Polyester Film Emerges As Key Electrical Insulation Material

Imagine the electrical appliances in your home—from the humming refrigerator to the high-speed hair dryer—all filled with intricate circuits. The safe operation of these circuits largely depends on an unassuming material: polyester film. Like an invisible guardian, it protects our electrical equipment under various harsh conditions. Today, we delve into the remarkable properties and applications of this versatile material.

Polyester film, commonly referred to as PET (polyethylene terephthalate) film, is a widely used polymer material. Known for its exceptional physical, chemical, thermal, and optical properties, it holds a significant position in industrial applications. In simple terms, it is a flexible, durable, and resilient film capable of withstanding demanding environments.

• Mechanical Strength: Polyester film boasts impressive tensile strength, averaging 210 megapascals (MPa). This means it can endure substantial pulling forces without breaking, ensuring reliability across various applications.
• Chemical Resistance: It resists most chemicals, making it stable in complex chemical environments without corroding or dissolving.
• Moisture Resistance: With excellent moisture-barrier properties, it effectively prevents water penetration, safeguarding electronic components from humidity damage.
• Temperature Tolerance: Polyester film maintains stability across extreme temperatures, typically ranging from -70°C to +150°C. Specialized variants can withstand even higher temperatures, with some meeting the B-class insulation standard for long-term use between -60°C and +130°C.

Polyester film plays a pivotal role in the electrical industry, particularly in:

• Complementing Primary Insulation: In motors, transformers, and other electrical devices, it works alongside materials like insulating paper and varnish to enhance overall insulation performance.
• Composite Insulation Materials: When combined with other flexible materials, it forms laminated insulating layers with superior dielectric strength, heat resistance, and mechanical durability.
• Switch Components: It serves as insulating membranes or gaskets in switches, ensuring circuit isolation and preventing short circuits or leakage.

Polyester film is typically supplied in rolls with a 76mm core diameter. Standard thickness options include: 12µm, 23µm, 36µm, 50µm, 75µm, 100µm, 125µm, 190µm, 250µm, 300µm, 350µm, and 500µm, allowing users to select based on application needs.

The market offers diverse polyester film models, each with slight performance variations. Notable examples include:

• ERGOPET Series: ERGOPET00, ERGOPET01, ERGOPET05, ERGOPET10, ERGOPET11, ERGOPET22, ERGOPET41, ERGOPET46, ERGOPET60, and ERGOPET M.
• Mylar® Series: A high-performance polyester film produced by DuPont Teijin Films.

When choosing polyester film, consider:

• Application Environment: High-temperature or humid conditions demand films with corresponding resistance.
• Electrical Performance: Insulation strength and dielectric constants must align with circuit design requirements.
• Mechanical Properties: Tensile strength and elongation affect processing and operational reliability.
• Thickness: Impacts insulation efficacy, durability, and cost.
• Brand and Supplier: Reputable sources ensure consistent quality.

Innovations in polyester film focus on:

• Enhanced Performance: Modified or composite films for greater heat/chemical resistance and strength.
• Functional Coatings: Conductive, anti-static, or UV-protective layers to expand applications.
• Sustainability: Biodegradable or recyclable alternatives to reduce environmental impact.
• Smart Integration: Embedding sensors for real-time temperature or humidity monitoring.

Polyester film is an indispensable engineering material, quietly ensuring the safety and reliability of electrical systems. By understanding its properties and evolving applications, we can better harness its potential. Next time you use an appliance, remember this unsung hero working behind the scenes.

DuPont™ and NOMEX® are trademarks or registered trademarks of E.I. du Pont de Nemours and Company. MYLAR® is a trademark or registered trademark of DuPont Teijin Films.