Phenolic Laminated Sheet (Bakelite Board) for Precision Machining & Punching

Bakelite sheet, also known as phenolic laminated board, is a high-performance insulation material made from phenolic resin and impregnated paper under heat and pressure. It is widely used in electrical, electronic, and industrial applications due to its stable electrical properties, strong mechanical performance, and excellent machinability.

At SJ, we specialize in precision punching and CNC machining of bakelite boards, delivering reliable insulation components for demanding industrial environments.

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✅ Core Technical Specifications of Bakelite Sheet

Electrical Properties

• Volume Resistivity: ≥ 10¹² Ω·m
• Dielectric Strength: ≥ 12 kV/mm

Ensures safe insulation performance in high-voltage environments.

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Mechanical Properties

• Flexural Strength: ≥ 80 MPa
• Compressive Strength: ≥ 250 MPa
• Impact Strength: ≥ 3 kJ/m²

Provides excellent load-bearing capacity and resistance to cracking.

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Thermal Performance

• Operating Temperature: -40°C to 120°C
• Short-term higher temperature resistance available

Maintains structural stability without deformation under heat.

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Dimensional Stability

• Water Absorption: ≤ 0.5% (24h)
• Density: 1.45 g/cm³
• Warping: ≤ 3‰

Ensures minimal deformation and high precision after machining.

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✅ Bakelite Punching Process & Technical Requirements

Punching is a critical process in bakelite machining. To ensure high-quality parts, the following parameters must be strictly controlled:

1. Tooling Precision

• Punching Clearance: 5%–8% of material thickness
• Tool Hardness: HRC 58–62 (SKD11 steel)

👉 Ensures clean edges without cracks or burrs

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2. Processing Parameters

• Punching Speed: ≤ 200 strokes/min
• Punching Force Formula:
  P = 1.3 × L × t × τ

(τ ≈ 60 MPa for bakelite)

👉 Prevents overheating and resin carbonization

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3. Quality Control Standards

• Burr Height: ≤ 0.05 mm
• No Delamination Allowed

👉 Ensures high-quality edge finishing and structural integrity

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✅ Key Advantages of Bakelite Sheet

Electrical & Insulation Performance

• Stable resistance (10⁸–10¹⁰ Ω)
• Anti-static performance across the entire surface
• Suitable for transformer oil environments

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Mechanical Strength & Wear Resistance

• Flexural strength ≥ 120 MPa (vertical layer)
• Excellent wear resistance after machining
• Ideal for precision fixtures and tooling

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Dimensional Stability

• Low deformation after machining
• High flatness for PCB drilling backup boards

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Environmental Resistance

• Heat resistance up to 140°C (continuous)
• Resistant to weak acids and alkalis
• Moisture-proof and oil-resistant

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Long-Term Reliability

• Resistant to organic solvents
• Wide operating temperature range (20–120°C)
• Stable performance in harsh environments

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Cost-Effective Solution

• Material cost ~50% lower than ABS
• Ideal alternative for large-scale applications

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✅ Applications

Bakelite sheets are widely used in:

Electrical Industry

• Motor and transformer insulation parts
• Switchgear and distribution panels

Machining & Tooling

• PCB drilling backup boards
• ICT / ITE test fixtures
• Mold clamping plates

Industrial Applications

• Packaging machinery components
• Surface grinding pads
• Silicone mold tooling

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✅ Thickness Selection Guide

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✅ Special Material Options

• Low Dielectric Loss (tanδ ≤ 0.02) – for high-frequency circuits
• Arc-Resistant Grade (≥180s) – with aluminum oxide filler

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✅ Why Choose SJ (Our Advantages)

• ✔ 20+ Years Machining Experience – Skilled technicians ensure precision
• ✔ Professional CAD Engineering Support – Custom drawings & optimization
• ✔ Wide Thickness Range (3–80mm) – Full customization available
• ✔ SGS Certified Quality – Reliable and tested materials
• ✔ Premium Raw Materials – Stable performance & durability
• ✔ Factory Direct Supply – Lower cost, faster communication

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✅ CNC Machining & Punching Capabilities

• Precision punching
• CNC cutting & milling
• Drilling & tapping
• Custom insulation components

👉 Tight tolerance and stable batch quality

👉 Send your drawings for fast quotation
👉 Get professional insulation machining solutions within 24 hours