Briefly introduce Electrical Insulation Precompressed Pressboard

1、 Basic Definition

Electrical Insulation Precompressed Pressboard is a high-density cellulose insulation board made from high-purity unbleached kraft coniferous wood pulp and pre compacted at high temperature and high pressure. It belongs to Class A heat-resistant insulation material and is specifically suitable for oil immersed high-voltage electrical equipment.

2、 Core materials and processes

The raw material is long fiber pine/spruce pulp, without additional adhesive; Add a high-temperature and high-pressure pre pressing densification process during production, with a density of 1.10-1.30g/cm ³, much higher than ordinary insulation cardboard (0.9-1.0g/cm ³), and a moisture content strictly controlled within 5%.

3、 Key performance advantages

Dimensional height stability: The product has been pressed to the maximum density state at the factory, and there will be no secondary shrinkage deformation after assembly and clamping. The oil passage clearance remains unchanged for a long time;

Mechanical compressive strength: compressive strength of 80-120MPa, able to withstand large clamping forces of windings without cracking or collapsing;

Excellent insulation performance: oil immersion breakdown strength of 45-60kV/mm, resistance to high voltage electric fields;

Suitable for transformer oil: uniform oil absorption, chemically stable, and will not release impurities to contaminate the insulation oil;

Heat resistant Class A (105 ℃), insulation does not age rapidly under long-term high temperature conditions.

4、 Main purpose

Oil immersed power transformer (core)

End insulation corner rings, interlayer barriers, oil passage pads, iron core clamping insulation, lead support tubes, tap changer insulation partitions, necessary for high voltage main transformers of 66kV and above;

Transformers and reactors

Insulation cylinder of current/voltage transformer and internal support barrier of shunt reactor;

High pressure oil immersed casing

The main insulation pressure bearing lining plate inside the casing;

A small amount is used for high-voltage capacitors and large motor stator insulation supports.

5、 Specification range

Thickness 2-50mm, capable of cutting, milling grooves, and rolling cylindrical parts; Compared to ordinary cardboard, it focuses on high-pressure, high load, and long-life working conditions.