Knowledge What are the electrical and water absorption properties of PTFE? Unmatched Insulation & Moisture Resistance
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Tech Team · Kintek

Updated 3 days ago

What are the electrical and water absorption properties of PTFE? Unmatched Insulation & Moisture Resistance

PTFE (Polytetrafluoroethylene) is renowned for its exceptional electrical insulation properties and near-zero water absorption, making it ideal for high-performance applications. Its dielectric properties include a low dielectric constant (2-2.1 at 1MHz), minimal dissipation factor (0.0003-0.0007), and high dielectric strength (50-170 kV/mm). These characteristics remain stable across a wide temperature range (-200°C to +260°C) and under high voltages/frequencies. PTFE's non-hygroscopic nature ensures no moisture absorption, unlike many other materials, which preserves its electrical integrity. These properties can be tailored further through fillers or processing methods for specific needs, such as custom ptfe parts.

Key Points Explained:

Electrical Properties

  1. Dielectric Strength:

    • Ranges from 50–170 kV/mm, allowing PTFE to withstand high voltages without breakdown.
    • Ideal for insulating components in high-voltage equipment like transformers or cables.
  2. Dielectric Constant & Dissipation Factor:

    • Dielectric constant: 2–2.1 (at 1MHz), one of the lowest among polymers, minimizing signal loss in high-frequency applications.
    • Dissipation factor: 0.0003–0.0007 (at 1MHz), indicating minimal energy loss as heat, critical for precision electronics.
  3. Resistivity:

    • Volume resistivity: 10¹⁸–10¹⁹ Ohm·cm (near-perfect insulator).
    • Surface resistivity: 10¹⁷ Ohm/sq, preventing surface leakage currents.
  4. Stability Under Extreme Conditions:

    • Retains properties across -200°C to +260°C and under high-frequency signals.
    • Virgin (unfilled) PTFE offers the best electrical performance; fillers (e.g., glass, carbon) may alter properties for specialized needs.

Water Absorption Properties

  1. Non-Hygroscopic Nature:

    • Water absorption: Practically zero (0.001–0.005% by weight), unlike materials like nylon or rubber.
    • Unaffected by humidity, ensuring dimensional stability and consistent electrical performance in wet environments.
  2. Chemical Inertness & Non-Reactivity:

    • Resists acids, bases, and solvents, preventing degradation or swelling that could compromise insulation.

Practical Implications for Buyers

  • For custom ptfe parts:
    • Specify virgin PTFE for optimal electrical insulation or filled grades for enhanced mechanical properties (e.g., wear resistance).
    • Consider processing methods (molding, machining) that preserve PTFE’s inherent properties.
  • Applications:
    • Electrical: Insulators, circuit boards, wire coatings.
    • Sealing: Gaskets in corrosive/water-exposed environments.

PTFE’s combination of electrical superiority and moisture resistance makes it unmatched for demanding industrial and electronic applications. Always validate properties for your specific use case, as fillers or processing can introduce variations.

Summary Table:

Property PTFE Value Range/Characteristics Key Benefit
Dielectric Strength 50–170 kV/mm Withstands high voltages without breakdown.
Dielectric Constant 2–2.1 (at 1MHz) Minimizes signal loss in high-frequency circuits.
Dissipation Factor 0.0003–0.0007 (at 1MHz) Near-zero energy loss as heat, ideal for precision electronics.
Volume Resistivity 10¹⁸–10¹⁹ Ohm·cm Near-perfect insulation, preventing leakage currents.
Water Absorption 0.001–0.005% by weight Zero moisture uptake, ensuring stability in wet environments.
Temperature Stability -200°C to +260°C Reliable performance under extreme thermal conditions.

Elevate your project with PTFE’s superior propertiesContact KINTEK today for custom PTFE solutions tailored to your needs. Whether you require high-voltage insulators, corrosion-resistant seals, or precision labware, our expertise in PTFE fabrication ensures optimal performance for semiconductor, medical, and industrial applications. From prototypes to high-volume orders, we deliver precision and reliability.


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