Transformer Insulation Materials
DDP Diamond Dotted Paper
Class A electrical kraft paper with a diamond-pattern epoxy dot on both faces
Diamond-pattern epoxy dots on both faces of Class A electrical kraft paper. The dots bond layers together after heat curing while the un-dotted area keeps the oil paths open for cooling and impregnation.
Class A (105°C)Thickness 0.08–0.25 mmWidth 5–960 mm
- Temperature class
- Class A (105°C)
- Thickness
- 0.08–0.25 mm
- Core ID / Roll OD
- 76 mm / approx. 250 mm
- Supply form
- Rolls, sheets, die-cut
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 |
|---|---|---|
| Thickness | mm | 0.08 / 0.13 / 0.18 / 0.25 |
| Width | mm | 5–960 |
| Core inside diameter | mm | 76 |
| Roll outside diameter | mm | approx. 250 |
| Density | g/cm³ | 0.85–1.10 |
| Adhesive thickness, one side | µm | 5–15 |
| Moisture content | % | 4.0–8.0 |
| Temperature class | — | Class A (105°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
- Diamond-pattern dots on both faces form localised bonds after heat curing, so layer position stays stable during the whole winding process.
- Available in rolls, sheets or die-cut pieces for continuous winding and manual insertion.
- Thickness and width can be specified to match the transformer rating and the existing winding process.
Applications
Turn-to-turn and layer insulation in oil-immersed power transformers, distribution transformers, instrument transformers and reactors.
Oil-Immersed TransformersDistribution TransformersInstrument TransformersReactors
Why it fits
The dotted pattern gives you positioning during winding without closing the oil channels between layers - the problem with a fully glued paper.
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.