The investigation upon the degradation of wood carbohydrates during the latter part of commercial bisulfite cooking was carried out by using the holocellulose prepared from red pine (Pinus densiflora) by a subsequent process: namely very mild bisulfite cooking, further defibrating and finally delignifying by repeated treatment with NaClO₂.
Thus prepared holocellulose was further hydrolyzed in Ca-bisulfite-sulfurous acid solution (bisulfite cooking liquor: total SO₂ 5.7% and combined SO₂ 1.5%), at max. temp. 140°C, changing the reaction time.
With these treated samples, the chemical analysis was carried out and the leveling off DP was determined by such modification of Maeda's method as each sample was hydrolyzed in 3 N-HCI, CH₃OH solution and also the swelling state of these samples in 79% phosphoric acid was observed by the same method described in Part VIII. The pH-value of reaction liquor at elevated temperature was determined by Rydholm's method. The results were as follows:
1. The hydrolysis reaction rate in pure Ca-bisulfite-sulfurous acid solution seemed to be relatively slow, however in the progress of the reaction, SO₂ was consumed despite of absence of lignin, further the acidity of reaction liquor increased by forming sugar sulfonic acid or sulfuric acid without lignosulfonic acid, consequently the degradation of carbohydrates was accelerated autocatalytically.
2. The leveling off DP of samples decreased with the progress of hydrolysis in proportion to their original DP, therefrom it was suggested that acid hydrolysis at such high temperature and high pressure influenced upon the fine structure of wood cellulose.
3. The swelling state of samples in phosphoric acid was improved more remarkably at the latter part of hydrolysis reaction than in usual sulfite cooked pulp having same average DP. This result seemed to be due to uniform contact of fibers with the reaction liquor, starting from defibrated holocellulose.

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By heat treatment papers coated with some water-soluble high polymers develop wet strength more markedly than in the uncoated paper.
The most effective polymer is protein like gelatin or milk casein. The effect of carboxymethyl-cellulose or polyvinyl-alcohol rank next to protein. The reason why protein is most effective seems to be due to the stronger proton accepting power of the functional groups in a protein molecule, and the lower activation energy of adhesion. The latter may be attributed to its special character of the functional groups and molecular structure. Carboxymethyl-cellulose contains carboxyl groups with strong proton accepting power. Polyvinyl-alcohol possesses in addition to its polar hydroxyl groups rather high ability of molecular free rotation.
It appears therefore that the high polymers, which forms hydrogen bond easily with cellulose fiber, are effective to increase the wet strength, i.e. a class of polymers having lower activation energy of adhesion. The high ability of molecular free rotation and non-existence of steric hindrance and strong proton accepting power of functional groups are also important factors.

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The zerospan tesile strength, tensile strength and load elongation curve of paper are determined, after being soaked in six kinds of media, water, glycerin, monoacetin, diacetin, triacetin, decarin, at room temperature or after being soaked in the same media at 180°C, followed by their replacement with water. The results obtained at room tenperature show that the dry strength of the untreated paper is more dominantly related to the bonding between fibers than the original strength of the fiber, and that the higher the media are in the cohesion energy density, the more readily they break the bonding. The results obtained at 180°C, show that the fiber bonding, which causes the development of the wet strength of the heat treated paper, is effectively formed in the media of lower cohesion energy density. These evidences seem to support the validity of the interpretation that the hydrogen bonds, which cause the development of the wet strength of the heat treated paper are formed between fibers.

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In order to observe the frictional properties of Angora rabbit fibres in water by means of the inclined-fibre method, an apparatus was devised and the preliminary test was made; the weight and the diameter of the Pt-rider used were 14.2mg and 0.3mm respectively. The results obtained are:
(1) The both frictional coefficients, the anti- and with-scale, increase when the fibres are degreased with CCl₄.
(2) The effect of the thickness of fur on the frictional coefficient is negligible.
(3) In the narrower range of a fibre surface the apparatus can give a definite value.

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The parts of knees of trousers or elbows of upper garments are largely deformed by means of the bending of knees or elbows. We deal with this deformation mechanism theoretically.
If the cylindrical knitted clothes is used as hosiery with redius r on the cylinder (as legs) having radius R, and stretch one point on the clothes with tension T₀, the tension derived decreases gradually along the length (x) owing to the friction between the clothes and cylinder. This relationship may bew expressed as:
This shows that the tension (strain) decreases along its length (x) exponentialy, and gives a schematic distribution of tension as slown in Fig. 1. Photo 1 and Fig. 2 are results of model experiments.
Tension T₀ in the above equation is assumptive, but this is obtainable when the deformation of knee or elbow of clothes is taken as fabric bursting, then;
Tension distribution expressed in this formula is shown in Fig. 4. Dimensionless number S depends upon the size of legs or arms of our body. This being given we can analyse these kind of deformation theoretically.

