Industry Overview
The sealing industry is one of the most important application areas for fluoroelastomers, accounting for over 60% of global FKM consumption. As industrial equipment evolves toward higher temperatures, pressures, and more aggressive chemical environments, traditional NBR and EPDM can no longer meet the demanding sealing requirements of extreme conditions. With exceptional high-temperature resistance (continuous service above 200°C), outstanding chemical media resistance, and excellent compression set properties, FKM has become the material of choice for high-performance sealing applications.
In aerospace, petrochemical, automotive, and semiconductor industries, sealing reliability directly impacts equipment safety and service life. A single seal failure can lead to media leakage, equipment downtime, or even safety incidents, making material selection critically important. FUERTAI has deep expertise in fluorinated materials and provides a full-chain solution from raw materials to end products for the sealing industry.
Core Material Solutions
Binary FKM: Binary fluoroelastomer contains approximately 66% fluorine, offering excellent high-temperature and oil resistance for general industrial sealing applications. It has good processability and relatively low cost, making it the highest-volume FKM grade. Typical applications include hydraulic system seals, pneumatic system seals, and general oil-resistant sealing components.
Ternary FKM: Ternary fluoroelastomer incorporates fluorinated vinyl ether monomers, achieving fluorine content above 70%, with significantly better fuel and chemical resistance than binary FKM. It is particularly suitable for sealing applications involving alcohol-containing fuels, sulfur-containing oils, and strong oxidizing media, serving as the core material for automotive fuel systems and chemical processing seals.
FFKM (Perfluoroelastomer): Perfluoroelastomer currently offers the best chemical and high-temperature resistance among all elastomers, with a continuous service temperature up to 327°C and resistance to over 1,600 chemical media. In extreme conditions such as semiconductor manufacturing and aerospace, FFKM seals are the only elastomeric sealing materials that can meet the requirements.
Custom Compounds (CMB): FUERTAI offers both bisphenol AF and peroxide cure system compounds. The bisphenol AF system provides excellent compression set performance for static seals like O-rings, while the peroxide system offers superior steam and amine resistance for demanding oilfield applications.
Technical Highlights
| Parameter | Binary FKM | Ternary FKM | FFKM |
|---|---|---|---|
| Fluorine Content | ~66% | ~70% | ~72% |
| Max. Service Temp. | 200°C | 200°C | 327°C |
| Fuel Resistance | Good | Excellent | Outstanding |
| Compression Set | Excellent | Excellent | Good |
| Relative Cost | Low | Medium | High |
Key technical considerations for seal design:
- Compression Set: The retention of recovery ability after long-term compression is a key indicator of seal life. Selecting compound formulations with low compression set can significantly extend seal service life
- Media Swell Resistance: Different media cause varying degrees of swell in FKM; choose appropriate fluorine content and cure system based on actual service conditions
- Low-Temperature Performance: Standard FKM has limited low-temperature capability (TR10 approximately -18°C); low-temperature applications require improved low-temperature FKM grades
- Cure System Selection: Bisphenol AF offers lower compression set; peroxide provides better steam and amine resistance
Application Cases
Hydraulic System Seals: Construction machinery hydraulic cylinder seals operating at 150°C in hydraulic oil, using binary FKM bisphenol AF cure compound, hardness 75±5 Shore A, compression set (200°C×22h) ≤15%, service life exceeding 2 years.
Fuel System Seals: Automotive fuel pump seals exposed to gasoline with 15% methanol, operating temperature -40°C to 150°C, using ternary FKM peroxide cure compound, fuel swell ≤5%, meeting full vehicle life requirements.
Semiconductor Seals: Wafer etching equipment seals exposed to plasma and strong acid etchants at 250°C, using FFKM perfluoroelastomer O-rings with chemical resistance to over 1,600 media, service life exceeding 6 months.
Selection Recommendations
FUERTAI recommends following these principles for seal material selection: First, clearly define service conditions (temperature, pressure, media, motion type); then determine the required fluorine content based on chemical resistance needs; next, select the cure system based on seal type; and finally, validate through sample testing. For special applications, FUERTAI offers custom formulation services to adjust hardness, color, and media resistance to perfectly match seal performance with operating conditions.
