A 2 1/2 in. model pump was tested on an unbleached sulphite stock. The test setup was incorporated with a screw feeder of disc-refiner so that a thick stock can be forced into the pump. The pump was run at oven-dry consistencies ranging from 3.08 percent to 10.48 percent at high discharge pressure.Beyond this consistency, the motor of screw feeder would be overloaded. Therefore, satisfactory operation in this test was limited to 10 percent consistency. At the high speed of the test, it was observed that volumetric and overall efficiency increased consistency of stock. And these increased values may explain the higher resistance to internal leakage. Comparing the curves for 220 r.p.m. and 550 r.p.m. for which the fiberizing consistency was the same, the higher speed gave lower internal leakage.For the same reason, it may explain that the efficiency increases with consistency of stock at a given speed.
The advantages of this pump over reciprocating pumps are quiet operation and absence of excessive stress in the pipe line owing to the uniform discharge, and the advantages over centrifugal pumps are its flexibility in regard to capacity, positive displacement, high pumping head and its nearly uniform efficiency under a wide range of conditions.

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At the bursting moment of testing sample, sudden expansion takes place accompanied by a violent sound due to the compressed air in the system and in such a condition, reliable values cannot be expected.Moreover, the rubber diaphragm should be damaged, resulting permanent distortion. There exist two air spaces over and under the rubber diaphragm. Consequently, two devices were conducted for each spaces as follows : (1) A conical separator was placed under the diaphragm and these bubbles were turned back to a liquid tank through a connected by-pass. (2) Regarding to the air in the upper space, small holes were bored through the diaphragm plate. The air lets out through the holes by itself accompanying with the expansion of rubber diaphragm. By repeated experiments, applying these devices, the deviations of the measurement values have much been lessened in comparison with those, when these devices were not applied.

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1) As regards viscoelastic properties of paper of z-direction (perpendicular to paper surface), it was showed that its properties were able to same treated as other two directions.
In compressed case, reciprocal curse for tensile curse was obtained. Apparent Young's modulus of Z-direction was known 10⁹ dyne/cm² as order, less than x, y direction and from this fact simple consideration about the calendering was made.
2) About the smoothness of paper, assuming the strain due to the press N^hich was added to paper surface is proportional to smoothness, straight line relation of compressed stressismoothness was explained, and adaptable region of this straight line relation was derived from the s aloe of apparent Young's modulus and second Young's modulus, fits experimental data considerably.

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[in Japanese]

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