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As usual the opening grade of cotton is tested by handling method, but it is very difficult to compare the results depending upon different method used.
In order to decide the degree of opening action of machinery, the terminal velocity and coefficient of air resistance of cotton tuft at free falling were measured. The coefficient of air resistance is usually better than the terminal velocity to indicate the opening efficiency of blowroom machinery.
Formula of the terminal velocity u_m, and coefficient of air resistance C are following:
where w′: apparent weight of cotton tuft,
l: length of cotton tuft,
pρ_f: density of air.
The smaller the terminal velocity or coefficient of air resistance is the more the cotton tuft is opened. Combination of the 1st Hopper Bale Breaker, Lattice Feeder, Exhaust Opener and Finisher Scutcher are more effective for opening action. 1st Crighton Opener with Deliverly Lattice and 2nd Crighton Opener are not so effective.

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This paper describes a study of the opening action on existing blowroom machinery by the density of cotton tuft in each process.
In order to measure the density of cotton, three methods were applied, (1) is derived from the actual weight W and volume V of each sample, (2) from the apparent weight w′ and volume v of each tuft, (3) from the shape factor of cotton tuft k, of these the third method is found most satisfactory.
Formulae of the densities γ₁, γ₂, γ₃ of cotton are
γ₁=W/V
γ₁=w'/v, v=(3/4)πabc
γ₂=k(cρζ)^3/2um/(w')^1/2, l³=kvwhere a, b, c: leng/th of cotton tuft on each tangential axis,
C: coefficient of air resistance of each tuft,
ρ_f: density of air,
u_m: terminal velocity of cotton tuft,
l: maximum length of each tuft.
The experimental results are given in Tables 1, 2 and are shown graphically in Fig. 1_??_5. And the result may briefly be summerised as follows: (1) the shape factor of cotton tuft are 11_??_14, (2) in opening action combination of 1st Hopper Bale Breaker, Hopper Feeder, Lattice Feeder, Exhaust Opener and Finisher Scutcher is effective for the opening action, (3) 1st Crighton Opener with Delivery Lattice and 2nd Crighton Opener produced compressed tufts.

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A relation between yarn tension and specific density for a cop is derived on the assumption that the compression of the mass consists solely of the bending of the yarns.
σ₀; Specific density of the cop at zero tension
R; Radius of the cop
r;₀; Radius of the pirn
This relation shows satisfactory agreement with observation. The specific density of the cop increases, at first rapidly then slowly, with increasing yarn tension.

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A complex-forming quality of condensed phosphates with calcium ion and their effects on raw silk when treated with hard-water were investigated, The procedures are the same as reported previously. The results were as follows:
(1) The order of the softening ability of condensed phosphates for hard-water is sodium meta phosphate glass (so-called hexameta phosphate)>sodium triphosphate>sodium pyrophosphate.
(2) The dissolving power of water, soap and silicate for sericin is decreased as the hardness of the solvent is increased respectively.
(3) The complex-forming quality of condensed phosphates for all metallic ions is enabled to remove the contaminations of metallic soaps easily, therefore, the mixture of soap and condensed phosphates is better than the other degumming agents for raw silk when the hardness of the solvent is high.

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Heat setting of nylon fibers under some tensile and cooling condition was studied. It is made clear that the internal structure of nylon fibers that has been affected by tension changes, especially in the degree of molecular arrangement, even at the same temperature. These changes influence their physical properties. Cooling condition, too, has evident bearing upon their physical properties.
But α-crystal structure was not seen by rapid cooling. These results indicate that it is very important to keep tensile and cooling condition exact for heat setting process of nylon.

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Dyeing velocity of nylon fibers, once stretched and then relaxed, was studied. The dyeing velocity of such fibers becomes very low, though the saturated amount of dye at equibrium does not differ greatly. The fact that tension given in weaving has very important bearing upon the dyeability is made clear. Tensile hysteresis of nylon fibers seems to be one of causes of so called stripe.

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The dyeing properties of nine acid azo dyes having the same skeletal structure as α-naphthylamine→β-naphthol and different number and position of sulphonic groups were determined.
The absorption spectra of these dyes in visible region are almost the same except the dyes containing R-acid as coupling component. The exhaustion percentages (S. D. C Method IV) of these dyes are proportional to the number of sulphonic groups.
The influence of the sulphonic groups to light fastness is not appreciated in these dyes.

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Study on the heat of dyeing ΔH, and entropy change ΔS, of several commercial disperse dyes is made by the desorption method, and the data are compared with the corresponding data on the dyeing of cellulosic fibre with direct dyes.
It was found that there is a certain correlation between ΔH and ΔS when these data are plotted on the abscisa and ordinate, respectively. The same correlation is found with direct dyes. This is represented by ΔS=a+bΔH where ΔS: entropy change of interaction ΔH: energy change of interaction a, b: constant
From these results it appears that the dyeing mechanism of cellulose acetate with disperse dyes is the same as the case of cellulose with direct dyes. Further discussion on the possible factor in dyeing process except hydrogen bonding is made.

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