Comoner-free unsaturated polyester impregnating resin with low emissions during processing

The paper describes a new system of unsaturated polyester resins without comonomers. These monomer-free unsaturated polyesters can be used for the impregnation of electrical windings by all techniques used with standard unsaturated polyesters. As they do not contain volatile comonomers the emissions during application and curing are very low. Nevertheless the impregnating processes have to be adapted to the physical properties of the uncured resins. In the first part of the paper some general remarks are made concerning impregnation techniques and unsaturated polyesters in general and monomer free unsaturated polyesters in special. In the second part the processes for the impregnation and the results are described in detail