Study On Metamorphic Gneiss Mica Paper And Aramid Fiber Mica Paper

Mica is indispensable insulating materials in electric industry. At present, although it already appeared a lot of new materials, but without a new type of insulating materials can completely replace the mica. Mica paper which is made by crushed mica piece as raw materials in the round nets dipping paper machine in slow speed is widely used in electrical industry. It maintained a variety of excellent properties of natural mica, good thickness, small dielectric strength fluctuating range, can be replaced in many fields of natural mica.With the rapid development of electrical industrythe demand mica is growing to bring problems of mica paper, on the one hand, the existing technology is rely increasingly scarce resources of high quality mica, on the other hand, richer and difficult to get into the low-quality mica paper reasonable use. Among them,in low quality mica,metamorphic gneiss mica of electrical properties is consistent with high-quality pegmatite type mica, But because of its weathering, serious oxidation, small diameter-thick ratio, low mica surface activity extremely cannot be into paper, so has not tried to make mica paper as raw materials, that has caused the waste of rich reserves metamorphic gneiss mica resources. Therefore, the study of mica is raw material with low-quality mica paper manufacturing technology, improving the comprehensive utilization of mica resources, appearing particularly important.Aramid fiber mica paper which is full of aromatic polyamide fibers is new material combinating with mica, have good electrical insulation, heat resistance and mechanical properties, moreover also corona resistance. This new material used in medium-sized high-voltage electromotor and transformers. Aramid fiber mica paper is made of mica powder and aramid sink post-mortem pulp and aramid short fibers, is the latest international high-performance mica paper. At present, the products are mainly dependent on import,therefore, mica paper of aramid fiber production technology research is necessary.This article in view of the above questions, conducted two aspects the research work, on the one hand, this paper adopts KH-550 silane coupling agent on the metamorphic gneiss mica piece for surface modification, Using the silane coupling agent"molecularbridge" effect to process mica surface, by adding the self-emulsifying modified epoxy resin and polyacrylamide, mica surface connected epoxy groups occurred the crosslinking reaction, which significantly improved the tensile strength of mica paper. The optimization experiments showed that, When the silane coupling agent KH-550 was 0.5% and modified epoxy resin was 1% and polyacrylamide was 0.5%, the tensile strength of mica paper increased 72.17N/m to 151.3N/m;on the other hand, this paper treated the surface of aramid short cut fiber by phosphoric acid, study of influence of composition and structure of aramid short cut fiber treated by phosphoric acid solution, discussed the adding amount of dispersants PEO and the ratio of aramid pulp and aramid short cut fiber, Optimized the technique of aramid fiber mica paper production. Experimental research showed that:phosphoric acid concentration 40%, PEO 0.2%, aramid short-cut fiber and aramid pulp mass ratio of 1.2:1, the performance of mica paper are excellent. Experimental measurement tensile strength for 187.7 N/m, dielectric strength for11.7 MV/m, penetration time averaged for 12.3s.