2006 年 37 巻 2 号 p. 24-28
Many industrial instruments use rubber; NBR(Nitrile Butadiene Rubber) is especially used for the packing attached to pneumatic equipment. Recently, with the spread of dry pneumatic pumps, the deterioration of NBR by ozone has become a serious problem. However, the process of the ozone degradation of NBR has not been sufficiently clarified. When examining the ozone degradation of NBR, it is very important to control the ozone concentration. In general, it is difficult to get a low ozone concentration using an ozonizer with an ultraviolet ray lamp. Therefore, we attempted the optimum control of the ozone concentration with dilution by adjusting the air flow rate through the ozonizer using the flow proportional valve. As a result, the ozone concentration in the testing chamber is controlled with greater accuracy than the method based on supplying voltage to the ozonizer.