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How does the RADOX cable radiation cross-linking process occur?

Since they are subjected to high pressure and high temperatures, electric motor components require special features.
In this article, we explore one of the processes that guarantees the resistance and stability of RADOX cables: the radiation cross-linking process.

Isolation of RADOX cables

  • Does not melt, even if subjected to high temperatures, such as when in contact with the stagnator.
  • Maintains its mechanical and insulating properties even at 250 °C
  • Has a similar behaviour to thermo-retractables, thanks to which small deformations caused by machining can be restored with just heat.


The cross-linking process of synthetic materials is like rubber vulcanisation.
Natural rubber is actually thermoplastic, but Good Year found that by adding sulphur, the rubber no longer sticks and becomes hard and elastic if exposed for a few minutes to a temperature of 150 °C.

The same result can also be obtained in synthetic materials, by means of cross-linking.
This process can be obtained:

  1. Through chemical reagents, under high temperatures and pressures
  2. Through radiation with electron beams (beta or gamma rays).

Today we are going to explain the radiation process with electron beams (cross-linking)


Thermoplastic materials are composed of long and thin molecules arranged in random order.

The resistance of these materials depends on:

  • The distance between the molecules
  • The links between the molecule chains
  • The crystalline structure of the molecules
  • The attraction force between molecules (in the case of polarised materials)
  • The various polymer chains inside a non-cross-linked thermoplastic material resemble a plate of spaghetti: the adhesion between one strand and the other is the only force that holds them together.

As soon as the material is heated, this simple adhesion bond is lost and the molecules are free to slide over each other, resulting in the melting of the material (a bit like if you added oil to the plate of spaghetti).

When the material cools, the bonds are reformed, establishing a new structure.

With electron beam radiation, the crystalline structure of polymer chains can be modified, transforming it from thermoplastic and to elastomeric and non-fusible.

il processo di reticolazione per irradiazione nei materiali sintetici

il processo di reticolazione per irradiazione nei materiali sintetici

The figures show the polyethylene cross-linking process: two adjacent molecule chains are bombarded with electrons, which break off some C-H bonds thus releasing hydrogen atoms.


To achieve a new energy balance, “splashed” carbon atoms create new bonds with other carbon atoms in adjacent chains, resulting in a highly resistant network structure supported by carbon double bonds.


Once cross-linked, the material will no longer melt, even at high temperatures.

In addition, the presence of simple adhesion forces coupled with carbon double bonds means the material acts similarly to thermo-retractables, since the compression-traction changes are eliminated as soon as the material is heated.

That’s why RADOX cables are the best for Electric Machinery – their unique features are the result of a highly technological production process that guarantees unlimited performance!

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