Our Diamond Dotted Insulation Paper (DDP) is produced by coating modified epoxy resin in a diamond-dotted pattern on electrical insulating paper. The epoxy adhesive is applied to both sides of the paper in a 9.5mm × 9.5mm diamond pattern with 15.9mm center spacing. During the coil drying process, the epoxy resin softens and cures, bonding the coil into a fixed unit. The bonding strength of the epoxy resin is sufficient to prevent layer displacement within the winding under short-circuit conditions, ensuring the long-term mechanical and electrical stability of the insulation structure. Diamond Dotted Paper is widely used for interlayer insulation and turn-to-turn insulation in oil-immersed power transformers.
1. Insulation class A (105 °C) according to IEC 641
2. Width: 960 mm (Can be customized)
3. Thickness: 0.08 mm, 0.13 mm, 0.18 mm, 0.20 mm, 0.25 mm (Can be customized)
4. Kraft paper, 100% sulfate pulp
5. High purity and mechanical strength
6. Baked enamel coating: Epoxy resin, rhombic, one or both sides
7. Good compatibility with liquid dielectric after the baked enamel coating has hardened
8. Care should be taken that the layers to be baked remain closely pressed against each other during baking time
9. Approved by UL (No.: E310670), ROHS, and REACH tests
| Item | Diamond Dotted Paper | ||||
| Units | DDP-01 | DDP-02 | DDP-03 | DDP-04 | |
| Thickness | μm | 77 | 129 | 177 | 260 |
| Thickness of Coating Film | μm | 9 | 9 | 10 | 10 |
| Mass per Unit Area | g/m² | 75.5 | 127.6 | 174.3 | 251.7 |
| Density | g/cm³ | 0.98 | 0.99 | 0.99 | 0.97 |
| Tensile Index | Nm/g | 101 | 97 | 103 | 73 |
| 59 | 48 | 50 | 34 | ||
| Tensile Strength | N/15mm | 114 | 186 | 269 | 274 |
| 67 | 92 | 131 | 130 | ||
| Elongation at Break | % | 2.1 | 2.3 | 2.4 | 1.7 |
| 8.8 | 7.0 | 6.2 | 6.0 | ||
| Tear Index | mNm²/g | 8.3 | 12.8 | 14.7 | 15.9 |
| 9.1 | 14.0 | 15.5 | 17.5 | ||
| Internal Tearing Resistance |
mN | 625 | 1634 | 2564 | 4002 |
| 689 | 1790 | 2707 | 4405 | ||
| Conductivity of Aqueous Extract |
mS/m | 1.4 | 1.9 | 1.9 | 2.0 |
| PH of Aqueous Extract | – | 6.9 | 6.7 | 6.9 | 7.0 |
| Ash Content | % | 0.15 | 0.18 | 0.11 | 0.2 |
| Electric Strength(a.c) | kV/mm | 10.4 | 7.7 | 8.0 | 7.8 |
| Bond Strength ※ | psi | 104 | 116 | 121 | 110 |
* Diamond dotted paper is suitable for turn-to-turn insulation of coil windings in oil-immersed power transformers and layer insulation in distribution transformers.
* It can also be used as a shielding isolation layer for cables and an anti-corona material for high-voltage motors and electrical equipment.
GBS Die Cut, as adhesive tape supplier, focuses on the research & development, production and sales of various types of adhesive tapes for different industries and has been authorized as golden distributor of many noted brands for so many years, such as Nomex, Formex, Rogers Poron, 3M, Tesa, and so forth.
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