Varnishes

Varnishes

Four different impregnation techniques are used according to the particular material, the type, quantity of parts to be treated and the desired result.

Spraying

  • This procedure is used for treating single parts, requires little material and is therefore quite attractive. 

Simple dipping

The conditions for good impregnation with this procedure are:

  • Vernisdipping at room temperature.
  • in certain cases, to improve the penetration of the varnish to the core of the winding, prior preheating of the parts to a temperature of 50°C is advisable.
  • weight related drainage to earth of the material impregnated and the ventilation of the installation.
  • a raising of the ambient temperature to the recommended level. 
  • outlet for the evaporation of solvents.
    rise in temperature and polymerisation.

Vacuum and pressure in an autoclave 

This version, more technical than the previous ones is used where penetration to the core of difficult parts is necessary: 
  • dehydration at 130°C
  • slow introduction of the varnish via a partial vacuum to avoid the effects of bubbling
  • subjection to pressure (between 1 and 3 bars)
  • drainage
  • a progressive raising of the temperature with strong ventilation
  • outlet
  • rise to the recommended temperature*
  • polymerisation*

* refer to the documentation for the varnish chosen.

This information is based on our current knowledge and the results obtained in our laboratory in objective tests. It is given with the best of our knowledge and must be adapted to each particular case and does not imply any commitment on our part as to the use of the product.aucun engagement de notre part quant à l'utilisation du produit.
Drop-by-drop impregnation

Procedure requiring principally two-component resins. Its principle is:

  • preheating of the winding to 80°C by Joule effect or some other method.
    rotation of the winding around its axis at between 30 and 60 revolutions per minute.
  • flow of the resin via nozzles on to the hot, rotating part. On contact with the hot part the resin.
  • flows and penetrates to the core. The winding then fills up via capillary action.
  • with the rotation maintained, re-apply the heat. The resin gels quickly (a few minutes).
  • a post-curing will allow the reaction to complete and give the resin its optimum quality.
To choose the impregnation varnish best suited to your material, the parts to be treated and the technical requirements, refer to the paragraph “Recommended Uses” in each technical document.

Our sales engineers will be happy to advise you in the choice of varnish to use and the method to employ.