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SynTherm® – Insulating Materials

SynTherm® NKN

SynTherm® NKN is a flexible 3-ply insulation. It consists of a 25 μm polyimide film with calandered Nomex® layer on both sides.


The excellent dielectric and thermal properties of the polyimide film and the outstanding thermal and mechanical properties of the Nomex® layers result in a high quality insulating material. The outer aramide layers protect the polyamide film against the effects of hydrolysis and mechanical load. The high specific volume resistance and the dielectric strength are not affected by temperatures below 200 °C.


SynTherm® NKN is used in electric motors with a high load factor as slot insulation, phase insulation and wedges. Furthermore, it can be used in transformers and other electrical equipment as core, interlayer and final insulation if very high temperature resistance is required with simultaneous mechanical load.

  • Suitable for class C (200 °C) systems
  • Insulating material according to IEC 60626
  • UL approved e. g. E247773
  • RoHS compliant according to 2011/65/EU
  • Test standard IEC 60626-2
  • Sample conditioning acc. to standard atmosphere 23/50
Delivery forms

Total thickness in μm:
200, 300, 400, 530

SynTherm® NKN can be supplied:

  • in slit rolls from widths of 6 mm (depending on thickness) and above
  • in rolls approx. width of 900 mm
  • in sheets approx. 600 x 900 mm
  • 900 x 1000 mm

Overall diameter of the slit rolls/ rolls as required
approx. 240, 330 or 450 mm.


  • depth approx. 1 - 12 mm, distance approx. 1 - 10 mm
  • from widths of 10 to 240 mm and thickness of 0.20 mm

Polyimid-film + calendered Nomex® 2-sided

Technical data
Total thickness  Thickness tolerance  Kapton® - thickness  Nomex® paper thickness  Specific weight  Tensile strength longitudinal  Tensile strength transversal  Elongation at break longitudinal  Elongation at break transversal 
Unit of measure        
mm  0.2 0.3 0.4 0.53
± 15 ± 15 ± 10 ± 10
µm  25 25 25 25
µm  80 130 180 250
g/m²  190 290 410 540
N/mm²  95 100 100 100
N/mm²  55 50 70 70
15 15 15 15
15 15 15 15
Total thickness  Dielectric strength 
Unit of measure        
mm  0.2 0.3 0.4 0.53
kV  8 10 11 12

SynTherm® is a registered trademark of SynFlex.
Nomex®, Kapton®, KAPTON® are registered trademarks of E.I. Du Pont de Nemours and Company.
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