CMC 70421 – Preliminary Technical Data Sheet Preliminary
CMC 70421 is a high-temperature insulating tape based on a polyimide film with high dielectric strength and good mechanical properties.
Issued: 2026-03
Product description
CMC 70421 is a high-temperature insulating tape based on a polyimide film with high dielectric strength and good mechanical properties.
| Property |
Value |
| Backing material |
Zenimid GF 100 (polyimide) by Arkema |
| Colour |
brown / amber |
| Substrate thickness in mm |
ca. 0.025 |
| Total thickness in mm |
0.060 ± 10% |
Adhesive properties
| Property |
Value |
| Type of adhesive |
polysiloxane |
| Adhesive strength in N/cm according to internal method PV 1006-32 (180° peel from steel) |
≥2 |
Thermal properties
| Property |
Value |
| Temperature performance in °C |
180 |
| Short term temperature performance in °C (ca. 1 hour) |
350 |
| Insulation class according to IEC 60085 |
H |
Electrical properties
| Property |
Value |
| Breakdown voltage based on IEC 60243-1 in Veff. |
≥ 6'000 |
Mechanical properties
| Property |
Value |
| Tensile strength in N/cm |
≥ 40 |
| Elongation at break in % |
≥ 25 |
Other properties
| Property |
Value |
| Recommended storage cond.: cool and dry (15 - 25°C, < 65% rel. humidity) |
03/26 |
The technical data are average values and do not replace the user's own testing. Subject to change without notice. The PDF data sheet is binding.