DMD prepreg is a triple layer laminating polyester (from 50 to 190 microns) with two layers of non-woven fabric, subsequently impregnated with an epoxy resin which is first applied on both sides, then, by controlled heating, the polymerization is started bringing the resin in stage B.
It is used as an electrical insulator mainly in dry-type transformers and is suitable for operating temperatures up to class F 155° C.