Mica Tape HT Winding without Accelerator
Mica Tape HT Winding without Accelerator is a mica paper winding insulation tape built from a woven glass fabric carrier, an impregnated muscovite mica paper, and a polyester fleece covering, with a total weight of 241 ± 15 g/m² (7.11 ± 0.44 oz/yd²) and a thickness of 0.18 ± 0.02 mm (7.09 ± 0.79 mil). It contains no accelerator and is rated for thermal class F (155°C) electrical insulation systems, designed for use in vacuum pressure impregnation (VPI) processing with a polyesterimide resin. Its porosity of ≤2000 s/100ml provides very good impregnability, and its polyester fleece covering allows additional processing stress during flexible coil manufacture.
Key Properties
- Thickness: 0.18 ± 0.02 mm (7.09 ± 0.79 mil)
- Glass Fabric Content: 23 ± 2 g/m² (0.68 ± 0.06 oz/yd²)
- Mica Paper Content: 160 ± 10 g/m² (4.72 ± 0.29 oz/yd²)
- Total Weight: 241 ± 15 g/m² (7.11 ± 0.44 oz/yd²)
- Resin Content: 38 ± 8 g/m² (1.12 ± 0.24 oz/yd²)
- Polyester Fleece Content: 20 ± 3 g/m² (0.59 ± 0.09 oz/yd²)
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- Specifications
- Applications
- General Info
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Physical Properties
| Property | Value | Test Method |
| Thickness | 0.18 ± 0.02 mm (7.09 ± 0.79 mil) | IEC 60371-2 |
| Glass Fabric | 23 ± 2 g/m² (0.68 ± 0.06 oz/yd²) | IEC 60371-2 |
| Mica Paper | 160 ± 10 g/m² (4.72 ± 0.29 oz/yd²) | IEC 60371-2 |
| Total Weight | 241 ± 15 g/m² (7.11 ± 0.44 oz/yd²) | IEC 60371-2 |
| Resin Content | 38 ± 8 g/m² (1.12 ± 0.24 oz/yd²) | IEC 60371-2 |
| Polyester Fleece | 20 ± 3 g/m² (0.59 ± 0.09 oz/yd²) | IEC 60371-2 |
| Porosity | ≤2000 s/100ml | ISO 5636/5 |
Mechanical Properties
| Property | Value | Test Method |
| Tensile Strength | ≥80 N/cm (≥45.7 lbf/in) | IEC 60371-2 |
| Stiffness | ≤80 N/m (≤0.457 lbf/in) | IEC 60371-2 |
Thermal Properties
| Property | Value | Test Method |
| Thermal Class | F (155°C) | IEC 60085 |
Storage Properties
| Property | Value | Test Method |
| Min. Shelf Life at 20°C | 12 months | — |
| Min. Shelf Life at 5°C | 24 months | — |
Compliance
- IEC 60371-2 — Compliant
- ISO 5636/5 — Compliant
- IEC 60085 — Compliant (Thermal Class F, 155°C)
- Main wall insulation for vacuum pressure impregnated (VPI) high voltage motor coils
- End winding insulation for high voltage motors up to 6.6 kV
- End connection insulation for VPI coil assemblies
- Coil insulation processed with polyesterimide VPI resin systems
- Thermal class F (155°C) electrical insulation systems for rotating machinery
Common industries: High-voltage motor manufacturing, electrical insulation systems, rotating machinery (VPI coil manufacturing).
Mica Tape HT Winding without Accelerator is a mica tape from Von Roll’s mica tapes product line, constructed from a woven glass fabric carrier, an impregnated muscovite mica paper, and a polyester fleece covering. It does not contain any accelerator and is intended as main wall insulation for vacuum pressure impregnated (VPI) coils, primarily designed to be used with a polyesterimide resin; the properties of the VPI resin selected will determine the final thermal, electrical, and mechanical properties of the finished insulation system.
The tape is flexible for rapid and easy coil manufacture, and its porosity of ≤2000 s/100ml (ISO 5636/5) gives it very good impregnability during VPI processing. The polyester fleece covering allows some additional stress on the tape during processing. Von Roll recommends applying the tape half-lapped, and optimal results can be achieved together with Damisol® 3308 or 3309 resin and Epoflex® 324.03 as a protection tape; the tape is rated thermal class F (155°C) per IEC 60085, with a minimum shelf life of 12 months at 20°C and 24 months at 5°C. Compliant with IEC 60371-2, ISO 5636/5, and IEC 60085.
What differentiates Mica Tape HT Winding without Accelerator from accelerator-containing mica tapes?
Mica Tape HT Winding without Accelerator does not contain any accelerator, so its cure behavior is governed entirely by the VPI resin system selected rather than by an accelerator built into the tape. Its polyester fleece covering allows additional processing stress compared to unbacked mica papers, and combined with the appropriate VPI resin — such as Damisol® 3308 or 3309 — it delivers thermal class F (155°C) electrical insulation performance while remaining flexible enough for rapid, easy coil manufacture.
Why is porosity critical for a VPI mica insulation tape like Mica Tape HT Winding without Accelerator?
Porosity determines how quickly and completely the VPI resin can penetrate the mica paper layer during vacuum pressure impregnation. Mica Tape HT Winding without Accelerator's porosity of ≤2000 s/100ml (ISO 5636/5) gives it very good impregnability, allowing the resin to fully saturate the tape and reducing voids that would otherwise compromise the electrical and thermal performance of the finished coil.
What is the thermal class rating for Mica Tape HT Winding without Accelerator?
Mica Tape HT Winding without Accelerator is rated thermal class F (155°C) per IEC 60085.
Is Mica Tape HT Winding without Accelerator suitable for high-voltage electrical insulation environments?
Yes. It is tested to IEC 60371-2 for its physical and mechanical properties and ISO 5636/5 for porosity, carries a thermal class F (155°C) rating per IEC 60085, and is designed as main wall insulation for VPI coils used in high voltage motors up to 6.6kV.
How should Mica Tape HT Winding without Accelerator be specified?
Specify grade (Mica Tape HT Winding without Accelerator), thickness, roll width, VPI resin system compatibility, compliance requirements (IEC 60371-2, IEC 60085), dimensional tolerances, and finished format.
