Effects of natural zeolite filler on tracking in paper phenolic laminate

In order to improve tracking failure, natural zeolite was used as filler in paper phenolic laminate. The X-ray diffraction pattern of the natural zeolite clearly shows the mineral structure. The main mineral is clinoptilolite. This zeolite structure was maintained at test temperatures up to 450°C. The improvement of the resistance to tracking in the natural-zeolite-filled paper phenolic laminate with 0.5 wt.% to 5.0 wt.% was investigated by a test method similar to the IEC tracking test. From the experimental results obtained by the IEC tracking test for copper electrodes, on the basis of comparative indices in the unfilled sample, the increasing percentages of comparative indices in samples with 0.5 wt.% to 5.0 wt.% are about 11% to 37%