High-strength, phenolic resin impregnated laminated wood designed for structural insulation and mechanical support in oil-immersed transformers and power equipment.
✔ Excellent mechanical strength
✔ Stable dielectric performance
✔ CNC machinable into custom parts
✔ Widely used in transformers & motors
Applications: Pressure rings | Support blocks | Yoke spacers | Clamping parts
Electrical Laminated Wood Board—also known as Insulation Laminated Wood, Transformer Wood, or Densified Wood— is a high-density insulating structural material made from multiple layers of birch or beech veneers bonded with thermosetting phenolic resin under high temperature and pressure.
It combines:
• The mechanical strength of hardwood
• The electrical insulation of resin systems
• The dimensional stability of engineered composites
It is widely used as a structural insulation and load-bearing component in transformers and high-voltage electrical equipment.
• High Mechanical Strength
Supports heavy mechanical loads in transformer assemblies without deformation.
• Reliable Electrical Insulation
Stable dielectric performance in oil-immersed environments.
• Excellent Machinability
Can be CNC machined into precision components such as rings, blocks, and spacers.
• Dimensional Stability
Low shrinkage and stable performance under long-term operating stress.
• Cost-Effective Engineering Material
Lower cost compared with epoxy glass cloth boards in structural insulation applications.
• Transformer Pressure Rings
Precision CNC-machined laminated wood pressure rings used in 10kV–110kV transformers. It provides uniform radial clamping strength, excellent compression stability, and good oil-impregnated thermal performance, serving as a lightweight alternative to epoxy glass rings.
• Load-Bearing Structural Insulation in Transformers
A replacement for epoxy boards, pressboard, and some metal fittings. It is used for clamping plates, yoke spacers, winding supports, and lead brackets in oil-filled transformers, ensuring both mechanical strength and electrical insulation.
• Winding Positioning & Short-Circuit Force Support
Maintains precise coil alignment and resists electromagnetic forces during short-circuit events, improving winding stability and structural integrity under high mechanical stress.
• CT & PT Internal Insulation Components
Used as structural insulation and support inside instrument transformers, replacing metal parts to reduce weight while maintaining insulation reliability and mechanical fixation.
1. Grade Selection Guide
| Grade | Recommended Voltage Level | Typical Application |
| DLW101 | >110 kV (Heavy duty) | High mechanical stress transformers |
| DLW201 | >110kV | Power transformers |
| DLW202 | 35-66kV | Medium voltage transformers |
| DLW301 | ≤35kV | Distribution transformers |
2. Technical Properties
| Item | Unit | Value | ||||
| DLW101 | DLW201 | DLW202 | DLW301 | |||
| Material | – | Birch / Beech veneers + phenolic resin (controlled formulation per grade) | ||||
| Thickness | mm | 8–150 (custom available) | ||||
| Sheet Size | mm | 1000×2000 / 1200×2400 (custom available) | ||||
| Insulation Class | – | Class A (105℃) | ||||
| Density | g/cm³ | 1.2-1.3 | 1.1-1.2 | 1.1-1.2 | 1.0-1.1 | |
| Vertical Layer Bending Strength (A/B Direction) | MPa | ≥80 | ≥65 | ≥65 | ≥55 | |
| Impact Strength (A/B Direction) | kJ/m² | ≥15 | ≥13 | ≥13 | ≥10 | |
| Interlaminar Shear Strength (ILS) | MPa | ≥9 | ≥8 | ≥8 | ≥7 | |
| Vertical Layer Electrical Strength (90 °C Transformer Oil) | kV/mm | ≥9 | ≥8 | ≥7 | ≥7 | |
| Shrinkage After Drying (A/B/Thickness Direction) | % | A/B Direction: ≤0.3 %; Thickness Direction: ≤3 % | ||||
| Water Content | % | ≤6 | ||||
| Oil Absorption | % | ≥5 | ≥8 | ≥8 | ≥10 | |
| Standard | – | GB/T 20634.3-2008 / IEC61061-2:1998 | ||||
• Not suitable for continuous high-temperature (>120°C) environments
• Moisture absorption may affect performance in humid conditions
• Not ideal for high-impact mechanical loads
• Requires proper sealing/storage before installation
We supply not only raw boards but also custom machined insulation parts:
• CNC cutting
• Drilling & tapping
• Precision shaping
• Pressure ring machining
• Custom transformer structural parts
👉 OEM / ODM available based on drawings
• Stable raw material sourcing (birch/beech veneer grade control)
• Consistent density control (1.0–1.3 g/cm³)
• Transformer-grade industrial supply
• CNC machining support for finished parts
• Export experience for electrical insulation materials
| Item | Laminated Wood | Epoxy Glass Cloth Board |
| Cost | Lower | Higher |
| Machinability | Excellent (CNC friendly) | Moderate |
| Mechanical strength | High | Very high |
| Heat resistance | Medium (≤105-120°C) | Higher (F/H class possible) |
| Moisture resistance | Lower | Higher |
| Best use case | Structural insulation parts | High-temp electrical insulation |
Laminated wood is best for structural + mechanical support parts, not extreme temperature insulation layers.
Q: Is laminated wood suitable for high voltage insulation?
Yes, it is widely used in oil-immersed transformer structural insulation.
Q: Can it replace epoxy boards?
Only in structural/mechanical support parts, not high-temperature insulation layers.
Q: Can you supply machined parts?
Yes, CNC machined transformer components are available.
Q: What is the main advantage?
High strength + insulation + low cost + easy machining.
We provide both raw boards and CNC-machined insulation components for global transformer manufacturers.
📩 Send your drawing or specification
📦 Get material recommendation + quotation within 24 hours
GBS Die Cut, as adhesive tape supplier, focuses on the research & development, production and sales of various types of adhesive tapes for different industries and has been authorized as golden distributor of many noted brands for so many years, such as Nomex, Formex, Rogers Poron, 3M, Tesa, and so forth.
Transformer insulation papers and flexible laminates are essential materials that ensure dielectric strength, thermal endurance, and mechanical stability in transformers, motors, and other electrical equipment. These materials are widely used
In the medical industry, medical tapes are not just for simple fixation; they play a crucial role in wound care, medical device adhesion, and surgical protection, directly impacting patient comfort
For inquiries about our products or price list, pls leave your email to us and we will be in touch within 24 hours.
