High Quality Bakelite Sheet

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Product details

AHD Bakelite Sheet: Industrial-Grade Thermoset Insulation Solution

Ⅰ. Product Overview

AHD Bakelite Sheet (also known as phenolic resin sheet) is a high-performance thermoset composite material, engineered by impregnating high-quality cellulose paper or cotton cloth with phenolic resin, followed by high-temperature pressing and curing. It is renowned for its exceptional electrical insulation, mechanical strength, heat resistance, and flame retardancy—making it a staple in industries requiring reliable performance in harsh operating environments.

As a popular product from AHD Polymer (a 31-year leader in engineering plastics), this Bakelite Sheet is produced is supported by 200+ technical specialists (including 30+ senior engineers). It delivers consistent quality across batches, meeting the strict demands of high-precision electrical, mechanical, and automotive applications, and serves as a cost-effective plastic sheets.

Bakelite sheet also know as 3021 plastic sheet

Ⅱ. Characteristics and Advantages of Bakelite

Bakelite's core properties stem from its thermoset cross-linked structure (after curing, the molecular chains form a three-dimensional network that cannot be remelted or reshaped). Combined with the synergistic effect of fillers, this material excels in multiple dimensions:

1. Physical and Mechanical Properties

High Hardness and Rigidity: Cured Bakelite achieves a Brinell hardness of 150-200 HB (Brinell hardness), a tensile strength of approximately 50-80 MPa, and an even higher flexural strength of 80-120 MPa, exceeding some common thermoplastics and making it suitable for applications subject to load or friction.

Low Shrinkage and Dimensional Stability: Bakelite's thermoset structure results in extremely low shrinkage during curing. After molding, it exhibits virtually no expansion or contraction with changes in temperature or humidity, making it suitable for precision parts (such as electrical contacts and mechanical molds).

Outstanding Wear Resistance: The addition of wood powder filler results in a high surface hardness and a dense structure, resulting in wear resistance superior to most general-purpose plastics and low wear rate under long-term friction.

2. Thermal Properties

Excellent Heat Resistance: The long-term operating temperature of unfilled Bakelite is approximately 120-150°C. Adding asbestos or mica can reach 180-200°C (with even higher short-term temperature resistance). It can operate stably in high-temperature environments (such as heating parts of electrical appliances and industrial ovens).

Flame Retardancy: The molecular chain contains a large number of aromatic rings (phenol structure) and is tightly cross-linked. It is self-extinguishing (quickly extinguishes upon removal from a flame source) without the need for additional flame retardants. It also generates very low smoke during combustion, meeting strict safety standards.

3. Electrical Properties

High Insulation: Bakelite is a typical electrical insulating material with a volume resistivity >10¹⁴ Ω·cm, a breakdown voltage (AC) of 15-30 kV/mm, a dielectric constant (1 MHz) of approximately 4.5-5.5, and an extremely low dielectric loss tangent (<0.01). It is suitable for insulating components in high-voltage, high-frequency environments.

Arc Resistance: Even in the event of partial discharge (arcing) under high electric fields, the carbonized layer formed on the surface hinders arc propagation and prevents instantaneous breakdown. It is widely used in critical insulating parts such as switches and relays in electrical appliances.

4. Chemical Properties

Chemical Corrosion Resistance: With the exception of strong oxidizing acids (such as concentrated nitric acid and sulfuric acid) and high-concentration strong bases, it is virtually unreactive with common organic solvents (such as alcohols and hydrocarbons), oils, and saline solutions. It can be used stably in chemical equipment and humid environments.

Aging Resistance: Its molecular structure is stable, and it offers strong resistance to UV rays (requiring the addition of light stabilizers such as carbon black) and oxidation. It maintains its performance even after long-term outdoor exposure (e.g., in electrical appliance housings).

5. Dimensional Stability

Bakelite's linear expansion coefficient is only approximately 10 × 10⁻⁶/°C (one-fifth that of ordinary plastics), and its moisture absorption rate is less than 0.1% (virtually unaffected by humidity). Therefore, it can maintain high dimensional precision even in environments with fluctuating temperature and humidity.

Core Advantages Summary

Bakelite's irreversible curing properties give it inherent advantages in heat resistance, insulation, and dimensional stability. Combined with the enhanced mechanical properties of fillers, it has become an irreplaceable material in environments with high temperature, high humidity, high abrasion, or strong electric fields, and has long held a dominant position in traditional electrical appliances and industrial machinery.

AHD Insulated Bakelite Board

Ⅲ. Main Processing Methods

Mechanical processing is the primary processing method for bakelite sheets and is suitable for parts of conventional shapes. It includes turning, milling, drilling, sawing, and grinding.

Turning

Applicable Applications: Machining of circular and shaft-like parts (such as insulating sleeves and bearing retainers).

Milling

Applicable Applications: Machining of flat surfaces, grooves, and contours (such as insulating pads and electrical mounting slots).

Drilling

Applicable Applications: Mounting holes and locating holes (such as mounting holes for conductive rods in electrical equipment).

Sawing

Applicable Applications: Blanking (cutting large sheets into smaller blanks).

Grinding

Applicable Applications: Surface finishing (such as improving flatness and roughness) or removing burrs.

AHD High-Quality Bakelite Sheet

Ⅳ. Typical Applications of Bakelite

The applications of Bakelite are highly dependent on its properties, primarily focusing on three areas: electrical insulation, wear-resistant mechanical parts, and high-temperature-resistant structural components. Specific applications are listed below:

1. Electrical and Electronics Industry

Electrical Switches and Sockets: Bakelite's high insulation and arc resistance make it a core material for switch panels, socket housings, and circuit breaker contacts.

Motor and Electrical Coil Bobbins: Insulation bobbins for motor stators and rotors, transformer winding dies, and relay core supports must withstand both high temperatures and electric field stress.

Electronic Component Packaging: Early insulating packaging for transistors and capacitors, although partially replaced by engineering plastics, still finds application in high-reliability applications.

2. Machinery and Industrial Equipment

Wear-resistant transmission parts: Gears, bearing retainers, cams, and sliders. Leveraging its high hardness and wear resistance, Bakelite is suitable for applications involving low speeds, heavy loads, or frequent friction, such as older machine tools and textile machinery. High-temperature-resistant structural parts: Insulation panels and heat-resistant fixtures for industrial ovens and boilers, as well as positioning pins and connectors for high-temperature environments.

3. Daily Necessities and Hardware

Kitchen and Bathroom Fixtures: Bakelite was initially used for electric kettle handles, spatula handles, and bathroom switch panels due to its high-temperature resistance and non-toxic properties.

Tool Handles: Grips for tools such as electric drills and wrenches (requires a rubber non-slip coating), utilizing its insulation and sweat-resistant properties.

4. Automotive Industry

Ignition System Parts: Ignition coil bobbins and spark plug insulators (early models) in automotive engines, which must withstand the high temperatures and vibrations of the engine compartment.

Low-voltage Electrical Components: Wiper control module housings, utilizing its insulation and temperature resistance (-40°C to 120°C operating temperature).

Choose Bakelite Parts, Choose Reliability and Efficiency

In the Industry 4.0 era, "safety," "reliability," and "efficiency" are core requirements for parts and components. Bakelite parts, with their century-proven material properties, precision-controlled processing, and comprehensive application capabilities, have become the "insulation and heat-resistant experts" in the electronics, automotive, and industrial equipment industries.

Whether you need a lightweight insulation alternative to traditional metal or a functional component with high-temperature and corrosion resistance, our Bakelite parts offer customized solutions. Choosing us means more than just choosing a product; it means choosing our commitment to quality and guaranteed efficiency.