Electrical Performance
Low dielectric constant, low dissipation factor and strong dielectric strength support demanding insulation and signal-sensitive applications.
Cathay™ FEP Film
Cathay™ FEP Film
Clarity.
Engineered.
High-performance fluoropolymer film engineered for electrical insulation, composite release, chemical resistance, heat sealing and demanding high-temperature environments.
Explore Grades
Technical Properties
Why Cathay™ FEP Film
One film.
More possibilities.
Cathay™ FEP Film combines the performance advantages of fluoropolymers with the processing flexibility required for modern electrical, chemical, composite and industrial manufacturing.
02
Chemical Resistance
Excellent resistance to many aggressive chemicals helps protect components and surfaces in corrosive process environments.
03
Low Surface Energy
Non-stick behavior supports clean release, reduced adhesion and simplified demolding in composite and specialty processing.
Melt Processability
FEP can be heat sealed, welded, thermoformed, heat bonded and laminated using appropriately designed processing conditions.
05
Weatherability
Strong UV stability and environmental resistance support demanding indoor and outdoor applications.
06
Clarity & Clean Surface
Transparent film options support applications where visual inspection, surface cleanliness and optical appearance are important.
Cathay™ FEP Film · S Grade
Precision
for signal.
Premium FEP film engineered for applications where dielectric performance, electrical insulation and optical clarity matter most.
2.1 Typical dielectric constant at 1 kHz
0.0003 Typical dissipation factor at 1 kHz
240 kV/mm typical dielectric strength at 25 μm
01
Premium virgin FEP resin for demanding electrical and insulation applications.
02
Low dielectric loss for high-frequency and signal-sensitive applications.
03
Excellent clarity and surface quality for visually critical constructions.
04
Suitable for PCB laminates, wire and cable insulation, flexible circuits and specialty electrical systems.
Cathay™ FEP Film · W Grade
Heat.
Sealed.
A practical FEP film grade engineered for welding, heat sealing, hot-melt bonding and industrial fabrication where dependable processing and cost efficiency matter.
FEP Melt-processable fluoropolymer platform
Weld Designed for sealing and joining operations
Value Economical choice for industrial fabrication
01
Designed for welding tape, heat sealing and hot-melt bonding applications.
02
A cost-conscious alternative where premium optical appearance is not the primary requirement.
03
Retains the essential chemical, thermal and fluoropolymer performance expected from FEP.
04
Suitable for fabricated assemblies, sealing operations and industrial fluoropolymer constructions.
Cathay™ FEP Film · M Grade
Flex.
Endure.
High molecular weight FEP film engineered for demanding applications where flex endurance, stress-crack resistance and long-term mechanical reliability are critical.
High MW High molecular weight FEP platform
Flex Designed for repeated movement and flexing
Resist Strong stress-crack resistance
01
High molecular weight construction supports demanding mechanical service.
02
Excellent flex life for applications exposed to repeated movement or deformation.
03
Strong resistance to stress cracking in chemically and mechanically demanding environments.
04
Suitable for tank linings, pump diaphragms, chemical equipment and specialty flexible assemblies.
Cathay™ FEP Film · R Grade
Release.
Conform.
High-elongation FEP release film engineered for composite molding, complex contours and demanding high-temperature processing where clean release and conformability are essential.
Release Low surface adhesion for composite molding
Conform Designed to follow complex mold geometry
Stretch High elongation for demanding forming processes
01
Excellent release behavior helps simplify demolding in advanced composite processing.
02
High elongation allows the film to conform around curved, recessed and complex mold surfaces.
03
Suitable for aerospace, automotive, wind-energy and specialty composite manufacturing.
04
Color and perforated formats may be specified for process identification and resin-management needs.
Cathay™ FEP Film · Applications
Built for places
ordinary films avoid.
From high-voltage insulation to composite molding and chemical processing, Cathay™ FEP Film delivers fluoropolymer performance across demanding industrial environments.
01
Electrical & Electronics
Insulation without compromise.
FEP film for wire and cable insulation, flexible circuits, PCB laminates, flat cables and high-temperature electrical systems.
02
Aerospace & Composites
Release. Cleanly.
Conformable FEP release film for aerospace,automotive, wind-energy and advanced composite molding.
03
Chemical Processing
Protection against aggressive environments.
Chemical-resistant film for linings, protective barriers,diaphragms and process equipment exposed to corrosive media.
04
Pharmaceutical & Clean Processing
Clean containment.
Specialty film for liners, bags, fluid-handling systems and assemblies requiring chemical inertness and low contamination.
05
Industrial Fabrication
Seal. Weld. Bond.
Melt-processable FEP film for heat sealing, welding tape, hot-melt bonding and laminated structures.
06
Optical & Outdoor Protection
Clear. Durable. Weatherable.
