Nonwoven nanofibers composites and their partial discharges behaviour

Summary

A promised needle-less electrospinning technology of nanofibrous layers with nanodielectrics properties is studied nowadays as an alternative to well-known dielectric nanocomposites filled by various nanofillers (metallic oxides, alumina, silica, carbon nanofibers or nanotubes). All of these nanofillers have been found, more or less, to improve some of the electrical, mechanical and thermal properties of nanocomposites. Unfortunately, its expensiveness and tendency to agglomeration remain as their disadvantages. In the contrary, the nonwoven nanofibers can be applied as a fabric over the surface of the composite with no tendency to create the cluster agglomeration as the nanocomposites with nanoparticles. The partial discharges behaviour was studied in two composites modifications. The experimental specimens are based on the modification of commonly used three- or two-component mica-based electrical insulating material (epoxy, mica and glass fibers). Whereas one of the specimen group contains a reinforcing glass fibre layer and the second specimen group was prepared without this layer. Both of these modification of common mica composites were prepared by incorporation of the nanofibrous layers (1, 2 or 3) to its structure always with different mass area density of the nanofibers were (1, 3 and 5 g/m2). Carrier composites were delivered in the form of resin-rich thermoset prepregs on which the layers of the nonwoven nanofibers made from Polyamide 6 (PA6) were applied. Specimens were subsequently cured using typical resin-rich curing process. Partial discharges results show differences between the specimens variations depending on nanofibers presence, the number of layers, the surface density of nanofibers and the presence of glass fibre layer. The decreasing of the partial discharge activity is recognizable when the nonwoven nanofabrics is settled into the composite.

Additional informations

Authors

RAHIMI, FARAHANI, DE LIMA NETA, GURGEL NETO

Keywords

nano insulation, nonwoven, glass fibre, mica