What is Bakelite? Properties, Types, and Applications
2025/11/6
What is Bakelite?
Bakelite (polyoxybenzylmethylene glycol anhydride) is a thermosetting plastic made from phenolic resin. It is produced by reacting phenol and formaldehyde with an alkaline catalyst, then forming the resin into laminated sheets, blocks, or rods by impregnating substrates such as paper or fabric.
Despite its low cost, Bakelite offers excellent strength, heat resistance, electrical insulation, and chemical resistance, making it a reliable material for industrial parts, electrical components, and tooling.
Brief History
Bakelite is considered the world’s first synthetic plastic. Initially popular in consumer goods like jewelry, kitchenware, and accessories, it became highly valued for electrical insulation as electricity spread. Though its use declined with the rise of mass-produced plastics, Bakelite remains cost-effective and durable for specific applications and tooling.
Types of Bakelite
Type | Description | Key Applications |
|---|---|---|
Paper Bakelite | Lightweight and inexpensive; mainly used for electrical insulation. | Terminal boards, insulators, lower-cost components |
Cloth Bakelite | Reinforced with cotton fabric, offering greater mechanical strength and impact resistance. | Knobs, switches, handles, industrial jigs, fixtures |
Key Properties
Property | Description | Notes |
|---|---|---|
Heat Resistance | Withstands continuous use around 130 °C. | Higher than most thermoplastics; thermosets cannot be remelted once cured. |
Electrical Insulation | Resistivity: 10¹²–10¹⁵ Ω. | Paper Bakelite is preferred for insulation-only applications due to lighter weight and lower cost. |
Mechanical Strength | High strength, especially in cloth-based types. | Strength varies by laminate direction; strong perpendicular to layers, weaker parallel. |
Water Absorption | Absorbs moisture from humid environments. | Can cause dimensional changes affecting performance. |
Weather Resistance | Limited; UV light and oxidation may darken color over time. | Mechanical properties remain largely unaffected. |
Chemical Resistance | Resists many chemicals but vulnerable to acrylic solvents and strong acids/bases. | Always confirm compatibility before use. |
Machinability
Bakelite sheets and rods have smooth, glossy surfaces, which can be lost during machining. Due to its laminated structure, care must be taken:
Perpendicular forces: Laminates are strong and maintain structural integrity.
Parallel forces: Laminates are weaker; screw-fastening along layers should use cloth Bakelite or consider alternatives like epoxy glass laminates for higher strength applications.
Applications
Bakelite is widely used in:
Electrical insulation: Printed circuit boards, transformers, breakers, terminal boards, distribution panels
Components: Knobs, switches, handles
Industrial tooling: Jigs, fixtures, and other durable, stable parts
Step Up Your Project with Yumoto Electric
Yumoto Electric delivers high-quality components fast, worldwide. We provide precision machining for a wide range of engineering plastics, including PEEK, PPS, MC Nylon, and POM.
If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.
