We have studied about beater sizing of paper by alkyl-ketene dimers. Chemical reaction between the alkyl-ketene dimers and the fiber surface is necessary for the development of hard durable sizing, and it appears that effectiveness at the low concentrations employed is largely a result of this chemical reaction.

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It has been a most common practice at the paper mills that the method called the acidic fixation in lower PH (PH 4-4.5) was applied to size the paper, however, due to the excess of aluminum sulphate would decompose alkaline earth filler such as calcium and magnesium carbonates and destroys its sizing effect.
After a long carefull studies and experiments were carried out we have finally succeeded in produce the neutral sizing agent which produced excellent sizing effect even in the nearly neutrality (near to PH 7.0).
For the example, we mixed with about 10-40% of precipitated calcium carbonate into the pulp in the beater adding with the neutral sizing of about 1-4% and the aluminum sulphate of 1-3%, then we are able to observe the perfect sizing effect on the tissues and printing papers. In other words, the test result of Stoickigt method was indicated about 30-50 seconds (60g/m²).
Also, it is known to manufat cure the high grade none-filled paper (such as writing, bond, name-card paper etc.) made with the process called the acidic sizings, in this connection the required amount of aluminum sulphate is to be limited approximately between 1/4-1/5 as to compare with previous method. Assuming as to obtain size of 2 per cent it only required between 0.4-0.5 percent of aluminum sulphate are sufficient.
Many tests carried by actual operation at the various paper mills, we are convinced more from those data and results, this is more effective medium for paper sizing than any other sizing agents. In this field and many Japanese paper mills are to start using and adopting the neutral sizing for the purpose, therefore we are prepared to state the merit and advantages of this material as follows.
1) In the past a most important filler for the papers are those of various clays, however to obtain with the whiteness (above 95 %) and perfect filling effect many paper mills are able to use of those calcium carbonate and magnesium carbonate as the filler from now on.
We recommend to use it for high grade tissue paper such as air mail and india paper which are required more translucent. It also can be used for a suitable common writing paper making because resistance against the Perker's fountain ink which consist of high degree of PH
2) In the manufacturing Japaness paper by the cylinder paper machine, this neutral sizing agent will give much satisfaction for the reason of it's nature which will not destroy the fibre dispersing ability of mucilages (abelmoschus manihot) which will be able to adjust the uniform suspension of long fibres to coagulation in the acidic reaction of rosin and aluminum sulphate sizing.
3) On account of the neutral nature in sizing, the durability and preservation of paper could be maintained and gain many other benefits by using it.
4) It is known fact that a close relationship exists between the rate of dryness of paper and or printing ink and in this connection the expert on this subject recently recommended of the neutral slightly alkaline fixation for the sizing. (Ref. A. Voet : Ink and Paper, Part II pp 193 5)
5) This neutral sizing agent is a quite effective and ideal method and proceed with the method of neutral size, it will not only save a larger amount of aluminum sulphate but also save a big amount of fluorescent dye which intended to improve the whiteness of papers thus by using it themanufacturing cost will be sufficiently reduced. (In the case of the size produced under the acid condition will have a tendency of change of the red shade)
6) Due to the neutral nature of itself, this will definitely help to reduce the erosive action on the machine wire thus prolong the life of the wire.
The neutral size is a sort of high-free rosin soap which is produced under a special saponification, process and it was prevented the coagulation of rosin particles by using the protective colloids.

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In manufacturing a synthetic fiber, such as nylon paper, the following differences in papermaking properties are observed between paper of cellulosic fibers and synthetic fibers.
(1) Because of the hydrophobic nature of nylon fiber, it is difficult to disperse it properly in water.
(2) Nylon fiber has no fibril structure.
(3) Nylon fibers do not bond on drying or with pressure alone, unlike hydrated and fibrillated cellulose.
It is possible that synthetic fiber papers, in general, may have the application to the non-woven fibric and the usual type of paper for printing.
This experiment was carried out to manufacturing the latter type of synthetic fiber paper. To overcome the lack of printability of nylon synthetic fiber paper, Mitsumata cellulosic fiber was blended into nylon stock with the ratio of 1 : 1.
In this paper a summary of the results of examination concerned with commercial production of the nylon blended Mitsumata paper is presented.
The following results were obtained in consequence of the experiments :
1. Polyacrylate was found to be effective to yield better fiber dispersion and better sheet formation in the fourdrinier machine process.
2. Bonding agent was added to the water leaves of nylon blended Mitsumata by dipping them in the emulsion or methanol solution of bonding agents.
3. Two types of nylon derivatives were used as the bonding agent of nylon blended Mitsumata sheet.N-methoxymethyl nylon 6 proved most effective to improve the wearing quality, strength properties and resistibility to chemicals of sheets.
4. The sheet properties were remarkably improved in folding endurance, wearing quality and resistibility to chemicals.
5. Amount of ink transfer from form to the nylon blended Mitsumata paper, in general, was less than to the Mitsumata paper.
6. The nylon blended Mitsumata paper had a weaker tendency to cause the troubles of strike through and show through of the print.

