Mica products for electrical insulation

Von Roll is highly committed to mica. Our added value is visible throughout the complete manufacturing chain. It starts by mining, preparation of the mica scrap, preparation of the mica paper pulp, production of mica paper and finally production of mica tapes that can be used to the highest standards to make electrical insulation materials.

Von Roll uses two types of mica, phlogopite and muscovite, for a variety of applications and depending on the needed thermal and electrical characteristics.

Von Roll has the right solution to improve the quality and cost-effectiveness of the high-voltage insulation you need for your applications.

With Samicapor®, Von Roll has designed a range of outstanding VPI mica tapes that fulfill the requirements of main wall and end-winding insulation, namely

  • High dielectric strength
  • Corona discharge resistance
  • Fast and easy impregnation
  • Resin retention without draining
  • Smooth application without creasing
  • Both manual and fast-running machine application
  • Full compatibility with predefined resin systems
  • Applicable for flat coil technology
Main wall insulation

Assuring optimum quality of main wall insulation requires careful selection of micaceous tape and detailed attention to the way the tape is applied and processed. We offer a complete range of resin-rich (RR) main wall insulation tapes and systems under the name Samicatherm® for both conventional and hydrostatic pressing and Filosam® and Samicaflex® for the overhang areas.

The advantages of these tapes are that they:
» Have high dielectric strength
» Resist corona discharge
» Can be applied smoothly without creasing
» Can be applied by fast-running machines or manually
» Have short cutting times

Main wall insulation for RR

Samicafilm® products are based on Von Roll Samica® mica paper impregnated, reinforced with one or two polyester or polyimide film backings and with or without adhesive coating (hot-melt).

Samicafilm® tape covering on bare or enameled wires is the preferred conductor insulation for stator and rotor coils due to its substantial advantages:

  • Better corona resistance
  • Reduced insulation thickness
  • Softer copper, enabling easier workability
  • Greater manufacturing flexibility


Samicafilm conductor insulation

Mica mastic is used as a filler in conductor strands of Roebel bars at the points where conductors cross over. The material contains mainly mica powder and epoxy resin.

Mica mastic