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SynTherm® – Insulating Materials

Kapton® CR polyimide film

Kapton® CR is a polyimide film specially developed for the effects of partial discharge which may cause ionisation and possible losses of insulating materials.


Kapton® CR combines the excellent features of Kapton® HN polyimide film with the advantages of a very glow-discharge resistant surface. Using a Kapton® CR polyimide film improves the resistance of the insulating systems of high-voltage generators or motors significantly.

  • rotating electrical machines
  • electrical insulation isolation
  • generators
  • traction motors
  • transformers
  • insulation of profile conductors and cables – specially in electrically highly utilized systems
  • UL liste, File Number E 39505
  • RoHS compliant acc. to 2011/65/EC
Delivery forms

Film thickness in µm:
25; 37.5



Technical data
Typical mechanical properties
Nominal thickness  Weight  Density  Tensile strength longitudinal  Tensile strength transversal  Elongation at break longitudinal  Elongation at break transversal 
Unit of measure     Test method 
µm  25 37.5 ASTM D-374-94
m²/kg  25.5 15.79  
g/cm³  1.54 1.72 ASTM D-1505-90
N/mm²  152 117 ASTM D-882-91
N/mm²  152 117 ASTM D-882-91
40 43 ASTM D-882-91
40 43 ASTM D-882-91
Typical electrical properties
Total thickness  Volume resistivity  Dielectric strength 
Unit of measure     Tetst method 
µm  25 37.5  
Ω x m  2.3 x 10^16 5.3 x 10^16 ASTM D-257-78
kV/mm  291 173 ASTM D-149-81

Nomex®, Kapton®, KAPTON® sind eingetragene Marken von E.I. Du Pont de Nemours and Company

Corona information, 31.03.2020

Dear business partners,

Despite the progressing corona pandemic, we as SynFlex have succeeded to date in maintaining our business operations at all locations. We offer our customers the accustomed high level of service in terms of delivery flexibility and advisory competence and we maintain existing agreements with our suppliers. Our staff currently provide excellent services despite the many precautionary measures necessary to protect everyone's health. They are fully available to you, in administrative areas usually from a home office.

It remains to be seen how things will continue. Crisis management dominates. It is simply impossible to make serious forecasts about future economic and social changes. All forecasts are plain guessing.

Thus, the resolutions remain: maximum solidarity, responsible action and best possible maintenance of all structures. There will be a time after SARS-CoV-2!

In this spirit we wish you all much steadfastness and good health.

Your SynFlex Team