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The smoothness of paper ranks as one of the most important properties in the evaluation of its printability.
Several types of measurements, air flow, optical, friction, physical, electrical and others have been devised to measure the smoothness of paper.
A smoothness tester equipped with a vacuum air micrometer has been manufactured for trial in our laboratory and its performance test has been carried out. The vacuum air micrometer works well without a cell of constant pressure, and exhibits a high magnification.
A basic experiment on the measurement of roughness of metal surface has been performed with this instrument, and the data obtained has been indicated in a diagramatic manner. After necessarry conditions for nozzle, orifice and indicator were introduced from these diagrams, the instrument has been applied to the measurement of smoothness of paper. The experimental results may be summarized in the following way :
(1) This smoothness tester consists of a nozzle, a manometer, an orifice and a vacuum pump as is illustrated in Figure 3. Facility in handling is its special merit.
(2) Accuracy and reproducibility of the values obtained with this instrument areenough to use it as a smoothness tester.
(3) When the data provided by this instrument are plotted against the roughness of all kinds of paper surface, a linear relationship is obtained ; while when plotted against the data obtained with the Bekk Tester, a hyperbolic relationship is found to exist. For art papers, there is scarcely any relationship between the data those with the Bekk Tester.
(4) This tester differs from the Sheffield Smoothness Tester in mechanism of nozzle, type of indication, direction of air supply and values for papers of higher smoothness.
(5) A good correlation exists between the data with this instrument and those with the Densometer, when measuring the air resistance of paper.

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In order to determine the composition of polysaccharides of pulp, E. Hägglund proposed a procedure of total hydrolysis of pulp, and later various modified procedures of his one were applied by many investigators. In the present paper, occurence and decomposition of monosaccharides during the total hydrolysis have been investigated by means of paper chromatographic technique.
From this investigation, it has been found that a procedure of total hydrolysis is enough to complete the hydrolysis of cellulose, which consists of a primary hydrolysis for 1 hr. at 30°C with 72 % H₂SO₄ and a secondary one for 6 hrs. with boiling diluted (4.0 %) H₂SO₄. But hydrolysis of xylan and mannan had already been completed within 4 hrs. secondary hydrolysis.
When much glucose in hydrolysate interfere the spot of mannose on the paper strip, it is recommended to use glucose oxidase, 10 mg of which can oxidize 10 and 50 mg of glucose within 5 and 20 hrs. respectively (pH 7.0, 37°C).
Water soluble polysaccharides (γ-cellulose) in pulp were completely hydrolyzed by boiling with 4% H₂SO₄ for 8 hrs. In this case hydrolysis of xylan was also easier than that of mannan and glucan.

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Holocellulose and dissolving grade unbleached and purified sulphite pulp prepared from Todomatsu (Abies sacchalinesis) were examined in respect to carbohydrate constituents of their alkali-soluble and -insoluble fractions.
Over 30 % of the holocellulose was dissolved out with 10 % and 18 % NaOH solutions, but only slight amount of β-fraction was found in it. Dissolved xylan, araban, mannan and galactan were present in γ-fractions and occupied about 60 % of the fractions. Pentosan was more easily dissolved than hexosan with alkali solution at 20°C.
As araban, galactan and much amounts of xylan and mannan were removed during the sulphite cooking, the amounts of γ-fraction of the produced pulp decreased, while β-fractions increased owing to the degradation of cellulose. About 80 % of xylan and mannan in the unbleached pulp was dissolved with 10 % and 18 % NaOH solutions and these xylan and mannan occupied about 60 % of the γ-fractions.Considerable amounts of mannan together with small amounts of xylan were found in the β-fractions.Xylan remained in the pulp during the cooking was hardly removed in the refining process (chlorination, alkali digestion and hypochlorite bleaching) but considerable amounts of mannan was removed.
When the unbleached pulps different in viscosity were refined under the same conditions of the above refining sequence, the bleached pulp had almost the same polysaccharide contents although the lower viscosity of unbleached pulp was, the lower refining yield was obtained.
The contents of mannan and xylan in the commercial dissolving sulphite pulps amounted to 2.9-4.1%, and 70-80% of these polysaccharides was dissolved out with 18% NaOH solution, so the polysaccharide contents in the residues (R18) became almost the same (about 1%), that is the difference being less than 0.3%.In comparing these pulps having almost the same α-cellulose contents, the amounts of γ-cellulose increased with the xylan and mannan contents (therefore β-cellulose contents decreased) and this may cause lowering the yield of viscose.

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