USA, Pennsylvania: Axalta Coating Systems (previously DuPont Performance Coatings) will soon showcase its growing range of solvent-free impregnating resins to be used in the electric motor, power transformer, automotive and electrical appliance sectors.
Due to strict manufacturing regulations in the US and EU, Axalta Coating Systems has been developing an alternative range of Voltatex® products for electrical insulating applications.
Traditionally a magnetic core and its windings are dipped into an impregnating varnish (resin in a solvent, such as ethyl acetate or acetone) and baked in an oven to improve mechanical stability and environmental resistance. In order for the varnish to harden and properly protect the device, the solvent must evaporate, giving off hazardous fumes. Because of the low flash point, there is also a fire risk.
Axalta's product is solvent-free, consisting of unsaturated polyester resin dissolved in proprietary oligomers along with the more traditional systems that utilise styrene or vinyl toluene monomers. The impregnating resin (or solvent-free varnish) still needs to be heated but not to evaporate the liquid – rather to catalyse the chemical reaction between the resin and the monomers. This can be done in an oven or by passing an electrical current through the windings.
“Of course, there is still some evaporation due to the elevated temperature required, but it is a significant improvement, and the emissions are less harmful to the environment.” says Manfred Lueg, global business development manager for Axalta’s Energy Solutions division.