Dielectric cardboard is formed by sheets one on top of the other, in brown. It is easy to ccut and is very resistant and less elastic. It has a density between 1’2 and 1’3 according to thickness.
It is quite higroscopic and so easily absorbs humidity. Chemically it’s fabricated by neuter materials, almost exempt from minerals and free of salts, alcalies and acids.
Within it’s chsracteristics and uses indicated, it is unsurpassable as an electric insulator. The tension of perforation in sheets, not superior than 2 mm in thicness is 10.000 volts per millimetre of thickness.
It’s specific or constant dielectric capacity is aproximately equal to transformer oil. Once submerged in oil it has a great resistance to heat.
In the Electrical Industry it has an infinite number of applications and without the necessity of insulating, also there is not humidity, for example, electrics meters, condensores, radios transformers, enginers, dynamos etc.
In the field of appication in the techique of high tension, it is used in the contruction of transformers in plaques of a thickness between 2 to 4 mm. For low tension of 0’5 to 2mm as insulating material in telephone switchboards, collector rings,coils insulation surfaces, assembly material etc.
Dielectric cardboard is underformed when it contains air. The pure cells which form it are already an insulator, the air contained between it’s fibres increases the insulating effect witch is even better when the material is drier. For this reason it is used to insulate pieces and conductores of electrical current.
|Thickness||Tension of perforation (volts)||Ash %||Insoluble test of colorings in mineral oil|