PTFE skived sheet is a versatile and high-performance material manufactured by skiving or peeling a block of molded PTFE into thin, uniform sheets. This process ensures exceptional dimensional stability and consistency, making it ideal for a wide range of industrial applications requiring superior chemical resistance, low friction, and excellent electrical insulation properties. Industries such as aerospace, automotive, chemical processing, and food and beverage rely on the unique characteristics of PTFE skived sheets for gaskets, seals, liners, and insulating components.
The skiving technique allows for the production of very thin sheets with tight tolerances, which is difficult to achieve with other manufacturing methods like compression molding. This results in a material that is not only functionally superior but also cost-effective for precision applications. Its non-stick properties and ability to perform across a wide temperature range further enhance its utility in demanding environments.
Our PTFE skived sheets are available in various grades and dimensions to meet specific application requirements. Below are the standard parameters and properties.
| Thickness (mm) | Width (mm) | Length (mm) | Tolerance |
|---|---|---|---|
| 0.1 - 0.5 | Up to 1500 | Up to 3000 | ±10% |
| 0.5 - 1.0 | Up to 1500 | Up to 3000 | ±8% |
| 1.0 - 3.0 | Up to 1500 | Up to 3000 | ±5% |
| 3.0 - 10.0 | Up to 1200 | Up to 2500 | ±5% |
| Property | Test Method | Standard Value | Units |
|---|---|---|---|
| Density | ASTM D792 | 2.15 - 2.20 | g/cm³ |
| Tensile Strength | ASTM D638 | 20 - 35 | MPa |
| Elongation at Break | ASTM D638 | 250 - 350 | % |
| Hardness (Shore D) | ASTM D2240 | 50 - 65 | - |
| Melting Point | ASTM D3418 | 327 | °C |
| Continuous Service Temperature | - | -200 to +260 | °C |
| Property | Test Method | Standard Value | Units |
|---|---|---|---|
| Dielectric Strength | ASTM D149 | 40 - 60 | kV/mm |
| Volume Resistivity | ASTM D257 | >10¹⁸ | Ω·cm |
| Surface Resistivity | ASTM D257 | >10¹⁶ | Ω |
| Dissipation Factor (1MHz) | ASTM D150 | < 0.0002 | - |
| Dielectric Constant (1MHz) | ASTM D150 | 2.0 - 2.1 | - |
| Property | Test Method | Standard Value | Units |
|---|---|---|---|
| Thermal Conductivity | ASTM C177 | 0.25 | W/m·K |
| Coefficient of Linear Thermal Expansion | ASTM D696 | 12 x 10⁻⁵ | cm/cm/°C |
| Specific Heat Capacity | ASTM C351 | 0.25 | cal/g·°C |
What is a PTFE skived sheet?
A PTFE skived sheet is a thin film or sheet of Polytetrafluoroethylene (PTFE) produced by skiving, which is a process of peeling layers from a solid, sintered PTFE billet. This method produces sheets with excellent uniformity, smooth surface finish, and consistent mechanical properties, making them suitable for high-precision applications.
How does skived PTFE differ from molded or extruded PTFE?
Skived PTFE sheets are manufactured by shaving thin layers from a cylindrical billet, resulting in superior dimensional stability and the ability to produce very thin sheets with tight tolerances. Molded PTFE is formed under pressure and heat into specific shapes but may have less consistency in thin sections. Extruded PTFE is forced through a die and is typically used for rods, tubes, or specific profiles, but it cannot achieve the thin, wide, and uniform dimensions of skived sheets.
What are the temperature limits for PTFE skived sheets?
PTFE skived sheets can typically operate continuously within a temperature range of -200°C to +260°C. Short-term exposure to higher temperatures (up to 300°C) may be possible, but this can lead to gradual degradation and loss of mechanical properties. At extremely low temperatures, the material remains flexible and does not become brittle.
Is PTFE skived sheet chemically resistant?
Yes, PTFE is one of the most chemically resistant polymers available. It is inert to virtually all industrial chemicals and solvents, including strong acids, bases, and oxidizing agents. Exceptions include certain reactive alkali metals and fluorine compounds under specific conditions of temperature and pressure.
Can PTFE skived sheets be used for electrical applications?
Absolutely. PTFE is an excellent electrical insulator with a very high dielectric strength, low dielectric constant, and low dissipation factor. It is widely used as insulation in wires, cables, capacitors, and other electronic components, especially in high-frequency and high-temperature environments.
How do I fabricate or machine a PTFE skived sheet?
PTFE skived sheets can be easily fabricated using standard workshop tools. They can be cut with razor knives, scissors, or die-cutters. For more complex shapes, punching, milling, or laser cutting are effective. It is crucial to use sharp tools and secure the material properly to prevent tearing or deformation due to its softness and flexibility.
Is PTFE skived sheet FDA approved for food contact?
Yes, virgin (unfilled) PTFE is generally recognized as safe for food contact by the U.S. Food and Drug Administration (FDA) under specific regulations (e.g., 21 CFR 177.1550). It is commonly used in food processing equipment as liners, gaskets, and conveyor belts. Always verify the specific grade and its certification with the manufacturer for your application.
What are the limitations of PTFE skived sheets?
While PTFE has many advantages, it also has some limitations. It has relatively low mechanical strength and wear resistance compared to some engineering plastics. It is susceptible to creep (cold flow) under continuous load. It has poor radiation resistance and can be degraded by high-energy radiation. Furthermore, it is not melt-processable, which limits some joining techniques.
How should PTFE skived sheets be stored and handled?
Store PTFE skived sheets in a cool, dry place away from direct sunlight and heat sources. They should be laid flat or rolled with a large diameter to avoid permanent creasing or cracking. Handle with clean gloves to prevent contamination from oils and dirt, which could affect performance in sensitive applications like electrical insulation.
Can PTFE skived sheets be bonded or adhesived to other materials?
Bonding PTFE is challenging due to its non-stick properties and low surface energy. Standard adhesives do not adhere well. For successful bonding, the surface must be pre-treated using methods like sodium etching (napthenate process), plasma treatment, or corona discharge to increase surface energy. Specialized PTFE-compatible adhesives or mechanical fastening methods are then recommended.