UV aging test chamber exposure conditions and methodSurface temperature is an important exposure parameter, general, high temperature The polymer degradation process is accelerated, and the allowed test temperature should be determined depending on the test material and the aging performance evaluation index. The infrared rays emitted by the fluorescent ultraviolet lamp are small than the xenon lamp and the carbon arc lamp. The heating effect of the sample surface is substantially formed by hot air convection, and therefore, the blackboard thermometer, the black standard temperature, the sample surface and the exposed chamber air The temperature difference is very small.
Recommended two two types of exposure methods:
1. After the sample is exposed, it is followed by radiation period (which changes in temperature and condensation on the sample) Cycle test. According to the relevant standard, if there is no specified cycle condition, it is recommended to use the following cycle: 4h or 8h in the black standard temperature 60 ° C PLUSMN 3 ° C, then in the black standard temperature 50 ° C 3 ° C Irradiation condensation is exposed 4h (Note: Some polymers such as PVC, husband degradation is very sensitive to temperature, in this case, it is recommended to use irradiated exposure temperature below 60 ° C to simulate climate of cold
. When the procedure of the passenger exposure is then condensed, the allowable irradiation or the condensation period zui is short of 2 h to ensure that each exposed condition is equilibrated. 2. Test continuously radiation exposure and has a cycle test of timed spray, the test period is required, if there is no specification, the following test conditions are recommended: 50 ° C in the black standard temperature 50 ° C 3 ° C The air relative temperature (10 PLUSMN 5)% is exposed to 5h, then continued to irradiate the irradiation in black standard temperature at 3 ° C