Transparent fluoropolymer protection for specialty glazing, optical surfaces and demanding outdoor environments.
Cathay™ FEP Film · Engineering Data
Performance.
Quantified.
Representative physical, electrical, thermal and optical properties for Cathay™ FEP Film. Final material selection should be confirmed against the applicable grade, thickness and current technical data sheet.
Typical at 1 kHz
Typical at 25 μm
ASTM D3418
Typical
| Property | Test Method | Unit | Typical Value |
|---|---|---|---|
| Specific Gravity | ASTM D792 | — | 2.15 |
| Water Absorption | — | % | <0.01 |
| Flammability | UL 94 | — | V-0 |
| Tensile Strength at Break | ASTM D882 | MPa | 24 |
| Elongation at Break | ASTM D882 | % | 300 |
| Tensile Modulus | ASTM D882 | MPa | 480 |
| Dielectric Strength, 25 μm | ASTM D149 | kV/mm | 240 |
| Dielectric Constant, 1 kHz | ASTM D150 | — | 2.1 |
| Dissipation Factor, 1 kHz | ASTM D150 | — | 0.0003 |
| Melting Point | ASTM D3418 | °C | 265 |
| Continuous Service Temperature | — | °C | 200 Typical |
| Limiting Oxygen Index | ASTM D2863 | % | 95 |
| Refractive Index | ASTM D542 | — | 1.341–1.347 |
| Solar Transmission | ASTM E424 | % | 96 |
Typical values are provided for engineering reference and are not specification limits. Actual performance may vary with film grade,thickness, processing history and test conditions.
Cathay™ FEP Film · Grade Selection
Start with the need.
Choose the grade.
Cathay™ FEP Film is available in multiple grades designed around different engineering priorities. Use the guide below to identify the most relevant starting point for your application.
S
Electrical + Clarity Need low dielectric loss?
Start with S Grade when electrical insulation, signal integrity, dielectric performance and optical clarity are the primary requirements.
Electrical insulation
Wire & cable
PCB laminates
Flexible circuits
W
Welding + Value Need reliable heat sealing?
Start with W Grade for welding, hot-melt bonding and industrial fabrication where practical processing and cost efficiency matter.
Heat sealing
Welding tape
Hot-melt bonding
Industrial fabrication
M
Flex + Durability Need flex endurance?
Start with M Grade for repeated movement, stress-crack resistance, chemical equipment and mechanically demanding flexible constructions.
Pump diaphragms
Tank linings
Repeated flexing
Chemical equipment
R
Release + Conformability Need clean mold release?
Start with R Grade for composite molding applications requiring high elongation, conformability and dependable low-adhesion release.
Aerospace composites
Composite molding
Complex contours
Release applications
Still comparing?
Ask an Engineer → Let the application decide.
Share your operating temperature, film thickness, width, dielectric requirements, chemical exposure, forming method and annual volume. Everflon can help narrow the grade selection for evaluation.
Cathay™ FEP Film · FAQ
Questions.
Answered.
Practical answers for engineers, buyers and manufacturers evaluating FEP film for electrical insulation, heat sealing, chemical protection, composite molding and high-temperature applications.
01 What is FEP film used for? +
FEP film is used in electrical insulation, wire and cable, flexible circuits, composite molding release, chemical processing,liners, heat sealing, welding and other applications requiring chemical resistance, low surface adhesion and thermal stability.
02 Can FEP film be heat sealed or welded? +
Yes. FEP is a melt-processable fluoropolymer and can be heat sealed, welded, thermoformed, heat bonded and laminated using appropriately designed process conditions.
03 Which Cathay™ FEP Film grade should I choose? +
Choose S Grade when dielectric performance and clarity are priorities, W Grade for welding and heat sealing, M Grade for flex endurance and stress-crack resistance, and R Grade for composite release and conformability.
04 Is FEP film suitable for electrical insulation? +
Yes. FEP film offers a low dielectric constant, low dissipation factor and high dielectric strength, making it suitable for many wire, cable, flexible circuit and high-temperature insulation applications.
05 Is FEP film suitable for high-temperature service? +
FEP film is widely used in elevated-temperature applications. Actual service limits depend on grade, thickness, mechanical load, chemical exposure, environment and service duration.
06 Is FEP film chemically resistant? +
FEP provides excellent resistance to many aggressive chemicals, making it useful for liners, protective barriers, diaphragms,chemical process equipment and fluid-handling applications.
07 Can FEP film be used as a composite release film? +
Yes. FEP's low surface energy and conformability make it well suited to composite molding and release applications. Cathay™ R Grade is specifically positioned for this type of use.
08 Can Cathay™ FEP Film be customized? +
Depending on grade and project requirements, thickness, width, color, perforation and converting options may be available. Contact Everflon with your application and qualification requirements.
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