Proven cellulose-based surface insulation material for insulation class A

Properties of pressboard

Depending on the type of cellulose, fibre preparation and machine settings, different types of pressboard with very special properties can be offered.

The composition and properties of pressboard are standardised in DIN 7733 and IEC 60641.

In addition to the high dielectric strength and the good impregnation ability with transformer oil, pressings do not have a melting point. Therefore, short-term, high thermal loads (e.g. a few seconds at 350 °C) can be tolerated.

Processing of pressboard

Pressboard can be punched, folded, cut and partially formed as well as laminated with various foils.

Stamped parts from pressboard

Pressboard can be processed into stamped parts and moulded parts for insulation purposes using all common stamping methods.

Adhesive tapes made from pressboard

Pressboard can be coated with various adhesive systems and then used as adhesive tape. Adhesive die-cut parts can then also be supplied on rolls.

Where to buy pressboard

Pressboard can be purchased from us or from our dealers and distributors.

Dr. Dietrich Müller GmbH also supplies pressboard with a diamond-shaped resin coating. The partial resin coating leads to a partial bonding of the electrical conductors with the layer insulation after curing. Through the resulting channels, air and moisture can be removed from the transformer in a short time and liquid insulating material can be filled in.

Corrugated chipboard with different geometries as well as strip grids and strip carpets are also used to form cooling channels. Shaped parts made of pressboard can be supplied as barriers at the coil ends of power transformers.

Pressboard is a very strong fine board made of high-quality raw materials with a glossy, smooth surface.

  • Insulation class A (up to 105°C)
  • made of unbleached sulphate pulp
  • high flexibility
  • high tensile and compressive strength
  • compatibility with impregnating and trickling resins
  • good impregnation properties
  • also with polyester film inner and outer layer

Brands available from us:

Flexiso®, Trivolton®, Triflexil®