Solvent based varnishes for impregnation

Solvent-based varnishes will be used less and less in the future because of their high solvent content and consequent emission into the atmosphere. They will still however, have an important role in the future because there are undisputed advantages due to their excellent tank stability, their ease of handling and good overall characteristics. Ideal for dipping impregnation at atmospheric pressure.

HI-THERM BC-325 is a phenolic-based varnish modified with polyester resin.
Its main properties are as follows:

  • Fast curing
  • Tough, smooth, glossy film, to which dirt doesn’t stick
  • Excellent bonding strength
  • Excellent oil resistance
  • High dielectric strength
  • Included in UL approved insulation systems

HI-THERM BC-346A is a modified polyester varnish, suitable for impregnating windings of electrical equipment windings up to the 200°C rating. It has exceptional compatibility both with the new Amide-Imide enamels and with conventional enamels. It has the following special characteristics:

  • UL approved (File OBOR2.E317427 and OBJS2.E317429)
  • Approved for MIL-V-1137A, CB grade, Type M and MIL-I-24092, Type M, Class 180 specifications
  • Excellent adhesion and flexibility
  • Excellent tank stability
  • Relatively short curing cycles
  • Excellent tank stability

HI-THERM BC-352 is a one-component epoxy varnish that has a very high resistance to chemical agents, solvents and moisture.
It guarantees the maximum protection for windings that have to operate in corrosive environments. It is particularly recommended for use on hermetic motors due to its low extraction value (less than 1%) in refrigerant gases.
Its main properties are as follows:

  • Excellent bonding strength at high temperatures.
  • Excellent insulation in damp conditions.
  • Very low extraction value with Freon 22.
  • Abrasion resistant.
  • Excellent base varnish for encapsulation systems using epoxy resins.
  • Included in UL approved insulation systems for 180°C

HI-THERM BC-359 is a new insulating varnish that has been specially developed to cure rapidly at low baking temperatures. Alternatively, the BC-359 varnish can be baked at higher temperatures when short curing times are required. The resulting energy savings during curing makes the BC-359 varnish very economical to use. Its main properties are as follows:

  • Rapid curing at low temperatures
  • High bonding strength
  • Excellent moisture resistance
  • Good tank stability
  • Suitable for class H applications
  • Included in UL approved insulation systems for 180°C.