Impregnating Varnishes
1040 Phenolic-Modified Polyester Varnish
Class F varnish with thick-layer curing and strong hot-state adhesion
1040 is composed of phenolic resin, modified polyester resin and solvents. It offers good moisture resistance, excellent thick-layer drying performance and strong hot-state adhesion for Class F motor and transformer windings.
Class F (155°C)Viscosity 40 ±8 sElectric strength ≥70 MV/m
- Temperature class
- Class F (155°C)
- Drying time (135°C)
- ≤90 min
- Thick layer curing
- 135°C / 4 h
- Storage
- Easy to use, stable
Request a quotation or a sample. Tell us thickness, width, temperature class, quantity and delivery form. We reply within one business day.
Technical data
| Property | Unit | Value |
|---|---|---|
| Appearance | — | Free of mechanical impurities, paint film smooth and glossy |
| Viscosity (No. 4 cup, 23 ±1°C) | s | 40 ±8 |
| Drying time (135 ±2°C) | min | ≤90 |
| Acid value | mgKOH/g | ≤10 |
| Thick-layer curing ability (135 ±2°C, 4 h) | — | Not inferior to S1, U1, 14.2, uniform |
| Power-frequency electric strength, normal | MV/m | ≥70 |
| Power-frequency electric strength, after water immersion | MV/m | ≥60 |
| Volume resistivity, normal | Ω·m | ≥1×10¹² |
| Volume resistivity, after water immersion | Ω·m | ≥1×10¹⁰ |
| Temperature class | — | Class F (155°C) |
Values are typical values or ranges from our product data. Bulk supply is subject to the approved specification, sample and test report. If a parameter you need is not listed here, ask our engineers for the full test report for that grade.
Key features
- Good thick-layer curing for large coils and repeated impregnation.
- High hot-state bond strength reduces coil loosening in service.
- Class F heat resistance with balanced mechanical, electrical and moisture performance.
Applications
Impregnation of Class F motors, transformers and appliance coils; windings requiring thick-layer curing.
Electric Motors & GeneratorsOil-Immersed TransformersDry-Type Transformers
Why it fits
The workhorse Class F varnish - it cures through thick layers where a thin varnish leaves the inside wet.
Ordering information
To receive a quotation, please confirm:
- Product and grade
- Thickness and width (and roll or sheet size)
- Temperature class
- Quantity and delivery form (roll / sheet / die-cut / machined)
- Destination port and required delivery date
For machined parts, attach a drawing in PDF, DWG or STEP format. Datasheets, COAs and batch test data are available on request.
Related materials
Often specified together
Send your specification
Our export team reviews the application, the process and the existing specification before recommending a construction.