Pre-treatment of films

Of course we offer different types of surface treatments upon request for optimizing surface tension to ensure that our films withstand even the highest strains in printing and bonding.

Corona pre-treatment
In the scope of this pre-treatment method, film webs are exposed to a “thunderstorm” of electrical discharge on one or on both sides. For this purpose, the film is inserted between an electrode and a counter electrode that is lit. The plasma of this corona discharge (ozone is released) oxidizes the film surface, thus increasing surface tension of the film. 
Depending on material grade, the effect of this method lasts about 4 to 6 months. The effect tends to last for a shorter period in TPU films and may also be reduced through greases and fluctuations in temperature. Thus Corona-treated films should only be touched when wearing gloves!

Flame treatment
During this treatment, radicals are created on the film surface using hot gas flames. Lightly bonded impurity layers are burned through the flame and the top film layers are oxidized. The oxygen atoms thus infused into the polymer structures increase the surface energy of the films and improve their wettability. Since absorption depth is very low, mechanical and optical properties of the substrates are hardly affected. 
Due to temperature effects this method can only be applied to materials with sufficient heat deflection temperatures (PA, PBT, PE, PP, etc.) and wall thickness (>=0.3mm)!
The effect of this method lasts about 6 to 12 months (depending on storage). Unlike in the case of corona pre-treatment the effect is largely preserved even upon exposure to temperature effects (i.e. during thermosublimation, tempering, etc.).

Flame polish (FPG)
This is a method with mainly optical effects.
Similar to flame treatment, the top surface layer of the film is melted, not only increasing clarity of the surface finish but evidently also improving abrasion resistance.

CC treatment (Controlled Crystallinity)
CC is a special tempering method – for which we hold the patent – for sintered skived films.
Brief heating of the film above the melting point and immediate subsequent cooling optimize the film’s properties, resulting in:

  • Reduced crystallinity
  • Higher transparency
  • Reduced density
  • Improved wax absorption (of ski surfaces)

Sanding (Surface sanding)
Employing this method the surface is mechanically enlarged by sanding to achieve even better bonding strength through mechanical anchoring of the adhesion system.
As standard, surface sanding of such materials is always executed in combination with flame treatment. For digital printing for our PE films we offer the Contour Finish sanding.