Electrical laminated wood sheet is widely used into manufacturing some devices for oil-filled transformer, such as upper and lower pressure plate, lead bracket and iron yoke cushion block. And it is used to make clamping device in mutual inductor. It can replace steel plate, insulation paper board, epoxy paper board and epoxy fiberglass board, which can lower the weight of the transformer and the cost of materials.

Advantages:

1. Proper specific weight

2. High mechanical strength,

3. Good compatibility with transformer oil

4. Easy machining

 

Item Unit Index

Physical

Property

Density t/m3 0.9~1.1
Rate of water content % ≤ 7
Thickness shrinkage ratio after drying ≤ 1.5
Oil absorption rate > 10
 Ultimate thickness expansion rate after oil impregnation ≤ 0.5
 Compatibility with transformer oil

Good

Mechanical

Property

 Tensile strength (Parallel direction) Mpa ≥ 50
 Compressive strength (Parallel direction) ≥ 50
(Vertical direction) ≥ 120
 Bending strength (Parallel direction) ≥ 100
(Vertical direction) ≥ 100
 Modulus of elasticity (Parallel direction) ≥ 7000

Electrical

Property

 Volume resistivity MΩ/m ≥ 10a
 Electrical strength (50Hz) 20℃ Transformer (Vertical) MV/ m ≥ 9
90℃ Transformer (Vertical) ≥ 7
20℃ Transformer (Parallel) KV/m ≥ 45
90℃ Transformer (Parallel)) ≥ 35
Dielectric loss factor (tg δ) (50Hz) 20℃ Transformer Oil   ≤ 0.02
 90℃ Transformer Oil   ≤ 0.13
Relative dielectric constant (∑ n)  20℃ Transformer Oil   ≤ 3
 90℃ Transformer Oil   ≤ 3.6