Polyglas® banding tapes have the following fields of application: · Rotor and comutator banding (main use) · Transformer core banding · Bracing end windings of form- wound stators
Resin bonded glass yarn banding tapes are wound around the outside of the coil ends of heavy duty direct current motor armatures to act as a mechanical restraining band. They secure the armature from the effects of large centrifugal forces which are normally experienced by such motors.
Banding tapes have largely replaced steel wires in performing this function; they provide equivalent mechanical strength, whilst solving the problems of using a conducting wire:
- Electrical conductivity which makes essential the use of an underlying electrical insulation to avoid shorting and flashover.
- The generation of eddy currents which cause local overheating and in turn contribute to fatigue and welding between adjacent end turns.
-Relatively high material and application cost.
-Susceptibility to corrosion on exposure to moisture with resulting mechanical failure.
The following products for banding applications are available:
Polyglas® P30 is a basic class F (155 °C) banding tape, used for banding rotors, overhangs, collectors and dry and oil filled transformer.
Polyglas® H200 is a standard class H (200 °C) moisture resistant banding tape, used mainly for banding rotors and overhangs.
Polyglas® H220 is an improved class C (220 °C) moisture resistant banding tape, used mainly for banding traction rotors, collectors and overhangs.
Polyglas® K220 is the ultimate class C (220 °C) moisture resistant banding tape, Kevlar® based, used mainly for banding permanent magnets rotors, high speed starters and whenever steep operative cycles or reduced spaces are required.