G4 High Density Transformer Insulation Pressboard

High density Transformer Insulating Pressboard is manufactured from 100% high-purity sulfate wood pulp through hot-pressing technology. As an essential dielectric material in the oil-paper composite insulation systems of transformers and transmission equipment, it provides reliable insulation and mechanical support.

Manufactured from high-purity cellulose fibers, high density pressboard is widely used for producing transformer insulation parts such as cylinders, angle rings, support blocks, oil duct strips and winding spacers.

What Is High Density Transformer Pressboard?

High density transformer pressboard is a cellulose-based insulation board specifically designed for oil-filled transformer applications.

Compared with ordinary insulation board, high density pressboard offers:

• Higher compressive strength

• Better dimensional stability

• Excellent dielectric properties

• Superior oil absorption characteristics

• Long-term performance in transformer oil

After drying and oil impregnation, the material becomes an integral part of the transformer insulation system and contributes to both electrical insulation and mechanical support.

Why High Density Pressboard Is Used in Transformers

Inside an oil-immersed transformer, insulation materials must do more than simply separate conductors.

They must also:

• Support winding structures

• Maintain insulation clearances

• Resist short-circuit forces

• Form oil circulation channels

• Withstand long-term thermal aging

High density transformer pressboard is widely used because it performs all of these functions simultaneously.

For this reason, nearly every oil-immersed transformer contains pressboard components in multiple locations.

Available Supply Forms

Chengrui Insulation  can supply high density transformer pressboard in:

Full Sheets: Suitable for transformer manufacturers and insulation processors.

Cut-to-Size Sheets: Ready for production and fabrication.

Semi-Finished Components: Pre-cut parts according to customer dimensions.

Finished Transformer Insulation Components: Pressboard cylinders, rings, strips etc

Application:

G4 high density pressboard meets the stringent insulation requirements of critical components in EHV/UHV AC/DC transformers, reactors, and UHV switches. It is widely used for transformer layer insulation, coil winding, and other specialized insulation applications in high-voltage electrical equipment.

Frequently Asked Questions

Q1: Is high-density pressboard suitable for power transformers?

A: Yes. High density pressboard is widely used in both distribution transformers and power transformers.

Q2: Can you manufacture according to drawings?

A: Yes. We regularly produce customized transformer insulation parts according to customer drawings and samples.

Q3: Do you supply finished transformer insulation components?

A: Yes. In addition to pressboard sheets, we supply cylinders, rings, angle rings, oil duct strips and various custom-machined transformer insulation parts.