its oxide film dy caustic soda or sand paper.

This paper deals with the experimental study on the aging of eight sorts of Al-alloy, e. g. 2S, 3S, 52S, 75S, Al-Cu-Sn alloy and so on, by means of specific volume analysis. The specimen of the standard dimension 10×10×20mm, is finished with a 04 emery paper as in the case of preparing the specimen for microscopy, polished with chromium oxide, and then its specific volume (significant figures: five figures) is measured by means of a precision chemical balance. After being kept in 500°C for 30 minutes, the specimens are quenched in water and temper aged for a long time at the prescribed temperature (seven degrees of 20, 80, 120, 150, 180, 200 and 220°C tempering). Then the changes of specific volume are pursued. Furthermore, some interesting results in the change of specific volume were obtained when the quenched specimens were aged in rising temperature.We add that this research owes its expence to the Grant-in-aid of the Scholarship of the Institute of Light Metal Foundation.

The utilization of CMC (carboxymethyl-cellulose) as a surface sizing agent has been studied. Through several experimental applications on a small size test paper machine, suitable conditions of CMC for the purpose of surface sizing were defined as follows : D.S. 0.50.8 Viscosity 50100 c.p. (3% soln., 25°C) Impurity Less than 25%The paper surface-sized by CMC showed such characteristics as high oil and air resistance and high wet tensile strength. These characteristics might enable us to use CMC for under coating besides general surface sizing. The practicality of CMC surface sizing was also approved qualitatively and economically by a test run on a commercial paper machine.

Several commercial pulps were beaten by laboratory beaters with steel roll and stone roll, respectively, and the relations between air resistance of paper and beating state were investigated mainly from the viewpoint of the effect of fines produced during beating. 1) Drainage characteristics of pulp suspension and air resistance of sheet are both affected extremely by existence of fines produced during beating (Fig. 2, 3 and 6). Contribution of fibrillation and change in fiber length distribution to air resistance may be neglected as compared with that of fines. 2) The amount of fines produced varies with beating method and kind of pulp (Fig. 4), while air resistance decreases nearly with a certain ratio by removal of fines irrespective of beating method and kind of pulp (Fig. 6). 3) Wet heating results in less amount of fines and higher air resistance at the same amount of fines (Fig. 7). So, air resistance may be determined by both the amount and the quality of fines. Fines produced in wet beating process larger specific surface than free beating. 4) Air resistance increases exponentially with the increase of specific surface of wet pulp. At the same amount of specific surface, free beating results in higher air resistance (Fig. 9). 5) Relation between logarithm of air resistance and specific scattering coefficient of sheet is linear almost irrespective of beating method (Fig. 10). 6) At the same S-R beating degree, wet beating results in higher air resistance (Fig. 12). While, relation between logarithm of air resistance and that of slowness measured with improved slowness tester (Fig. 1) is nearly linear irrespective of beating method and kind of pulp (except NDKP) used in this experiment (Fig. 15). So, improved slowness is thought to be very effective measure for estimating air resistance.

This paper presents brief discussion on the relationship between Hunter Whiteness, Brightness and yellowness of pulp sheet.Hunter Whiteness (W) is defined as follow, W= [1- {(30√α2+β2) 2+ (1-G/2) 2} 1/2] ×100α;2.5 (A-G) /10Gβ; (G-B) /10GBrightness (B) is a numerical value of the reflection of pulp sheet to light in the blue portion of the spectrum, specifically to a wave length of 457 millimicrons.Yellowness (Y) is given as fellow, Y= (A-B) /G×100Whiteness, Brightness and Yellowness of the about 150 samples; commercial, aged, and deteriorated pulps, were calculated from the measurements of Hunter Reflectmeter, respectively.It was confirmed that (W) and (B) were closely connected with each other. However, in the limited Brightness range the reliability of this relation was doubtful.It was found that Yellowness had a high intensive connection with Whiteness and was useful as a aviable measure to determine the pulp sheet colouring.

In order to obtain a good pulp with suitable qualities for wrapping purpose, the bagasse should be sufficiently depithed before digestion and also the SiO2 in the black liquor be removed. The usual differences between bagasse pulp and wood pulp of the same freeness are as follows:-1. Extracts with 10% NaOH sol : greater2. Beating time : shorter3. Bursting resistance : higher4. tearing resistance : slightly lower5. Folding endurance : higher6. Opacity : lower

Four important problems in Rayon Consultant's slurry system are as follows : i) Easiness of disintegration to slurry.ii) Agitation resistance.iii) Favourable property to pressing.iv) Adhesion of alkali cellulose fibers to the surface of the press rollers.Some investigation was made upon these factors and the effects of the properties of pulp.Then it was obtained that the fiber length of pulp has very important influence to these four factors.