Presspahn: Presspaper, pressboard, corrugated board

Presspahn is a proven surface insulation material on cellulose basis for the insulation class A. Depending on the type of cellulose, fibre conditioning and machinery settings, KREMPEL supplies a variety of presspaper and pressboard types with very specific characteristics.

The properties and characteristics of the presspaper and pressboard materials are standardised in DIN 7733 and IEC 60641. Besides the high breakdown voltage and the high capacity for impregnation with transformer oil (dielectric mix of oil-cellulose), the pressboard can withstand high heat loads for short periods of time (e.g. 350 °C for a few seconds) because the material has no melting point. Also, the presspaper and pressboard can be punched, folded, cut and in some cases be shaped as well.

With „KREMPEL-DPP“ – Diamond-Pattern epoxy-coated Papers – KREMPEL presspaper is available with a diamond dotted resin coating. Applying pressure at an elevated temperature for a certain length of time leads to partial adhesive bonding of the electrical conductors with the vertical separators. The channels that thereby develop can be used to remove air and the moisture from the transformer. The voids can subsequently be filled with liquid insulation material.