Impregnated glass fibre yarns are used for the insulation of round and rectangular conductors. The glass may be applied in woven tape form or as a continuous fibre. It has proved to be an efficient insulation providing coil winders with thermal stability, adequate electrical properties and good resistance to abrasion after varnishing. The glass is bonded with a varnish for dielectric strength to improve mechanical properties.

The working temperature of our standard glass fibre covering is 155°C (Temperature Index: "F"). We also offer a 180°C (Temperature Index: "H") covering with a high temperature varnish. An epoxy varnish can also be supplied "B" staged.

The glass fibre insulation can be either narrow or wide angle lapped onto the conductor. With the development of the wide angle tangential lapping process it has become possible to apply varnish during the lapping process, and several coats after completion. The higher the varnish contents the higher the electrical breakdown voltage.

Tangentially lapped glass fibre is now used by many large manufacturers and repairers of electric motors. Concentric narrow glass lapped insulation continues to have many applications and it has undergone extensive research and development programs on impregnation techniques.

A recent development is the application of a film backed glass cloth tape, which is bonded to the conductor, offering higher dielectric strength, and low build.

Please contact our technical department for details.