Diamond dotted insulation paper(DDP)
Diamond dotted insulation paper (DDP) is made by coating special modified epoxy resion on the high-performance and low dielectric loss insulating paper.It is widely applied in inter-layer insulation and turn insulation of oil-immersed power transformers. During application, the coated layer starts to melt under certain temperature in the process of coil drying and results in adhesion effect. As temperature rises, it starts to solidify and make coils’ adjacent layers reliably bond into a fixed unit. The adhesive strength of epoxy resin is strong enough to prevent the displacement of coil layers in case of short-circuit, so as to ensure the long-term mechanical and electrical performance of insulation structure.
As the resin coat of diamond pattern adhesive insulating paper is dot shaped, the paper ensures oil immersion and the discharge of gas from insulation materials, effectively prevents electric corona and partial discharge, thus ensuring the safety and reliability of insulation structure.
Product Solidification Conditions
First curing under temperature 90℃±5℃ for 3 hours, and then rise temperature to 125℃±5℃ and keep 6 hours to cure;curing in accordance with the privision of both parties is also available.
Storage
Store in a dry,clean and well-ventilated warehouse, and keep away from fire and heat point, also keep away from the sun. The storage period is one year, qualified products exceeding the storage period can still be used.
Specification
No. | Property | Unit | Requirements | |||||||
1 | Base material thickness and tolerance | mm | 0.08±0.005 | 0.13±0.007 | 0.18±0.010 | 0.20±0.010 | 0.25±0.010 | 0.38±0.020 | 0.50±0.030 | |
2 | Base material tightness | g/cm³ | 0.85~1.10 | |||||||
3 | Single-sided adhesive thickness | um | 5~15 | |||||||
4 | Moisture | % | 4.0~8.0 | |||||||
5 | Ash contant | % | ≤1.0 | |||||||
6 | Conductivity of water extract | mS/m | ≤10 | |||||||
7 | PH value of water extract | - | 6.5~8.5 | |||||||
8 | Oil absorbtion | % | ≥20 | |||||||
9 | Bonding strength | Normal | kPa | ≥650 | ||||||
100℃±2℃ | ≥400 | |||||||||
10 | Contamination of transformer oil | - | No pollution（tanδ<0.001） | |||||||
11 | Tensile strength | MD | N/10mmWidth | ≥60 | ≥110 | ≥160 | ≥180 | ≥230 | ≥250 | ≥300 |
CD | ≥20 | ≥35 | ≥55 | ≥60 | ≥70 | ≥120 | ≥150 | |||
12 | Tear strength | MD | mN | ≥450 | ≥900 | ≥1350 | ≥1500 | ≥2000 | ≥3500 | ≥5000 |
CD | ≥500 | ≥1000 | ≥1500 | ≥1700 | ≥2300 | ≥4000 | ≥6000 | |||
13 | Breakdown Voltage | In air | kV | ≥0.88 | ≥1.37 | ≥2.00 | ≥2.10 | ≥2.25 | ≥3.00 | ≥4.00 |
In oil | ≥4.40 | ≥7.00 | ≥9.00 | ≥9.80 | ≥11.5 | ≥15.00 | ≥20.00 | |||
