Araldite impregnating resin system used for production of high quality glass fibre rods for HV insulators
Lapp Insulator, based in Wunsiedel, Germany has a long tradition in the production of high quality technical ceramics and was the first manufacturer to produce silicone rubber composite insulators.
For the pultrusion of high quality glass rods for high voltage insulators, Lapp has now started using Araldite MY 740 / Aradur HY 5917-1 impregnating resin system from Huntsman’s electrical insulation materials range.
A hot-curing, low-viscosity system with high reactivity, Araldite MY 740 / HY 5917-1 is specifically designed for the effective manufacturing of electrical composites, such as tubes and rods and the impregnation of high voltage bushings and coils.
“We chose to use this Araldite system because standard three component systems have a tendency to decarboxylation which can lead to gas bubbles in the matrix, if it is not properly degassed,” explained Dr. Jens Martin Seifert, director for R&D and quality at Lapp Insulator.
“This new system is decarboxylation free, so no bubbles are produced. This leads to better quality consistency in the rods we produce for high voltage insulators and no degassing process is required.”
Lapp’s RODURFLEX composite insulators comprise two components – a rod made of glass fibre reinforced plastics (FRP) and a silicone elastomer housing covering the rod.
“Using Araldite MY 740 / HY 5917-1 in production of the FRP component has helped improve the insulator’s mechanical properties. It also exhibits good transparency levels and because it is a pre-accelerated two-component system this has improved production rates. The number of rods rejected on quality grounds has also been reduced,” said Dr. Seifert.
The rods produced using Araldite MY 740 / HY 5917-1 are compliant with all tests for composite insulators, including IEC 61109.
Araldite MY 740 is a medium viscosity, solvent-free Bisphenol-A epoxy resin.
Aradur HY 5917-1 is a formulated, pre-accelerated low viscosity anhydride hardener. In addition to pultrusion, this two-component system is also suitable for other composite processing methods including filament winding, wet laminating and trickle impregnation. It exhibits good mechanical and dielectric properties at elevated temperatures (up to 120oC). It offers good aging resistance and a low exothermic reaction.
Twitter