From material principles to engineering applications

1、 Material Definition and Basic Principles

FEP（F46）It is a copolymer of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP), with a mass fraction of approximately 15% HFP. Compared with PTFE (polytetrafluoroethylene), FEP retains the chemical inertness of the "plastic king", low dielectric loss, and wide temperature range stability, while also possessing the ability to introduce branched structures into its molecular chainsThermoplastic processing capabilityIt can be formed using conventional processes such as extrusion, molding, injection molding, etc., which solves the long-term pain point of difficult processing of PTFE.

FEP aluminum plated filmA dense layer of metallic aluminum (nanometer to submicron scale) is deposited on the surface of FEP film through vacuum evaporation process. The aluminum layer forms a strong bond with the FEP substrate, and the final product simultaneously possesses:

• Flexibility, chemical penetration resistance, and electrical insulation of polymer layers
• Reflectivity, gas barrier, and thermal radiation shielding of metal layers

Common understanding: FEP is the "shield", aluminum layer is the "armor", and the two are combined to form a highly reliable protective system.

2、 Core technical parameters

3、 Key points of processing technology

3.1 Preparation of FEP film (pre process)

3.2 Vacuum evaporation aluminum plating process

• degree of vacuum≤ 10 ⁻³ Pa (high vacuum environment)
• Aluminum layer thicknessFrom nanometer to submicron scale
• Combining mechanismsPhysical deposition interface diffusion forms a "double insurance" structure - the FEP matrix provides a chemical barrier, while the aluminum layer provides airtightness and reflection.

3.3 Common process difficulties and countermeasures

4、 Main application scenarios

1. 5G/6G millimeter wave communication (24-77 GHz)

The fluctuation of the dielectric constant of FEP film is only ± 0.02, and when used as an FCCL insulation layer in the 28GHz frequency band, the transmission rate can reach 20 Gbps (the unused scheme is only about 4 Gbps). High quality FEP films can be prepared using the integrated process of "dual axis synchronous stretching online plasma surface treatment". In 2025, the demand for FEP in the domestic 5G millimeter wave field is about 1120 tons, a year-on-year increase of 34.7%.

2. Aerospace

The ultra-thin F46 film with a thickness of 0.025mm has been applied to the insulation layer of wide body aircraft cables, which complies with DO-160G aviation standards; Simultaneously used for insulation and thermal control layer structure of satellite cables, with a radiation dose resistance of 10 ³~10 ⁴ Gy.

3. Photovoltaic new energy

The F46/PET three-layer co extruded composite film has passed T Ü V aging certification, and the light transmittance remains above 90% after ten years of outdoor exposure, meeting the 25 year design life of photovoltaic power plants. The cumulative installed capacity exceeds 8 GW. In 2025, the demand for F46 composite film driven by n-type high-efficiency photovoltaic modules will be about 680 tons, a year-on-year increase of 41.7%.

4. Chemical strong corrosion protection

In an environment of 65 ℃ and a mixture of 49% hydrofluoric acid and 30% nitric acid, FEP lining can achieve leak free operation for no less than 800 hours (refer to T/CAMIE 028-2025 standard), suitable for scenarios such as reactor lining, pipeline valves, pump body sealing, etc.

5. Medical devices

F46/PTFE composite film is used for cardiovascular catheters, endoscope sheaths, and pacemaker seals, requiring a water vapor transmission rate (WVTR) of less than 0.1 g/(m ² · day) and meeting biocompatibility standards.

6. High end equipment/non stick coating

The friction coefficient is as low as 0.16, and it can be safely used for a long time within 260 ℃, suitable for industrial scenarios such as demolding and anti sticking.

5、 Market data and industrial pattern

According to public channels such as Toubao Research Institute, China Fluorosilicon Organic Materials Industry Association, General Administration of Customs, and Electronic Fifth Institute of the Ministry of Industry and Information Technology:

Overview of the industrial chain:
-The upstream F46 resin supply concentration is relatively high, and localization has been achieved, with a resin purity of over 99.99%.
-The manufacturing process of FEP aluminum plated film and composite film in the midstream has formed a large-scale layout of domestic production capacity.
-The domestication rate of biaxially oriented film production equipment has reached over 75%.

6、 Policy and standard support

7、 Technological Evolution Trends (2026-2030)

8、 Quick Reference Table for Selection Suggestions