Electrical Insulation Wood for Transformers | Weshare Complete Product Specification
1. General Overview
Made of high-quality wood veneers, processed by automatic patching machines to repair wood defects, and manufactured with advanced production technology before hot pressing forming. This series of electrical insulation wood is applicable to voltage environments of 110kV and above.
1.1 Electrical Laminated Wood Board
Electrical laminated wood board is a core insulating and supporting material widely used in transformers and instrument transformers.
Key Advantages
Moderate specific gravity and excellent mechanical strength
Suitable for vacuum drying and easy for mechanical processing
Dielectric constant close to transformer oil with optimized insulation matching
Long-term serviceable in transformer oil at a constant temperature of 105℃
Application Scenarios
Oil-immersed transformers: Upper/lower pressure plates, lead brackets, yoke cushion blocks
Instrument transformers: Clamping parts
Replaces steel plates, insulating paperboards, epoxy paperboards and epoxy glass cloth boards, reducing transformer weight and material costs
Production ProcessMade from high-quality hardwood including birch, maple and ash. The raw wood goes through cooking, rotary cutting and drying to form veneers. After coated with special insulating adhesive, the veneers are pressed and molded under high temperature and high pressure.
1.2 Mitered Joint Electrical Laminated Wood Board
Traditional electrical laminated wood boards adopt lap joint connection, which easily causes common defects including uneven density, unbalanced internal stress and internal air holes.
To upgrade overall product performance, Weshare adopts domestically advanced veneer grinding & lengthening units. All veneers are precisely ground and connected at a 7° mitered angle to realize integral whole-sheet veneer production.
The mitered joint laminated wood board perfectly solves the defects of ordinary lap-joint products, greatly improving mechanical strength and electrical properties, and fully meeting the technical requirements of high-voltage grade transformers.
1.3 X-type One-Piece Pressed Transformer Pressure Ring
The pressure ring is a key large-consumption insulating component inside transformers, requiring strict mechanical and electrical performance standards.
Defects of Traditional ProductsConventional pressure rings are processed from standard electrical laminated wood boards, which are stacked with veneer fibers arranged vertically between adjacent layers. After finished into pressure rings, the vertical bending strength in the radial direction varies greatly, with a maximum strength error up to 70%. This defect weakens the resistance to electromagnetic force of transformer wires and brings hidden dangers to transformer operation safety.
Weshare Exclusive Production TechnologyWe adopt an innovative one-step forming process:The fiber direction of the electrical wood blank is arranged in an X-shape along the radial direction, integrally pressed into a circular blank at one time, and finally processed into finished products by CNC woodworking centers.
Core Features
Integral high mechanical strength and high elastic modulus
Uniform vertical bending strength in all radial directions
Density ≥ 1.1 g/cm³
Radial bending strength: over 120 MPa stably
Customized large size: maximum finished diameter up to 2400mm
2. Standard Specifications (Unit: mm)
| Standard Size (mm) | Standard Thickness (mm) |
|---|---|
| 3000 × 2000 | 10 ~ 120 |
| 3000 × 1500 | 10 ~ 120 |
| 2400 × 1200 | 10 ~ 120 |
| 2000 × 1000 | 10 ~ 120 |
| 2000 × 2000 | 10 ~ 120 |
| 2200 × 2200 | 10 ~ 120 |
| 2400 × 2400 | 10 ~ 120 |
Customized sizes are available upon request.
3. Flatness Tolerance
3.1 Boards Flatness (Unit: mm)
Maximum distance of points on the veneer face from light-weight straight ruler:
| Nominal Thickness (mm) | 500 mm Straight Ruler | 1000 mm Straight Ruler |
|---|---|---|
| ≤ 15 | 2.0 | 4.0 |
| > 15 ~ ≤ 25 | 1.5 | 3.0 |
| > 25 ~ ≤ 60 | 1.0 | 2.0 |
| > 60 | 1.0 | 1.0 |
3.2 Ring Flatness (Unit: mm)
Maximum distance of points on the ring face from light-weight straight ruler:
| Nominal Thickness (mm) | 500 mm Straight Ruler | 1000 mm Straight Ruler |
|---|---|---|
| ≤ 15 | 2.5 | 6.0 |
| > 15 ~ ≤ 25 | 2.0 | 4.0 |
| > 25 ~ ≤ 60 | 1.5 | 2.0 |
| > 60 | 1.0 | 1.5 |
4. Surface Quality Standard
| Item | Allowed Range |
|---|---|
| Swelling, Cracking, Dead Knot, Foreign-body Adhering, Insect Hole, Rot, Contamination | Not Allowed |
| Bruising, Impression, Color-odds and Splash | A few allowed, not affecting usage |
| Patches per sq.m. on surface | ≤ 3 |
5. Pricing & Customization
The price of transformer insulation wood series (laminated wood board, mitered joint wood board, X-type pressure ring) is not fixed.
The final quotation is comprehensively determined by:
Product type and voltage grade (110kV and above)
Size, thickness, density and processing requirements
Order quantity and delivery destination
Special certifications or custom formulations
For wholesale, OEM and project bulk orders, please contact Weshare sales team to get the latest ex-factory price, bulk discount and custom solution.
6. FAQ (Frequently Asked Questions)
Q1: What is the maximum operating temperature of your electrical laminated wood?
A: Our standard electrical laminated wood is specially formulated to operate continuously at 105℃ in transformer oil, meeting the long-term thermal stability requirements for oil-immersed transformers. For higher temperature grades, we can provide customized adhesive formulations upon request.
Q2: Can your products be custom machined to specific shapes?
A: Yes. All our laminated wood boards and pressure rings can be precisely machined via CNC cutting, drilling, milling, and sawing to meet your exact design requirements, including custom pressure rings with diameters up to 2400mm.
Q3: What is the minimum order quantity (MOQ)?
A: We offer flexible MOQs to support both small trial orders and large-scale bulk projects. Standard sheet MOQ is typically 1 sheet; custom pressure rings and processed parts may have higher minimum quantities based on complexity. Please contact our sales team for details.
Q4: What certifications or standards do your products comply with?
A: Our electrical insulation wood products are manufactured in compliance with major industry standards for transformer insulation materials. We can provide test reports and certificates for key performance indicators such as density, bending strength, dielectric properties and oil compatibility upon request.
Q5: How do you package the products for international shipping?
A: We use export-grade fumigated wooden crates with waterproof plastic wrapping and foam padding inside, to prevent moisture, scratches and mechanical damage during long sea or land transportation. Custom packaging solutions are available based on your destination and logistics requirements.
Q6: Can you provide samples for testing before bulk order?
A: Yes. We offer small sample sizes for performance and fit testing. Please contact our sales team with your specific requirements, and we will arrange samples with the most suitable specifications.
Q7: What is the typical lead time for production?
A: Standard size boards usually take 7-15 working days. Custom pressure rings or special machined parts take 15-30 working days, depending on order quantity and complexity. Urgent orders can be prioritized upon request.
