This range of solvent-free impregnating resins helps manufacturers in the electric motor, transformer, automotive and electrical appliance sectors meet tightening environmental and safety legislation. An alternative range of Voltatex® products for electrical insulating applications, these resins, which greatly minimize the generation of VOCs, can reduce emissions during the impregnation process to below 2%, while also lessening fire risk and eliminating odor in the work area.
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.
These resins offer a true solvent-free option, with a single-component material consisting of unsaturated polyester resin dissolved in proprietary oligomers. The impregnating resin (or solvent-free varnish) still needs to be heated but not to evaporate the liquid, rather to catalyze 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.