Abstract
Stress relaxation behavior of nylon (6 nylon) stretched under various degrees of elongation was measured in order to know the influence of the relative humidity and temperature. The data on relaxation were obtained under R. H. 8%, 33%, 55%, 75%, and in water at 25°C. The influence of the change of temperature at 25°C, 40°C, and 55°C under R. H. 55% and in water was further studied,
The values of E (stress/strain) obtained under various degrees of elongation, temperature, and R. H. were plotted for log t (see) and are shown in Fig. 2_??_Fig. 6, Fig. 8 and Fig. 9. It was found that the relaxation curve for nylon under various conditions could be approximated by the following.
where t is time, and E0, t0 is constant.
The results obtained are as follows.
1) Under the small elongation (2%), stress-relaxation behavior of nylon is much affected by R. H, and temperature.
2) In the low R. H., the high rate of stress relaxation is obtained under the 2% and 4% elongation.
3) In the high R. H. (including the tests in water) and under larger elongation, there is a small difference among the rates of stress relaxation.
