Insulation pressboard Introduction:

 Insulation pressboard  is made of 100% sulfate wood pulp and has high density (similar to T4). It has excellent properties of very flat, highest mechanical and electrical strength and little shrinkage. It is used in oil-immersed power transformer. Pressboard standard: IEC 641-3-1

Pressboard Thickness: 1.0-8.0mm

Size (mm): 6300*3200, 6300*1600, 4200*3200, 4200*1600, 3200*3150, 3200*2100, 2000×1000 1000×1000

 

   

 

Index.

 

 

Unit

Values
≤1.6 >1.6~3.0 >3.0
1 Nominal thickness tolerance % ≤10(±)
 

2

 

Nominal Grammage

 

g/cm3

1.00~1.20 1.00~1.25 1.15~1.30
3 Shear strength ,M.D. Mpa ≥100 ≥105 ≥110
4 Shear strength, C.M.D. Mpa ≥75 ≥80 ≥85
5 Elongation (M.D.) % ≥3.0
6 Elongation (C.M.D.) % ≥4.0
7 Shrinkage % ≤10.0 ≤7.5 ≤5.0
 

8

 

Shrinkage which would resume

 

%

 

≥45

 

≥50

 

≥50

 

 

 

 

11

 

 

 

 

Shrinkage:

M.D.  

 

 

 

%

≤0.5
C.M.D. ≤0.7
Thickness direction ≤4.0
12 Moisture content % ≤6.0
13 Ash content % ≤1.0
14 Electrical conductivity of aqueous extract ms/m ≤1.6 >1.6~3.0 >3.0
15 Aquesous extract (PH) 6~9
16 Oil absorption % ≥11.0 ≥9.0 ≥7.0
17 Voltage resistant strength(In air) MV/m ≥12 ≥11 ≥10
18 Voltage resistant strength(In oil) MV/m ≥40 ≥35 ≥30