where PD is the polymerisation degree and Str is the tensile stress resistance of paper.
The paper submitted to the aging process in oil there was measured the volume of CO+CO2 dissolved in oil; the gases extraction was made according to the CEI 567 norm and through the Torricelli method.
In fig. 2 the dependency between the volume of gases dissolved in oil (noted with GD, in gas millilitres per paper gram) and the polymerization degree of the paper (noted DP,
in percentage) is represented.
For the dependency between the volumes of gases dissolved in oil (GD) and tensile strength (Str), there results, through the processing of experimental data, the following analytic expression of the curve: