Studies on the Strength of Kraft Paper Report 3

Influence of the Tension during Drying upon the Mechanical Properties of the Paper Sheet (2)

Abstract

Hand-sheets were made and dried by the same method as described in the auther's previous report, and dried sheets were dipped in the water and expansion on wetting was measured
The wet expansion is as large as the actual dry shrinkage of the paper sheet dried under relatively high tension, but unrecoverable part on wetting is produced in the dry shrinkage of the sheet dried under lower tension. (See Fig. 5, Fig. 6)
A part of the breaking elongation is assumed to be ascribed to the reversal process of the dry shinkage, and the rest part of the elongation is about 3% in both longitudinal and transversal directions, which is affected a little by the tension during drying. This part of elongation is possibly ascribed to the extension of the fibers themselves and slipping between fibers accompanying fiber-bonds breakage.
It is ascertained that the tendency of the strength of paper for the increase of the tension is affected by the difference of stock preparation, beating and press.